Permethrin, pyrethrin, resmethrin and malathion were tested as ULV ground aerosols against caged, field collected Anopheles quadrimaculatus and Culex quinquefasciatus. Pyrethrin-malathion, resmethrin malathion (91%) mixtures were also tested. The synthetic pyrethroids alone were more effective at 1 hr posttreatment than any mixture or malathion alone.