PREDATORY BEHAVIOR AND PREDATORY VERSATILITY IN YOUNG LARVAE OF THE DRAGONFLY XANTHOCNEMIS-ZEALANDICA (ODONATA, COENAGRIONIDAE)

The predatory activities of naive second-instar Xanthocnemis zealandic a larvae (the first free-living stage) were investigated under six tre atments-no prey, ciliates, rotifers, nematodes (two densities), copepo ds, and cladocerans. Some differences observed could have been due to sensory, or to morphological, limitations of the predator. Other behav iour patterns strongly indicated some CNS-mediated response. Larvae ap parently distinguished between prey types and used prey-specific condi tional behaviours (i.e. displayed predatory versatility). Changes in r esponse were observed during exposure to unpalatable prey but did not occur when larvae ate palatable prey or repeatedly made futile attacks on invulnerable prey..Such changes indicate learning. In contrast to calopterygid species investigated by earlier authors, X. zealandica se cond-instar larvae were both more co-ordinated and more flexible in th eir predatory behaviour. The predatory behaviour of small insect larva e may be more complex than has traditionally been assumed.