The role of the arthropod stomatogastric nervous system in moulting behaviour and ecdysis.

A possible role of the insect stomatogastric nervous system (STNS) in ecdysis was first implied in early studies reporting on internal air pressure build-up in the digestive tract and air swallowing during ecdysis. The frontal ganglion, a major component of the insect STNS, was suggested to play an important part in this behaviour. Recent neurophysiological studies have confirmed the critical role of the STNS in the successful completion of both larval and adult moults in insects. In aquatic arthropods, though much less studied, the STNS plays an equally important and probably very similar role in water swallowing. Water uptake is instrumental in splitting the crustacean cuticle and allowing successful ecdysis. Current data are presented in a comparative view that contributes to our understanding of the role of the STNS in arthropod behaviour. It also sheds light on the question of homology of the STNS among the different arthropod groups. New insights into the neurohormonal control of ecdysis, related to the STNS in both insects and crustaceans, are also presented and comparatively discussed.