Emerald ash borer (EAB) (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) is an invasive pest of ash trees (Fraxinus spp.) in the United States. EAB is best managed via insecticides and biological control by wasps and woodpeckers. Neonicotinoids are often used for EAB due to cost and ease of use but are becoming restricted worldwide and are toxic to beneficial insects. Anthranilic diamides, a newer insecticide class, can manage beetle larvae with limited off-target effects. If diamides control EAB, they could replace neonicotinoids. We tested if drenches of chlorantraniliprole and cyantraniliprole at 3 rates controlled EAB larvae without affecting parasitoids in 41 recruit-sized white ash, Fraxinus americana L. (mean +/- SE = 11.0 +/- 0.7 cm diameter at breast height (DBH)) in central Kentucky 6 months after application. Only the high chlorantraniliprole rate (0.157 g a.i./L per cm DBH) significantly reduced EAB densities (1.3 +/- 0.5 larvae per m2) relative to controls (9.5 +/- 4.2 larvae per m2). Three treatments reduced parasitism by Phasgonophora sulcata Westwood relative to controls while no treatment affected nonnative parasitism or woodpecker predation. Thirty-six percent of larvae were parasitized even though the nearest parasitoid releases were over 20 km away and occurred 7 years prior. Spathius galinae Belokobylskij & Strazanac parasitism, never released in Kentucky at the time of this project, averaged 7.8 +/- 2.9 % and is the furthest south this species has established in the United States. Chlorantraniliprole may control EAB in small diameter ash and reduce parasitism by P. sulcata but not introduced parasitoids.
Ecologically simplified corn fields lack the plant diversity-derived resources necessary for supporting robust beneficial insect populations capable of preventing pest outbreaks. Interseeding cover crops into established corn is a way that farmers can diversify cropland plant communities and restore ecosystem functions. Here, we examine how foliar, epigeic, and subterranean arthropod communities differ between corn monocultures and corn interseeded with cover crops. We also examine how predator activity and predation are affected by interseeded cover crops in corn fields. Predators, herbivores, numerous individual taxa, and all combined arthropods were more abundant on the soil surface in interseeded corn fields. Adding cover crops also increased the number of epigeic species. Within the subterranean environment, community structure was similar in the bare soil and interseeded corn fields, and only 4 commonly collected species differed in abundance. Below-ground arthropod diversity increased when cover crops were interseeded in corn fields. Community characteristics in the corn foliage were not affected by the cover crops. Twice as many wax moth (Galleria mellonella (L.)) sentinel larvae were eaten by generalist predators in cover-cropped corn (45.5%) than in corn monocultures (22.6%). The effect of cover crops on corn stand density and yield varied significantly between study locations. Diversification of the corn agroecosystem by interseeding cover crops had a spatially compartmentalized effect on invertebrates in corn fields, favoring the abundance and diversity of surface-dwelling invertebrate fauna and predator activity. This management tool should be further explored by researchers and farmers, as it is a viable method for conserving biodiversity and bolstering biological control of crop pests.
Lepidoptera are a highly diverse lineage of predominantly terrestrial insects, yet their larvae occupy diverse habitats where they may experience unexpected contact with water or accidental submersion. Such exposure may have favored adaptations that enable terrestrial lepidopteran larvae to survive underwater for short periods. Using a combination of personal and crowd-sourced observations, we document a striking diversity of behaviors displayed by Lepidoptera (32 species across 16 families) when suddenly exposed to water. This includes swimming, which we observed in 4 lepidopteran families. We developed a behavioral ontology comprising 9 distinct behaviors and 5 non-directional behaviors, each observed on the water surface. Our study highlights a largely overlooked dimension of Lepidoptera biology and establishes a framework for future research on the significance of this behavior.
Abstract The bioconversion of aquaculture sludge using Hermetia illucens larvae represents a promising strategy for sustainable waste management; however, the physiological impact of such complex matrices on the insects remains poorly understood. This study investigated the temporal dynamics of the cellular stress response (heat shock protein 70, HSP70) and metabolic vigor (vitellogenin, VTG) in relation to the functional antimicrobial activity of the hemolymph against the fish pathogen Aeromonas salmonicida. Larvae were exposed to a standard control diet, a 50% sludge blend, and 100% undiluted sludge. Our results show an immediate antimicrobial activation, resulting in the complete inhibition of bacterial viability within 4 h (T1) of exposure to the 100% sludge substrate. Conversely, molecular analysis revealed a significant transcriptional downregulation of VTG by 24 h (T2) across sludge-exposed groups. In the 100% sludge cohort, this metabolic crash coincided with a delayed upregulation of HSP70 and a 15% mortality rate. These findings suggest a potential physiological resource reallocation, where acute immune activation and cytoprotective mechanisms suppress anabolic pathways, indicating that while complex waste streams can boost acute immunological defenses, the severe subchronic metabolic costs establish strict biological limits for their acute utilization.
Abstract In recent decades, wildfires have increased in frequency and severity, reshaping forest structure and biodiversity. Yet it remains unclear whether postfire insect assemblages are driven primarily by fire severity, vegetation structure, or broader temporal community turnover, particularly in fragmented range-edge forests. We investigated flight-active beetle (Coleoptera) assemblages 2 years after a 2022 wildfire in the Lost Pines region of Texas, an isolated loblolly pine (Pinus taeda L.) forest at the species’ western range margin. Using historical data from 2011, we evaluated temporal turnover and compared diversity and assemblage composition between contemporary burned and unburned sites. We also quantified fire severity and vegetation structure to analyze their effects on richness and abundance. Contemporary and burned sites supported higher richness and abundance than historical and unburned sites, although evenness declined as opportunistic species became dominant. Beetle assemblage differed significantly between sampling periods and burn status, indicating substantial temporal turnover amplified by wildfire. Fire severity showed strong positive associations with richness and abundance, whereas vegetation structure played a secondary but important role. Richness and abundance increased with woody plant richness, tree diversity, tree size, live tree density, and shrub richness. In contrast, dead tree variables were generally weak or negative predictors, suggesting that the influence of fire-generated deadwood may be transient and strongest shortly after disturbance. Together, these findings indicate that postfire flight-active beetle assemblages in the Lost Pines are shaped by the interaction of long-term temporal turnover and fire-driven successional dynamics, with fire severity acting as the dominant driver of community change.
