Cuticular Encystment in Larvae of Plusiinae Looper (Lepidoptera: Noctuidae) Parasitized by the Gregarious Endoparasitoid <I>Cotesia glomerata</I>

Abstract

Abstract Lepidopteran larvae can exclude some organelles that have invaded the hemocoel by defense systems such as phagocytosis, encapsulation, and nodule formation. However, Plusiinae loopers have another system that can exclude organelles such as endoparasitoids by forming a cyst on the penultimate segment, i.e., cuticular encystment. In this study, we examined whether cuticular encystment is common in six species of Plusiinae loopers [Autographa nigrisigna Walker, Anadevidia peponis F., Trichoplusia ni (Hubner), Acanthoplusia agnata Staudinger, Erythroplusia rutilifrons Walker, and Trichoplusia intermixta Warren) from the first to the fourth stadia. Loopers were parasitized artificially by the gregarious endoparasitoid Cotesia glomerata L. Different rates of cuticular cyst formation were shown among species. More than one-half of the loopers formed a cuticular cyst in all species except T. intermixta. A. nigrisigna and A. peponis, in particular, formed >80% cysts in the first to third instars. However,...