Insights from specimen data for two economic Chrysobothris species (Coleoptera: Buprestidae) in the western United States.

Chrysobothris mali Horn and Chrysobothris femorata (Olivier) (Coleoptera: Buprestidae) are wood-boring beetles native to western North America. Both species are highly polyphagous, feeding on a wide range of deciduous trees and shrubs, including fruit and nut trees as well as shade trees grown as nursery stock. Chrysobothris femorata is widely distributed across North America, while C. mali occurs west of the Rocky Mountains. There is a notable lack of basic biological information regarding both species' phenology and distributions in the Pacific Northwest. To better understand the biology of these economically important insects, seasonal adult collection information, host plant association data, and morphological measurements were collected from preserved specimens residing in 5 major regional arthropod collections. Label information was collected from 661 C. mali and 165 C. femorata specimens. Collection location data were used to create a map of C. femorata and C. mali distributions in the western United States, indicating that C. femorata is significantly less abundant in California, Oregon, and Washington than C. mali. Of the 50 associated plant taxa noted on specimen labels, only 4 associations were shared between the species, potentially indicating host specialization. New reproductive hosts are recorded for C. femorata (2 hosts) and C. mali (3 hosts). Tree species commonly damaged by flatheaded borers in commercial orchards and nurseries were not present in the historical records. The insights gleaned from specimen data allow researchers to better understand the biology and ecology of these understudied, yet economically impactful insects in the western United States.

Characterizing Damage of Brown Marmorated Stink Bug (Hemiptera: Pentatomidae) in Blueberries.

Brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is a severe economic pest of growing importance in the United States, Canada, and Europe. While feeding damage from H. halys has been characterized in tree fruit, vegetables, and agronomic crops, less is known about the impacts of stink bugs on small fruits such as blueberries. In this study, we examined H. halys feeding on two representative early and late ripening blueberry cultivars in Oregon and New Jersey. This research examined how different densities of H. halys confined on blueberry clusters for week-long periods affected fruit quality at harvest. After fruit were ripe, we stained and quantified the number of salivary sheaths on berries as an indication of feeding pressure. Feeding by H. halys damaged the fruits by causing increased levels of external discoloration, and internal damage in the form of tissue necrosis. Exposure of berries to H. halys was also associated with decreasing berry weights and lower soluble solids in fruits. However, the different cultivars did not respond consistently to feeding pressure from H. halys. Weekly variability in feeding pressure of two of the cultivars as quantified by the number of stylet sheaths per berry was largely accounted for by environmental variables. We conclude that H. halys does have potential to severely damage blueberries and may become an important economic pest. Characterization of damage is important because correct identification of insect damage is key for successful management.

Age-based mating success in the codling moth, Cydia pomonella, and the obliquebanded leafroller, Choristoneura rosaceana.

In this study, the passage of spermatophores was examined between 1-day-old males mated in no-choice situations with females 0, 2, 4, or 6 days old and the converse for both the codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), and the obliquebanded leafroller, Choristoneura rosaceana (Harris). For C. pomonella, female age had no effect on the passage of spermatophores from males, and only 6-day-old female C. rosaceana had reduced spermatophore number. The ages of moths at the time of mating had a greater effect on males, with C. pomonella males older than 2 days showing significant reductions in the ability to successfully pass a spermatophore to 1-day-old females. For C. rosaceana, 2- and 6-day-old males were significantly less likely to pass a spermatophore, but reduced transfer from 4-day-old males did not reach statistical significance. Wind-tunnel assays were used to evaluate the ability of 1- or 4-day-old males to fly upwind and successfully contact a young calling female. Four-day-old males were more likely to initiate flight upwind, but were less efficient at finding and contacting the females than younger males. This study suggests that evaluation of multiple components of the mating process are required to understand the effect of age at the time of mating on population dynamics of these moths.

Temperature-Dependent Life Table Parameters of Brown Marmorated Stink Bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) in the United States.

Brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is a generalist pest that causes serious injury to a variety of crops around the world. After the first detection in the USA, H. halys became a serious threat to growers resulting in significant crop damage. Understanding the effect of temperature on H. halys development will help to achieve successful control by predicting the phenological timing of the pest. Here, life table parameters (survival, development, reproduction, and daily mortality) of H. halys were evaluated for New Jersey and Oregon populations in the US. Parameters were determined from field-collected and laboratory-reared individuals. The results indicated that New Jersey populations had higher levels of egg-laying than Oregon populations and exhibited higher and earlier fecundity peaks. Survival levels were similar between populations. Linear and nonlinear fit were used to estimate the minimum (14.3 °C), optimal (27.8 °C), and maximum (35.9 °C) temperatures where development of H. halys can take place. An age-specific fecundity peak (Mx = 36.63) was recorded at 936 degree days for New Jersey populations, while maximum fecundity (Mx = 11.85) occurred at 1145 degree days in Oregon. No oviposition was recorded at the lowest (15 °C) or highest (35 °C) trialed temperatures. Developmental periods increased at temperatures above 30 °C, indicating that such higher temperatures are suboptimal for H. halys development. Altogether the most optimal temperatures for population increase (rm) ranged from 25 to 30 °C. Survival rates of H. halys at suboptimal low temperatures of 8 °C (i.e., 61%) is comparable to previous reports. The present paper provides additional data and context from a range of experimental conditions and populations. Such temperature-related H. halys life table parameters can be used to provide determine the risk to susceptible crops.

Flight Potential of Western Tarnished Plant Bug (Hemiptera: Miridae).

The western tarnished plant bug, Lygus hesperus Knight, is an economically important pest of several agricultural crops in the western United States. It is an increasing threat to potato, Solanum tuberosum L. (Solanales: Solanaceae), in the diverse landscape of the Columbia Basin of Oregon and Washington. In this study, flight mills were used to investigate the flight capacity of L. hesperus with the aim of better understand its dispersive characteristics in the agricultural landscape. Explicitly, we investigated the effects of biological factors such as generation, gender, and body weight on the flight potential of adult L. hesperus adults collected from field populations during spring and summer of 2019 and 2020. The study flight parameters assessed were distance, activity, velocity, and diel periodicity. In 24-h flight mill assays, a clear dichotomy pattern was found in sum flown distance for adults that travelled 1 km or shorter and adults that travelled greater than 1 km. Individuals from the summer population flew farther and more actively than those from the overwintered population. Female L. hesperus flew farther and were more active compared to males. Adult body weight before the flight was directly proportional to flight distance and number of flights, but not with velocity. Overwintered L. hesperus adults lost a higher percentage of their pre-flight body weight compared to summer adults over the course of the study. To the best of our knowledge, this is the first study that demonstrated that L. hesperus summer adult population has the flight ability to disperse greater distance in the agricultural landscape than overwintered population.

Using Red Panel Traps to Detect Spotted-Wing Drosophila and its Infestation in US Berry and Cherry Crops.

Spotted-wing drosophila (SWD), Drosophila suzukii Matsumura (Diptera: Drosophilidae), is an invasive pest of thin-skinned fruits in the United States. Monitoring traps are an integral part of SWD integrated pest management, allowing early detection and timely management of this pest. An ideal monitoring trap should be easy to use, effective in capturing SWD, sensitive and selective to male SWD which are easy to identify due to their spotted wings, and able to predict fruit infestation from trap captures. Deli-cup-based liquid traps (grower standard), which make in-situ observations difficult, were compared with red-panel sticky traps, both baited with commercial lures (Scentry, Trécé Broad-Spectrum (BS), and Trécé High-Specificity (HS)), across several US states in blueberries (lowbush and highbush), blackberry, raspberry, and cherry crops during 2018 and 2021. Results showed that red-panel traps effectively captured SWD, were able to detect male SWD early in the season while also being selective to male SWD all season-long, and in some cases linearly related male SWD trap captures with fruit infestation. Scentry and Trécé BS lures captured similar numbers of SWD, though Trécé BS and Trécé HS were more selective for male SWD in red panel traps than liquid traps in some cases. In conclusion, due to its ease of use with less processing time, red-panel traps are promising tools for detecting and identifying male SWD in-situ and for predicting fruit infestation. However, further research is needed to refine the trap captures and fruit infestation relationship and elucidate the trap-lure interactions in berry and cherry crops.

Evaluating invasion risk and population dynamics of the brown marmorated stink bug across the contiguous United States.

BACKGROUND: Invasive species threaten the productivity and stability of natural and managed ecosystems. Predicting the spread of invaders, which can aid in early mitigation efforts, is a major challenge, especially in the face of climate change. While ecological niche models are effective tools to assess habitat suitability for invaders, such models have rarely been created for invasive pest species with rapidly expanding ranges. Here, we leveraged a national monitoring effort from 543 sites over 3 years to assess factors mediating the occurrence and abundance of brown marmorated stink bug (BMSB, Halyomorpha halys), an invasive insect pest that has readily established throughout much of the United States. RESULTS: We used maximum entropy models to estimate the suitable habitat of BMSB under several climate scenarios, and generalized boosted models to assess environmental factors that regulated BMSB abundance. Our models captured BMSB distribution and abundance with high accuracy, and predicted a 70% increase in suitable habitat under future climate scenarios. However, environmental factors that mediated the geographical distribution of BMSB were different from those driving abundance. While BMSB occurrence was most affected by winter precipitation and proximity to populated areas, BMSB abundance was influenced most strongly by evapotranspiration and solar photoperiod. CONCLUSION: Our results suggest that linking models of establishment (occurrence) and population dynamics (abundance) offers a more effective way to forecast the spread and impact of BMSB and other invasive species than simply occurrence-based models, allowing for targeted mitigation efforts. Implications of distribution shifts under climate change are discussed. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Susceptibility of Some Corylus avellana L. Cultivars to Xanthomonas arboricola pv. corylina.

Bacterial blight of hazelnut (Corylus avellana L.) is caused by Xanthomonas arboricola pv. corylina (Xac). In the past, bacterial blight has been a key disease impacting the Oregon hazelnut industry where 99% of the United States hazelnut crop is grown. The disease is re-emerging in young orchards, as acreage of newly released hazelnut cultivars rapidly increases. This increase in hazelnut acreage is accompanied by renewed interest in developing control strategies for bacterial blight. Information on susceptibility of hazelnut cultivars to Xac is limited, partially due to lack of verified methods to quantify hazelnut cultivar response to artificial inoculation. In this research, Xac inoculation protocols were adapted to two hazelnut growing environments to evaluate cultivar susceptibility: in vitro tissue culture under sterile and controlled conditions, and in vivo potted tree conditions. Five hazelnut cultivars were evaluated using the in vitro inoculation protocol and seven hazelnut cultivars were evaluated using the in vivo inoculation protocol. Under in vitro conditions, there were severe bacterial blight symptoms on each cultivar consistent with those seen in the field, but no significant differences in the susceptibility of the newly released cultivars were observed compared to known Xac-susceptible cultivar ("Barcelona"). Under in vivo conditions, the proportion of necrotic buds were significantly higher in "Jefferson" and "Dorris" compared to all of the other tested cultivars, including "Barcelona." The symptom progression seen in vivo mirrored the timing and symptom progression of bacterial blight reported from field observations. The in vitro conditions significantly reduced the amount of time required to measure the inoculation efficiency compared to the in vivo environment and allowed for greater replication. Further studies on the effects of Xac can use the results of these experiments to establish a dose-response model for bacterial blight, a wider range of germplasm can be tested under in vitro conditions, and management strategies that can be evaluated on large populations of new cultivars using the in vivo methods.

Field and Laboratory Testing of Feeding Stimulants to Enhance Insecticide Efficacy Against Spotted-Wing Drosophila, Drosophila suzukii (Matsumura).

The invasive spotted-wing drosophila, Drosophila suzukii (Matsumura), is a key insect pest of berries globally, causing lost revenues and increased production costs associated with applications of insecticides. The insecticides utilized are commonly broad-spectrum pyrethroids, organophosphates, or carbamates in conventionally managed fields and spinosad in organically managed fields. Adoption of more selective insecticides has been limited due to their lower residual activity, and the requirement that some must be ingested to be effective. We investigated the use of feeding stimulants for D. suzukii as a method to improve longevity and efficacy in a range of insecticides. In laboratory bioassays, sugar increased the efficacy of all chemical classes tested; however, the inclusion of yeast only showed a benefit with malathion. Feeding stimulants had a limited effect in some cases under field conditions. Similarly, infestation in field plots and a semifield bioassay showed no significant decreases in infestation with the inclusion of feeding stimulants for the insecticides tested in these trials. We discuss the implications of these findings for managing D. suzukii in fruit crops to help ensure the harvest of marketable fruit.

Refining Pheromone Lures for the Invasive Halyomorpha halys (Hemiptera: Pentatomidae) Through Collaborative Trials in the United States and Europe.

Brown marmorated stink bug, Halyomorpha halys, is native to Asia and has invaded North America and Europe inflicting serious agricultural damage to specialty and row crops. Tools to monitor the spread of H. halys include traps baited with the two-component aggregation pheromone (PHER), (3S,6S,7R,10S)-10,11-epoxy-1-bisabolen-3-ol and (3R,6S,7R,10S)-10,11-epoxy-1-bisabolen-3-ol, and pheromone synergist, methyl (2E,4E,6Z)-decatrienoate (MDT). Here, an international team of researchers conducted trials aimed at evaluating prototype commercial lures for H. halys to establish relative attractiveness of: 1) low and high loading rates of PHER and MDT for monitoring tools and attract and kill tactics; 2) polyethylene lure delivery substrates; and 3) the inclusion of ethyl (2E,4E,6Z)-decatrieonate (EDT), a compound that enhances captures when combined with PHER in lures. In general, PHER loading rate had a greater impact on overall trap captures compared with loading of MDT, but reductions in PHER loading and accompanying lower trap captures could be offset by increasing loading of MDT. As MDT is less expensive to produce, these findings enable reduced production costs. Traps baited with lures containing PHER and EDT resulted in numerically increased captures when EDT was loaded at a high rate, but captures were not significantly greater than those traps baited with lures containing standard PHER and MDT. Experimental polyethylene vial dispensers did not outperform standard lure dispensers; trap captures were significantly lower in most cases. Ultimately, these results will enable refinement of commercially available lures for H. halys to balance attraction and sensitivity with production cost.

Fatty Acid Profile as an Indicator of Larval Host for Adult Drosophila suzukii.

Drosophila suzukii is a severe economic invasive pest of soft-skinned fruit crops. Management typically requires killing gravid adult female flies with insecticides to prevent damage resulting from oviposition and larval development. Fruits from cultivated and uncultivated host plants are used by the flies for reproduction at different times of the year, and knowledge of D. suzukii seasonal host plant use and movement patterns could be better exploited to protect vulnerable crops. Rearing and various marking methodologies for tracking movement patterns of D. suzukii across different landscapes have been used to better understand host use and movement of the pest. In this study, we report on potential to determine larval host for adult D. suzukii using their fatty acid profile or signature, and to use larval diet as an internal marker for adult flies in release-recapture experiments. Fatty acids can pass efficiently through trophic levels unmodified, and insects are constrained in the ability to synthesize fatty acids and may acquire them through diet. In many holometabolous insects, lipids acquired in the larval stage carry over to the adult stage. We tested the ability of a machine learning algorithm to discriminate adult D. suzukii reared from susceptible small fruit crops (blueberry, strawberry, blackberry and raspberry) and laboratory diet based on the fatty acid profile of adult flies. We found that fatty acid components in adult flies were significantly different when flies were reared on different hosts, and the machine learning algorithm was highly successful in correctly classifying flies according to their larval host based on fatty acid profile.

Season-Long Monitoring of the Brown Marmorated Stink Bug (Hemiptera: Pentatomidae) Throughout the United States Using Commercially Available Traps and Lures.

Reliable monitoring of the invasive Halyomorpha halys abundance, phenology and geographic distribution is critical for its management. Halyomorpha halys adult and nymphal captures on clear sticky traps and in black pyramid traps were compared in 18 states across the Great Lakes, Mid-Atlantic, Southeast, Pacific Northwest and Western regions of the United States. Traps were baited with commercial lures containing the H. halys pheromone and synergist, and deployed at field sites bordering agricultural or urban locations with H. halys host plants. Nymphal and adult captures in pyramid traps were greater than those on sticky traps, but captures were positively correlated between the two trap types within each region and during the early-, mid- and late season across all sites. Sites were further classified as having a low, moderate or high relative H. halys density and again showed positive correlations between captures for the two trap types for nymphs and adults. Among regions, the greatest adult captures were recorded in the Southeast and Mid-Atlantic on pyramid and sticky traps, respectively, with lowest captures recorded in the West. Nymphal captures, while lower than adult captures, were greatest in the Southeast and lowest in the West. Nymphal and adult captures were, generally, greatest during July-August and September-October, respectively. Trapping data were compared with available phenological models showing comparable population peaks at most locations. Results demonstrated that sticky traps offer a simpler alternative to pyramid traps, but both can be reliable tools to monitor H. halys in different geographical locations with varying population densities throughout the season.

Sensitivity of the Egg Parasitoid Trissolcus japonicus (Hymenoptera: Scelionidae) to Field and Laboratory-Applied Insecticide Residue.

The spread of adventive Trissolcus japonicus (Ashmead, 1904) populations in North America is anticipated to increase biological control of Halyomorpha halys (Stål; Hemiptera: Pentatomidae), the brown marmorated stink bug. In an agricultural context, biological control will succeed if it can be integrated in an environment with insecticide applications. We investigated T. japonicus compatibility with nine conventional and organic insecticides commonly used in integrated pest management in perennial crops. Through evaluating mortality and longevity in field and laboratory trials, we determined that T. japonicus fares poorly when exposed to residues of neonicotinoids and pyrethroids. Spinosad resulted in the highest percentage of T. japonicus mortality, 100% in the laboratory and 97% in a field trial. The anthranilic diamide, chlorantraniliprole, had the lowest lethality, with no differences compared to an untreated control. Trissolcus japonicus survived insecticide applications in hazelnut orchards, and over 50% of wasps remained alive after contact with the anthranilic diamides, chlorantraniliprole and cyantraniliprole, the biopesticide Chromobacterium, and an untreated control. Our results indicate that T. japonicus is unlikely to survive and parasitize H. halys in settings that coincide with broad-spectrum insecticide application. Future T. japonicus redistributions could continue in orchards treated with anthranilic diamides and Chromobacterium. As H. halys is a landscape-level pest, orchards may also benefit from biological control if T. japonicus are released in unsprayed areas adjacent to agriculture and in urban sites.

Identity and pathogenicity of some fungi associated with hazelnut (Corylus avellana L.) trunk cankers in Oregon.

Four fungi isolated from trunks and branches of European hazelnut (Corylus avellana L.) from commercial orchards in the Willamette Valley, Oregon were characterized and pathogenicity was tested on potted hazelnut trees. The acreage of hazelnuts in Oregon has expanded greatly in recent years in response to the availability of Eastern filbert blight resistant cultivars. Fungi were characterized using the BLASTn algorithm and the GenBank database with multiple partial gene sequence(s). If BLASTn and GenBank were not sufficient for species-level identification, then a multilocus sequence analysis (MLSA) was performed. The four pathogens were identified as Diplodia mutilla (Fr.) Mont., Dothiorella omnivora B.T. Linaldeddu, A. Deidda & B. Scanu, Valsa cf. eucalypti Cooke & Harkn., and Diaporthe eres Nitschke. All pathogens but D. omnivora have not been previously reported from European hazelnut in the literature. All four pathogens caused lesions on trunks bare root hazelnut trees cv. 'Jefferson' planted in pots in the greenhouse and fungi were re-isolated from inoculated trees. D. mutilla appeared particularly aggressive in repeated inoculation experiments.

Establishment in an Introduced Range: Dispersal Capacity and Winter Survival of Trissolcus japonicus, an Adventive Egg Parasitoid.

The herbivorous brown marmorated stink bug, Halyomorpha halys, has spread globally, and one of its key parasitoids, Trissolcus japonicus, has recently been detected in the pest's introduced range. For an exotic natural enemy to impact its targeted host in a novel environment, it must disperse, locate hosts, and potentially be redistributed to susceptible sites. Through intentionally releasing T. japonicus across four Oregon eco-regions, we investigated an introduced parasitoid's dispersal capacity in urban sites and in two perennial crops, hazelnut and raspberry. In a second paired field and laboratory study, we investigated T. japonicus survival in different plant materials. Within three days of release, adult T. japonicus located host egg masses at 45% of sites and, one year later, were detected at 40% of release sites. Areas where released wasps survived winter were mostly urban or semi-natural. In commercial crop release experiments, we recovered the highest percentage of wasps in raspberry within 5 m of the release site but found no statistical difference in dispersal distance with some wasps dispersing up to 50 m. Adult parasitoids survived up to 16 weeks outdoors in the winter, with greater survival over time in bark compared to leaf litter. Wasp survival remained above 50% over the course of a simulated winter environment without precipitation. Our work affirms the continuation of H. halys parasitism by T. japonicus in novel environments and provides insight into the high population sizes necessary to survive winter and locate host egg masses the following season.

Comparison of delayed female mating on reproductive biology of codling moth and obliquebanded leafroller.

Delay of mating was examined as a possible mechanism for population decreases associated with mating disruption for codling moth, Cydia pomonella L., and obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae). We examined the effect of delaying female mating 0, 2, 4, or 6 d while holding male age constant on life table parameters of both species. We found that increasing delays in mating were accompanied by two responses: (1) an increase in the percentage of sterile pairs and (2) a reduction in net reproductive rate and population growth unrelated to sterility. On a percentage basis, obliquebanded leafroller population growth was more strongly affected than codling moth. However, the net fertility rate of obliquebanded leafroller was nearly eight-fold higher than that of codling moth, so that obliquebanded leafroller females that experienced a 4-d delay in mating had nearly the same reproductive rate as codling moth females that experienced no delay. Leslie matrix simulations using life tables with field-based adult longevity estimates showed that codling moth females experiencing >2-d delay in mating resulted in decreases in population density or extinction within two generations. In contrast, obliquebanded leafroller females delayed <6 d showed rapid population growth that decreased as female age at mating increased; only the 6-d delay treatment resulted in decreased population levels. Our results indicate that obliquebanded leafroller females must on average experience a much longer delay in mating to significantly reduce population growth compared with codling moth females, suggesting that delay of mating likely plays a greater role in codling moth mating disruption than for obliquebanded leafroller.

Longevity of the adult codling moth, Cydia pomonella, and the obliquebanded leafroller, Choristoneura rosaceana, in Washington apple orchards.

The longevity of adult codling moth (Cydia pomonella (L.) Lepidoptera: Tortricidae) and obliquebanded leafroller (Choristoneura rosaceana (Harris) Lepidoptera: Tortricidae) held in shaded vials in the tree canopy was measured during the normal flight periods during 2004 and 2005. In both years all codling moths were dead by 130 degree-days (DD) (21 d) in the spring and 121 DD (8 d) in the summer. On a degree-day basis, data were similar across sex, generation, and year, and a common curve adequately predicted the survival distribution. For the obliquebanded leafroller, there were longevity differences between the sexes, but not between generations or years. Use of empirical quantile-quantile plots showed that the female obliquebanded leafroller lived an average of 32% longer than males. Maximum longevity observed in these studies for obliquebanded leafrollers was 117 DD (11 d) across both generations. The implications of these data for population biology studies and quarantine requirements are discussed.

Monitoring Nutrient Status of Brown Marmorated Stink Bug Adults and Nymphs on Summer Holly.

Halyomorpha halys (Stål), or brown marmorated stink bug (BMSB), has become a major pest and nuisance for both agricultural growers and homeowners since its arrival in North America and Europe. The nutritional ecology of BMSB is important for understanding its life history and rearing requirements. However, little is known about the nutritional status of wild populations, especially in the U.S. This research monitored the nutrient status of nymphal and adult BMSB collected from English holly in western Oregon. We measured their weight, nutrient index (weight/(prothorax × width)³), lipid, glycogen and sugar levels and egg load from May⁻September/October. First, glycogen and sugar levels of adults were often lowest sometime in June-August with a general increase by September. Meanwhile, their lipid levels varied without a discernible trend. Second, adult females had few eggs in May, with the highest egg load in June and July, and no eggs by September. Lastly, first and second nymphal instars were found in June, and fourth and fifth instars in September. Because nothing is known about the nutrient levels of nymphs, the reported values from this survey can assist future research on physiological responses of BMSB to treatments or environmental impacts in the field.

Enhanced Response of Halyomorpha halys (Hemiptera: Pentatomidae) to Its Aggregation Pheromone with Ethyl Decatrienoate.

The invasive stink bug species, Halyomorpha halys (Stål) (Hemiptera; Pentatomidae), severely damages multiple agricultural commodities, resulting in the disruption of established IPM programs. Several semiochemicals have been identified to attract H. halys to traps and monitor their presence, abundance, and seasonal activity. In particular, the two-component aggregation pheromone of H. halys, (3S,6S,7R,10S)-10,11-epoxy-1-bisabolen-3-ol and (3R,6S,7R,10S)-10,11-epoxy-1-bisabolen-3-ol (PHER), in combination with the pheromone synergist, methyl (2E,4E,6Z)-decatrienoate (MDT), were found to be attractive. Here, we report that an analogous trienoate, ethyl (2E,4E,6Z)-decatrienoate (EDT), enhances H. halys captures when combined with PHER. In trials conducted in Eastern and Western regions of the United States, we observed that when traps were baited with the H. halys PHER + EDT, captures were significantly greater than when traps were baited with PHER alone. Traps baited with EDT alone were not attractive. Thus, the addition of EDT to lures for attracting H. halys to traps may further improve monitoring efficiency and management strategies for this invasive species.

Two Pests Overlap: Drosophila suzukii (Diptera: Drosophilidae) Use of Fruit Exposed to Halyomorpha halys (Hemiptera: Pentatomidae).

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) and brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), are global economic pests that may co-occur on small fruits. We investigated whether fruit recently exposed to H. halys affected subsequent host use by D. suzukii. Laboratory no-choice and choice tests presented D. suzukii with H. halys-fed and unfed raspberries and blueberries immediately or 3 d after H. halys feeding. Resulting D. suzukii eggs, or larvae and pupae, were counted. The number of D. suzukii immatures among fed and unfed fruit was not significantly different in lab studies. There was no relationship between the intensity of H. halys feeding, as estimated by the number of stylet sheaths, and D. suzukii oviposition on blueberry. Lastly, field studies compared D. suzukii infestation between H. halys-fed and unfed raspberries. Raspberries were previously exposed to H. halys for 3 d or simultaneously exposed to both pests for 7 d. Natural infestation by D. suzukii in the field was similar among raspberries previously or simultaneously exposed to H. halys compared to control fruit.