Function of abdomen wave behavior in larvalischnura verticalis (Odonata: Coenagrionidae)

Odonate larvae are important predators in the littoral zone of freshwater systems, and in an effort understand their population dynamics, researchers have described and analyzed many of their behaviors. The behavior we call abdomen wave has been considered to be both an aid to respiration and an aggressive display to conspecifics. We found that, under laboratory conditions, abdomen wave was not increased when the oxygen concentration was low or when larvae were in the presence of conspecifics. These results suggest the behavior is not involved in oxygen uptake or in agonistic interactions. The behavior was increased when larvae had food in their guts and was most dramatically increased in the hours preceding a molt. Abdomen wave may function to loosen the exoskeleton prior to molting and/or release of metabolites.