Comparative sensitivity of larval mosquitoes to vegetable polyphenols versus conventional insecticides

The larvicidal effects of polyphenols of natural crude decomposed alder lea f litter and commercially available tannic acid were experimentally compare d with those of two common conventional insecticides (Bacillus thuringiensi s ssp. israelensis: microbial insecticide; temephos: organophosphate insect icide). Comparative standard bioassays using third instar larval Aedes aegy pti, A. albopictus, Culex pipiens and Coquillettidia richiardii as referenc es indicated that Aedes and Culex taxa are far more sensitive to alder leaf litter than to tannic acid and conventional insecticides. C. richiardii is far more resistant to conventional insecticides than Aedes and Culex taxa, but its sensitivity to tannic acid is close to that of those taxa. Dietary vegetable polyphenols are thus proposed as new, practical, alternative che micals for mosquito control when conventional insecticides are difficult an d costly to be used (e.g., in the management of Aedes and Culex populations in man-made breeding sites and Coquillettidia control strategy).