Egg Morphology of Key Stored-Product Insect Pests of the United States

Abstract

Abstract Eggs of Carpophilus hemipterus (L.) (Coleoptera: Nitidulidae), Lasioderma serricorne (F.) (Coleoptera: Anobiidae), Ephestia elutella (Hiibner) (Lepidoptera: Pyralidae), and Amyelois transitella (Walker) (Lepidoptera: Pyralidae) were imaged using scanning electron microscopy to explore how respiratory openings on the chorion surface may affect the relative efficacy of fumigation. Each C. hemipterus egg had two aeropyles and no micropyles; A. transitella and L. serricorne eggs had many aeropyles and several micropyles; and each E. elutella egg had many aeropyles and a single micropyle. Our data suggest that gases, including fumigants, differentially diffuse into the eggs of these species, with penetration through aeropyles and micropyles likely occurring to a greater extent in L. serricorne, E. elutella, and A. transitella than in C. hemipterus. Although confirmatory measurements of fumigant diffusion into eggs are needed, these findings suggest that species-specific ovicidal efficacies are related, at least in part, to the surface morphology of eggs and that chorionic respiratory structures differentially affect fumigant penetration and/or uptake.