Satiation time and predatory behaviour in the larva of Lestes elata Hagen (Zygoptera: Lestidae)

Different weight classes (W) of larval L. elata (15± 1.5, 25± 1.5 and 40 ± 2.0 mg) were allowed to predate on healthy larvae of the mosquito, Culex pipiens quinquefasciatus or the chironomid, Kiefferulus barbitarsis. Odonate larvae starved for 24 h were exposed to a constant density of 15 mosquitoes per dragonfly. Satiation time (ST) ranged from 8.5 ± 0.62 min for 15 mg W classes exposed to K. barbitarsis larvae. The ST was significantly prolonged when the mosquito larvae were offered as prey. Longer deprivation of prey for about 25-48 hr extended the ST to 10, 17 and 22.5 min in the 15, 25 and 40 mg W classes feeding on K. barbitarsis larvae. Increase in the prey density significantly shortened the ST. On the other hand, ST significantly increased with increase in the volume of water. Briefly, increase in body weight, extension of food deprivation duration and decrease in prey density extended the ST of the dragonfly.