Predation propensities of the larva of Orthetrum sabina (Drury) (Anisoptera: Libellulidae)

The predatory propensities oflarval O. sabina in the spawn of the common carp (Cyprinus carpio) were studied under laboratory conditions. The satiation time was about 40 min, and it took 85 s to consume a prey. The dragonfly predatory capacity amounted to about 16 spawn, whereupon the same maximum appetite was restored after 24-36 h of deprivation. It is shown that a decline in predatory efficiency occurs after the first 10 min of feeding. The time required for predation and consumption of a single spawn was less at high than at low prey densities. Quantitative data on the number and rate of attacks, and on the effect of food deprivation are provided.