%D 2003 %0 ARTICLE %T Effects of the agricultural insecticide lambda-cyhalothrin ( Warrior ) on mosquitofish ( Gambusia affinis ) . %J J Am . Mosq . Control Assoc . %V 19 ( 4 ) %P 430-2 %A Lawler SP %A Dritz DA %A Godfrey LD %M pub14710748 %X Because agricultural insecticides have potential to disrupt biological control of mosquitoes , we quantified whether an insecticide used in rice fields causes mortality of mosquitofish . Laboratory studies have shown that lambda-cyhalothrin ( Warrior ) is toxic to fish ; however , some studies report low field toxicities of pyrethroids to fish because they degrade rapidly and adsorb to soil . We tested whether Warrior kills mosquitofish under field conditions . Replicated enclosures in a rice field were either sprayed with Warrior at 5 . 8 g active ingredient/ha or were untreated . Mosquitofish were either added before the spray , or 7 days later . Of those added before the spray , none survived . Most fish added 7 days later survived .