Beetle communities are most complex in small, warm, ponds, where the many species are separated by habitat, trophic role, period of activity, and body size. Temporary ponds are often well populated. The open channel of lotic habitats normally has few species, but may have large densities. The beach zone of both lentic and lotic waters may have many specialized species. Adults and larvae normally have the same habitat, but there are notable exceptions.
Aquatic species are far less consequential to man.
Some are eaten by fish, others may eat fish, may help control nuisance organisms, many are good water quality indicators. Zoogeography Long-lived, strong flying adults make many species widely distributed. Species in springs are sometimes flightless and more local. Collecting The aquatic larvae and adults are usually collected in similar manners. Lotic, open channel species are easily collected by routine benthic samples, some are very small, some may cling strongly to the substrate and to the net.