Efficacy of cypermethrin for the control of mosquito larvae and pupae, and impact on non-target organisms, including fish.
In laboratory tests, cypermethrin was highly toxic to mosquito larvae and pupae. It was more toxic at low temperatures after a 24 hr exposure. Larvae of Aedes stimulans were less susceptible than Culex restuans. Technical cypermethrin was more toxic than an emulsifiable concentrate formulation. In outdoor simulated pools cypermethrin 40% EC was consistently effective against larvae and pupae of Ae. stimulans at 10 g AI/ha and Culex spp. at 50 g AI/ha. When stickleback fish were tested, no mortality occurred at the lowest effective dosage in each trial. The residual toxicity of cypermethrin increased with dosage and was much higher in a test at 8 degrees C than at 20 degrees C. In natural snowmelt pools, cypermethrin at 20 g AI/ha provided 92-100% control of Aedes spp. larvae and pupae by 7 days after treatment. Non-target amphipod, anostracan, cladoceran and insect populations were usually reduced 80-100% while copepods, ostracods and hydracarinid mites were generally less affected. No significant mortality of caged stickleback fish occurred in these pools.
Helson
B V
BV
Department of Environmental Biology, University of Guelph, Ontario, Canada.
Surgeoner
G A
GA
D000818:Animals; D001517:Coleoptera / Q000187:drug effects; D003445:Crustacea / Q000187:drug effects; D009033:Culicidae; D004175:Diptera / Q000187:drug effects; D005399:Fishes; D007306:Insecticides; D007814:Larva; D009032:Mosquito Control; D011679:Pupa; D011722:Pyrethrins / Q000633:toxicity; D000002:Temefos / Q000633:toxicity
D007306:Insecticides; D011722:Pyrethrins; C017160:cypermethrin; D000002:Temefos