Perspectives on management of pestiferous Chironomidae (Diptera), an emerging global problem.

In recent years, adult Chironomidae emerging from some urban natural or man-made habitats have increasingly posed a variety of nuisance and economic problems, and in some situations medical problems to humans in different parts of the world. Although there are an estimated 4,000 or more species of chironomid midges worldwide, less than 100 species have been reported to be pestiferous. Among midge control methods, numerous laboratory and field studies have been conducted on the use of organochlorines, organophosphates (OPs), pyrethroids and insect growth regulators (IGRs). Field use of OP insecticides such as chlorpyrifos, temephos and others in the USA and Japan has generally resulted in larval control for 2-5 wk or longer with application rates below 0.56 kg AI/ha (USA) and less than 1-5 ppm (Japan). Frequent use of some OP insecticides in the USA and Japan has caused their increased tolerance in several midge species. The IGRs, diflubenzuron and methoprene, provide alternate means for midge control. These IGRs in some situations suppressed adult midge emergence by greater than 90% at rates less than 0.3 kg AI/ha. A number of parasites and pathogens have been reported from midges in different parts of the world. Bacillus thuringiensis serovar. israelensis is effective against some midge species, but at rates at least 10x or higher established for mosquito larvicidal activity. The flatworm, Dugesia dorotocephala, and some fish species offer a good potential for midge control in some situations. In large habitats covering hundreds or thousands of ha, information on the basic ecology of larval midges and adult behavior is essential for formulating midge control criteria. More research is needed on the biological and physical and cultural control of these pestiferous insects.