Activity of new formulations of methoprene against midges (Diptera: Chironomidae) in experimental ponds

The IGR, 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 liters/ha (0.015 kg AI/ha) and at 5.86 liters/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/8m2 (0.82 kg AI/ha), respectively. The low rate of A.L.L. was ineffective, but the high rate produced 84-100% control of Tanytarsini and 30-100% of Chironomini during 2 wk posttreatment. The granular formulation gave 61-87% control of total midges in 2 wk posttreatment. Altosid Pellets gave initial and prolonged good control of Tanytarsini (64-99% for 7 wk), Chironomini (79-94% for 5 wk) and total midges (64-98% for 7 wk). The briquets at almost 4x the rate of pellets, yielded 38-98% control of midges for 7 wk posttreatment. Altosid Pellets have an excellent potential for midge control.