Abstract
In recent years, numerous natural or manmade lentic and lotic habitats in urban and suburban areas exposed to intensive human use (residential, recreational, agricultural, etc.) in different parts of the world are becoming increasingly eutrophic, resulting in thee survival and profuse breeding of more pollution-tolerant organisms, such as midges. Methoprene may have good potential for midge control, particularly against organophosphate-resistant midges, but until recently there has been little interest by the industry to develop insect growth regulator (IGR) for midge control. Methoprene, in 3 solid (Altosid Pellet, Altosid XR Briquet and a granular) and a liquid formulation (A.L.L.) was evaluated against chironomid midges in experimental ponds. The A.L.L. was applied at 0.293 L/ha (0.015 kg AI/ha) and at 5.86 L/ha (0.28 kg AI/ha). The granules, pellets and briquets were applied at 13 kg/ha (0.17 kg AI/ha), 5.6 kg/ha (0.22 kg AI/ha) and one briquet/8 sq m (0.82 kg AI/ha), respectively. The low rate of A.L.L. was ineffective, but the high rate produced 84 to 100% control of Tanytarsini and 30 to 100% of Chironomini during 2 wk posttreatment. Altosid pellets gave initial and prolonged good control of Tanytarsini (64 to 99% for 7 wks), Chironomini (79 to 94% for 5 wks) and total midges (64 to 98% for 7 wks). The briquets at almost four times the rate of pellets, yielded 38 to 98% control of midges for 7 week posttreatment. Altosid pellets have an excellent potential for midge control. (Author's abstract)