Browsing by Author "Leskey, Tracy C."
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- Behavioral Response of the Brown Marmorated Stink Bug (Hemiptera: Pentatomidae) to Semiochemicals Deployed Inside and Outside Anthropogenic Structures During the Overwintering PeriodMorrison, William R. III; Acebes-Doria, Angelita L.; Ogburn, Emily C.; Kuhar, Thomas P.; Walgenbach, James F.; Bergh, J. Christopher; Nottingham, Louis B.; DiMeglio, Anthony S.; Hipkins, Patricia A.; Leskey, Tracy C. (2017-06)The brownmarmorated stink bug, Halyomorpha halys (Stal), is an invasive species from Asia capable of causing severe agricultural damage. It can also be a nuisance pest when it enters and exits anthropogenic overwintering sites. In recent years, pheromone lures and traps for H. halys have been developed and used to monitor populations in field studies. To date, no study has investigated the applicability of these monitoring tools for use indoors by building residents during the overwintering period. Herein, we 1) assessed when in late winter (diapause) and spring (postdiapause) H. halys begins to respond to its pheromone (10,11-epoxy-1-bisabolen-3-ol), 2) evaluated whether pheromone-based tools can be used reliably for monitoring H. halys adults in unheated and heated buildings, and 3) elucidated the potential for indoor management using pheromone-baited traps. A 2-yr trapping study suggested that H. halys began to respond reliably to pheromone-baited traps after a critical photoperiod of 13.5h in the spring. Captures before that point were not correlated with visual counts of bugs in buildings despite robust populations, suggesting currently available pheromone-baited traps were ineffective for surveillance of diapausing H. halys. Finally, because baited traps captured only 8-20% of the adult H. halys known to be present per location, they were not an effective indoor management tool for overwintering H. halys. Our study contributes important knowledge about the capacity of H. halys to perceive its pheromone during overwintering, and the ramifications thereof for building residents with nuisance problems.
- Biogeography and biosystematics of plum curculio, Conotrachelus nenuphar (Herbst)/Wolbachia interactionsZhang, Xing (Virginia Tech, 2006-11-28)This research focused on the reproductive incompatibility and genetic differences between the two strains of plum curculio, Conotrachelus nenuphar (Herbst). Two molecular markers served as the basis for the strain distribution analysis of plum curculio and Wolbachia symbiont. One marker is the partial mitochondrial cytochrome oxidase gene subunit I (mtCOI) of plum curculio. Another marker is the Wolbachia Surface Protein (wsp) gene of Wolbachia associated with plum curculio. First, the reproductive compatibility of cross-populations mating in plum curculio was studied during the summers of 2004 and 2006. The results confirmed the reproductive incompatibility among plum curculio geographic populations. A unidirectional incompatibility was revealed in an approximate north and south transect of the range of plum curculio (4 x 4 two factorial design: NY, VA, FL, and WV): there was a significant low fertility in WV males mated with NY (40%) and VA (29%) females. The Florida population showed a different pattern: FL males have a significantly lower fertility with VA (46%) and WV (37%) females while FL females were compatible with all males from the four populations. The results of experiment 2 indicated that within the northern geographic area populations (3 x 3 two factorial design: NY, MA, and NJ) were compatible with each other. An opposite unidirectional reproductive incompatibility was revealed in the combination of NJ males with FL females, which showed a significant low fertility (47%). A bi-directional incompatibility occurred between FL and WV reciprocal cross mating. FL males mated with WV females (26%) and WV males mated with FL females (21%) both have the significant low fertility compared to fertility of within their population matings. The genetic diversity among plum curculio populations from different geographic locations was investigated using the partial mtCOI gene. A total of 50 samples from 10 populations were sequenced. PCR products were 863 bp in length. A total of 23 unique sequence haplotypes were found in the 50 samples tested. Haplotype G (n = 5), L (n = 12) and T (n = 13) comprised 60% of 50 samples. The nucleotide distances between those haplotypes ranged from 0.12% to 4.87%. Genetic distances between northern and southern group plum curculios range from 4.17% to 4.87%. Two distinct major clades were found, using three different phylogenetic analyses: 1) neighbor joining (NJ), 2) maximum-parsimony (MP), and 3) maximum-likelihood (ML). 100% bootstraps support the northern clade and the southern clade was strongly supported (100/100/86, NJ/MP/ML) as well. The mid-southern subclade within the southern clade was also strongly supported (70/82/71, NJ/MP/ML) and the far-southern subclade was supported in NJ tree (81%) but was not resovled in MP and ML trees. The mid-southern subclade included haplotypes from two NJ, Washington, VA (Ra), Blacksburg, VA (BL) and 50% of WV populations and the far-southern subclade included haplotypes from FL, GA, Whitethorne, VA (Ke), Troutville, VA (Bo) and another 50% of WV populations. The results suggested that the northern and the southern clade could correspond with the northern and southern strains, respectively, of plum curculio. In this study, the mtCOI sequence was highly informative as a molecular marker in that it was useful to distinguish C. nenuphar from northern and from southern geographic locations in the eastern United States. However, the number of generations per year of several geographic populations within the southern clade still needs to be determined. The distribution of Wolbachia infection associated with plum curculio strains was investigated. 91 of 93 samples were infected by Wolbachia. Three unique Wolbachia strains were identified. The strains wCne1 and wCne2 (593 bp) were 97% identical, and their sequences were both 84% identical with wCne3 (590 bp). The wsp sequence of wCne1 was 99% identical to Wolbachia sequenced from the neotropical beetle, Chelymorpha alternans Boheman (Keller et al. 2004). The wCne2 sequence was 98.5% identical to the flower bug, Orius nagaii Yasunaga (Miura and Tagami, unpublished). The wCne3 sequence was 100% identical to Wolbachia sequenced from the tephritid fruit fly, Dacus destillatoria (Jamnongluk et al. 2000) and the ant, Formica exsecta (Reuter and Keller 2003). PCR - Restriction Fragment Length Polymorphism (RFLP) was used for superinfection detection. Of 93 samples, 15 (16.1%), 21 (22.6%), 19 (20.4%), 36 (38.7%) samples were infected by wCne1, wCne2, wCne1 plus wCne2, and wCne3, respectively. Only two (2.2%) samples had no infection. The wCne3 strain was always present as a single infection. Therefore, current results suggest that Wolbachia strains approximate the distribution of plum curculio strains: the northern strain is infected with wCne1 and wCne2 strains in supergroup B, the southern strain is infected with wCne3 strain in supergroup A and the mid-Atlantic region is the convergence area. Compared with the haplotype distribution of plum curculio mtCOI gene, there was a closer relation of the mid-southern PC clade to the far-southern clade than to the northern clade. However, Wolbachia symbionts in mid-southern PC are more closely related to those in northern PC than to those in far-southern PC. The relationship of Wolabchia infection with reproductive incompatibility between plum curculio populations is also discussed.
- Biology and Management of Brown marmorated Stink Bug, Halyomorpha halys (Stål), in Agricultural and Urban EnvironmentsAigner, John D. (Virginia Tech, 2016-04-29)Brown marmorated stink bug, Halyomorpha halys (Stål), is a crossover pest impacting agriculture and invading urban environments. Studies were conducted to better understand the management of the bug through its physiology, behavior and susceptibility to insecticidal intervention. Halyomopha halys exhibit great variability in overwintering site selection with choices including manmade structures and tree bark. Because of these diverse sites, the bug must have the ability to withstand varying conditions throughout the overwintering cycle. We were able to determine that H. halys is chill intolerant and capable of adapting its tolerance to temperatures by season, sex, and location of acclimation. The mean supercooling point (± SEM) in the winter in Minnesota was -17.06°C ± 0.13° and in Virginia was -13.90°C ± 0.09°. Laboratory experiments conducted in Blacksburg, VA were able to determine baseline lethal high temperatures over time against H. halys adults. To achieve 100% mortality, temperatures fell between 45°C and 50°C, 40°C and 45°C, and 42°C and 45°C, over 15-min, 1-h, and 4-h, respectively. Moving forward, we were able to utilize this information to develop heat treatment guidelines for export shipping cargo infested with overwintering H. halys. In a controlled field experiment, we determined that exposing the coldest areas of an infested vehicle to temperatures greater than 50°C for a minimum of 15 minutes resulted in 100% mortality of overwintering BMSB adults. In 2012 and 2013, citizen scientists were recruited through Virginia Cooperative Extension to assist in evaluating several in home light traps designed to help eradicate overwintering H. halys adults in homes. Over the course of the two year study, fourteen houses participated in the study with 72% of those houses having stink bug activity. It was found that the most effective trap was an aluminum foil pan trap. In 2013, the trap was 19 times more effective at catching stink bug adults than any other trap tested. In September of 2014, a near-field experiment was conducted to determine the residual efficacy of several recommended and labeled insecticides for treatment of homes against invading H. halys adults. This study used constructed window screen bags that were dipped in insecticide solution. After the initial treatment, bugs were exposed to the bags for 24h weekly, up to 54 days after treatment (DAT). It was determined that 2 DAT all insecticides had activity except for indoxacarb. All insecticides lost efficacy after 29 DAT except for lambda-cyhalothrin, beta-cyfluthrin, beta-cyfluthrin + imidacloprid, lambda-cyhalothrin + thiamethoxam, and dinotefuran, which had some measureable activity even after 40 DAT. Each of these insecticides contained a pyrethroid alone or in combination with a neonicotinoid. Laboratory bioassays were conducted to determine the LC50 values of clothianidin, dinotefuran, imidacloprid, and thiamethoxam against H. halys nymphs using a systemic application method. Those LC50 values were found to be 0.077, 0.013, 0.068, and 0.018 ppm, respectively. Field experiments conducted in Virginia in 2012 and 2013 showed a significant reduction of stink bug damage using two soil applications of neonicotinoid insecticides in pepper and tomato. In North Carolina, a single drip irrigation application significantly reduced stink bug damage in 2012 and 2014 using dinotefuran or imidacloprid.
- Biology, ecology, and management of brown marmorated stink bug (Hemiptera: Pentatomidae)Rice, Kevin B.; Bergh, J. Christopher; Bergmann, Eric J.; Biddinger, David J.; Dieckhoff, Christine; Dively, Gale; Fraser, Hannah; Gariepy, Tara; Hamilton, George; Haye, Tim; Herbert, D. Ames Jr.; Hoelmer, Kim A.; Hooks, Cerruti R. R.; Jones, Ashley; Krawczyk, Greg; Kuhar, Thomas P.; Martinson, Holly; Mitchell, William; Nielsen, Anne L.; Pfeiffer, Douglas G.; Raupp, Michael J.; Rodriguez-Saona, Cesar; Shearer, Peter W.; Shrewsbury, Paula M.; Venugopal, P. Dilip; Whalen, Joanne; Wiman, Nik G.; Leskey, Tracy C.; Tooker, John F. (2014)Brown marmorated stink bug, Halyomorpha halys Stål, is an invasive, herbivorous insect species that was accidentally introduced to the United States from Asia. First discovered in Allentown, PA, in 1996, H. halys has now been reported from at least 40 states in the United States. Additional invasions have been detected in Canada, Switzerland, France, Germany, Italy, and Lichtenstein, suggesting this invasive species could emerge as a cosmopolitan pest species. In its native range, H. halys is classified as an outbreak pest; however, in North America, H. halys has become a major agricultural pest across a wide range of commodities. H. halys is a generalist herbivore, capable of consuming >100 different species of host plants, often resulting in substantial economic damage; its feeding damage resulted in US$37 million of losses in apple in 2010, but this stink bug species also attacks other fruit, vegetable, field crop, and ornamental plant species. H. halys has disrupted integrated pest management programs for multiple cropping systems. Pesticide applications, including broad-spectrum insecticides, have increased in response to H. halys infestations, potentially negatively influencing populations of beneficial arthropods and increasing secondary pest outbreaks. H. halys is also challenging because it affects homeowners as a nuisance pest; the bug tends to overwinter in homes and outbuildings. Although more research is required to better understand the ecology and biology of H. halys,we present its life history, host plant damage, and the management options available for this invasive pest species.
- Border Habitat Effects on Captures of Halyomorpha halys (Hemiptera: Pentatomidae) in Pheromone Traps and Fruit Injury at Harvest in Apple and Peach Orchards in the Mid-Atlantic, USABergh, J. Christopher; Morrison, William R. III; Stallrich, Jon W.; Short, Brent D.; Cullum, John P.; Leskey, Tracy C. (2021-05)Simple Summary Brown marmorated stink bug (BMSB) is a significant threat to the production of tree fruit, corn and soybean, and some vegetable crops in much of the USA and abroad. Its feeding causes injury that reduces crop quality and yield. BMSB invades crop fields from adjoining habitats, where it also feeds and develops on a broad range of wild and cultivated plants. Thus, it is considered a perimeter-driven threat, and research on management tactics to reduce insecticide applications against it has focused on intervention at crop edges. Woodlands often border one or more edges of crop fields in the Mid-Atlantic, USA, and are considered a main source of BMSB invasion, although tree fruit orchards in this region are typically also bordered along other edges by other habitats, including other tree fruit blocks and field crops. The effect of woodlands and other habitats bordering orchards on BMSB captures in pheromone traps and crop injury at harvest has not been compared. A two-year study in Mid-Atlantic fruit orchards confirmed that BMSB captures and fruit injury were often highest at edges bordering woodlands, but that other border habitats also contributed significantly to captures and injury in some instances. The invasive Halyomorpha halys invades crop fields from various bordering habitats, and its feeding on crops has caused significant economic losses. Thus, H. halys is considered a perimeter-driven threat, and research on alternative management tactics against it has focused on intervention at crop edges. Woodlands adjacent to crop fields contain many hosts of H. halys and are therefore considered "riskiest" in terms of pest pressure and crop injury. However, tree fruit orchards in the Mid-Atlantic, USA, are often bordered on one or more sides by woodlands and other habitats, including other tree fruit blocks, and field crops. Monitoring H. halys using pheromone traps has most often focused on the crop-woodland interface, but the relative effects of woodlands and other habitats bordering orchards on pest pressure and crop injury have not been examined. A two-year study comparing seasonal captures of H. halys and fruit injury among different habitats bordering commercial apple and peach orchards in the Mid-Atlantic revealed that while woodland borders often posed the greatest risk, other border habitats also contributed significantly to captures and injury in numerous instances. The relevance of these findings to refining and optimizing perimeter-based monitoring and management approaches for H. halys is discussed.
- Border Habitat Effects on Captures of Halyomorpha halys (Hemiptera: Pentatomidae) in Pheromone Traps and Fruit Injury at Harvest in Apple and Peach Orchards in the Mid-Atlantic, USABergh, J. Christopher; Morrison, William R.; Stallrich, Jon W.; Short, Brent D.; Cullum, John P.; Leskey, Tracy C. (MDPI, 2021-05-08)The invasive Halyomorpha halys invades crop fields from various bordering habitats, and its feeding on crops has caused significant economic losses. Thus, H. halys is considered a perimeter-driven threat, and research on alternative management tactics against it has focused on intervention at crop edges. Woodlands adjacent to crop fields contain many hosts of H. halys and are therefore considered “riskiest” in terms of pest pressure and crop injury. However, tree fruit orchards in the Mid-Atlantic, USA, are often bordered on one or more sides by woodlands and other habitats, including other tree fruit blocks, and field crops. Monitoring H. halys using pheromone traps has most often focused on the crop–woodland interface, but the relative effects of woodlands and other habitats bordering orchards on pest pressure and crop injury have not been examined. A two-year study comparing seasonal captures of H. halys and fruit injury among different habitats bordering commercial apple and peach orchards in the Mid-Atlantic revealed that while woodland borders often posed the greatest risk, other border habitats also contributed significantly to captures and injury in numerous instances. The relevance of these findings to refining and optimizing perimeter-based monitoring and management approaches for H. halys is discussed.
- Cavity Tightness Preferences of Overwintering Halyomorpha halys (Hemiptera: Pentatomidae)Chambers, Benjamin D.; Leskey, Tracy C.; Cullum, John P.; Pearce, Annie R.; Kuhar, Thomas P. (2020-06)Brown marmorated stink bug (Halyomorpha halys) (Stal) is a household nuisance pest that seeks shelter in buildings during the winter months. It has been found in a variety of cavities and spaces between building elements, as well as in the objects stored within buildings. This experiment examined the cavity tightness preferences for these insects as they settled in winter refugia. Adult overwintering H. halys were placed in two types of simulated refugia made from rigid material. Each type had a cavity of constant width, while one had a flat lid and constant tightness, and the other had a sloped lid that became tighter as insects moved inside. Adults were allowed to enter and settle, then their locations were recorded. In sloped lid cavities, H. halys tended to settle where the cavity tightness was between 4.5 and 5.5 mm. In the flat lid cavity boxes, H. halys tended to move all the way back. In both configurations, H. halys had a significant tendency to orient their heads towards the cavity entrance. A field comparison of cavity tightness in refugia with less rigid cardboard substrates was also performed, with spacers consisting of one or two layers of 3-mm cardboard. This comparison found differences in cavity selection by sex, with males more likely to pick single-spaced layers, and females more likely to select double-spaced layers. Understanding these preferences could be useful for collection, pest management, trap design, and study of impacts on structures.
- Characterizing spring emergence of adult Halyomorpha halys using experimental overwintering shelters and commercial pheromone trapsBergh, J. Christopher; Morrison, William R. III; Joseph, Shimat V.; Leskey, Tracy C. (2017-03)To improve our understanding of adult Halyomorpha halys (Stal) (Hemiptera: Pentatomidae) overwintering biology and to better inform models of its population dynamics, its temporal pattern of spring emergence was investigated using experimental overwintering shelters in screened cages within protective structures. In 2012, plastic shelters containing 100 adults were deployed in unheated, unlighted buildings, and adjacent woodlots in Virginia, USA. In 2013 and 2014, wooden shelters containing 300 paint-marked adults were deployed in pairs in six woodlots across Virginia, West Virginia, and Maryland, USA; one in a closed cage and one in a cage with the top removed, enabling emerged adults to be counted or to disperse, respectively. In 2013 and 2014, pheromone-baited and non-baited pyramid traps encircled the shelters at each site. Regular counts of adults that emerged into the closed cage and of marked and wild' (unmarked) adults captured in traps were conducted from February or March through early July. In 2012, emergence patterns from shelters in buildings and woodlots were very similar and matched those recorded from woodlots in 2013 and 2014. In all years, a small peak of emergence occurred in about mid-April, a larger and more prolonged peak was observed between mid-May and early June, and emergence ended by early July. Of the 449 H.halys adults captured in traps between 2013 and 2014, only three were marked individuals from shelters in the open cage, suggesting that adults emerging from overwintering sites may require a dispersal flight before responding to pheromone-baited traps. In 2013 and 2014, respectively, 98 and 93% of captures were in pheromone-baited traps, but there was no correlation between the weekly number of adults that emerged from shelters in the closed cages and captures in traps.
- Deltamethrin-Incorporated Nets as an Integrated Pest Management Tool for the Invasive Halyomorpha halys (Hemiptera: Pentatomidae)Kuhar, Thomas P.; Short, Brent D.; Krawczyk, G.; Leskey, Tracy C. (Oxford University Press, 2017-04-01)Long-lasting insecticide nets (LLINs), which have insecticide incorporated within the fibers, have been widely used for control of malaria and other insect-vectored diseases. Only recently have researchers begun exploring their use for control of agricultural pests. In this study, we evaluated the toxicity of a deltamethrin-incorporated LLIN, ZeroFly (Vestergaard-Frandsen, Washington, DC) for control of the brown marmorated stink bug, Halyomorpha halys (St (a) over circlel). In the lab, exposure to the ZeroFly net for 10 s resulted in > 90% mortality of H. halys nymphs and > 40% mortality of H. halys adults. Longer exposure to the net resulted in higher mortality. In another experiment, a 15-cm(2) sheet of ZeroFly net placed inside of the stink bug trap provided long-lasting kill of H. halys adults equal to or better than standard dichlorvos kill strip. Potential for the use of ZeroFly nets for H. halys IPM is discussed.
- Dendrochronology reveals different effects among host tree species from feeding by Lycorma delicatula (White)Dechaine, Andrew C.; Pfeiffer, Douglas G.; Kuhar, Thomas P.; Salom, Scott M.; Leskey, Tracy C.; McIntyre, Kelly C.; Walsh, Brian; Speer, James H. (Frontiers, 2023-09-01)The spotted lanternfly, Lycorma delicatula (White) (Hemiptera: Fulgoridae), was first detected in the United States in Berks County, Pennsylvania, in 2014. Native to China, this phloem-feeding planthopper threatens agricultural, ornamental, nursery, and timber industries in its invaded range through quarantine restrictions on shipments, as well as impacts on plants themselves. The long-term impacts of L. delicatula feeding on tree species have not been well studied in North America. Using standard dendrochronological methods on cores taken from trees with differing levels of L. delicatula infestation and systemic insecticidal control, we quantified the impact of L. delicatula feeding on the annual growth of four tree species in Pennsylvania: Ailanthus altissima, Juglans nigra, Liriodendron tulipifera, and Acer rubrum. The results suggest that L. delicatula feeding is associated with the diminished growth of A. altissima, but no change was observed in any other tree species tested. The results also suggest that systemic insecticides mitigate the impact of L. delicatula feeding on A. altissima growth.
- Development and comparison of trunk traps to monitor movement of Halyomorpha halys nymphs on host treesAcebes-Doria, Angelita L.; Leskey, Tracy C.; Bergh, J. Christopher (2016-01)Halyomorpha halys Stal (Hemiptera: Pentatomidae) has recently become a major orchard pest in the Mid-Atlantic, USA. Large H. halys populations can develop on wild tree hosts adjacent to orchards, posing an ongoing threat to fruit. Adults and nymphs feed on tree fruit, causing economic injury. Understanding the seasonal patterns of nymphal host use among trees at the orchard-woodland interface may aid the development of integrated pest management strategies for this pest. In laboratory and field experiments, modified versions of published trap designs - 'Circle', 'Hanula', 'M&M' (after Moeed & Meads) traps - were compared for their effectiveness for capturing H. halys nymphs walking up and down tree trunks. In the laboratory, second instars were released at the top and bottom of ailanthus (tree of heaven), Ailanthus altissima (Mill.) Swingle (Simaroubaceae), logs and captures were recorded after 24 h. Circle and M&M traps, respectively, were most effective for capturing nymphs walking up and down. In the field, traps were deployed on ailanthus trees next to apple orchards and captures were recorded weekly from 24 July to 11 September 2013. As in the laboratory, Circle and M&M traps captured the greatest number of upward- and downward-walking nymphs. Hanula traps were least effective in both experiments. In the field, 88% of total captures were of nymphs walking up trees. This was at least partially explained by behavioral assays in the laboratory demonstrating that nymphs exhibited negative gravitaxis and positive phototaxis. Stage-specific trends in captures of instars walking up during field sampling were observed. These results suggest that trunk traps can be used to address important ecological questions about seasonal patterns of host use by H. halys nymphs.
- Development of behaviorally based monitoring and biosurveillance tools for the invasive spotted lanternfly (Hemiptera: Fulgoridae)Nixon, Laura J.; Leach, Heather; Barnes, Caitlin; Urban, Julie; Kirkpatrick, Danielle M.; Ludwick, Dalton C.; Short, Brent; Pfeiffer, Douglas G.; Leskey, Tracy C. (Oxford University Press, 2020-10-01)The spotted lanternfly, Lycorma delicatula White, is an invasive planthopper (Hemiptera: Fulgoridae) that was first detected in the United States in Berks County, PA, in 2014, and has since spread in the mid-Atlantic region. This phloem-feeding pest has a broad host range, including economically important crops such as grape where their feeding causes dieback of infested plants. Monitoring the presence and abundance of L. delicatula is of utmost importance to develop pest management approaches. Current monitoring practices include sticky bands deployed on tree trunks, sometimes paired with commercially available methyl salicylate lures. A drawback associated with sticky bands is the high numbers of nontarget captures. Here, we developed traps for L. delicatula based on a circle trap originally designed for weevils. These traps are comprised of a screen funnel that wraps around the trunk of a tree and guides individuals walking up the trunk into a collection device. In 2018 and 2019, we compared circle trap designs with sticky bands in Pennsylvania and Virginia. In both years, circle trap designs yielded captures that were equivalent to or exceeded captures of L. delicatula on sticky bands. Nontarget captures were significantly lower for circle traps compared with sticky bands. Presence of a methyl salicylate lure in association with traps deployed on host trees or vertical tree-mimicking posts did not increase L. delicatula captures compared with unbaited traps. Circle traps, modified using vinyl screen and a larger collection device, present an alternative to the current approach with reduced nontarget capture for monitoring L. delicatula.
- Development of rearing methodology for the invasive Spotted Lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae)Nixon, Laura J.; Jones, Sharon; Dechaine, Andrew C.; Ludwick, Dalton; Hickin, Mauri; Sullivan, Liam; Elsensohn, Johanna E.; Gould, Juli; Keena, Melody; Kuhar, Thomas P.; Pfeiffer, Douglas G.; Leskey, Tracy C. (Frontiers, 2022-09-21)Lycorma delicatula, White (Hemiptera: Fulgoridae), spotted lanternfly, is a univoltine, phloem-feeding, polyphagous and invasive insect in the USA. Although a primary host for this species is Ailanthus altissima, tree of heaven, L. delicatula also feeds on a wide range of hosts important to the USA including cultivated grapevines. Due to the need for classical or augmentative biological control programs to reduce impacts of L. delicatula across invaded areas, we developed a laboratory-based rearing protocol for this invasive species. Here, we evaluated the use of A. altissima apical meristems, epicormic shoots, and fresh foliage cut from A. altissima as a food source for rearing newly hatched L. delicatula. On these sources of plant material <20% of L. delicatula developed into adults and no oviposition occurred. However, when young, potted A. altissimatrees were used as a food source, >50% of L. delicatula nymphs developed to the adult stage under natural daylengths and temperatures ranging from 20–25°C. The addition of wild grapevine, Vitis riparia, did not increase survivorship or reduce development time. To elicit mating and oviposition, adults were provided with A. altissima logs as an oviposition substrate and maintained under shortened daylengths and reduced nighttime temperatures (12L:12D and 24°C:13°C). This resulted in 2.12 egg masses deposited per female, which was 4× more than when adults were maintained in standard rearing conditions (16L:8D and 25°C). Based on these experiments, we present a protocol for reliably rearing L. delicatula under laboratory and/or greenhouse conditions.
- Effect of pre-harvest exposures to adult Halyomorpha halys (Hemiptera: Pentatomidae) on feeding injury to apple cultivars at harvest and during post-harvest cold storageBergh, J. Christopher; Joseph, Shimat V.; Short, Brent D.; Nita, Mizuho; Leskey, Tracy C. (2019-10)The effect of exposing apples to brown marmorated stink bug, Halyomorpha halys, for discrete intervals before harvest and of post-harvest cold storage on feeding injury expression was evaluated in 2011 and 2012. Individual apples from four cultivars in experimental orchards in Virginia and West Virginia, USA were caged soon after fruit set to protect them from insect injury. During each of the four weeks preceding harvest of each cultivar, five adult H. halys were placed in a subset of cages for 7-days, then removed. Control fruit were not exposed. The proportion of injured fruit and the number of external injuries was evaluated at harvest, after which the fruit were held in cold storage for about 5 weeks, followed by assessments of the proportion of fruit injured and the number of external and internal injuries. Most exposure timings resulted in external injury at harvest, but fruit exposed closer to harvest tended to show less injury than those exposed earlier. Fruit from all cultivars showed external injury at harvest, with variation in the proportion of injured fruit among them. The proportion of injured fruit and the number of external injuries tended to increase during post-harvest cold storage in some, but not all cultivars. The number of external injuries at harvest and after cold storage underrepresented the number of internal injuries. Results are discussed in the relation to the length of pre-harvest protection required to mitigate fruit injury from H. halys.
- Environmental and behavioral factors associated with the infestation of vineyards by larvae of grape root borerRijal, Jhalendra P. (Virginia Tech, 2014-04-03)Grape root borer, Vitacea polistiformis (Harris), is an oligophagous pest of grapevines in the eastern USA. Neonates must burrow into the soil to find grape roots. In Virginia, larvae feed on roots for ~2 years, then pupate just beneath the soil surface. Emerging adults leave an empty pupal exuviae at the soil surface around the vine base. There was no relationship between weekly captures in pheromone traps and pupal exuviae counts, indicating that exuviae sampling is most appropriate to assess infestations. Exuviae sampling in Virginia vineyards revealed infestations that ranged from light to very heavy. Eighteen biotic and abiotic variables were measured and used in analyses that assessed their relative contributions to differences in exuviae density. Water holding capacity and clay/sand ratio were most strongly associated with pupal exuviae density; these variables were used to develop a model for predicting the extent of infestation of individual vineyards. The spatial distribution of pupal exuviae was characterized using non-spatial and geospatial techniques. Although the non-spatial method (Taylor's Power Law) indicated that exuviae showed an aggregated distribution in all blocks, spatial methods (variograms, SADIE) revealed aggregated distributions only in blocks with ≥ 0.5 pupal exuviae per vine. Independent pupal exuviae samples for population assessment in vineyards can be achieved using sampling points separated by >8.8 m. Combined results from geospatial analyses and the temporal distribution of pupal exuviae within years enabled the development of a practical and quantitative sampling protocol. Bioassays used to measure the behavioral response of larvae to host stimuli revealed that neonates were attracted to grape root volatiles. In soil column bioassays, larvae moved vertically and horizontally over distances of up to 120 cm and apparently perceived the presence of grape roots from a distance of 5 cm in soil. Results are discussed in relation to their potential implications for monitoring and managing grape root borer.
- Evaluating Chemical Cues Associated with Halyomorpha halys Toward Enhanced Sensitivity of Surveillance for Trissolcus japonicusDyer, Jared E.; Talamas, Elijah J.; Leskey, Tracy C.; Bergh, J. Christopher (Oxford University Press, 2022-08-19)In Asia, Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae) is the predominant egg parasitoid of the brown marmorated stink bug, Halyomorpha halys (Stal) (Hemiptera: Pentatomidae). Detections of adventive T. japonicus populations in North America since 2014, where invasive H. halys populations have impacted various specialty crops, spurred surveillance efforts to track T. japonicus, and yellow sticky cards (YSC) deployed in H. halys host trees have proven effective for this purpose. While T. japonicus exhibits positive behavioral responses to several olfactory stimuli associated with H. halys under laboratory conditions, these have not been evaluated for their potential utility to enhance surveillance of T. japonicus in the field. In northwestern Virginia, where both H. halys and T. japonicus are well-established, we examined the effect of baiting tree of heaven, Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae), with lures containing the H. halys aggregation pheromone and pheromone synergist on the abundance of H. halys egg masses and captures of T. japonicus in YSC. We also assessed the effect of baiting YSC with newly-laid H. halys egg masses or n-tridecane, a component of H. halys tarsal prints, on T. japonicus captures. Destructive sampling of pheromone-baited and nonbaited trees revealed no significant differences in H. halys egg mass abundance on foliage. Similarly, YSC deployed in pheromone-baited and nonbaited trees showed no significant differences in T. japonicus captures. Moreover, YSC augmented with H. halys egg masses or n-tridecane showed no increase in T. japonicus captures compared with nonbaited controls. The implications for surveillance of adventive T. japonicus are discussed.
- Evaluating invasion risk and population dynamics of the brown marmorated stink bug across the contiguous United StatesIllán, Javier Gutierrez; Zhu, Gengping; Walgenbach, James F.; Acebes-Doria, Angel; Agnello, Arthur M.; Alston, Diane G.; Andrews, Heather; Beers, Elisabeth H.; Bergh, J. Christopher; Bessin, Ricardo T.; Blaauw, Brett R.; Buntin, G. David; Burkness, Erik C.; Cullum, John P.; Daane, Kent M.; Fann, Lauren E.; Fisher, Joanna; Girod, Pierre; Gut, Larry J.; Hamilton, George C.; Hepler, James R.; Hilton, Richard; Hoelmer, Kim A.; Hutchison, William D.; Jentsch, Peter J.; Joseph, Shimat V.; Kennedy, George G.; Krawczyk, Grzegorz; Kuhar, Thomas P.; Lee, Jana C.; Leskey, Tracy C.; Marshal, Adrian T.; Milnes, Joshua M.; Nielsen, Anne L.; Patel, Dilani K.; Peterson, Hillary D.; Reisig, Dominic D.; Rijal, Jhalendra P.; Sial, Ashfaq A.; Spears, Lori R.; Stahl, Judith M.; Tatman, Kathy M.; Taylor, Sally V.; Tillman, Glynn; Toews, Michael D.; Villanueva, Raul T.; Welty, Celeste; Wiman, Nik G.; Wilson, Julianna K.; Zalom, Frank G.; Crowder, David W. (Wiley, 2022-11-01)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.
- Factors Influencing Behavior of Overwintering Brown Marmorated Stink Bugs (Halyomorpha halys) in Human DwellingsChambers, Benjamin D. (Virginia Tech, 2017)The brown marmorated stink bug (Halyomorpha halys) (Stål) is known for overwintering in human homes. Studies were conducted to understand the behavior of adult bugs in response to characteristics of potential overwintering structures including gap sizes, light, and presence of dead conspecifics. In a test where bugs were placed in increasingly tight boxes, most bugs settled in gaps 4.5 - 5.5 mm high. None settled in a space less than 3.5 mm high. In boxes with constant tightness, bugs tended to move to the back, and primarily settled along walls and in corners. In both box types, bugs tended to turn and face the cavity entrance during settling. In tests of responses of disturbed overwintering bugs to common household light bulbs over the course of a year, bugs were taken from shelters and exposed to lit bulbs. Bug responses were seasonal, with attraction to light bulbs in spring and summer, but little or no consistent response in fall or winter. The lack of response occurred more often at night than in afternoons. Because not all bugs survive the winter, corpses can accumulate. Single shelter-seeking H. halys were found not to respond to the presence of dead aggregations from the previous years unless touch was possible, in which case aggregations were joined. Dead aggregations from the same year had a repellent effect. Presence of a single dead bug from the same year did not provide any survivorship advantage to overwintering bugs. Results suggest possible improvements to trap shelters.
- Female sex pheromone of the dogwood borer (DWB), Synanthedon scitula, and attraction inhibitor (antagonist)(United States Patent and Trademark Office, 2011-05-17)A composition for attracting male Synanthedon scitula, containing a male Synanthedon scitula attracting effective amount of Z,Z-3,13-octadecadienyl acetate, optionally E,Z-2,13-octadecadienyl acetate, optionally Z,E-3,13-octadecadienyl acetate, and optionally a carrier material or carrier; the composition containing less than about 0.3% E,Z-3,13-octadecadienyl acetate based on the molar amount of the Z,Z-3,13-octadecadienyl acetate in the composition. A method for attracting male Synanthedon scitula to an object or area, involving treating an object or area with a male Synanthedon scitula attracting composition containing a male Synanthedon scitula attractant effective amount of Z,Z-3,13-octadecadienyl acetate, optionally E,Z-2,13-octadecadienyl acetate, optionally Z,E-3,13-octadecadienyl acetate, and optionally a carrier material or carrier; the composition containing less than about 0.3% E,Z-3,13-octadecadienyl acetate based on the molar amount of the Z,Z-3,13-octadecadienyl acetate in the composition. A method for inhibiting (antagonizing) male Synanthedon scitula attraction to female Synanthedon scitula, involving exposing a Synanthedon scitula population to a composition containing E,Z-3,13-octadecadienyl acetate in a quantity sufficient to inhibit (antagonize) male Synanthedon scitula attraction to female Synanthedon scitula, and optionally a carrier material or carrier.
- Foraging ecology and sampling of Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae) and its host Halyomorpha halys (Stal) (Hemiptera: Pentatomidae) in wild host treesQuinn, Nicole Frances (Virginia Tech, 2019-11-27)The brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is an invasive agricultural and nuisance pest in the United States and an increasing number of countries abroad. In the absence of other long-term solutions, biological control presents one of the most promising H. halys management options. An adventive population of Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), one of the most effective egg parasitoids of H. halys in their shared native range in Asia, was discovered in the Maryland in 2014 and in Frederick County, VA in 2015. Adventive populations of T. japonicus have also been detected recently in several other states and show strong indications of ongoing range expansion. Despite their importance, the foraging ecology of H. halys and especially of T. japonicus in the USA need further study. Small pyramid traps baited with a low-dose H. halys aggregation pheromone lure and deployed as vertical transects in the canopy of female tree of heaven (Ailanthus altissima (Mill.) Swingle), male tree of heaven, or hackberry (Celtis occidentalis L.), captured significantly more H. halys adults and nymphs near the top of the canopy than at mid- or lower canopy, regardless of host plant. The majority of H. halys egg masses collected via destructive sampling of felled tree of heaven were from mid-canopy, and the majority of those parasitized by T. japonicus were also from mid-canopy, with no T. japonicus emergence from egg masses collected from the lower canopy. A comparison of sentinel H. halys egg masses and yellow sticky traps deployed as vertical transects in tree of heaven revealed that the majority of T. japonicus detections occurred at mid-canopy and that while both methods proved to be equally effective, yellow sticky traps were more efficient for this purpose. This led to the development of a novel T. japonicus sampling method in which a yellow sticky trap is deployed atop a bamboo pole in the mid-canopy of wild host trees. This method was employed to compare the effect of habitat type on T. japonicus captures in female tree of heaven growing in spatially isolated patches, thin windbreaks, and at the edge of contiguous woodlots. Consistent habitat effects on T. japonicus detections were not found between sampling years, but provided the first documentation of the seasonal activity of T. japonicus in the USA. A study of host plant effects on T. japonicus detection in mid-canopy yellow sticky traps did not reveal consistent host plant effects on captures. These data provide important insights into the foraging ecology of H. halys and T. japonicus in the USA, as well as efficient sampling methods for future studies of T. japonicus.
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