The IGR Diflubenzuron and Organophosphorus Insecticides Against Nuisance Midges in Man-Made Residential-Recreational Lakes

Publisher Website
Google Scholar
Abstract
In the laboratory, chlorpyrifos, temephos, and phenthoate were highly active against 4th instars of Chironomus utahensis (Malloch); this species was tolerant to methyl parathion and fenthion. Proclacidius freemani Sublette and P. sublettei Roback were most susceptible to chlorpyrifos and phenthoate but were resistant to temephos. Circotopus bicinctus (Meigen) and C. sylvestris (F.) were most susceptible to phenthoate and least to methyl parathion. In the field, chlorpyrifos at 0.22 kg AI/ha in 3-m deep lake fingers controlled C. utahensis (6–7 wk), and P. freemani and P. sublettei (beyond 8 wk). At 0.14 kg AI/ha in 4–5 m depths in the entire lake, chlorpyrifos yielded control of the 3 midge species for a comparable duration and extent to that achieved in fingers. The latter treatment also controlled Chironomus decorus Johannsen. Temephos, at 0.28 kg AI/ha in fingers, yielded excellent control of C. utahensis for 6 wk, but at 0.17 kg AI/ha in main lake areas, it provided mediocre control of C. utahensis and C. decorus. P. freemani and P. sublettei were not affected by temephos treatments. Diflubenzuron [1-(4-chlorophenyl)-3 (2,6-difluorobenzoyl) – urea] at 0.11 kg AI/ha in fingers inhibited emergence of C. utahensis, P. freemani, and P. sublettei for 3 wk, and at 0.22 kg AI/ha for 4–5 wk. The IGR affected C. decorus only for one wk following treatments.