Larval Odon. were identified from quantitative samples of water lettuce made from a single pond. 3 spp. of Zygoptera accounted for more individuals but less biomass than 4 spp. of Anisoptera. Numbers of larvae were highest in the winter when smallest size classes predominated, and lowest in the spring and summer when larger size classes were present. Size class data indicated a probable spring emergence for Telebasis byersi and Pachydiplax longipennis and an autumnal emergence for Coryphaeschna adnexa. Foregut dissections of freshly caught larvae revealed identifiable remains of certain prey, the commonest being larvae of Mansonia mosquitoes which attach to roots of P. stratiotes.