FUNCTION OF ABDOMEN WAVE BEHAVIOR IN LARVAL ISCHNURA-VERTICALIS (ODONATA, COENAGRIONIDAE)

Odonate larvae are important predators in the littoral zone of freshwa ter systems, and in an effort understand their population dynamics, re searchers have described and analyzed many of their behaviors. The beh avior we call abdomen wave has been considered to be both an aid to re spiration and an aggressive display to conspecifics. We found that, un der laboratory conditions, abdomen wave was not increased when the oxy gen concentration was low or when larvae were in the presence of consp ecifics. These results suggest the behavior is not involved in oxygen uptake or in agonistic interactions, The behavior was increased when l arvae had food in their guts and was most dramatically increased in th e hours preceding a molt, Abdomen wave may function to loosen the exo- skeleton prior to molting and/or release of metabolites.