Feeding rate of larvae of Enallagma cyathigerum (Charpentier) in the presence of conspecifics and predators (Zygoptera: Coenagrionidae)

In the laboratory, larvae of E. cyathigerum show no significant depression of feeding rate when exposed to an active predator, or to equal-sized or smaller conspecifics, detectable by sight alone, or to an active predator detectable visually, hydrodynamically and chemically. In this respect E. cyathigerum differs from another coenagrionid, Ischnura elegans, studied recently by P.A. HEADS (1986, Ecol. Em. II: 369-377).