Larvicidal activity of synthetic pyrethroids against Aedes albopictus (Skuse).

Nine pyrethroids and nine of its optical and geometrical isomers were tested for insecticidal activity against fourth instar larvae of Aedes albopictus. The most active of the pyrethroids was permethrin and its (+)-trans and (+)-cis isomers. Resmethrin, RU 22725 (ethanoresmethrin), NRDC 161 and phenothrin also showed good activity. The potential of using permethrin which has good photostability as a larvicidal insecticide is discussed.