Toxicity of newly synthesized pyrethroids against the yellow fever mosquito larvae, Aedes aegypti (Diptera: Culicidae).

Synthesis of p-substituted benzyl esters of (+/-) cis 2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropane-carboxylic acid has been reported. (+/-) cis Dichlorovinyl acid esters of p-substituted phenols acquired insecticidal activity after introduction of methylene group. The insecticidal activity shown against mosquito larvae A. aegypti by compounds having electron withdrawing groups such as -NO2, -CN was substantially higher than that of the compounds having electron-donating groups such as -CH3, -OCH3.