Feeding-related behaviour in larvae of Enallagma cyathigerum (Charpentier) (Zygoptera: Coenagrionidae)

Larvae of E. cyathigerum, even when densely aggregated, exhibit no evident spacing or agonistic behaviour. Cannibalism is rare or non-existent among healthy larvae, even after they have been denied food for several days and are exhibiting heightened feeding activity. When exposed to high densities of prey, larvae show no detectable sign of "wasteful killing" (sensu JOHNSON et al., 1975, Ecology 56: 1081-1093). The feeding-related behaviour of larvae of £. cyathigerum, as exhibited in the laboratory, differs markedly from that of Pyrrhosoma nymphula and Lestes sponsa (which themselves differ inter se) in some respects and resembles it in others.