(BF Eldridge) Abate, fenthion, and malathion were tested against Cx. tritaeniorhynchus, Cx. quinquefasciatus, and An. sinensis in both the laboratory and field in Okinawa. Abate was found to be somewhat more effective against all 3 mosquito species than fenthion, and many fold more effective than malathion. None of the insecticides were effective more than 3 weeks after treatment.