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Brown marmorated stink bug, Halyomorpha halys (Stål), is an invasive pest of Asian origin first detected in North Carolina in 2009. By 2015, it became an important pest in the mountain and Piedmont regions, but its population densities have remained low in the eastern plains regions. Starting with a cohort of diapausing adults in January of 2018 and 2019, semi-field cage studies were used to document the phenology and reproductive capacity of H. halys through October of each year at Mills River (mountains) and Goldsboro (Southeastern Plains) sites, which have the same photoperiod, but different temperature profiles. Halyomorpha halys was univoltine in the cooler mountain site, but bivoltine in the warmer plains site, leading to earlier emergence from overwintering diapause, greater heat unit accumulations, and a F1 adult generation that emerged before on-set of diapause-inducing conditions, which allowed for an F2 generation. However, only 17.2% of ovipositing F1 females laid egg masses that hatched, compared to > 90% of overwintered females. Poor establishment of H. halys in the plains versus mountains was attributed to heat stress that contributed to a higher percentage of overwintered adults that emerged early and did not oviposit, a truncated oviposition pattern by overwintered adults, and poor F2 egg hatch. Quadratic equations fit relationships between cumulative degree-days from biofix and proportional oviposition and adult eclosion of respective generations. Utility of the phenology model on a wider scale will depend on how well H. halys populations in other areas conform to North Carolina population's response to photoperiod and temperature. [ABSTRACT FROM AUTHOR]

Hexanoic acid, 1-octanol, 1,8-octanediol, octyl hexanoate, 1,8-octanediol monohexanoate, and 1,8-octanediol dihexanoate were identified in headspace volatiles collected from the crushed abdomen of a female click beetle of the species Parallelostethus attenuatus (Say) (Elaterinae, tribe Elaterini). In field trials carried out in Illinois, South Carolina, North Carolina, and Virginia, adult male beetles were strongly attracted to 1,8-octanediol dihexanoate alone. Blends of the dihexanoate with one or more of the other compounds proved to be less attractive than the dihexanoate alone, suggesting that the pheromone of this species may consist of a single compound. The symmetrical diester structure of the pheromone is a novel natural product and appears to be structurally unique among insect pheromones. [ABSTRACT FROM AUTHOR]

Genetically engineered crops expressing Bacillus thuringiensis (Bt) Cry toxins have transformed insect management in maize and cotton, reducing insecticide use and associated off-target effects. To mitigate the risk that pests evolve resistance to Bt crops, the US Environmental Protection Agency requires resistance management measures. The approved resistance management plan for Bt maize in cotton production regions requires a structured refuge of non-Bt maize equal to 20% of the maize planted; that for Bt cotton relies on the presence of an unstructured natural refuge comprising both non-Bt crop and non-crop hosts. We examined how abundance of Bt crops (cotton and maize) and an important non-Bt crop (soybean) component of the natural refuge affect resistance to Bt Cry1Ac toxin in local populations of Helicoverpa zea, an important lepidopteran pest impacted by Bt cotton and maize. We show refuge effectiveness is responsive to local abundances of maize and cotton and non-Bt soybean, and maize, in its role as a source of H. zea infesting cotton and non-Bt hosts, influences refuge effectiveness. These findings have important implications for commercial and regulatory decisions regarding deployment of Bt toxins targeting H. zea in maize, cotton, and other crops and for assumptions regarding efficacy of natural refuges. [ABSTRACT FROM AUTHOR]

The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is an agricultural pest of solanaceous crops which has developed insecticide resistance at an alarming rate. Up to this point, little consideration has been given to unintended, or inadvertent effects that non-insecticide xenobiotics may have on insecticide susceptibility in L. decemlineata. Fungicides, such as chlorothalonil and boscalid, are often used to control fungal pathogens in potato fields and are applied at regular intervals when L. decemlineata populations are present in the crop. In order to determine whether fungicide use may be associated with elevated levels of insecticide resistance in L. decemlineata, we examined phenotypic responses in L. decemlineata to the fungicides chlorothalonil and boscalid. Using enzymatic and transcript abundance investigations, we also examined modes of molecular detoxification in response to both insecticide (imidacloprid) and fungicide (boscalid and chlorothalonil) application to more specifically determine if fungicides and insecticides induce similar metabolic detoxification mechanisms. Both chlorothalonil and boscalid exposure induced a phenotypic, enzymatic and transcript response in L. decemlineata which correlates with known mechanisms of insecticide resistance. [ABSTRACT FROM AUTHOR]