The Neuroendocrine Regulation of Larval Development in the Maize-Stem Borer, Busseola fusca (Fuller) (Lepidoptera: Noctuidae)

Abstract

Busseala fusca (Lepidoptera:Noctuidae) is one of the most important insect pests of maize and sorghum in Africa, south of the Sahara. Last instar larvae of this species survive the dry season in the stalks and stubbles of their host plants by undergoing diapause. The present study was done with the main objective of investigating the involvement of the neuroendocrine system during the development of the last instar larvae with respect to non-diapause and diapause development. The main aspects studied were the biology of last larval instar, histology, ultrastructure and physiology of the components of the larval neuroendocrine system, particularly the type-A neurosecretory cells, corpus cardiacum, corpus allatum and prothoracic glands. Endocrine involvement in the regulation of development during the last instar larvae and in induction, maintenance and termination of diapause development were also investigated. Studies on the biology of the last instar showed that two types of development, namely, non-diapause and diapauae occur in Buseeala flusca.... (continue from the attached PDF)