The Chironomidae, 1995 Biology and ecology of non-biting midges

The dipteran family Chironomidae is the most widely distributed and frequently the most abundant group of insects in freshwater, with rep­ resentatives in both terrestrial and marine environments. A very wide range of gradients of temperature, pH, oxygen concentration, salinity, current velocity, depth, productivity, altitude and latitude have been exploited, by at least some chironomid species, and in grossly polluted environments chironomids may be the only insects present. The ability to exist in such a wide range of conditions has been achieved largely by behavioural and physiological adaptations with relatively slight morphological changes. It has been estimated that the number of species world-wide may be as high as 15000. This high species diversity has been attributed to the antiquity of the family, relatively low vagility leading to isolation, and evolutionary plasticity. In many aquatic ecosystems the number of chironomid species present may account for at least 50% of the total macroinvertebrate species recorded. This species richness, wide distribution and tolerance to adverse conditions has meant that the group is frequently recorded in ecological studies but taxonomic difficulties have in the past prevented non-specialist identification beyond family or subfamily level. Recent works, including genetic studies, have meant that the family is receiving much more attention globally.

Introduction. Taxonmomy, morphology and biogeography. Morphology. Systematics. Biogeography. Biology, behaviour and ecology. Biology of the eggs and first-instar larvae. The habitats of chironomid larvae. Larval food and feeding behaviour. The pupa and events leading to eclosion. Behaviour and ecology of adults. Life cycles and population dynamics. Production ecology. Species interactions and community structure. Interactions with humans. Nuisance, economic impact and possiblities for control. Medical significance. Classification of water-bodies and pollution. Chironomids as indicators of past environmental change. Chironomidae as food. Conclusions. References. Index.