Month: April 2025

To appropriately account for repeated measurements made over time, our analysis consisted of a linear mixed-effects model with binomial error, a random effect of block, and fixed effects of treatment , year , and symptom severity category . Next, we analyzed the rate at which PD reappeared in only severely pruned vines from category 3 in subsequent years using a survival analysis. Specifically, we used a Cox proportional hazards model with a fixed effect of plot .Accurate and time- or cost-efficient methods of diagnosing infected plants are important elements of a disease management program, both with respect to roguing to reduce pathogen spread , and the efficacy of pruning to clear plants of infection . Accurate diagnosis of PD in grapevines is complicated by quantitative and qualitative differences in symptoms among cultivars and other aspects of plant condition . Our results suggest that a well-trained observer can accurately diagnose PD based on visual symptoms, particularly for advanced cases of the disease. The small number of false positives in disease category 1 and 2 vines may have been due to misdiagnosis of other biotic or abiotic factors . Alternatively, false positives might indicate bacterial populations that are near the detection limit; conventional PCR has at least as low a detection threshold as other methods that rely on the presence of live bacterial cells . Regardless, although scouting based on visual symptoms clearly captured most cases of PD in the current study, some caution should be used when trying to diagnose early disease stages to ensure that vines are not needlessly removed. There is no cure for grapevines once infected with X. fastidiosa, plastic growers pots except for recovery that can occur in some overwintering vines .

The virulent nature of X. fastidiosa in grapevines, and the corresponding high mortality rate for early season infections, increases the potential value of any cultural practices that can cure vines of infection. Moreover, new vines replanted into established vineyards generally take longer to develop compared to vines planted in newly developed vineyards, potentially due to vine-to-vine competition for resources that limits growth of replacement vines. As a result, vines replanted in mature vineyards may never reach full productivity . Thus, management practices that speed the regeneration of healthy, fully developed, and productive vines may reduce the economic loss caused by PD . A multinomial logistic regression showed significant differences in the relative frequency of different grapevine growth outcomes between the two restoration methods . Chip-budded vines showed significantly lower frequency of strong growth and significantly higher frequencies of vines with developing growth and, especially, of no growth . Nearly 30% of chip-budded vines showed no growth in the following season, compared to 0% of vines on which established shoots were trained. These results indicate that training newly produced shoots from the remaining section of the scion was more likely to result in positive regrowth outcomes. As a result, of the two methods we evaluated, training of shoots that emerge from the scion of a severely pruned trunk is recommended for restoring growth. However, it is important to note that the current study did not estimate the amount of time required for severely pruned vines to return to full productivity. Moreover, the study did not include mature vines, in which growth responses may differ from young vines.

Additional studies may be needed to quantify vine yield, and perhaps fruit quality, in severely pruned vines over multiple seasons. The usefulness of pruning for disease management depends on its ability to clear plants of pathogen infection . A comparison of symptom prevalence among severely pruned and control vines from different disease severity categories showed significant effects of the number of years after pruning , pruning treatment , and initial disease symptom category . The analysis also showed significant interactions between year and treatment and between treatment and symptom category , a non-significant interaction between year and symptom category , and a marginally significant three-way interaction . Overall, more vines had symptoms in the second year compared to the first , and there was a higher prevalence of returning symptom in vines from higher initial disease categories . Severe pruning showed an apparent benefit to reducing symptoms of PD after the first year, but this effect weakened substantially by the second year, with no differences for category 1 or 3 vines, and a slightly lower disease prevalence for severely pruned category 2 vines . A survival analysis of severely pruned category 3 vines showed a significant difference in the rate of symptom return among plots . All vines in plots 1 to 3 had symptoms by autumn 2000, two years after pruning . In plots 4 and 5, more than 80% of vines showed symptoms after three years. Only plot 6 showed markedly lower disease prevalence; in plot 6, ~70% and 50% of severely pruned category 3 vines showed no symptoms after two and four years, respectively, versus ~36% of control vines overall, after two years. It is important to note that at the time of this study, disease pressure may not fully explain the return of symptoms in severely pruned vines.

Surveys conducted during the first two years of the study throughout the entirety of the six research blocks showed that the prevalence of PD in control vines actually declined slightly from the first to the second year , but not due to an increase in replanting efforts or vine death , Rather, this decline in prevalence likely reflects overwinter recovery of mild cases of the disease . Thus, the observed return of symptoms in most severely pruned vines does not appear to be explained by reinfection with X. fastidiosa after clearing of infection during the severe-pruning process. Our results indicate that the apparent effectiveness of severe pruning depended on the initial disease severity, and the effectiveness weakened over time. This suggests at least two constraints exist regarding the general utility of pruning as a PD management tool. First, severe pruning does not appear to be useful for mild cases of PD, as many of those same vines would recover from the infection over the winter . Second, there appears to be little value in pruning severely diseased vines; the high frequency of symptom return within a few years indicates that even severe pruning does not clear most vines of X. fastidiosa infection. That leaves a statistically significant window with respect to intermediate severity cases, which may benefit from severe pruning. The apparent benefit for this category of diseased vines would stem from infections that are not so localized that they are highly susceptible to natural recovery over the winter, but also not fully systemic such that the infection has developed below the pruning point . Reliable identification of this narrow class of diseased vines may require substantial experience with PD scouting, detailed record keeping, and an appreciation for variability in symptoms or infection dynamics based on grapevine cultivar and environmental conditions . Research in other bacterial plant pathosystems has evaluated the potential benefit of pruning and whether pruning extent is related to its effectiveness at clearing hosts of infection . A study of the citrus disease huanglongbing, blueberry in pot associated with infection by Candidatus Liberibacter spp., evaluated two levels of pruning severity, neither of which showed promise as a disease management tool . In this pathosystem, it is plausible that a very protracted incubation period may undermine the effectiveness of pruning, because by the time the first symptoms are visible, the infection may have already moved throughout much of the tree. Collectively, our results are more similar to a study of citrus variegated chlorosis . In this study, the presence of X. fastidiosa in plant tissues at different distances from symptomatic leaves was determined for varying levels of disease severity. X. fastidiosa was more widely distributed in trees with severe disease symptoms compared to those with early stage foliar symptoms. Although ColettaFilho et al. did not test whether pruning at various distances proximal to symptomatic leaves would eliminate X. fastidiosa infections, the current recommendation is to prune citrus material if early symptoms are present, and to not prune plants with severe disease symptoms . Citrus plant age is also an important consideration; Coletta-Filho and de Souza recommend that symptomatic citrus trees up to three-years-old be removed rather than pruned, whereas trees four-years-old or older should be pruned. We did not examine vine age as a factor in this study, but the biology of citrus and grape differ in terms of the overwinter recovery that can occur in grape and the apparently slower movement of X. fastidiosa in citrus compared to grape. Anecdotally, the two most mature plots in our study showed the most rapid return of disease, and the youngest plot showed the slowest return.

More studies of the effect of vine age are needed before concluding that interactive effects of plant age and pruning differ between the PD and citrus variegated chlorosis pathosystems.Most bee species are considered mass provisioners—i.e., they build a brood cell into which they pack a mixture of pollen and nectar, deposit an egg on the pollen provision, and seal off the brood cell while the offspring develops. This brood cell is left sealed until the fully developed bee emerges by breaking through the cell cap. While the mother bee creates the pollen provision for the developing bee, numerous other creatures may enter the brood cell. Organisms found in bee brood cells include—but are surely not limited to—nematodes, mites, springtails, bacteria, and fungi. The bee brood cell can therefore be considered a miniature ecosystem, and how the interactions occurring within these tiny ecosystems affect bee health is a fascinating question. High-throughput sequencing has allowed for detailed surveys of the diversity of the microbes that inhabit pollen provisions. Early next-generation sequencing surveys of pollen provisions suggested that many bacteria found in pollen provisions may be acquired from flowers. The observation that the same bacteria inhabit flowers, pollen provisions, and bee guts was subsequently verified. Further studies then linked foraging to microbial transmission, which is more apparent when characterizing a network of plants, multiple bee species, and bacteria than when studying a single population of bees. When looking at multiple populations of one species across habitats, pollen usage and fungi co-vary more than pollen usage and bacteria. The consensus arising from these studies is that flowers serve as transmission hubs for pollen-associated microbes, but the characteristics of pollen provisions may determine which microbes thrive there. The genomes of pollen-associated lactobacilli contain genes involved in osmotic stress tolerance, detoxification of metals and other toxicants, and pollen wall degradation. That these microbes exhibit genomic adaptations for rapid growth in nutrient-rich environments suggests that they likely ferment sugars found in pollen provisions and may exclude spoilage organisms, as their close relatives do in sourdough bread dough. Experimental evidence for a nutritional role of pollen-borne microbes is also mounting. Isotopic signatures of diet suggest that bee larvae from a diversity of bee species are not truly herbivores as one would expect, but instead exhibit omnivorous or even carnivorous traits. This finding suggests that bee larvae are consuming microbes in their pollen provisions. Feeding bee larvae different ratios of sterilized to normal pollen leads to differences in growth rates and survival, again suggesting that larvae consume pollen-borne microbes. Similarly, whether microbes were present or absent in pollen had a greater influence on larval development compared to whether the pollen was collected by con-specific or different bee species for larvae of the specialist blueberry pollinator Osmia ribifloris. Altogether, these studies are beginning to illustrate the importance of microbes in the pollen provisions of wild and solitary bees for larval health. One open question in the study of the microbiome of the pollination landscape is how diet breadth affects exposure to and acquisition of microbes. Across the bee phylogeny, there is a diversity of diet breadths, with some bees visiting a broad diversity of plant species and others visiting a limited number of plants , or even a single plant , with gradations in between these groups. As specialist bees visit fewer plants, they may acquire a distinct microbial community compared to generalist bees. Conversely, if specialists interact with the same plants as generalists do, both classes of bees may be exposed to the same microbes. The microhabitats of specialist and generalist bee pollen provisions may filter different microbes based on pollen and nectar chemistry, altering microbial composition as has been found with nectar microbial communities.

Similarly, it will be pertinent to explore the effects of heattolerant microbes like Acinetobacter on pollinator health and behaviour in the face of climate warming. Our results are a product of the microbe taxa we chose for our synthetic community and the plant species inoculated. However, our findings are likely generalisable to other bioregions, given the widespread geographic distributions of our focal microbes and the inclusion of both native and non-native plant species. Regardless, future research will benefit from incorporating additional plant and nectar traits and increasing replication within clades of plant taxa to clarify mechanisms influencing nectar microbe ecology.Drosophila suzukii Matsumura causes economic damage to susceptible small and stone fruit in North America, Asia, and Europe . Adult female flies oviposit in fruit and developing larvae render the high-value fresh fruit unmarketable and reduce processed fruit quality. Damage from D. suzukii in Western U.S.A. production areas may cause up to $500 million in annual losses assuming 30 % damage levels , and $207 million losses in Eastern U.S.A. production regions . Worldwide, the potential economic impacts due to D. suzukii damage are significant. In any integrated pest management system, it is important to use multiple strategies to manage key pests. For D. suzukii, some of these strategies include monitoring, fruit sampling, and direct control methods . For example, in Trento Province, Northern Italy, prior to the adoption of IPM, the potential losses to D. suzukii were about 13 % of the berry industry’s revenue, plastic planters bulk while after the implementation of an IPM strategy including mass trapping, field sanitation, and insecticide programs, the sum of losses and associated control costs decreased to about 7 % .

The ability to describe, forecast, and more effectively manage damaging pest populations can benefit producers, extension agents, and practitioners . Phenology models based on accumulation of heat units or degree days have become the standard method for determining when to treat crops for pests. These DD accumulation models can be used to predict important life history events based on pest development rates . With phenology models, a specific life stage of a pest, such as adults, can be targeted for management, maximizing efficacy of insecticides. DD phenology models tend to work best for pests with a high level of synchrony and few, non-overlapping generations . Previous data have shown that D. suzukii moves through generations rapidly, and has high reproductive levels and overlapping generations . This suggests that limited benefits are to be gained from a traditional DD phenology model. However, insect population models can also be helpful to predict impending damage of agriculturally and medically important insect pest populations . The major factors affecting population dynamics of D. suzukii include temperature, humidity , and the availability of essential food resources . Although DD phenology models may have limited application for a pest such as D. suzukii, accumulation of heat units can play an important role in predicting population dynamics. Temperature-dependent developmental, survival, and reproductive data are available for all life stages of D. suzukii . Recent D. suzukii modeling has used a combination of mean temperature and calendar-based matrices . The two published demographic models for D. suzukii include a discrete-time stage-specific Leslie matrix model, which did not estimate transition between different life stages for D. suzukii , and a physiologically based demographic model featuring distributed maturation time .

Asplen et al. used D. suzukii physiological data and included non-linear sub-models to capture temperature-dependent developmental rates and survivorship. Neither model takes into consideration winter survival, early-season reproductive potential, or host availability . However, attempts to model insect survival and fecundity using physiological time and matrices have been conducted successfully for other insects . Management strategies for D. suzukii include chemical , biological , and cultural controls. Additional control strategies may include genetic techniques such as RNAi biopesticides . Little information is available at the population level on the impact of insecticide sprays. Insecticides are typically targeted against specific life stages of D. suzukii and result in differential levels of mortality on the different life stages. Currently, calendar-based insecticide spray intervals are focused on preventing oviposition by D. suzukii , but their impacts on populations over a larger spatial scale are unknown. Organophosphate, pyrethroid, carbamate, spinosyn, and some diamide insecticides show efficacy against D. suzukii adults . Residual activity of currently available insecticides is between 5 and 10 days but can be shorter due to rainfall . There is increasing evidence that some insecticides that are active on adult D. suzukii, including spinosad family compounds, which, may also achieve control through mortality of egg and larval life stages . Biological control agents known to attack D. suzukii have been identified in areas of recent pest invasion . However, parasitoid success appears generally lower in these regions compared to levels observed in the indigenous range of the pest . In North America and Europe, specialist parasitoid species are absent.

Field studies indicate that natural populations of generalist species are not having a meaningful effect on populations of this pest; however, in the scope of an IPM program, a conservation biological control approach using these agents may contribute to an overall reduction in local D. suzukii populations . The complex of biological control agents for D. suzukii includes predators and pathogens ; however, parasitic hymenoptera have been the primary focus of current research. Numerous parasitoid species are known to attack frugivorous drosophilids and most attack larvae or pupae in decaying fruits on the ground . Recent studies in the U.S.A. and Europe found that most resident larval drosophila parasitoids were unable to develop on D. suzukii , but in Asia, several parasitoid species of Asobara, Ganaspis, and Leptopilina can attack and develop from larvae of D. suzukii . Collection trips to South Korea in 2013 and 2014 and China in 2013 yielded parasitoid species that readily attack D. suzukii larvae and pupae . Given the increasing availability of D. suzukii physiology data, the goal of this paper is to provide key insights into how physiological time can be utilized to integrate survival, development, and reproductive data from diverse environments. We demonstrate how physiological time is appropriate to describe population dynamics over the growing season. We also demonstrate how the physiological time concept breaks down during overwintering by examining how extreme temperatures cause mortality in non-acclimated D. suzukii at both high and low temperatures. D. suzukii enters reproductive diapause in November/ December in parts of the U.S.A. , and phenotypic changes among individuals in the population can affect winter survival . We focused on the latter portion of winter and spring to determine if DD accumulation could estimate female reproductive potential. Finally, we examined a cohort-level population model based on accumulation of DD utilizing daily high and low temperatures from different field sites to estimate DD for conditions within known thermal thresholds. These data were used to consider the impacts of current and possible future IPM with the cohort DD population model at the field level. Materials and methods The environmental factors described below illustrate the impacts of environmental conditions within and outside of known temperature thresholds of D. suzukii. Additionally, we describe the role of DD accumulation for estimating sexual maturity of reproductive flies collected during the late dormant period. During late winter and early spring, collection pot there is a transition from temperatures outside of thermal thresholds to conditions falling within thermal thresholds. The D. suzukii population model was used to demonstrate how management practices could affect populations on a relative scale.

We examined survival trends of D. suzukii populations under cold and warm temperature extremes outside the developmental and reproductive thresholds. Populations are expected to decrease substantially after exposure to extremes ; however, even after extended periods of unfavorable conditions and lack of suitable reproductive hosts, D. suzukii are known to respond to traps, indicating persistence of populations . We describe the impacts of such unfavorable conditions on population structure by plotting D. suzukii pupal and adult survival levels at extreme low and extreme high temperatures. Survival was fitted in this case with a Gompertz distribution over calendar days because no DD are accumulated at the extremes. Currently, we lack field data to illustrate the role of such environmental conditions on populations. We do not include these parameters in the model described below as this paper focuses on seasonal population fluctuation only.In this analysis, we examined how warming temperatures at the onset of the growing season affect female reproductive potential of field-collected D. suzukii. The goal was to determine if DD accumulation could be used to estimate reproductive potential of flies, and to determine whether laboratory-generated reproduction data are supported by field observations. Collections of females were conducted using established methods and the late dormant reproductive potential of D. suzukii females was classified by dissection of females under magnification to determine whether mature eggs were present and if they were in the ovaries or free in the abdomen . Collections from Seattle, Washington, U.S.A. were made from March 2011 to February 2012, and collections from Corvallis, Oregon, U.S.A. were made from April 2011 to June 2013 . Flies were collected using container traps baited with apple cider vinegar or yeast-sugar solution. Collections in Italy utilized container traps baited with 200 ml of the liquid bait Droskidrink , composed of 3 parts apple cider vinegar to 1 part red wine, with 4 g raw brown sugar dissolved into the mixture. In all sites, the total numbers of females dissected per location and date were used to calculate the percentage of females containing mature eggs. The percentage of females containing mature eggs was plotted over the midpoint for the time period in DD calculated from the daily high and low temperature using the single sine method. Temperature data originated from weather stations proximate to collection sites representing the regions where collections were made. In all regions, the relationship between accumulated DD and reproductive potential was determined with multiple regression .For the model runs, we used two of the temperature datasets originally from Wiman et al. . The first was from the 2013 growing season in Salem, Oregon, U.S.A. and the second from 2013 in Parlier, California, U.S.A. Mortality factors simulating management activities were applied to select life stages for the periods outlined below. Model runs started early in the season because the population structure during the beginning of the growing season was composed of mostly adults. This timing allows us to see how pesticides targeting adult or immature life stages perform in relative terms. For California, we assume that adults colonize blueberry fields to oviposit on ripening fruit on April 1. Whereas growers would likely apply insecticides more than one time per season, for simplicity, hypothetical insecticides were applied one time at the beginning of the season. Two insecticides with different effects on specific life stages were independently input into the model to compare population-level impacts. The two compounds represented active ingredients that control both adults and immature stages of D. suzukii at different levels . Insecticide A elicited an adult mortality factor of 95 % and an immature mortality factor of 5–100 %. Insecticide B caused 60 % adult mortality and 60–95 % mortality of immature stages. These mortality factors included a range of efficiency in order to simulate reduced residual activity over time. This technology has undergone major advances as a tool for pest management. Double-stranded RNA is administered to targeted insects by genetic modification of the crop, or synthesized in vitro and topically applied to host plants . Murphy et al. described a novel dsRNA delivery system in which researchers genetically engineered yeast to produce dsRNA that knocks down genes that are predicted to be critical for D. suzukii fitness. The yeast biopesticide, Insecticide C, was shown to decrease larval survivorship and to reduce adult locomotor activity and reproductive output. Using these findings, we applied realistic mortality levels as highlighted by Murphy et al. , assuming efficient delivery and persistence, in which D. suzukii egg production and egg viability was 63.2 % lower , and 22 % of the larvae were killed for a period of 7 days. The mortality factors for each class of toxicant were applied using weather data from Parlier, California, U.S.A. for 20–30 April 2013 using these treatment scenarios.

Among 1605 phylogenies analyzed , the lowest Smap values were for highly conserved CDSs such as ribosomal and cell division proteins. On the other hand, the highest Smap values found were ~0.5 belonging to CDSs encoding TonB-dependent receptor and the hypothetical protein PD0014 . Only 9 orthologous CDSs previously identified or predicted to be virulence and pathogenicity factors were among the 100 CDSs with Smap values greater than 0.44 with confidence >90% . These 9 CDSs include two related to adhesion , two related to polysaccharide hydrolysis , two related to polysaccharide synthesis and three that encode, respectively, quorum sensing response regulator , multidrug efflux pump and lipase/esterase . However, we reasoned that these medium Smap scores do not provide strong support to consider these CDSs as candidates to host specificity determinants.The enrichment of accessory genome with mobilome-associated CDSs prompted us to explore the full set of MGEs in X. fastidiosa strains. Using a combination of prediction tools, we identified a comprehensive set of sequences related to the MGEs in the 94 genome assemblies analyzed here. The content of MGEs varies considerably among the strains, ranging from 3.8% to 27.76% of the genome, with a mean value of 13.92% ± 5.77%. Among the strains with the higher MGE content are Dixon, U24D, 3124, Ann-1, MUL0034 and 9a5c . It is important to note that the strains whose genome assemblies are in contigs showed the lower percentages of MGE content than the strains with complete genomes, blueberry containers possibly due to a reduced efficiency of the programs to predict MGEs in fragmented genomes.

Overcoming this limitation will have to wait for the availability of complete versions of these genomes which, in most cases, requires resequencing with long-read technologies. X. fastidiosa genome assemblies harbor 11.6 ± 2.71 prophage-related regions. Among the complete genomes, the strains RH1 and LM10 of subspecies multiplex have the greatest number of prophage regions while those with the least prophage regions are the subspecies pauca strains Pr8x, Salento-2, De Donno . We found 5 intact, 2 incomplete, 1 questionable and 3 remnant prophages in 9a5c strain , and 4 intact, 5 incomplete, 3 questionable and 1 remnant prophages in Temecula1 strain . The genomes of X. fastidiosa also harbor on average 6.47 ± 2.57 genomic island regions. The strains U24D and 9a5c have the greatest number of genomic islands while the strains IVIA5235 and Bakersfield-11 have only 5 regions each. We found on average 6 ± 1.53 insertion sequences within certain prophages, genomic islands, chromosomes, or, occasionally, in plasmids.We performed a screening of the known immunity systems in X. fastidiosa to explore the strategies used by this bacterium to deal with their numerous MGEs . The screening of 94 X. fastidiosa genome assemblies detected only CDSs belonging to Restriction Modification , Toxin-Antitoxin , Cyclic-oligonucleotide-based antiphage signaling systems , Gabija and Wadjet systems. For each detected system, the CDS neighborhood was evaluated. The prediction of R-M systems showed that all strains possess at least one of the three main R-M system types previously reported for 9a5c and Temecula1 strains. The type II was usually found in multiple operons per genome, while the type III was observed in a single operon per genome. R-M type I and II were frequently found in all strains, and in most instances more than one subunit homolog was observed.

In contrast, R-M type III was mainly found among strains of subspecies pauca and fastidiosa. Curiously, the strains lacking R-M type III , have more homologs of the R-M type II subunit . The TA type II system was found mainly in the strains from the subspecies pauca from South America. This TA system is widely distributed among prokaryotes and has been confirmed to be involved in diverse biological processes including plasmid maintenance, phage inhibition, stress response, and others. The CBASS phage defense system is composed of an oligonucleotide cyclase, which generates signaling cyclic oligonucleotides in response to phage infection, and an effector that is activated by the cyclic oligonucleotides and promotes cell death. This system was found in strains from the subspecies pauca from Europe, and also in strains from the subspecies fastidiosa.The comparative analyses of 94 publicly available whole-genome sequence assemblies of X. fastidiosa strains revealed a pangenome comprising 4549 orthologous CDSs and a core genome of 954 CDSs . These values are somewhat different than previously reported because we have used different algorithms for genome annotation and clustering of orthologous CDSs as well as a larger number of genomes in the analyses. We found that the vast majority of the CDSs previously identified or predicted to be virulence and pathogenicity factors for X. fastidiosa belong either to the core or soft-core genomes. A core genome-scale phylogeny grouped the 94 X. fastidiosa strains in three major clades defined by strains from the subspecies fastidiosa , multiplex , and pauca consistent with previous k-mers based phylogeny of 72 X. fastidiosa strains as well as with phylogenetic reconstructions from 349 X. fastidiosa genomes. While several of the subclades sharing ST groups are congruent with country of origin of the strains, plant species from which strains were isolated are less congruent with these subclades. Although some strains isolated from Citrus, Olea, Vitis, and Morus group in separated subclades, other strains mainly isolated from Coffea, Prunus, and Nerium are distributed into the three distinct major clades .

It has been shown that citrus and coffee strains from subspecies pauca seem to be limited to their original hosts, despite crop proximity and the presence of insect vectors. In addition, there is experimental evidence of host specialization for certain X. fastidiosa strains. On the other hand, it is known that some strains can infect multiple hosts and that intersubspecific homologous recombination has been associated to X. fastidiosa adaptation to novel hosts. The factors that drive X. fastidiosa host-specificity or adaptation to new hosts have not been clearly elucidated despite recent evidence of a genetic basis to the host range of X. fastidiosa. Here we have explored the soft-core and core genomes for potential candidates related to this trait using comparative genomics, an approach that has been applied for some bacterial pathogens. Using a mapping metrics applied to phylogenetic trees for 1605 orthologous CDSs we found no CDS with Smap values that would provide strong support to point a CDS as candidate to host specificity determinant. The highest Smap values found were ~0.5, and among these CDSs only a few CDSs were related to virulence, including two related to adhesion , two related to polysaccharide hydrolysis , two related to polysaccharide synthesis and three encode, respectively, quorum sensing response regulator , multidrug efflux pump and lipase/esterase that present medium Smap scores. We call attention to CDS PD0815 related to LPS biosynthesis. It has been shown that O-antigen delays plant innate immune recognitionin grapevine and as such the heterogeneity of O-antigen composition may be related to X. fastidiosa host range. In summary, the approach we have used did not provide strong supporting evidence for CDSs that would contribute to X. fastidiosa host-specificity. It has been suggested that the X. fastidiosa pangenome is linked to host association and the presence/absence of a few genes in strains isolated specific plant genera have been correlated to host-specificity. However, at the present time some limitations for an experimental study of X. fastidiosa host-specificity should be considered such as prompt availability of sequenced isolates as well as the difficult genetic manipulation of some strains. Our comparative analyses revealed that the content of MGEs varies among X. fastidiosa strains and includes a considerable diversity of sequences related to prophages, GIs, ISs and plasmids with variable sizes . While several MGE sequences are conserved among X. fastidiosa strains some are unique MGEs, belonging to a single strain among the ones we analyzed here. The X. fastidiosa 94 genome assemblies harbor 11.6 ± 2.71 prophagerelated regions and 6.47 ± 2.57 genomic island regions.

A previous study reported 6 and 8 prophage-like elements respectively in genomes of 9a5c and Temecula1 strains, and a comparison of 72 X. fastidiosa genomes revealed an average of 9.5, 9.3 and 8.5 prophage regions, respectively, for strains from subsp. fastidiosa, multiplex and pauca. It remains to be investigated whether multiple prophage regions confer any fitness advantage to X. fastidiosa, as has been observed for Pseudomonas aeruginosa, best indoor plant pots where multiple prophage carriage seems to be beneficial during mixed bacterial infections. It is worth noting that inoviruses sequences are found in most of the analyzed strains and that they encode a Zot protein. Inoviruses have a relevant role in the structure in P. aeruginosa biofilm and have been reported to encode Zot in several Vibrio species. Zot protein seems to play a dual function as it is essential for inovirus morphogenesis and has also been reported to contribute for Vibrio cholerae pathogenesis. This toxin has been postulated as virulence factor for plant pathogens, including X. fastidiosa. Interestingly EB92-1, a proposed X. fastidiosa biocontrol strain, lacks both Zot homologous genes found in Temecula1 strain. Moreover, a X. fastidiosa Zot protein was shown to elicit cell death-like responses in the apoplast of some Nicotiana tabacum cultivars. Besides Zot, other prophage-encoded genes may play a role in the biology of X. fastidiosa as observed in other bacteria, where the so called “moron” loci have been related to virulence, stress resistance, phage resistance and host adaptation. More studies are necessary to understand the contribution of “moron” loci, such as Zot genes, as well as events of prophage induction to X. fastidiosa biology. There is experimental evidence X. fastidiosa releases phage particles but the impact of prophage induction in host colonization is unknown. To cope with the MGEs, bacteria have developed a diversity of immunity systems. The numerous immunity systems of some genomes protect the cell from a broad range of MGEs, and the MGEs themselves encode defense systems, which tend to be different across strains of a species. Although X. fastidiosa strains are devoid of most of these systems, R-M systems and one conserved cluster with genes of Gabija system were found widely distributed among the genome assemblies analyzed in this work. TA type II system and CBASS immunity systems were found only in some strains. It should be mentioned that the R-M systems have been reported to impact the stable acquisition of foreign plasmid DNA by X. fastidiosa. The low amount and diversity of immunity systems found in X. fastidiosa genomes, with the notable absence of important immune systems, especially CRISPR-Cas, gives a hint to understanding the high amount of MGEs found in this bacterial species. It seems that R-M, Gabija and CBASS systems are not enough to protect X. fastidiosa against phage acquisition. For instance, Temecula1, one of the most studied X. fastidiosa strains, carries 12 prophage regions, but only three immunity systems. This lower amount of immunity systems relative to high number of prophages differs from the positive correlation between the number of prophage and families of antiphage systems observed at species level. Therefore, we do not exclude the possibility that X. fastidiosa genomes might encode immunity systems yet to be discovered. The comprehensive comparative analyses of 94 whole-genome sequences from X. fastidiosa strains from diverse hosts and geographic regions contribute to a better understanding of the diversity of phylogenetically close genomes, explores candidates to host specificity determinants for this phytopathogen as well as greatly expands the knowledge of its mobile genetic elements content and of its immunity systems.The phylum Negarnaviricota, composed of viruses with negative-stranded RNA genome, includes species characterized by non-segmented or segmented genomes, the presence or absence of a membrane enveloping the capsid, and a diverse host range including plants and animals. Examples of nsRNA viruses associated with economically important diseases in plants are rose rosette virus , rice stripe virus, citrus psorosis virus, and blueberry mosaic associated virus. Historically, only a relatively small number of nsRNA viruses infecting plants as their primary host have been reported. Recently, however, more novel viruses infecting plants have been discovered around the world. In the last few years, the use of high throughput sequencing technology has allowed the identification and characterization of new nsRNA viruses in pistachio, citrus, watermelon , and apple. Interestingly, most of these novel nsRNA viruses were classified under the family Phenuiviridae . To date, there are fifteen recognized generaintegrating the family Phenuiviridae : Banyangvirus, Beidivirus, Goukovirus, Horwuvirus, Hudivirus, Hudovirus, Kabutovirus, Laulavirus, Mobuvirus, Phasivirus, Phlebovirus, Pidchovirus, Tenuivirus, Wenrivirus, and Wubeivirus. Except for members of the genus Tenuivirus that are plant-infecting viruses, the members of the other genera infect vertebrates, including humans, and arthropods.

Non-aborted carpels, and seed production as the counts of developed seeds vs. undeveloped seeds, both of which are structurally binomial variables. Relative to a binomial distribution, however, our data for both analyses were overdispersed which we corrected by including an individual-level random effect . We ran GLMMs with binomial-errors using the default logit link in the ‘lme4’ package for R . We assessed the relative contribution of the quantities of heterospecific and conspecific pollen on reproductive output and carpel abortion using a modelcomparison framework. In these models conspecific pollen and heterospecific pollen, as well as their interaction, are the fixed effects that we assess in different combinations. We specifically compared five mixed-effects models: full model including an interaction between the two fixed effects ; additive model ; amount of conspecific pollen only; amount of heterospecific pollen only; and a model including no fixed effects . For all analyses, we used AICc, Akaike’s Information Criterioncorrected for small sample size , to determine the best model. We reported all models within two ΔAICc points of the best model. We used the ‘AICcmodavg’ package in R for model selection. We excluded observations in which there was seed set with either zero stigmatic pollen recorded , blueberries in pots or zero proportion of conspecific pollen . We assume that these observations were due to loss of stigmatic pollen in the field between fertilization and stigma collection.

To understand the association between naturally deposited heterospecific pollen and seed production, we used a field approach linking stigmatic pollen deposition to seed set in the same individual carpels in wild plants. Heterospecific pollen deposition was highly variable on D. barbeyi stigmas in the field and while some degree of heterospecific pollen was found on most sampled flowers, it was typically present in low amounts . Neither heterospecific pollen nor conspecific pollen was a good predictor of carpel abortion in our sites. Conspecific pollen deposition was positively related to viable seed production, but we also found a significant negative interaction between heterospecific pollen and conspecific pollen. That is, with increasing heterospecific pollen, the positive relationship between conspecific pollen deposition and viable seed production in D. barberyi became weaker . We found that heterospecific pollen on D. barbeyi stigmas is widespread, highly variable, and typically occurs at relatively low levels. In terms of variability, heterospecific pollen represented anywhere from 0 to 97% of the grains present in a pollen load. The widespread nature of heterospecific pollen deposition is reflected by the fact that 85% of stigmas had some heterospecific pollen present. Still, most stigmas received only low levels of heterospecific pollen deposition . These results are broadly consistent with patterns reported in a comprehensive review of studies assessing the impact of heterospecific pollen transfer, including 77 species from 17 different sources . This review found that, although receipt of heterospecific pollen was variable, all species received at least some heterospecific pollen on their stigmas. Similarly, in a community-wide analysis of pollen transfer, Fang and Huang found that of the 57 plant species they surveyed, heterospecific pollen deposition was common but highly variable, representing 0-66% of the total pollen on stigmas.

The co-flowering plant community and pollinator behavior are just two of the factors that might influence variation in HP receipt between plants of the same species within and between sites. Variation in heterospecific pollen receipt within species or even within a population obviously has important implications for evolution of coping mechanisms and remains an area ripe for more research . A large proportion of carpels aborted in our study , yet contrary to our expectations we found that neither heterospecific pollen nor conspecific pollen was a good predictor of carpel abortion in D. barbeyi. Thus, it seems likely that resource limitation, rather than pollen limitation, drove carpel abortion in our system. Extrinsic factors such as weather conditions, flower phenology, herbivory, competition , and disease can lead to within plant variation in carpel abortion . Furthermore, intrinsic factors including architecture , plant size, developmental constraints or allocation strategies are also known to affect patterns of carpel abortion . In contrast to carpel abortion, both conspecific pollen and heterospecific pollen played a role in seed production in D. barberyi. As expected, conspecific pollen deposition on its own was positively related to viable seed production. Heterospecific pollen on its own did not affect seed set, but there was a significant negative heterospecific pollen × conspecific pollen interaction. In other words, with greater heterospecific pollen deposition, a fixed amount of conspecific pollen would result in lower seed set. Because this was a correlational study, we were not able to tease apart other factors that may have lead to a decrease in seed production such as diversity of heterospecific pollen.

To our knowledge, this is the first demonstration of an interaction between heterospecific pollen and conspecific pollen in their effects on plant reproduction. We hypothesized that we would find such an interaction as we expected that the negative effects of heterospecific pollen might occur only in the context of conspecific pollen. In a case comparing deposition of a small vs. a large heterospecific pollen load in stigmas with no conspecific pollen should yield the same result: zero seeds produced. Following the same logic, we would expect the impact of depositing a medium-sized load of heterospecific pollen on a stigma would differ in stigmas with just a few conspecific pollen grains versus a large conspecific pollen load . We are aware of only one previous assessment of the statistical interaction between stigmatic pollen load quantity and the proportion ofheterospecific pollen grains . This study found no evidence for a pollen quantity × proportion heterospecific pollen interaction, but the study design was oriented at a different objective and thus included just two heterospecific pollen load sizes, which corresponded to 28% and 16% of total pollen load proportions. Finally, we were not able to distinguish between self and outcrossed conspecific pollen in this study. Self pollen has been shown to intensify the negative impact of HP receipt in Mimulus guttatus and self pollen has been shown to produce fewer seeds in D. barbeyi . More studies examining how mixed mating plant species cope with HP receipt would be valuable, particularly in a field setting where plants may receive HP from a variety of plant species. Putting this result in the context of previous findings highlights that there has been a gulf between field studies and hand-pollination studies in greenhouse settings, a gulf that, if bridged, would improve our understanding of the effects of heterospecific pollen transfer in nature. Future work in hand-pollination studies should contribute to bridging the gap by integrating what we have learned from field studies so far. First, hand-pollination studies should be designed using parameters explicitly drawn from field studies, in terms of heterospecific and conspecific pollen amounts, and heterospecific pollen diversity, considering not only means but also variability. To date, most hand-pollination studies have used only one proportion of heterospecific pollen , and we are aware of only one hand-pollination study that specifically applied a full range of heterospecific pollen deposition. Second, the results from our field study, particularly our finding of a heterospecific pollen × conspecific pollen interaction in seed production, highlights the advantage of understanding this result mechanistically, via hand-pollination studies that vary the quantity of both conspecific pollen and heterospecific pollen factorially. Third, our finding that neither conspecific pollen nor heterospecific pollen was strongly linked to carpel abortion rates underscores that hand-pollination studies that control both pollen and resource limitation in a greenhouse setting could greatly improve our understanding of how these factors interact. Similarly, field studies on the effects of heterospecific pollen can look to hand-pollination experiments—with their typically more mechanistic focus—for inspiration. A critical first step is to increase the number of field studies that directly link pollen deposition and seed production within the same carpel . To our knowledge the work we present here was the first time that this approach has been applied to understanding the effects of heterospecific pollen, which should be repeated in a wide range of plant species with different mating systems .

Another particular need is for field studies that assess multiple sites. We continue to have a poor understanding of how plant genotype and environmental factors interact to shape the effects of heterospecific pollen, square plant pots and work along environmental gradients could be informative, especially in disentangling the relative effects of pollen vs. resource limitation in shaping seed set. Similarly, experimental approaches to assessing the relative effects of resource vs. pollen limitation in the context of heterospecific pollen deposition in field settings would also be a valuable research direction. Finally, hand-pollination and field approaches should be explicitly integrated by conducting more hand-pollination experiments in field settings. Our understanding of the impact of heterospecific pollen deposition is growing, but there is still much to learn about the way that co-flowering plants interact through pollinator sharing and how heterospecific pollen deposition impacts plant reproductive fitness. In a changing world where we can expect to see both increasing disruptions in pollination as well as the emergence of new interactions via introduced species and climate change, studies that unify both field studies and controlled hand pollination studies will allow us to better understand the implications of heterospecific pollen deposition for reproductive output in natural plant communities.Pollinator foraging behavior directly impacts plant reproductive output and ecosystem function through the transfer of pollen between plant individuals within a single foraging bout. If pollinators move between different plant species they can transfer heterospecific pollen, potentially reducing reproductive output . Given the functional significance of pollinator resource use, it is important to understand the factors driving pollinator foraging behavior. The plants that pollinators forage on is a function of a number of factors including innate and learned preference, morphological traits, as well as direct and indirect competition with other pollinators in the community . This study focuses on how competitive interactions between pollinators shape pollinator foraging behavior. Decades of research has demonstrated that interspecific competition can influence pollinator foraging behavior. In one example, Pimm et al. found that in the presence of a dominant competitor, two other hummingbird species spent more time at a less rewarding feeder. In contrast, without interspecific competition, all three hummingbird species visited a feeder with high sucrose concentrations. Brosi and Briggs found that after a release from interspecific competition, bumble bees decreased their floral fidelity . These changes in foraging behavior led to a significant decrease in reproductive output in a common alpine plant species. Fründ et al. provide another example in which pollinators’ flower preferences can be flexible, and depend on community context . In their system, as competition between pollinator species increased, the species reduced their niche overlap by shifting to new plant species, which resulted in increased plant reproduction. Thus, we know bees respond to competition and often do so strongly, but we do not know if bee species vary in their response to competition in complex assemblages of bee species or what traits are important in determining how they will respond. Trait based differences between species may reduce interspecific competition and maintain diversity within a community . Generally, we still have a poor understanding of which traits influence the outcome of competition and community structure but some animal traits such as body size or bill size/shape and plant traits related to resource acquisition, such as root depth , can limit competition thus encouraging species coexistence. Bumble bee communities provide an excellent system in which to empirically explore how trait differences drive foraging plasticity in response to interspecific competition, all within a community context. Bombus assemblages are often species-rich, and sympatric species typically have substantial overlap in their life history requirements . Furthermore, traits that affect resource acquisition and foraging efficiency can influence how species partition resources within a community . Tongue length is a trait that directly determines which resources a bumble bee can access and how resource selection varies among species . In general, long-tongued bumble bee foragers visit flowers with deep corollas and short-tongued bumble bees forage on shallow flowers . Still, bumble bees are known to be labile in their foraging patterns if more rewarding floral resources become available or the competitive landscape shifts .

The anthocyanin content of elderberries strongly correlates to the antioxidant potential of the fruit, which may confer health-promoting properties, which is one reason why elderberries are used in supplements and value-added products. Elderberry is also used as a source of natural food colorants due to the levels of anthocyanins. Understanding the levels of anthocyanins in the blueelderberry grown in hedgerows is critical towards establishing this native fruit as an additional and more sustainable elderberry. The average TMA measured in blue elderberry ranged from 34.2 ± 9.7 to 113.4 ± 18.2 mg CGE per 100 g FW in 2018 and from 43.1 ± 11.5 to 121.5 ± 11.5 mg CGE per 100 g FW in 2019 . TMA was variable between hedgerows in both years of harvest, with relative standard deviation values between 16% and 30%, yet there was not a significant difference in the overall average TMA between 2018 and 2019 . Furthermore, most hedgerows were not significantly different from the other hedgerows harvested that year despite significant differences in TMA values found between farms in both years . Regarding the age of the elderberry shrub, hedgerows 2 and 14 had two of the three highest concentrations of TMA in 2019 . This suggests that blue elderberries can be harvested from plants as young as two years without a significant loss of TMA concentrations. TMA values for the blue elderberries are lower than those found in other elderberry subspecies. In European elderberries, TMA levels range from 170 ± 12 to 343 ± 11 with an average of 239 ± 94 mg CGE per 100 g FW 49.

A study of American elderberry grown in Ohio showed a range from 354 ± 59 to 595 ± 26 mg CGE per 100 g FW.52 In the present study, plastic plants pots bare root prerooted cuttings of American elderberries were planted, along with blue elderberries, on Farm 1 in 2018, and three shrubs were harvested in 2019. These American elderberries had an average TMA value of 263 ± 5.4 mg CGE per 100 g FW, which is more similar to what has been observed in other studies on this subspecies. This suggests it is a subspecies difference contributing to the lower anthocyanin concentration in the blue elderberry and not the difference in growing conditions. Compared to other berries, blue elderberries have similar levels of anthocyanins as raspberries, but lower levels than blueberries and blackberries 100 . The lower concentration of anthocyanins in the blue elderberry may require adjustment of levels used in supplements, food and beverages for optimal performance or health benefit, or as natural coloring agents.In addition to anthocyanins, elderberries contain other phenolic compounds, such as flavonols and phenolic acids, which also contribute to the health promoting properties of elderberry. Phenolic compounds are responsible for organoleptic properties and can help protect foods against lipid oxidation. Therefore, TPC can be useful for making approximate comparisons, for example, between varieties of the same fruit, between similar fruits or in the evaluation of a processing step . It is important to note that the TPC assay is a non-selective assay and is easily impacted by extraction conditions and interfering substances, such as ascorbic acid and reducing sugars. Although there is no evidence that the beneficial effects of polyphenol-rich foods can be attributed to the TPC of a food, it can be a useful measure for making general comparisons with other studies in the literature which reported these values but should be supported by quantitative HPLC data. Herein, the range of TPC measured in the blue elderberries was from 514 ± 41 to 791 ± 34 mg GAE per 100 g FW in 2018 and from 459 ± 50 to 695 ± 41 mg GAE per 100 g FW in 2019 . TPC in the blue elderberries was significantly higher in 2018 than in 2019 .

While there were significant differences found between the farms in both years , most hedgerows were not significantly different than most other hedgerows in the given year when evaluated together . Although the farms in this study were near each other and experience similar climates, there can still be differences in growing conditions for each hedgerow, such as water availability, which has been shown to influence the levels of phenolics in blueberries 101 and strawberries 102 . Hedgerows 2 and 14 were not significantly different from other hedgerows in 2019, indicating that the blue elderberries can be harvested early in the plant’s lifetime, which allows farmers to earn an early return on the investment of establishing hedgerows. These comparisons show that blue elderberries from hedgerows are a rich source of phenolic compounds.Phenolic compounds were identified and quantified in the blue elderberry based upon retention time, absorbance spectra and authentic standards when available. Concentrations for samples from 2018 are presented in Table 4, while samples from 2019 are presented in Table 5. Two peaks with significant area were observed in the HPLC chromatograms at 6.96 min and 11.70 min that did not correlate to standards or library matching. Both compounds eluted between the retention time of gallic acid and protocatechuic acid. The first eluting compound had a maximum absorbance at 300 nm while the second compound had a maximum absorbance at 280 nm. These peaks were collected individually and further evaluated by accurate mass quadrupole time-of-flight tandem mass spectrometry . TOF acquires mass spectral data by pulsing ions entering the flight tube in an orthogonal beam, therefore full spectra are collected. The data captured is accurate enough to determine the elemental composition therefore allowing identification without standards 104 . The two compounds were tentatively identified using high mass accuracy as 5-hydroxypyrogallol hexoside, a tetrahydroxybenzene , and protocatechuic acid dihexoside . Accurate mass was especially helpful since commercial standards for these compounds are not available. 5- HPG hexoside was identified by its fragmentation pattern , showing a precursor ion [MH]- at m/z 303.0723 and product ion [M-hexose-H]- at m/z 141.0186 . This compound was one of the most abundant phenolic compounds in the blue elderberry. While no evidence of5-HPG glycoside was found in the literature, the aglycone has shown to have a high radical scavenging activity compared to other simple phenols 105 .The other novel phenolic compound identified was protocatechuic acid dihexoside, also present in relatively high amount in almost all the samples. The precursor ion [M-H]- at m/z 477.1609 fragmented to give product ions corresponding to [dihexoside – H]- at m/z 323.0981 and [M-dihexose -H]- at m/z 153.0562 m/z .

The loss of 324 amu has been identified as the loss of a dihexoside on other phenolic compounds and was proposed to be sophorose or gentiobiose106. PA is a breakdown product of cyanidin-based anthocyanins and has been quantified in elderberry juice during thermal processing 107. PA has been shown to have pharmacological potential in the prevention and/or treatment of neurodegenerative diseases in humans based on in vitro and in vivo studies 108 .Like other elderberry species, blueberry pot rutin was the predominant flavonol and overall had the highest concentration of any of the flavonols measured, with an average of 57.01 ± 17.42 mg per 100 g FW in 2018 and 51.89 ± 25.53 mg per 100 g FW in 2019. These values fall within the range of what has been found in European elderberry 8,42,49,59. Other flavonols identified include isoquercetin , kaempferol-3-rutinoside, and isorhamnetin-3-rutinoside, which was also a major phenolic compound in the berry. Isorhamnetin- 3-rutinoside averaged 28.30 ± 14.03 mg per 100 g FW in 2018 and 24.71 ± 14.83 mg per 100 g FW in 2019, which is higher than what has been found in other subspecies. Overall, the blue elderberry analyzed in the present study has much higher levels of total flavonols as compared to European elderberry. In the American elderberry, the main flavonols are rutin followed by isorhamnetin-3-rutinoside whereas in European elderberries, the main flavonols are rutin followed by isoquercetin. In blue elderberry grown in Slovenia, rutin and isoquercetin were the two predominant flavonols, though the total flavonols in found for the subspecies was similar to the levels found in this study. The predominant anthocyanin present in the blue elderberry is cyanidin-3-sambubioside, like the European subspecies. The average concentration in 2018 was 32.70 ± 10.18 mg per 100 g FW and 29.66 ± 16.81 mg per 100 g FW in 2019. Cyanidin-3,5-diglucoside was the next most concentrated anthocyanin, averaging 20.11 ± 5.63 mg per 100 g FW in 2018 and 19.80 ± 6.92 mg per 100 g FW in 2019. This is unlike European elderberries, in which cyanidin-3-glucoside is typically the second most prominent anthocyanin, except for the Ljubostinja cultivar which has more cyanidin-3,5-diglucoside than cyanidin-glucoside. Cyanidin-3-sambubioside-5-glucoside and cyanidin-3-glucoside were also quantified in the berries. Cyanidin-3,5-diglucoside and cyanidin-3-sambubioside-5-glucoside were not detected in blue elderberries grown in Slovenia,suggesting the growing location impacts the profile of phenolic compounds or perhaps the two samples going by the same name are not, in fact, related. There were no acylated anthocyanins identified in the blue elderberry, like those abundant in the American elderberry. Overall, total anthocyanin concentrations averaged 61.54 ± 16.70 mg per 100 g FW in 2018 and 58.58 ± 22.18 mg per 100 g FW in 2019. The total concentration of anthocyanins in the berries was much lower compared to the other subspecies. Analysis of European elderberries that measured cyanidin-based anthocyanins found an average of 863.8 ± 49.9 mg per 100 g FW 8 . European elderberries grown in different locations at different altitudes had a range of 289.74 ± 66.18 to 792.66 ± 27.97 mg per 100 g FW 6 . In studies on American elderberries, one had an average of 265 ± 74 mg per 100 g FW 49, another had average of 248 ± 83 mg per 100 g FW 18, and a third had an average of 242.7 ± 91.0 mg per 100 g FW 50 . The flavan-3-ols catechin and epicatechin were measured in the elderberry, with epicatechin typically present in higher concentrations. The concentrations found in the present study are similar to those found in others, even across subspecies. Blue elderberry grown in Slovenia had 4.40 ± 0.26 mg per 100 g FW of catechin and 8.49 ± 0.37 mg per 100 g FW of epicatechin. The same study found no catechin present in S. nigra ssp. nigra, but 6.37 ± 0.28 mg per 100 g FW of epicatechin. In a study of European berries growing in different locations at different altitudes, total flavanol concentrations ranged from 1.93 ± 0.22 to 9.67 ± 0.66 mg per 100 g FW 6 . The variability in phenolic and anthocyanin content observed in this study is not surprising, as multiple other studies have shown significant variability in other commercialized elderberry subspecies, even with clonally propagated cultivars. For example, Lee and Finn saw an average of 45% higher anthocyanins in their second harvest of American elderberries grown in Oregon as compared to their first harvest, though the total phenolics only increased an average of 20%. Johnson et al. observed significant changes between subsequent years in anthocyanin and phenolic compound concentrations in juices prepared from American elderberry grown in two locations in Missouri. For example, in the Adams II sample grown in one Missouri location, the quercetin 3-rutinoside content was 298 ± 48 mg L-1 in 2012, 792 ± 143 mg L-1 in 2013, and 47 ± 13 mg L-1 in 2014. In a study of 107 wild American elderberries samples grown in five regions of the eastern United States by Mudge et al. high variability was found in selected flavonoid compounds with an average RSD of 55.3% across samples. Overall, there is a body of evidence demonstrating that elderberry composition can vary year to year or by growing conditions even in clonally-propagated cultivars; therefore, it may be necessary to use standardization techniques for bio-active compounds in order to maintain consistent quality in elderberry products. Blue elderberry grown in California hedgerows has similar levels of sugar, organic acids, and TPC to the European and American elderberry subspecies. Furthermore, the phenolic profile of blue elderberry is similar to European elderberry, in that chlorogenic acid, rutin, and cyanidin-3-sambubioside are the predominant hydroxycinnamic acid, flavonol, and anthocyanin, respectively. However, anthocyanin levels are significantly lower in the blue elderberry compared to European and American subspecies, yet the levels of total flavonols appears to be much higher than the other subspecies.

The whole fruit extract of Vitex agnus-castus is thought to act on follicle-stimulating hormone and luteinizing hormone levels in the pituitary to increase progesterone levels. Vitex supplementation appears to cause an increase in estrogen levels, as well. In ovariectomized mice, Vitex supplementation attenuated learning and memory loss associated with low levels of estrogen, even causing an increase in estrogen receptor mRNAs. Along with Vitex agnus-castus, hops and red clover were shown to bind to estrogen receptors in human breast cancer cells. Ginseng and licorice root showed some downstream estrogenic activity, though they did not bind to estrogen receptors. These plants have been commonly used in traditional Chinese medicine for menopausal symptoms, but their role as estrogen analogues also make them promising for attenuation of acne.It is accepted that acne has some microbial etiology, though the exact pathology is not known. Typical treatments, like benzoyl peroxide and antibiotics, target this component of the condition. However, there are several plant-based antimicrobials that could be viable alternatives, especially in combination with other dietary changes that address insulin resistance and hyperandrogenism. A randomized, double-blind, placebo-controlled clinical trial in India with fifty-three patients between 14 and 28 years old tested Ayurvedic plant extracts for safety and efficacy. Study subjects had mild to moderately severe acne exhibiting a minimum of 10 inflammatory lesions and five non-inflammatory lesions . Plant extract tablets containing a mixture of Aloe barbadensis, Azadirachta indica, Curcuma longa, Hemidesmus indicus, Terminalia chebula, Terminalia arjuna and Withania somnifera were formulated. The study found the combined treatment of tablets and topical formulation of the plant extracts showed better results than the tablets alone, plant pot with drainage but the oral preparation was more efficacious than the topical alone.

The Ayurvedic formulation was also evaluated for in vitro antibacterial and anti-inflammatory activity. Azadirachta indica contains many essential oils that have antipyretic and anthelmintic properties. Additionally, it was shown to help control biliary secretion. Some Indian foods including Curcuma longa and Azadirachta indica have been shown to have anti-inflammatory effects by suppressing Propionibacterium acnes-induced reactive oxygen species and pro-inflammatory cytokines. This direct anti-inflammatory property is considered to be the basis for the clinical effect of these plants in treating acne. Sunder Vati is an Ayurvedic herbal formulation containing various herbs such as Holarrhena antidysenterica, Emblica officinalis, and Zingiber officinale. A double-blind placebo-controlled trial of oral Sunder Vati suggested that the formulation is efficacious for the treatment of acne. Subjects treated with oral Sunder Vati had a 60% reduction in their lesion count. Gugulipid is made from the sap of the Commiphora mukul tree, which is native to India. Gugulipid has been traditionally used alone or combined with other herbs for the treatment of a variety of ailments, including rheumatism, arthritis, skin diseases, and obesity. A randomized study treated twenty patients with nodulocystic acne with either tetracycline 500 mg or gugulipid 25 mg for three months. The results of the study demonstrated that both groups had a reduction in acne lesions . Interestingly, patients with oily faces responded remarkably better to gugulipid. This study suggests that gugulipid extract may replace tetracycline in the treatment of acne given its equivalent efficacy, improved safety profile and lack of antibiotic resistance. Gugulipid is a potent hypolipidemic agent. Apart from its hypolipidemic activity, a large number of therapeutic activities like antimicrobial, anthelmintic, anti-inflammatory, anti-arthritic, and antioxidant have been reported.Native to East Asia, Drosophila suzukii has been a major invasive pest of soft-and thin-skinned fruits since it was first detected in 2008 in North America and Europe and has been found recently in South America. Drosophila suzukii is highly polyphagous, being able to oviposit and/or reproduce in various cultivated and wild fruits.

Its fast development and high reproductive potential can lead to explosive population increases and significant economic losses to crops. Though various management strategies, including behavioral, biological, chemical and cultural approaches, have been implemented to suppress D. suzukii populations and reduce crop damage, current control programs rely heavily on insecticides that target adult flies in commercial crops. Because non-crop habitats can act as a reservoir for the fly’s reinvasion into treated crops, area-wide Integrated Pest Management strategies that reduce population densities at the landscape level need to be developed for such a highly mobile and polyphagous pest. To develop area-wide programs, it is critical to understand how D. suzukii populations persist and disperse in the landscape as the season progresses. Many environmental factors, such as local climatic and landscape traits, may trigger the dispersal of D. suzukii populations to escape resource-poor habitats or unfavorable weather conditions. Landscape composition surrounding cultivated crops, such as forests and shrub vegetation, could act as sinks, sources, shelters or overwinter sites for the fly populations. For this reason, the availability of alternative hosts could play an important role in sustaining fly populations and dictating their local movement patterns when favorable hosts are not available. Researchers have provided a better understanding of local D. suzukii population dynamics. Still, there are gaps that limit our understanding of the relative importance of different hosts for D. suzukii within some geographical regions. For example, the seasonal periods of host utilization and the importance of non-crop hosts within the agricultural landscape need to be understood to develop area-wide programs. In this framework, this study aimed to illustrate the temporal dynamics of host use by D. suzukii in California’s San Joaquin Valley, one of the world’s major fruit growing regions. Drosophila suzukii was first detected in California when it was found infesting strawberries and cranberries in Santa Cruz County in 2008. Since then, damaging populations have been recorded from cherries, cranberries, mulberries, raspberries and strawberries, mainly in the coastal or northern California fruit growing regions with relatively mild summer. In comparison, California’s interior San Joaquin Valley has hotter summers and colder winters, and while D. suzukii is collected in cherry, citrus, fig, grape, kiwi, mulberry, nectarine, peach, persimmon, plum and pomegranate as well as in non-crop habitats surrounding the orchards, reported crop damage has been mainly on cherries. Adult fly captures show two main periods of activity—spring and fall—and low captures in winter and summer. The number of captured flies was positively related between pairs of sampled sites based on their proximity, but it was negatively related to differences in fruit ripening periods among crops, suggesting that fly populations might move among crop and/or non-crop habitats during the year . Though adult flies are captured in various orchard crops, it is not clear whether these fruits are vulnerable and serve as hosts. For example, the potential impact of D. suzukii on wine grapes in Italy was discussed by Ioriatti et al., who observed D. suzukii oviposition in soft-skinned berries, and, in Japan, some grape cultivars were reported as hosts for D. suzukii.

In Oregon, Lee et al. found that D. suzukii was able to successfully oviposit in some wine grape cultivars but that offspring survival was low , whereas other studies observed no or low levels of infestation of intact grapes in the field or laboratory. Some of the initial work in Japan reported that D. suzukii emerged only from fallen and damaged apple, apricot, loquat, peach, pear, persimmon and plum, but Sasaki and Sato reported that healthy peach fruit can be infested. However, in California, Stewart et al. reported that intact peach fruit are unlikely hosts. No doubt, growing blueberries in pots many fruits with hard or hairy skin can be colonized if wounds are available to allow flies to oviposit in the pulp. In this study, we document the temporal patterns of host use by D. suzukii in California’s San Joaquin valley by sampling intact and damaged fruits of various crop and no-crop plants throughout the fruiting season. We evaluated the suitability of key fruits, including several unreported ornamental and wild host fruits as hosts for the fly, particularly focusing on the host status of grapes—considered to be a non-preferred host—and cherry—considered to be a preferred host. Wine grapes can contain uniquely high levels of organic acids that are important for producing wines less susceptible to microbial and oxidative damage and with more vibrant color . The levels of acidity decrease as fruit are ripening, but they remain high throughout the ripening process. For this reason, we also examined the impact of tartaric acid concentrations on the fly’s fitness. For cherries, we examined the effects of cultivar and fruit size on the fly’s performance. We additionally monitored adult fly populations at different elevations—from the Valley floor east to the foothills and Sierra mountains—to determine if the fly is active at higher elevations during the hot summer when the fly populations were extremely low in the Valley’s agricultural areas. We discuss the implications of this information for area-wide management in the San Joaquin Valley.A total of 17 common fruits were sampled in a temporal sequence of fruit ripening, including twelve important crops , three ornamentals , and two wild host plants . Samples were taken from 2013 to 2015 at the University of California’s Kearney Agricultural Research and Extension Center, near Parlier, California and near Brentwood, California . Ornamental fruits were also collected in riparian areas surrounding agricultural crops near Bentwood. Bitter cherry, Prunus emarginata Eaton , and the Cascara buckthorn, Frangula purshiana are endemic to western North America; these fruits were collected at higher elevations 1683 m near Shaver Lake, California . For all species, both intact fruit and damaged fruit were collected as available, as the fruit were at a susceptible ripening stage for D. suzukii oviposition. A total of 30–50 fruit were collected when at a susceptible ripening stage for each species, although the number of intact ornamental and wild fruits varied depending on the availability.Collected fruits were placed individually or in groups of 10–50 in deli cups and held under controlled conditions at the University of California’s Kearney Agricultural Research and Extension Center . Deli cups were covered with fine organdy cloth and fitted with a raised metal grid on the bottom to suppress mold growth. Emerged flies were collected every 2–3 d, frozen, and then identified as either D. suzukii or other drosophilids. Only those flies that emerged within 2 weeks following field collection were counted to exclude the possibility of second-generation flies.All laboratory studies were conducted under controlled conditions, as described above . A laboratory colony of D. suzukii was established from field collections of infested cherries at Kearney. The fly larvae were maintained on a standard cornmeal-based artificial diet using methods described by Dalton et al. , and adult flies were held in Bug Dorm2 cages supplied with a 10% honey–water solution and petri dishes containing standard cornmeal medium sprinkled with brewer’s yeast for feeding and oviposition. Field-collected D. suzukii were introduced into the colony yearly to maintain the vigor of the colony. All tests used 1–2-week-old adult female flies that had been housed with males since emergence .To determine if D. suzukii can oviposit within and develop from damaged or rotting navel oranges , a single adult female D. suzukii was exposed to a whole fresh fruit, halved fresh fruit, rotting whole fruit, or halved rotting fruit for 24 h in the acrylic cage. To simulate the natural decay process of a fallen orange, fresh oranges were placed individually on wet sandy soil in deli cups until the fruit started to rot. The halved fruit were allowed the same amount of time as the whole fruit but were cut into halves just prior to the test. On average, rotted fruit had 42.3 ± 7.3% of their surface covered by mold growth. Following exposure, the numbers of eggs laid were counted, and the fruit was then held in the cage until the emergence of adult flies. Each treatment started with 25 replicates; however, a few replicates were discarded because of contamination by other drosophilids that likely occurred during the regular examination for the decay status of the fruit. A sub-sample of 10 fruit was measured to determine the Brix levels of fresh and rotting fruits.To determine the possible effect of tartaric acid on D. suzukii survival and development, seven different concentrations of tartaric acid were mixed with a standard artificial diet. The powdered tartaric acid was purchased from a wine and beer brewing store in Fresno, CA, USA, and mixed with the diet just before the diet solidified.

The Star variety had the numerically highest numbers of total eggs and larvae per plant compared with any other variety. The likelihood ratio chi-square test indicated a significant effect of egg count on the top third of the plant as well as a significant effect of larval count on the two plant locations, i.e. the top third also having the highest count . More eggs were found on the top third of the blueberry plants and there was a higher percent of larvae present on the top third of the plant ,regardless of plant variety. However, in the choise test, the Star variety had the highest percent of eggs found and larvae present. The Snowchaser variety had the lowest numbers of thrips counted overall, with fewer eggs, larvae and adults collected on that variety. The Misty variety had fewer larvae present than eggs laid and the number eggs laid were comparable to levels on Emerald.Under the conditions of these trials , citrus thrips egg hatch typically would take place within 4-9 days , therefore numbers of motile insects counted in both studies would be larvae from the first generation and surviving adults. The primary focus of this work was to determine if there was a difference in the number of eggs laid on the different types plants and our data clearly show this was the case . The no-choice oviposition test showed that the highest number of eggs and larvae were found on citrus and sumac and the blueberry varieties Star and Jewel. Intermediate levels were found on Emerald and Misty, round plant pot and the lowest numbers on Snowchaser and O’Neal. The highest numbers of larvae present in clipcages were on the citrus, sumac and Star blueberry variety.

The Tukey HSD separation for total counts of eggs and larvae group Jewel with the citrus, sumac, and Star, but these data may be skewed due to the negative correlation between the number of eggs laid on the Jewel variety and the number of larvae present.The choice oviposition test also showed a correlation between the number of eggs located and the number of larvae present on the plant. Evaluation of count means showed a difference in citrus thrips numbers on the Star variety over the other blueberry varieties in the test. When given the choice to move about the plants, the citrus thrips’ activities at the time of isolation and counting appear to be similar for Emerald and O’Neal with a mean of less than 10 adults recovered from those plants. In the choice oviposition tests, the negative correlation between egg and larval counts is also apparent for the Jewel variety. Some explanations for this negative correlation could be: first instars eclosing from the egg suffered high mortality, the larvae did not or cannot feed and/or develop well on this variety, and/or the larvae dispersed away from the plant onto other plants. If the latter were the case, then one would expect to see one or more other blueberry varieties with higher numbers of larvae present, but that was not the case and given the fact the canes did not remain in contact with one another, it is unlikely that high levels of larval dispersion to different pots took place.

There are several possibilities which explain the results: 1) females chose to lay eggs preferentially in some varieties over others, 2) egg survivorship influenced the numbers counted/found, 3) first instar egg eclosion varied across variety, 4) differential larval survivorship and development on the plants, and 5) larval dispersion, possibly to other plants, but possibly off the plants with mortality ensuing in unevaluated portions of the bug dorm. The Chi-square values for plant location were significant indicating that there were disparate numbers of eggs laid and larvae counted between the two locations, with the top third of the plants, regardless of variety, preferentially chosen over the bottom two-thirds. This was likely due to the amount of flush growth present on the top third of the plants. Also, given data in our studies, thrips activities appear higher on the top third of the plant; this is likely a good area to sample when looking for thrips on blueberries. Combining all the data, our studies clearly show that the Star variety had more citrus thrips than the other blueberry varieties, and numbers of oviposited eggs found on Star, Jewel, citrus and sumac were similar. This quite possibly is due to Star’s parentage. The Star variety is a variety that produces flowers the earliest and for the longest period during the season and while yield may not be as high as some of the other varieties, it is planted as a season long fruit bearer. Because the highbush blueberries are hybrids of one another and the nurseries have proprietary rights to the genetics of these varieties, we are therefore unsure how closely related the varieties we tested are. Snowchaser was the variety least preferred by the citrus thrips based on our data, however, to our knowledge it is not a variety currently grown commercially in California.

There are countless factors that need to be considered to fully understand insect host choice, including but not limited to, host plant finding, host plant acceptance, host plant relatedness, resource concentration, resource availability and host use . The insect’s ability to locate the host plant, settle, feed, reproduce and successfully produce the next generation that achieves reproductive maturity involves countless steps and subtle interactions that are beyond the scope of the work presented here. We provide a platform for further work on the distribution, abundance and avenues for research related to citrus thrips as a pest of blueberries in California. We anticipate citrus thrips will remain a pest of concern to the blueberry industry of California as the industry continues to expand.The role of a public university such as the University of California is to improve the human condition through research, teaching, and public service. At the Center for Agroecology and Sustainable Food Systems we strive to meet the ideals of a public university by working to improve ecological sustainability and social justice in the food and agriculture system. Our work is multifaceted, covering a spectrum that includes research , education and public service . The Center provides a unique academic and practical forum for exploring alternative visions for food and agriculture, and pursues a research and education agenda that is broader than most agriculture—even sustainable agriculture—programs. The Center works to give special attention to the silent voices in sustainable agriculture. This includes conceptual work that expands the way in which sustainability is defined so that it addresses political economic and social justice issues related to class, ethnicity, and gender . Empirical research at the Center also addresses these issues through projects that focus on fair trade, farm labor issues, round garden pot and alternative agrifood institutions. The Center’s broad agenda is enabled by specific historical factors and constrained by the same conditions that affect all public universities.Several factors have converged to make our broad agenda possible: the Center’s location in a social sciences division on an interdisciplinary, non-land-grant campus; the incorporation of practitioners and academics on our staff; and the concentration of nongovernmental organizations in the region focused on sustainable agriculture, the environment and family farms. The Center is housed within the Division of Social Sciences at a campus that does not have an agriculture school. This unconventional setting is probably what enabled the Center to pioneer work in sustainable food systems and organic agriculture at a time when mainstream agriculture campuses were vehemently opposed to these ideas. It also makes possible the development of a strong social science research program to complement the natural science work, which is unusual in a program focused on food and agriculture. This hybrid structure has enabled us to combine basic and applied research within and across disciplines, as well as provide research support and outreach programs for multiple partners and audiences. This provides a fluid, mutual “reality check” on theoretical and applied work.

Practitioners provide academics with ideas and questions that need to be addressed, along with practical information, experience, and feedback on the relevance of research to the community in question. In turn, academics provide practitioners with new information, research support, and a broader context for their work and understanding of the agrifood system. In addition to its work with graduate and undergraduate students, the Center works with nontraditional students through nonformal education programs. For example, the Apprenticeship program provides experiential training on gardening and farming techniques, small farm viability, marketing, social justice, and the environmental impacts of agriculture to nontraditional students. The Center has also developed a collaborative arrangement with a local NGO that provides training and education programs in Spanish to Latino farmers and farm workers in the Central Coast region. The Center’s work with these kinds of organizations is facilitated by a fortuitously high density of sustainable agriculture nongovernmental organizations in the Santa Cruz region, such as the California Sustainable Agriculture Working Group , the Community Alliance with Family Farmers, the California Certified Organic Farmers, and the Organic Farming Research Foundation. The geographical proximity between the Center and these organizations facilitates joint research and education projects, as well as the kinds of casual interactions that build networks. In addition, a project funded by the U.S. Department of Agriculture has strengthened the work of a multidisciplinary team of researchers and fostered collaborations with County, State and Federal agencies, local NGOs, Farm Bureaus, Cooperative Extension and researchers in other UCSC departments and other institutions. Thus, the Center’s history and location make it well situated for fulfilling the academic and service missions of a public university. However, challenges remain. A primary issue is how to provide service to the nontraditional students and underserved members of the public. In particular, how can programs that serve groups considered marginal to the traditional research and education of the university agenda secure adequate resources for their work? Ironically, some of the programs for which the Center is renowned are also those that face the greatest challenges.Many of the same factors that have enabled the Center to pursue a whole-systems, progressive agenda have also constrained our ability to have legitimacy among conventional agricultural institutions and resulted in considerable uncertainty in funding and support from year to year. In particular, being outside of the land grant system with no major agriculture program on campus presents both funding challenges and limits the recognition of our work A key issue is how to effectively serve the scope of “publics” who have the right to claim resources of a public university. The Center prioritizes working with community groups that have largely been outside of the traditional agricultural extension frame, including organic farmers, food security groups, and food-system workers. While working with a diversity of farmers, including those typically underserved by mainstream agriculture programs such as those with limited capital and small-scale organic growers, has been a priority for the Center as well as for other sustainable agriculture programs, even this emphasis is skewed relative to their numbers among agrifood system workers. Of those who work in the agrifood sector, 78 percent work in food processing, retailing, and distributing; 11 percent supply inputs such as equipment and agrichemicals. Only 11 percent are farmers and farm workers directly involved in agricultural production. In California most of those who are involved in farming are hired farm workers. In California there are 18 farm workers for each farmer, and hired farm workers perform at least 80 percent of all the farm work in the state . How can research and education programs do a better job of addressing the needs of low-capital and small-scale farmers, farm workers, food industry workers, and consumers? This is much more challenging than working with the traditional producer clients of agricultural universities. The most disadvantaged and impoverished may not have the time and resources to participate in committee meetings and actions or actively engage with participatory or community-based research processes . In addition, working with these groups may alienate more traditional clients. For example, credibility with growers is a major issue for sustainable agriculture programs that include social issues as a priority in their research agendas.

Control leaves for both species were treated with a mixture of the same suspension ingredients minus the protein. Bioassays were conducted concurrently in the following manner for both species: adult female thrips were placed on leaves coated with activated or inactivated forms of both Cyt1A and Cry11A, immature thrips were also placed on leaves coated with activated or inactivated forms of both Cyt1A and Cry11A, and all combinations for adults and immature thrips were carried out along with the corresponding control cells. The Munger cells were closed and placed in an environmental chamber at 28ºC, 55% RH, and long daylight conditions . Each cell was carefully removed daily and the filter paper doused with water to prevent leaf desiccation. The bioassay was replicated on two separate dates . A minimum of 10 individuals was placed into each Munger cell and thrips were checked daily for eight days to assess mortality. Post seven days, the integrity of the leaves was questionable and in all but one bioassay, mortality was observed before seven days; thus data were analyzed using day 7 mortality. Mortality was determined by lack of movement after gently probing each thrips with a small brush.Six strains of B. bassiana were obtained from the USDA-ARS Western Integrated Cropping Systems Research Unit located in Shafter, CA. GHA is the commercially available strain found in the field formulation of B. bassiana, Mycotrol O and the greenhouse formulation BotaniGard ES, large plastic planting pots and each of the other five strains were obtained via isolation from soils in Kern County by USDA-ARS collaborators in 2000.

They were stored at – 80ºC. Culture methods for the thrips experiments were similar to those described previously for Lygus hesperus Knight bioassays and were conducted by collaborators from USDA-ARS, Shafter, CA. Briefly, isolates were grown on SDAY media, or Sabouraud’s dextrose agar plus yeast extract . The conidia were harvested from culture plates after 10–14 days incubation by scraping with a sterile rubber policeman into a 0.01% solution of Silwet L- 77 . The conidia were then enumerated with a hemocytometer. For preservation and storage, glycerol was added to the conidial suspension and stored in aliquots of 2 × 108 in a 2 ml solution at −80°C until needed for bioassays. Conidial viability was assessed following incubation for 16 h in potato dextrose broth just prior to use in experiments. Viability was determined by adding a sample of approximately 107 conidia to 20 ml potato dextrose broth and incubating ca. 16 h in a rotary shaker at 28°C. Conidia germination was examined under a compound microscope at 400× and scored as viable if the germ tube was at least twice the length of the conidium. Percentage viability was measured on 250 conidia of each isolate. All bioassays were conducted on the basis of the number of viable conidia measured after thawing and the desired concentrations were formulated by serial dilution. The strain from Mycotrol was isolated and cultured exactly asabove to eliminate possible effects of production methods and formulation ingredients on insecticidal activity. Glycerol was not removed prior to using the conidia in bioassays. All six B. bassiana strains were suspended in 0.01% Silwet in a de-ionized water solution and evaluated on the same date at four concentrations for each thrips species. The control consisted of 0.01% Silwet in de-ionized water solution. Each of the 25 treatments was evaluated using five Munger cells , which contained a minimum of ten adult female thrips. These bioassays were repeated on 10 dates with both species tested simultaneously on each date . Groups of thrips were anesthetized by exposure to CO2 for 15-30 sec, and each strain was administered to the dorsum of the abdomen of each knocked out thrips quickly and carefully in a 1µl drop with a Burkard Hand Microapplicator over filter paper.

The droplet spread the length of the thrips immediately and the thrips was then deposited, still knocked out, onto the leaf tissue in the Munger cell. Once a minimum of 10 treated thrips were added, Munger cells were closed and sealed with binder clips and placed in an environmental chamber at 28ºC, 55% RH, and long daylight conditions . Each cell was checked daily for seven days to observe infection by the fungus. Each cell was carefully removed daily and the filter paper doused with water to prevent leaf desiccation. Individuals infected with B. bassiana were defined as those whose natural activity was retarded and/or showed arrestment and subsequently produced mycelia, which was confirmed post bioassay. Mortality caused by mycosis was confirmed on the basis of visual observation and then crushing individuals to reveal the presence of mycelial growth. When mycelial growth was not apparent, crushed individual thrips were placed on potato-dextrose agar plates for 5 days and then re-examined for the presence of mycelial growth. Data were analyzed after Abbott’s correction for control mortality using log-probit analysis with PROC PROBIT on SAS 9.2 and using the Raymond Statistics package . The purpose of the probit analysis was strictly for gross strain comparison. Probit analysis was used to estimate the LC50 and LC95 levels, confidence intervals, and χ 2 values for each strains. Lethal concentrations with overlapping 95% confidence intervals were not considered significantly different. The daily check data were analyzed as non-cumulative counts per day via the Survival Distribution Function on SAS 9.2 , where observation time represented the probability that the experimental unit from the population would have a lifetime exceeding that time with the variables strain and concentration. Assessments for each variable by species were done with Log-rank and Wilcoxon tests and multiple comparisons for the log-rank test were adjusted by using Tukey-Kramer method. Data were then plotted as estimates of the survivor function for the different strains separately for each species.Screening Bacillus thuringiensis endotoxins for activity. Bacillus thuringiensis israelensis produces two groups of toxic proteins, the Cry and Cyt toxins that have different modes of action. In this investigation, results with Cyt1A and Cry11A were disappointing as both activated and inactivated forms of both proteins showed little effect against adult and second instar citrus thrips and avocado thrips. To our knowledge, there have been no reports of Bt endotoxins with activity against Thysanoptera, although Cyt1Aa was found to be toxic to the non-target species Chrysomela scripta Fabricius . Many hypothesize that because thrips feed with a punch and suck method, rather than direct chewing and mastication of leaf tissues, they do not receive toxic amounts of the Bt proteins . Alternatively, they may not possess the proper binding receptors for the Bt proteins tested to date and thus, no pore can be formed in the midgut lining and the Bt proteins are excreted . The literature indicates the latter hypothesis is more likely based on findings from life table parameters where development, fecundity, and adult longevity or relative abundance are not significantly different from thrips reared on Bt positive versus Bt negative corn, cotton, or potato plants. The aforementioned studies were not specifically looking at Bt effects on thrips nor were the Bti toxins tested here involved in previous studies involving thrips.

It is indeed possible that there are no Bt endotoxins currently available that cause mortality to Thysanoptera. Screening Beauveria bassiana strains for percent infection. Beauveria bassiana was pathogenic to adults of both species of tested thrips. Results with citrus thrips. The LC50 with strain GHA was 8.61 x 104 conidia/ ml and was two orders of magnitude lower than for the other five B. bassiana strains tested . GHA also gave the only statistically valid dose-response values in probit analysis, and provided the only data that fit the probit model. The other B. bassiana strains failed to provide a linear relationship based on their p-values , i.e. the probit regression lines were of poor quality, except for GHA. Therefore, black plastic planting pots data were evaluated based on line slopes as is commonly seen in the scientific literature with other biological agents where data lines are not straight and do not fit the model . Strains 1741ss, SFBb1, S44ss, and NI1ss showed a flat dose-response between concentrations, did not fit the model, and LC50’sranged from 2.7 x 106 – 9.6 x 108 . Assessment of Beauveria strain while adjusting for concentration, in both Logrank and Wilcoxon tests showed that strain and concentration had a highly significant effect on the infection rate. Multiple comparisons for the Logrank test to assess the strain effect while adjusting for the concentration differences showed that strains 1741ss, S44ss, 3769ss, and NI1ss infection rates were not distinct from one another. Strain GHA and SFBb1 had infection rates different from each other as well, and GHA had the fastest infection rateand SFBb1 showed the slowest kill rate . The Survival Distribution Function analysis coupled with the probit analysis clearly shows that GHA would be the best strain choice for citrus thrips control. Results with avocado thrips. The LC50 for strain GHA was 2.2 x 106 conidia / ml and was similar to that obtained with the other five B. bassiana strains tested . Again, because a strong linear response was not observed, the performance between strains was rated based upon the LC50 and relative linearity of the response. Based on overlap of confidence intervals, there were no significant differences between any of the strain LC50’s or LC95’s . Assessment of Beauveria strains while adjusting for the concentration, using both Log-rank and Wilcoxon analysis showed that strain did not have an effect on the infection rate. The multiple comparisons for the Log-rank test to assess the strain effect while adjusting for the concentration differences showed infection rates for all 5 strains were not distinct from one another . The Survival Distribution Function analysis coupled with probit analysis indicated there was no one best strain to select for avocado thrips management. Citrus thrips were more susceptible to Beauveria than avocado thrips; citrus thrips LC values were much lower for the most active strain, GHA, indicating that significantly lower dosages of strain GHA were required to infect and kill citrus thrips compared with avocado thrips. The overall survival analysis results showed a similar pattern to the results of the probit analysis; GHA had the fastest infection rate and SFBb1 had the slowest rate . Infection rates for the other three strain’s fit in between the rates for GHA and SFBb1, and 1741ss, S44ss, 3769ss, and NI1ss infection rates were not separable. This low dosage association and having the fastest infection rate suggest GHA is the best candidate for field-testing among the strains examined. Except for the worst performing strain, SFBb1, the performance of all of the strains with avocado thrips were similar. The LC50 value for citrus thrips was 8.6 x 104 conidia/ml, which may suggest economical feasibility in some cases, e.g., for use on organic products. The maximum recommended field application rate is 5.0 x 1012 conidia/ha. Therefore, 8.6 x 1011 conidia/ha of GHA is needed based on the estimated LC50 of 86 conidia/µl and this amount is reasonable to obtain in a field setting. Conducting the same analysis for avocado thrips control using GHA, with an LC50 of 2.2 x 106 , 2.2 x 1013 conidia/ha would be required. This is 4.4 times greater than the standard field use rate of GHA. We hypothesize that differences in susceptibility between citrus and avocado thrips may be due to the different habitats in which they evolved. Citrus thrips are adapted to hot and dry environments and thus, they are less likely to have evolved natural tolerance to fungi, whereas, avocado thrips thrive in a very wet environment where exposure to fungi is more likely. The differences may be due to different habitat adaptations and the different origins of the two thrips species . We find it interesting that two congenerics have such widely different habitat preferences and this may explain differences in fungal tolerance. Differences were seen when citrus thrips and avocado thrips were placed on leaves of their associated host plants, then placed separately in sealed zip-lock bags where the moisture that condensed in the bags was lethal to citrus thrips but not to avocado thrips. Thus, it is possible that avocado thrips, due to their adaptation to living in cool and wet climates , have a higher tolerance to fungal pathogens, as they may encounter them more frequently than citrus thrips, which prefer a hot and drier climate . Many researchers have investigated alternatives to traditional insecticides such as bio-pesticides, i.e. natural or organismal methods of controlling pest populations.

Many polyphenols found in dates have been studied as isolated compounds in in vitro and ex vivo systems with respect to their effects on markers of vascular function. Protocatechuic acid, a metabolite of the anthocyanin cyanidin-3-glucoside , and its phase II metabolites were effective in modulating the production of the key inflammatory mediators IL-6 and vascular cell adhesion molecule-1 at dietary-relevant concentrations as low as 100 nmol L−1 , with maximum reduction observed for the sulfate conjugates in human umbilical vein endothelial cells stimulated with either oxidized LDL or a cluster of differentiation CD40L. In the same study, C3G and its metabolites reduced IL-6 production in CD40L-stimulated cells, whereas both C3G and its metabolite, ferulic acid, reduced VCAM-1 production. Anthocyanins and ferulic acid have also been found to significantly reduce monocyte adhesion to HUVECs under physiologically relevant conditions, an important step in reducing atherosclerosis development . In human intestinal cells in vitro, the addition of a freeze-dried date extract from California-grown dates with a total proanthocyanidin content of 13% was demonstrated to act as a potent co-agonist ligand for the farnesoid x receptor , a nuclear structure important for maintaining triglyceride and cholesterol homeostasis. This study provides a potential mechanism by which dates may exert a hypotriglyceridemic effect, as observed in the human study noted above. The tea catechin, epigallocatechin- 3-gallate , plastic pot plant containers has also been shown to modulate FXR in a tissue- and gene-specific manner. Further studies are warranted with dates and their extracts using both wild-type and FXR knockout mouse models.

While the above in vitro work is promising, data from dietary interventions that specifically examine the association between circulating date polyphenols or phenolic metabolites with physiological effects have yet to be reported. Additionally, clinical studies are needed, since in vitro and animal studies, while potentially relevant as preclinical models, do not directly assess outcomes such as the vascular effects in humans. Clinical and mechanistic data on the biological effects of polyphenols derived from dates are limited . Such evidence is crucial for agriculture, health professionals and consumers, particularly as the concept of personalized nutrition grows more popular. In addition to randomized clinical trials on the fruit in general, more data is needed to identify which polyphenols are the most vasculoprotective and then determine how best to cultivate, harvest and process the fruit for maximum bioactivity. The efficacy of date consumption also needs further interrogation in various at-risk groups such as those with lipid disorders, hypertension, obesity or diabetes. Since all fruits are not equal in composition, identification of unique bioactive compounds or fractions in dates would help define benefits that may not be obtained from other fruits or plant-based foods.Dates contain folic acid and vitamin C. Folic acid is required to metabolize homocysteine to methionine. Elevated levels of serum homocysteine have been associated with increased risk for CVD. Although the mechanisms by which increased homocysteine promotes CVD are incompletely defined, suggested alterations include impaired vascular tone due to decreases in NO bio-availability and increases in ET-1, promotion of damaging ROS, and endothelial inflammation and the activation of the coagulation cascade. The vitamin C in dates, while modest in amount compared to most citrus fruits, can nonetheless help to scavenge free radicals via enzymatic and non-enzymatic activities, and help protect lipoproteins from oxidative damage. In addition, vitamin C can improve measures such as arterial stiffness and endothelial function, and low serum concentrations of vitamin C have been linked to increased CVD risk and mortality. Some of the cardioprotective effects of dates have been ascribed to dietary fibers, which have a well-established lipid-lowering effect . Serum triacylglycerol, total cholesterol, and LDL-C levels were significantly lowered in rats given 100 g/kg of date dietary fibers.

Most of the fibers in dates are insoluble. These fibers can bind to cholesterol and triacylglycerols in the intestine and facilitate their excretion, which helps lower circulating cholesterol levels. As a result, less lipoprotein is also susceptible to oxidation, thus reducing the impact on atherogenesis. Further, fiber-rich foods can promote production of beneficial commensal bacteria while limiting the growth of known opportunistic pathogens. A high-fiber diet was reported to increase acetate producing microbiota, lower blood pressure and decrease cardiac hypertrophy and fibrosis in hypertensive mice. Bacterial fermentation of prebiotic soluble fiber generates short chain fatty acids, which are thought to exert several beneficial effects including differentiation of immune regulatory T cells, and decreasing the expression and activation of peroxisome proliferator-activated receptor-γ. Downregulation of PPAR-γ activates a mitochondrial uncoupling protein 2 and an AMP-activated protein kinase network, shifting metabolism in adipose and liver tissue from lipogenesis to fatty acid oxidation. Conversely, activation of PPAR-γ has been shown to have antiinflammatory effects, promote the expression of genes for fatty acid oxidation, and decrease lipotoxicity in macrophages. The interaction of date fibers and polyphenols may also impact vascular function. The gut microbiota are critical for enhanced bio-availability and activity of ingested polyphenols, as most parent compounds are not well absorbed in the small intestine. Following the ingestion of polyphenols, typically in their glycosylated forms, bacteria in the gastrointesti-nal tract metabolize these molecules to low-molecular-weight phenolic compounds that are then absorbed by intestinal epithelial cells. Polyphenols have been shown to undergo a variety of enzymatic processes by bacterial populations in the gastrointestinal tract, including the hydrolysis of glycosylated flavonoids, acylation of flavanol-3-ols and esterification of hydroxycinnamic acids. A detailed description of these mechanisms can be found elsewhere.While the health promoting cardiovascular benefits of a number of fruits, nuts and berries rich in select polyphenols have been characterized through animal and human studies, no such data exists for dates to our knowledge. Given the polyphenol and fiber content of dates, vascular function and gut microbiome studies would be useful. Vascular function is commonly assessed by two noninvasive techniques: flow-mediated dilation of the brachial artery and peripheral arterial tonometry in the fingertip. Both methods have demonstrated prognostic value for the assessment of cardiovascular risk factor burden. High dietary intakes of select polyphenols, such as the flavanols and PACs found in berries, tea, red grapes, and cocoa have been reported to significantly improve FMD and PAT in various population groups. Importantly, no data exists with respect to the impact of date products and their polyphenols on vascular dysfunction via measurement of FMD and PAT. An inherent challenge with most nutrition studies is the identification of suitable controls. This is particularly difficult when examining the potential health effects of whole foods that contain a multitude of compounds that are bioactive either separately or through their interaction with other constituents in the food matrix. One model for testing foods or extracts is to use a control product that is closely matched in calories, large plastic gardening pots macro- and micronutrients, taste, and color, but devoid of the test fraction or compound. This model has been used successfully in studies that assess the effects of a dietary strawberry powder and a flavanol-rich cocoa drink. Another model is to employ a no-intervention control group, although operationally, this may skew the results since a number of those assigned to the control group may withdraw from the study prior to its completion, and those remaining may not fully represent the population initially enrolled. Future human research on dates must select the study population carefully, and focus mainly on groups at risk for CVD. Accordingly, hormonal status, age and sex are factors that can produce significant interindividual variability in cardiometabolic responses to phenolic compounds and must be considered. Factors such as microbial metabolism and genetic polymorphisms may be other contributors to outcome variability. Recent attention has also emphasized the challenge of reproducibility and accuracy in human nutrition research. As noted above, more complete compositional profiles of dates are needed rather than simply recognizing the total amount of GAEs, a gross index of flavonoid content.

A more detailed characterization of products, reagents, and model systems used, as well as better rigor and reporting of experimental designs, protocols, and data analysis, will help achieve this goal. Worthy of note, many of these elements were limiting factors in the in vitro and in vivo animal reports discussed above.While dates have positive biological effects, concerns have been raised about their potential concentrations of heavy metals. Exposure to heavy metals can result in cardiovascular diseases, encephalopathy, renal dysfunction, dementia, and certain cancers. A recent study of seven date varieties collected from different locations in Saudi Arabia noted that aluminum, chromium, and antimony were within a safe range based on the maximum allowable levels set by the World Health Organization, while arsenic, lead, and cadmium exceeded the upper limit in some of the date cultivars. Numerous environmental factors can increase concentrations of heavy metals such as mining, fertilizer applications and industrial emissions, as well as naturally occurring amounts normally found in some soils.Tephritid fruit flies are well-known agricultural pests, and there are approximately 4500 species worldwide . As typical herbivores, host plant expansion is an important survival strategy for tephritid flies, especially when introduced into new areas. Host plant expansion is the ability of an herbivore to use novel host plants without losing their ability to use their original hosts , which facilitates the establishment of tephritids when entering new geographic areas and expanding their damage . Therefore, understanding the mechanism of host plant expansion will be helpful for the control of tephritid pests. Host expansion is well documented in the most destructive species of the genera Anastrepha, Bactrocera, Ceratitis, Dacus, and Rhagoletis among tephritid flies because they have expanded their range worldwide . For example, the ancestral hosts of Zeugodacus cucurbitae in India are primarily cucurbits, but it began to infest papaya in Hawaii , and it expanded its host range to include mango in Africa . The peach fruit fly Bactrocera zonata expanded to oranges and tomatoes when introduced from southeastern Asia to Egypt . Because of the typical frugivorous pest, the tephritids spend some stages of life from eggs and larvae to pupae in the fruit of host plants. Therefore, the microenvironment of host fruits to which flies try to expand will have an important influence on the survival and adaptation of fruit flies. Therefore, when tephritids successfully expand their host range from ancestral host fruits to new hosts, they must adapt well to the chemical and nonchemical properties of the microenvironment from the novel host fruits, including theirphytochemicals, color, and phenology. The color of the host fruit is an important cue to many fruit-infesting insects when selecting a new host . The phenology of the novel host, such as the timing of flowering and fruiting, also affects the ability of a tephritid to use a new host . Importantly, host chemicals are key drivers when herbivores encounter a novel host and serve as attractants and barriers to adaptation . Phytochemicals include volatile compounds and secondary metabolites that serve as attractants or defensive compounds to herbivores, such as tephritids. Volatile compounds allow tephritid adults to select among potential hosts while in fight, similar to fruit color. Once tephritid flies overcome the volatile chemicals of a potential new host, they eventually make contact with the host fruit, and then they must adapt to any secondary metabolites present to successfully colonize the host fruit. These chemical and nonchemical cues of a potential novel host fruit act as selective pressures on tephritids when a novel host is encountered . These selective pressures involve visual identification; behavioral selection; and physical, chemical, and neurophysiological responses by tephritid flies to the novel host fruit . There is likely a genetic basis for each of these processes, which suggests that various genes are involved in regulating the host plant expansion of tephritids. Therefore, increasing our knowledge of the categories and roles of these genes in regulating host expansion will deepen our understanding and allow for improved management strategies for tephritid fruit flies. Gene regulation of host plant expansion has been revealed in several herbivorous insects, including Subpsaltria yangi Chen , Drosophila mettleri Heed , and Chilo suppressalis Walker . For example, research on host plant expansion in a cactophilic fly, Drosophila mojavensis , revealed cytochrome P450, glutathione S-transferases, and UDPglycosyl transferases as major gene classes involved in new host use . Therefore, the present review summarizes current knowledge on the categories and roles of the genes involved in host plant expansion in tephritids and the related regulatory mechanisms and relates these findings to the development of new control methods for tephritid species.

Calling UCSC’s programs “near and dear to my heart,” Farr said there was no place he would rather have been than on campus among the pioneers and contemporary leaders of sustainable agriculture. Farr hailed UCSC’s spirit of innovation and ability to accomplish a lot with minimal resources, and he credited UCSC leaders with fighting for agroecology, even when it meant taking on vested interests within the University of California system who wanted to confine agriculture programs to the Davis and Riverside campuses. Reading from remarks he entered into the Congressional Record on October 4 to honor the 40th anniversary of sustainable agriculture programs at UCSC, Farr called the Center for Agroecology and Sustainable Food Systems “one of the most prominent centers of agricultural research and education in the world.” In Congress, Farr has helped secure more than $3 million to support CASFS research and extension projects. Farr has been a proponent of organic farming since his service in the Peace Corps in Colombia in the 1960s, when he saw the importance of helping people improve their ability to grow food. In UCSC’s programs, he recognized the relevance of developing small-scale, intensive, organic food production systems. Over the years, Farr has made several landmark contributions to UCSC’s programs, and CASFS director Patricia Allen thanked him for his commitment to sustainable food and agriculture research and education. As host of the program, Allen read from remarks prepared by environmental studies professor Stephen Gliessman, who was unable to attend the ceremony because he was teaching a class. “We owe the existence of agroecology and CASFS to Sam, and it is up to us to continue to carry his vision of sustainable food systems forward,” Allen read on behalf of Gliessman, who was the first director of agroecology and who holds the Alfred E. Heller Chair in Agroecology.

Farr also authored the 1990 state law that established standards for organic food production and sales in California, square plastic plant pots which became the basis for recent federal organic food standards. In Congress, he has insisted that U.S. Department of Agriculture research stations include a focus on organic agriculture. Former CASFS director Carol Shennan, a professor of environmental studies, thanked Farr for his recent support of research efforts, including UCSC’s Central Coast water monitoring project that has helped farmers reduce pesticide runoff into the Monterey Bay National Marine Sanctuary, and for research on regional food systems. As part of the celebration, Farr and garden manager Christof Bernau planted an heirloom climbing rose—the first in a new rose garden established in Farr’s honor. An adjacent plaque honors Farr for his “visionary support of sustainable food and agriculture research and education.”The second national conference on Facilitating Sustainable Agriculture Education, held July 11–14 at Cornell University in New York, brought together nearly 200 educators and students to share ideas for improving sustainable agriculture education at colleges, universities, apprenticeship programs, and other settings. Center for Agroecology and Sustainable Food Systems graduates, students, and staff have played key roles in developing this new organization, whose mission is to “. . . promote and support the development, application, research, and exchange of best teaching and learning practices in sustainable agriculture education and curricula through communication, training, development, and collaborative activities for teachers and learners.”

The burgeoning interest in sustainable agriculture education prompted the founding of the SAEA. “We did a survey of stakeholders around the U.S. before moving forward with developing the association,” says Albie Miles, former curriculum editor at CASFS who helped organize the first national conference, held at Asilomar in 2006. “It was clear from that survey that there was a lot of interest in creating an organization that would help promote educational opportunities and move sustainable agriculture forward as a mainstream academic discipline,” he says. Although the SAEA was originally envisioned as a group that would promote sustainable agriculture programs at post-secondary schools, this year’s conference attendees broadened that scope to include education at a variety of levels. “I was impressed by how enthusiastic everyone was about not defining ourselves too narrowly,” says Katie Monsen, a UCSC graduate student in Environmental Studies who has helped develop the new organization. “We had people there from universities, but also growers and others with educational programs. For example, people are really interested in getting high school students involved in order to increase enrollment in college agronomy programs; other say we need to start sustainable agriculture education even earlier—this opens us up to work with a broad range of folks.” That range was reflected in this year’s group of conference participants, who came from throughout the country to share resources, discuss teaching methods, and create new networks. Monsen notes that despite the geographic differences, attendees found common ground in their educational goals. “We didn’t have a lot of conversations about ‘what is sustainable agriculture,’” she says. “Although there are certainly differences in regional cropping systems, people from across the country had very similar interests when it comes to creating educational opportunities.” In contrast to the typical “top down” approach to education, students have had a major voice in SAEA’s development. UC Davis graduate student Damian Parr, a graduate of UCSC and the CASFS apprenticeship program, is a leading advocate for giving students an equal voice in developing sustainable agriculture programs.

That goal is reflected in SAEA’s statement of values, which include, “A focus on learning and the development of communities of co-learners,” and “The democratization of knowledge and learning.” Next steps for the new organization include developing an online resource directory. “We want to make the web a place where people will be able to put up curricula, ask questions, post ideas and resources,” says Miles. That effort is already underway, with resources shared at this summer’s conference now available online .SAEA subcommittees are also working on student outreach, fundraising, and developing plans for next summer’s conference, which will take place in the Midwest.In Together at the Table, Patricia Allen provides a comprehensive and critical analysis of the potential for alternative agrifood movements to create substantial change in the entire food system. She looks in particular at the sustainable agriculture and community food security movements as examples, weighing the strengths and weaknesses of each. The UC Sustainable Agriculture Research and Education Program was, happily, accurately showcased in the discussion of sustainable agriculture programs. Then, in the final chapter , she suggests specific strategies for how we can all work together to improve and build the capacity of these movements for creating lasting changes that address all aspects of sustainability—ecological, economic viability, and social equity for all people in the food system. In her conclusions, Allen points out two key areas we, in the sustainable food systems research/practitioner communities need to work on: • Develop a broad-based vision for an alternative agrifood system that goes beyond the traditional ideological framework, and • Continue to broaden constituencies and engage them in democratic processes that can provide political power to move us toward significant change in the agrifood system. Developing a broad-based vision. In Chapter 4, Allen articulately describes the dominant epistemological approach that guides research and education in sustainable agriculture programs. In a nutshell, this is a focus on natural sciences, production innovations, and farm-level projects, mostly at the expense of resources devoted to social equity issues . She points out that sustainable, square pot plastic agrifood systems research and education must be larger in scope and more truly interdisciplinary than the current involvement of mostly production-oriented natural science disciplines. Broadening constituencies. Allen also makes the case that we clearly need constituents that participate in local food system actions, and those that help us link local efforts in larger movements that involve national and international politics. Some of this is happening already through sustainable food and farm advocates that are working on the Farm Bill. We also need to be vigilant about enlarging our “circles” to include those left out of the discussion. The new Agricultural Sustainability Institute at UC Davis is one new promising organization for addressing the above concerns in California. Through its strategic planning process, the ASI is developing a broad-based vision that includes diverse stakeholders and encourages participation at all levels. Its vision, core values and operating principles attest to its commitment to be inclusive . This may be one example of what Allen is saying in Together at the Table—that we need to work at many levels in the food system simultaneously from the local to the international.

To do that well, we need many kinds of people with different expertise and local knowledge to be involved. Moreover, we need to acknowledge the importance of each of our contributions and communicate with each other effectively if we really want to make a lasting difference in changing our food system to one that is more sustainable and equitable.Conventional strawberry growers rely on multiple applications of pesticides per year to control lygus bugs , a pest capable of damaging berries badly enough to make them unacceptable for fresh market sale. According to CASFS entomologist and extension specialist Sean Swezey, typical control programs entail 6–8 biweekly calendar applications of insecticide per season, with costs capable of exceeding $500/acre. Yet even these efforts are beginning to fall short of controlling the pest, as lygus has started to display resistance to commonly applied insecticides in California. Swezey and Charlie Pickett of the California Department of Food and Agriculture’s Biological Control Program recently received a two-year grant from the USDA’s Pest Management Alternatives Program to extend trap crop techniques developed in organic systems to conventional strawberry operations in an effort to reduce the need for insecticide applications. Trap crops of alfalfa offer lygus a preferred “host” plant: by establishing strips of alfalfa in strawberry plantings, growers can concentrate the pest in one place and control it with either a vacuum system or conventional sprays. The PMAP grant will fund efforts by Swezey, Pickett, and CASFS research associates Janet Bryer and Diego Nieto to fine tune techniques they’ve developed over the past several years in organic operations using alfalfa trap crops combined with periodic trap crop vacuuming, supplemented by an introduced lygus parasitoid. In the organic research site, the team will determine the number of vacuum passes over an alfalfa trap crop that will optimize lygus removal. “We want to find out whether a significant or economically important number of lygus bugs are removed after each successive vacuuming pass,” says Swezey. “We may find that the first pass or two removes the majority of the lygus present, and that further passes don’t make enough difference in decreasing the remaining number of lygus to be justified.” Establishing an optimal ratio of lygus bug reduction-to-tractor expense will help prevent unnecessary passes, thereby lowering labor costs and tractor operation expenses. The research team will also determine the extent to which an introduced parasitoid of lygus, the braconid wasp Peristenus relictus, is helping control lygus populations in strawberry rows planted between strips of alfalfa. Introduced into a Central Coast organic strawberry operation in 2004, the wasp is now established at the site. Research efforts over the next two years will focus on the percent of lygus parastized by P. relictus in strawberry rows 1, 5, 10, 15, 20, and 25 . In the 40-acre conventionally managed strawberry system, the researchers want to determine whether treating a trap crop with insecticides will control the pests effectively enough to decrease or eliminate the need to spray the crop itself. They also hope to determine the best way to manage a trap crop in a conventional system. “We want to optimize the way alfalfa plantings are managed to make them effective ‘traps’ for lygus throughout the season,” says Swezey. This will entail mowing the crops to stimulate new growth and flowering during the summer as a way to enhance the alfalfa’s attractiveness to lygus. Alfalfa plantings have already been established for the upcoming field season at the organic and conventional research sites. Results of the study will appear in future issues of The Cultivar, and will be presented at grower field days planned for late 2009 and 2010.As interest in farm-to-college programs designed to bring local, sustainably produced food into college cafeterias grows, there is also a growing need to understand how to best address the interests and needs of the consumers served by such programs.