Neuroendocrine control of vitellogenesis in the dragonfly, Orthetrum chrysis (Selys) (Odonata: Libellulidae).

1. Histological correlative studies on the cerebral neurosecretory cells, the corpora allata and the oocyte development strongly suggest the involvement of cerebral NSM mostly produced by the A cells of pars intercerebralis and the CA hormone in the vitellogenesis. 2. Biochemical studies reveal the incorporation of haemolymph proteins and lipids in the yolk during vitellogenesis. 3. Exogenous administration of the extract of the brain-CC and FME demonstrates, to some extent, the stimulation of protein synthesis during vitellogenesis in the haemolymph by the cerebral NSM and the CA hormone, while the lipid metabolism lies, mostly, under the control of juvenile hormone.