Sex dimorphism in pupae and adults of the specialist Ipomoea batatas defoliator Bedellia somnulentella (Lepidoptera: Bedelliidae)

Abstract Bedellia somnulentella Zeller, 1847 (Lepidoptera: Bedelliidae), a global pest of the sweet potato Ipomoea batatas, was recorded in Brazil, but morphological information on sexual dimorphism of this insect is scarce. The objective was to evaluate morphological characters of sexual dimorphism of B somnulentella pupae and adults. External structures with sexual dimorphism were not detected in the last abdominal segments of B. somnulentella pupae, but the females are heavier and could be a distinctive sex characteristic in this insect. A pair of frenulum on the hind wings of females and only one on those of males, in addition to elongated cerci and bipartite genitalia in the latter and smaller cerci involving the last abdominal segment and an ovipositor in females, differentiate sexes of B. somnulentella.