Dan Region Waste Stabilization Ponds (DRWSP) were first operated in 1970 in a rural area south of Tel-Aviv. In subsequent years, with the massive urbanization of central Israel, residence has expanded within 2 km of the ponds. The ponds were found to be a suitable habitat for non-biting midges Chironomus spp. (Diptera; Chironomidae) larvae, giving birth to billions of adult chironomids per day. Since 1998, evening breezes have been carrying large adult swarms into the adjacent town of Rishon Le-Zion where they become a severe nuisance mainly during the spring and midsummer (April–July). Midges may penetrate human mouths, eyes, and ears, restricting evening activity outdoors. In addition, dead midges create aesthetic problems, demanding frequent cleaning. The combination of intensive urbanization near DRWSP and the improved water quality, that optimized the midges developmental conditions in the ponds, may be blamed for the current situation.

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