Impact of Background Fruit Odors on Attraction of Drosophila suzukii (Diptera: Drosophilidae) to Its Symbiotic Yeast.

Background odors produced by plants in the environment can interfere with the response of insects to a point-releasing attractant, especially when their compositions overlap. In this study, a series of binary choice tests was conducted in a wind tunnel to investigate whether background odors emitted from cherry, blueberry, blackberry, or raspberry fruits would affect the level of Drosophila suzukii (Matsumura) attraction to its symbiotic yeast, Hanseniaspora uvarum (Niehaus) (Saccharomycetales: Saccharomycetaceae). Whether an increase in the intensity of background odors would affect the attractiveness of H. uvarum to D. suzukii was also investigated, either by increasing the number of cherry or raspberry fruit per cup or by increasing the number of fruit cups surrounding the cup baited with the yeast. In wind tunnel assays, background fruit odors interfering with D. suzukii attraction to the yeast varied among fruit types. Raspberry odor inhibited the attractiveness of H. uvarum to the fly the most, followed by blackberry odor, whereas cherry and blueberry odors had no significant impact on the attraction. An increase in the intensity of odors by adding more cherry or raspberry fruit per cup did not increase the impact of fruit odor on the attraction; however, adding more raspberry cups around H. uvarum linearly decreased its attractiveness, suggesting that background host fruit abundance and likely increase in host odor may influence D. suzukii attraction to yeast odor depending on host species.

Mismatched outcomes for biodiversity and ecosystem services: testing the responses of crop pollinators and wild bee biodiversity to habitat enhancement.

Supporting ecosystem services and conserving biodiversity may be compatible goals, but there is concern that service-focused interventions mostly benefit a few common species. We use a spatially replicated, multiyear experiment in four agricultural settings to test if enhancing habitat adjacent to crops increases wild bee diversity and abundance on and off crops. We found that enhanced field edges harbored more taxonomically and functionally abundant, diverse, and compositionally different bee communities compared to control edges. Enhancements did not increase the abundance or diversity of bees visiting crops, indicating that the supply of pollination services was unchanged following enhancement. We find that actions to promote crop pollination improve multiple dimensions of biodiversity, underscoring their conservation value, but these benefits may not be spilling over to crops. More work is needed to identify the conditions that promote effective co-management of biodiversity and ecosystem services.

Optimizing Aerosol Dispensers for Mating Disruption of Codling Moth, Cydia pomonella L.

Experiments were conducted in commercial apple orchards to determine if improved efficiencies in pheromone delivery may be realized by using aerosol pheromone dispensers for codling moth (CM), Cydia pomonella L., mating disruption. Specifically, we tested how reducing: pheromone concentration, period of dispenser operation, and frequency of pheromone emission from aerosol dispensers affected orientational disruption of male CM to pheromone-baited monitoring traps. Isomate® CM MIST formulated with 50 % less codlemone (3.5 mg/ emission) provided orientation disruption equal to the standard commercial formulation (7 mg / emission). Decreased periods of dispenser operation (3 and 6 h) and frequency of pheromone emission (30 and 60 min) provided a level of orientational disruption similar to the current standard protocol of releasing pheromone over a 12 h period on a 15 min cycle, respectively. These three modifications provide a means of substantially reducing the amount of pheromone necessary for CM disruption. The savings accompanying pheromone conservation could lead to increased adoption of CM mating disruption and, moreover, provide an opportunity for achieving higher levels of disruption by increasing dispenser densities.

Separating the attractant from the toxicant improves attract-and-kill of codling moth (Lepidoptera: Tortricidae).

The behavior of codling moth, Cydia pomonella (L.), responding to three attract-and-kill devices was compared in flight tunnel experiments measuring attraction and duration of target contact. Placing a 7.6 by 12.6 cm card immediately upwind of a rubber septum releasing pheromone, dramatically increased the duration on the target to > 60 s. In this setting, nearly all the males flew upwind, landed on the card first, and spent the majority of time searching the card. In contrast, male codling moths spent < 15 s at the source if given the lure only. In a forced contact bioassay, knockdown rate or mortality of male codling moths increased in direct proportion to duration of contact on a lambda-cyhalothrin-loaded filter paper. When this insecticide-treated paper was placed immediately upwind of the lure in the flight tunnel, > 90% of males contacting the paper were knocked down 2 h after voluntary exposure. These findings suggest that past attempts to combine insecticide directly with sex pheromones into a small paste, gel, or other forms of dollops are ill-advised because moths are likely over-exposed to pheromone and vacate the target before obtaining a lethal dose of insecticide. It is better to minimize direct contact with the concentrated pheromone while enticing males to extensively search insecticide-treated surface nearby the lure.

Estimating plume reach and trapping radii for male and female Cydia pomonella (Lepidoptera: Tortricidae) captured in pheromone-kairomone baited traps in Washington State apple orchards under mating disruption.

Male Cydia pomonella (L.) (Lepidoptera: Tortricidae) dispersion has largely been studied in nonmating disrupted orchards due to synthetic pheromone interference with capture in monitoring traps. Little is known about female dispersion. This study aimed to characterize male and female dispersion in mating disrupted commercial apple orchards. Sterile C. pomonella recapture data from single-trap multiple-release experiments using PHEROCON CM-DA COMBO + AA Lure-baited orange Pherocon VI delta traps was interpreted to determine pheromone-kairomone lure-baited trap effective area, trap deployment density for effective monitoring, and absolute male and female C. pomonella density in mating disrupted Washington commercial apple orchards. The maximum plume reach of the pheromone-kairomone lure in mating disrupted orchards was <5 m from the baited trap for both sexes. Maximum dispersive distances for 95% of the released C. pomonella in mating disrupted orchards were 106 and 135 m for males and females, yielding trapping areas of 3.87 and 6.16 ha, respectively. Estimates were consistent across 3 growing seasons and represent the first records of male and female dispersal distance and monitoring trap efficacy from commercial C. pomonella mating disrupted apple orchards. With relevance to commercial monitoring programs and economic thresholds in mating disrupted orchards, traps should be deployed at a density of 1 per 3-6 ha. Capture of a single male or female C. pomonella corresponds to at least 82-104 C. pomonella within the 3-6 ha trapping area. This refined C. pomonella capture interpretation in pheromone-kairomone baited traps in mating disrupted commercial apple orchards yields more precise damage estimates and assists in insecticide-use decision making.

Fungicide Exposure in Honey Bee Hives Varies By Time, Worker Role, and Proximity to Orchards in Spring.

Fungicides are commonly applied to prevent diseases in eastern North American cherry orchards at the same time that honey bees (Apis mellifera L. (Hymenoptera: Apidae)) are rented for pollination services. Fungicide exposure in honey bees can cause negative health effects. To measure fungicide exposure, we sampled commercial honey bee colonies during orchard bloom at two commercial tart cherry orchards and one holding yard in northern Michigan over two seasons. Nurse bees, foragers, larvae, pollen, bee bread, and wax were screened for captan, chlorothalonil, and thiophanate-methyl. We also looked at the composition of pollens collected by foragers during spring bloom. We found differences in fungicide residue levels between nurse bees and foragers, with higher captan levels in nurse bees. We also found that residue levels of chlorothalonil in workers were significantly increased during tart cherry bloom, and that nurse bees from hives adjacent to orchards had significantly higher chlorothalonil residues than nurse bees from hives kept in a holding yard. Our results suggest that fungicide exposure of individual honey bees depends greatly on hive location in relation to mass-flowering crops, and worker role (life stage) at the time of collection. In some pollen samples, captan and chlorothalonil were detected at levels known to cause negative health effects for honey bees. This study increases our understanding of exposure risk for bees under current bloom time orchard management in this region. Further research is needed to balance crop disease management requirements with necessary pollination services and long-term pollinator health.

Field releases of the exotic parasitoid Trissolcus japonicus (Hymenoptera: Scelionidae) and survey of native parasitoids attacking Halyomorpha halys (Hemiptera: Pentatomidae) in Michigan.

An adventive population of the exotic parasitoid wasp, Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), discovered in Michigan in 2018, is a promising biological control agent of the invasive Halyomorpha halys (Stål) (Hemiptera: Pentatomidae). Following its discovery, field releases of Tr. japonicus were conducted over 2 yr in southern Michigan, to test how release size or release frequency impacts establishment. Sentinel eggs of H. halys and of the native Podisus maculiventris (Say) (Hemiptera: Pentatomidae) were used alongside yellow sticky cards to monitor parasitoids. In 2019 and 2020, 7,200 Tr. japonicus were released at 16 sites. Monitoring between 2019 and 2021 yielded only 49 individuals. The captures suggest reproductive activity and overwintering success in the field but do not allow for evaluation of best release methods. Parasitism by native parasitoids was below 7%, which is similar to other states and unlikely to provide sufficient control of H. halys. The placement of sentinel eggs or sticky traps either in the lower or middle canopy of trees did not influence parasitoid capture rates. Frozen and fresh H. halys sentinel eggs were attacked at the same rate, but more native parasitoids emerged from frozen eggs. We did not find signs of nontarget effects on P. maculiventris thus parasitism rates overall were very low. These results could indicate dispersal of Tr. japonicus from the release sites or slow population growth. The latter may be due to the relatively low densities of H. halys in Michigan or may stem from the small founding size of our laboratory colony.

Predicting the Risk of Tart Cherry (Prunus cerasus) Infestation by Drosophila suzukii (Diptera: Drosophilidae).

Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae) is a vinegar fly native to East Asia that has rapidly expanded its range to become a pest of sweet cherry (Prunus avium, L. 1753 [Rosales: Rosaceae]) and tart cherry (P. cerasus, L. 1753) in North America and Europe. The goal of the research presented herein was to improve the decision-making process for managing D. suzukii in tart cherry. Knowing that D. suzukii females are attracted to ripening fruit, we measured fruit infestation by D. suzukii as it relates to an existing fruit development model that uses full bloom as a biofix, calculating accumulated growing degree days (GDD) with a lower threshold of 4°C. Increasing larval infestation was highly correlated with fruit development expressed as GDD post-bloom with very few larvae developing in fruit subjected to no-choice assays prior to 530 GDD (base 4°C) and no larvae detected in naturally infested fruit prior to 800 GDD. Our findings provide the first quantification of the relationship between fruit development and D. suzukii infestation that allows for pinpointing the timing of fruit susceptibility and that could be used as the basis for a more sustainable management program for this pest in tart cherry orchards.

CropPol: A dynamic, open and global database on crop pollination.

Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open, and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e., berry mass, number of fruits, and fruit density [kg/ha], among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), North America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-2005 (21 studies), 2006-2010 (40), 2011-2015 (88), and 2016-2020 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA).

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.

Drosophila suzukii (Diptera: Drosophilidae): A Decade of Research Towards a Sustainable Integrated Pest Management Program.

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) also known as spotted-wing drosophila (SWD), is a pest native to Southeast Asia. In the last few decades, the pest has expanded its range to affect all major European and American fruit production regions. SWD is a highly adaptive insect that is able to disperse, survive, and flourish under a range of environmental conditions. Infestation by SWD generates both direct and indirect economic impacts through yield losses, shorter shelf life of infested fruit, and increased production costs. Fresh markets, frozen berries, and fruit export programs have been impacted by the pest due to zero tolerance for fruit infestation. As SWD control programs rely heavily on insecticides, exceedance of maximum residue levels (MRLs) has also resulted in crop rejections. The economic impact of SWD has been particularly severe for organic operations, mainly due to the limited availability of effective insecticides. Integrated pest management (IPM) of SWD could significantly reduce chemical inputs but would require substantial changes to horticultural management practices. This review evaluates the most promising methods studied as part of an IPM strategy against SWD across the world. For each of the considered techniques, the effectiveness, impact, sustainability, and stage of development are discussed.

Effect of pheromone dispenser density on timing and duration of approaches by peachtree borer.

The timing and duration of approaches by male peachtree borer Synanthedon exitiosa Say (Lepidoptera: Sesiidae) to commercial pheromone dispensers placed singly or at high density in peach orchards was determined by using field-deployed video cameras and digital video recorders. Cameras were trained on one dispenser, and one standard lure was placed in a peach orchard, and on 12 dispensers in a separate orchard where dispensers for mating disruption had been placed at 371 per hectare. Male moth approaches were video recorded at the peak of peachtree borer annual flight, from 13 to 18 August 2009. The mean approach timing (h:min:sec±SD) during the study period was 11:33:12 ± 00:46:43, 11:43:52 ± 00:45:58, and 11:41:21 ± 00:45:54 AM with the single dispenser, high-density dispensers, and lure, respectively. Day-to-day variability in approach timings suggested that there were no biologically significant differences among treatments. The frequency distribution of approach durations varied among treatments, as the high-density dispensers had mostly short approaches, while the distribution of approaches to the single dispenser and lure was wider. The median (interquartile range) approach duration was 3 (2-4), 1 (1-2), and 4 (2-6) seconds with the single dispenser, high-density dispensers, and lure, respectively. The relative rank of median approach durations was constant throughout the period, indicating differences among treatments. This study showed that the presence of pheromone dispensers for mating disruption did not cause an advancement of peachtree borer diel rhythm of response. Shorter approaches to dispensers placed at high density than singly suggest that dispenser retentiveness is not constant with peachtree borer, which may bias estimates of disruption activity as a function of dispenser density.

Effect of varying dispenser point source density on mating disruption of Grapholita molesta (Lepidoptera: Tortricidae).

Hand-applied dispensers are successfully used in mating disruption programs, but cost of labor to apply these dispensers limits their adoption. Creating hand-applied dispensers that release larger amounts of pheromone and that can be applied at lower densities per hectare could reduce the cost of mating disruption and increase its use. The effect of reducing the number of point sources per hectare while keeping the amount of pheromone applied per hectare constant on the success of Grapholita molesta (Busck) (Lepidoptera: Tortricidae) mating disruption was investigated with Confuse-OFM, paraffin disk, and Isomate-M Rosso dispensers. For all dispensers, as point source density decreased, numbers of moths captured increased, percentage of orientation disruption to traps decreased, and variability in these measures increased. Decreasing point source density, even while keeping the amount of pheromone applied per hectare constant is not a viable option for reducing the cost of G. molesta mating disruption with hand-applied dispensers. Puffers (aerosol dispensers) are applied at 2.5-5 dispensers per ha for G. molesta control. However, hand-applied dispensers fail when clumped at such low numbers of release sites. Potential explanations for the success of Puffers and the failure of hand-applied dispensers at very low point source densities are presented. The utility of paraffin disk dispensers as experimental devices also is discussed.

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.

Reproductive maturity of cherry fruit fly (Diptera: Tephritidae) in managed and natural habitats.

We studied the timing of reproductive maturity of cherry fruit fly, Rhagoletis cingulata (Loew), a key pest of sweet and tart cherries in the eastern United States. To determine when cherry fruit fly females become reproductively mature in managed and natural habitats, we deployed traps in sweet and tart cherry orchards and nearby stands of the ancestral host tree, black cherry. Flies were removed from the traps and females were dissected to determine the presence of fully developed eggs. We found that capture of reproductively mature female flies occurred earlier in orchards that are not sprayed with insecticides than in sprayed orchards or in black cherry tree sites. In addition, the gap between the flights of immature and mature females in unmanaged sweet or tart cherry orchards was shorter than in managed orchards or black cherry tree sites. We also determined fruit color, size, and skin hardness to characterize the progression of fruit maturity. We found that fruit became mature earlier in sweet and tart cherry orchards than in black cherry tree sites. This study indicates that the timing of female reproductive maturity is plastic and varies among cherry fruit fly populations present in distinct habitats. Variation in the timing of reproductive maturity is related to the fruit maturity period of distinct host plant species and to orchard management.

Lethal and sublethal effects of chlorantraniliprole on three species of Rhagoletis fruit flies (Diptera: Tephritidae).

BACKGROUND: Chlorantraniliprole formulated as a 350 g kg(-1) WG (Altacor 35WG) for management of apple maggot Rhagoletis pomonella (Walsh), blueberry maggot R. mendax Curran and cherry fruit fly R. cingulata (Loew) (Diptera: Tephritidae) was evaluated in laboratory assays and field trials. RESULTS: A tarsal contact toxicity bioassay showed that a surface residue of 500 mg L(-1) of chlorantraniliprole caused significantly higher mortality of male and female flies of all species compared with a control. Male apple maggot and blueberry maggot mortality was significantly higher than that for females, but there was similar mortality of male and female cherry fruit flies. An ingestion toxicity bioassay showed that 500 mg L(-1) of chlorantraniliprole in diet caused significantly higher mortality of male and female flies of all species than the control, but there were no significant differences among the sexes. Delayed egglaying by females that had ingested chlorantraniliprole was found, but there were no significant sublethal effects on either the number of eggs laid or the egg hatch. Field trials with apple maggot and cherry fruit fly showed that protection of fruit by chlorantraniliprole was comparable with that of standard broad-spectrum insecticides. CONCLUSIONS: The present data indicate that chlorantraniliprole has suppressant activity against Rhagoletis fruit flies, preventing fruit infestation primarily through direct lethal effects.

Paraffin wax emulsion for increased rainfastness of insecticidal bait to control Rhagoletis pomonella (Diptera: Tephritidae).

In regions with a humid summer climate, the use of water-soluble bait to control apple maggot is often limited by rainfall. We studied increasing the rainfastness of GF-120 fruit fly bait by adding paraffin wax emulsion. First, we verified that adding 10% wax to a mixture containing 16.7% GF-120 did not reduce the mortality of female apple maggot compared with GF-120 without wax. In addition, we determined that fly mortality caused by GF-120 plus wax subjected to simulated rain was similar to that caused by GF-120 without wax not subjected to rain. Other assays showed that higher fly mortality resulted from increasing the proportion of wax from 10 to 15%, and lower mortality resulted from decreasing GF-120 from 16.7 to 10 or 5%. The availability of spinosad on or near droplets of a mixture consisting of 5, 10, or 15% GF-120 and 15% wax was determined before and after the droplets were subjected to three 15-min periods of simulated rain. We found an initial steep decline in dislodgeable spinosad and smaller decreases after subsequent periods of rain. In a small-plot field trial, fruit infestation by apple maggot in plots treated with a mixture consisting of 16.7% GF-120 and 19.2% wax was less than in plots treated with 16.7% GF-120 without wax but not less than in control plots. Overall, we found that adding paraffin wax emulsion to GF-120 increased rainfastness in laboratory bioassays, and specifically that it retained the active ingredient spinosad. However, our field data suggest that optimal rainfastness requires the development of mixtures with > 19.2% wax, which may preclude application using standard spray equipment.

Choristoneura rosaceana (Lepidoptera: Tortricidae) Resistance to Insecticides in Michigan Apple and Cherry Orchards.

Field populations of Obliquebanded leafroller, Choristoneura rosaceana (Harris), collected from one commercial apple and one commercial cherry orchard in Kent and Newaygo Counties in western Michigan, respectively. A baseline toxicity study of eight insecticides including phosmet, bifenthrin, methomyl, indoxacarb, chlorantraniliprole, spinetoram, emamectin benzoate, and novaluron was conducted on 12- to 24-h-old larvae of the C. rosaceana field populations and compared with a susceptible strain. The resistance levels were low (<10-fold) in all cases except for indoxacarb (>10-fold) in both populations. The cherry population showed levels of resistance to spinetoram, bifenthrin, emamectin benzoate, and indoxacarb with 4.1-, 4.9-, 5.8-, and 21-fold resistance, respectively. The apple population showed levels of resistance to spinetoram, chlorantraniliprole, phosmet, bifenthrin, emamectin benzoate, and indoxacarb with 4.3-, 4.7-, 5-, 5-, 6.3-, and 620.4-fold resistance, respectively. Generally, the apple population showed lower resistance levels to more compounds than the cherry population. Resistance to these insecticides should be monitored periodically for further changes. This represents the first documented case of insecticide resistance for C. rosaceana collected from a cherry orchard in Michigan. A statewide survey of more commercial orchards would help determine the extent of insecticide resistance across Michigan's five tree fruit production regions.

Spray coverage and pest management efficacy of a solid set canopy delivery system in high density apples.

BACKGROUND: Air blast sprayers are not optimized for spraying the short statured trees in modern apple orchards, resulting in off target drift and variable coverage. A solid set canopy delivery system (SSCDS) consisting of a microsprayer array distributed throughout the orchard was investigated as a replacement agrochemical application method in this study. SSCDS's have the potential to optimize coverage, rapidly spray applications, and remove the operator and tractor from the orchard. RESULTS: Air blast and SSCDS applications were compared using water sensitive paper, bioassays, and pest damage assessments. Pest management and coverage were compared using application volumes of 700 and 795 L ha-1 , respectively. In 2013, adaxial coverage measurements showed no difference between the treatments, but air blast sprayers had higher coverage levels on the abaxial surfaces. There were no significant differences in coverage in 2014. Bioassays using Choristoneura rosaceana fed on leaf discs treated by the SSCDS displayed 95.8% mortality in 2013 and 94.2% mortality in 2014, and air blast treated larval mortality was 95% in 2013 and 100% in 2014. Damage evaluations in both years generally showed no significant differences between the air blast plots and the SSCDS plots, but significant differences between the treated plots and untreated control. CONCLUSIONS: The prototype SSCDS was an effective pest management tool in high density apples, and offered a number of advantages over an air blast. Further engineering and research into coverage optimization would offer producers a novel tool for foliar agrochemical applications. © 2019 Society of Chemical Industry.

Estimating Monitoring Trap Plume Reach and Trapping Area for Nymphal and Adult Halyomorpha halys (Hemiptera: Pentatomidae) in Crop and Non-crop Habitats.

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), the brown marmorated stink bug, is an invasive polyphagous insect that can cause serious economic injury to specialty and row crops in the United States and globally. To date, H. halys has been managed with repeated insecticide applications. While progress has been made toward development of trap-based monitoring tools to guide management decisions, little is known regarding the trapping area over which a single pheromone-baited trap captures H. halys. We conducted single trap, multiple distance mark-release-recapture experiments; results were used to estimate trapping area for nymphs and adults in sites without host plants present (open field) and for adults in sites with host plants present (apple orchard). Plume reach for pheromone-baited sticky traps was consistently estimated to be <3 m. Maximum dispersive distance in an open field devoid of host plants was estimated to be 40 m for nymphs and 120-130 m for adults resulting in trapping areas of 0.58 ha and 4.83-5.56 ha, respectively. When traps were deployed in association with host plants within the border row of an apple orchard, adult maximum dispersive distance and trapping area was reduced to 70 m and 1.67 ha, respectively. These results indicate that the behavioral response of H. halys to pheromonal stimuli is influenced by the presence of host plants and that trapping area for pheromone-baited traps will likely change relative to the cropping system in which it is deployed. Caution should be taken when extrapolating these results, because the measured values may differ in other crop systems.