Corixids (Hemiptera — Heteroptera), the new top predators in acidified lakes

Summary

The corixid (Corixidae, Hemiptera—Heteroptera) populations in acidified Swedish lakes are characterized by high abundances of “open water species”. Especially Glaenocorisa propinqua (Fieb.) are abundant also in the limnetic zone of deeper acidified lakes. We stress, that the primarily cause is the reduced fish predation in these lakes. However, altered food and competition cannot be excluded as contributing causes.

We have found several corixid species to be zooplankton predators and as they together with other pelagic invertebrates have taken over the role as top carnivores, it is probable that they are of importance also in regulating the zooplankton community.