Structure-activity relationships of phosphorus amides in Aedes aegypti and Culex pipiens fatigans (Diptera: Culicidae).

Larval and pupal stages of Aedes aegypti (L.) and Gulex pipiens fatigans Wiedemann were treated with 42 amides of phosphoric or phosphorothioic acid, and the toxic and sterilizing effects of the compounds were evaluated in adults. Structure-activity correlations indicated both species of mosquitoes were similarily susceptible to these compounds, but in both species the sulfur compounds were more toxic to larvae than to pupae. Sterilizing effects varied with the structure of the compounds: in larvae, highly methylated amides were often more effective than the less methylated analogs, but no similar relationship was evident in the pupae. Both sexes were affected by the most effective compounds, but males were more susceptible than females. Selected phosphorus amides may have promise for sterilization of A. aegypti larvae.