THE NEUROENDOCRINE ORGANS OF LARVAE OF NEODIPRION LECONTEI, N. SWAINEI, AND DIPRION HERCYNIAE (HYMENOPTERA: DIPRIONIDAE)

Abstract

AbstractLarvae and eonymphs of the diprionid sawflies Neodiprion lecontei (Fitch), Neodiprion swainei Midd., and Diprion hercyniae (Htg.) were dissected and stained to demonstrate the nervous system and endocrine organs. Morphologically and anatomically the endocrine organs in both larvae and eonymphs of all three species are very similar. The cephalic structures comprise lateral and medial neurosecretory cells in the brain which discharge their secretions through a single pair of nerves (NCC) to the corpora cardiaca. The NCC divide before they enter the corpora cardiaca sending a branch to the corresponding corpus allatum. No other nervous connections with these organs are apparent.Paired neurohaemal organs occur in each thoracic segment, forming distinct dilations on slender nerves arising from the ventral cord connectives. They receive secretions from groups of lateral neurosecretory cells in the thoracic ganglia.Each abdominal ganglion has three neurohaemal organs associated with it, a single small spherical structure antero-medially, and paired lateral organs of a diffuse structure, overlying the base of each segmental nerve. They are less conspicuous than the thoracic organs and have different staining properties.