Size and Chemical Composition of Heliothis virescens (Lepidoptera: Noctuidae) Spermatophores

Abstract

Abstract The tobacco budworm, Heliothis virescens (F.) (Lepidoptera: Noctuidae), is a polyandrous species of economic importance on the American continent. This sexual behavior allows for the presence of multiple spermatophores inside a female and the possibility of different males fertilizing the female's offspring, which can make insecticide resistance management or sterile insect release programs particularly challenging. The presence of spermatophores in a female can greatly influence her behavior, physiology, and offspring production. The role that these reproductive structures have is directly influenced by their size and the amount and type of substances that they contain as they are passed into the female during copulation. In this study, we investigated the role that male feeding has on mating potential, including the basic chemical composition and coloration of three sequentially produced spermatophores by male moths that were fed nothing, water, sucrose solution, or nectar. Male moth feeding had a direct influence on spermatophore weight, which was used as an indicator of polyandrous behavior. Nectar-fed moths produced heavier spermatophores and copulated in greater proportion than moths exposed to the other treatments. The total sugar and protein content of spermatophores was not influenced by the type of male feeding. Red or pink spermatophores were more prevalent in the first-produced spermatophores, diminishing in proportion on the second, and increasing again on the third-produced spermatophore, but this coloration proportion was prevalent of males not fed or fed only water. There were no differences in the chemical composition of the different colored spermatophores. These results indicate that polygynous behavior on H. virescens can be influenced by the type of male feeding.