Morphology of the neuroendocrine systems of two larval blackflies, Prosimulium mixtum/fuscum and Simulium venustum

Abstract

The anatomical relations of the neuroendocrine systems of simuliid larvae Prosimulium mixtum/fuscum and Simulium venustum were examined histologically. The neuroendocrine system in the brain showed morphological similarities to culicids (viz., three pairs of cerebral neurosecretory cell clusters, one pair of nervi corporis cardiaci entering the corpus cardiacum glandular system). The retrocerebral glandular portion of the neuroendocrine system was comprised of a corpus allatum, corpora cardiaca, and surrounding peritracheal gland. The morphology of the blackfly neuroendocrine system is discussed in relation to those of other families of Nematocera and higher Diptera.