Response of Liriomyza trifolii (Diptera: Agromyzidae) Larvae to Insecticides, with Notes About Efficacy Testing

Abstract

Efficacy of 12 insecticides against first- and third-stage larvae of Liriomyza trifolii (Burgess) was determined in the greenhouse. With use of larval emergence and pupariation as the criteria for efficacy, most insecticides provided greater mortality of first-stage larvae. The exception was chlorpyrifos 25W, which was more efficacious against third-stage larvae. When adult emergence from pupae was used as a measure of efficacy, most insecticides provided better control of third-stage larvae than of first-stage larvae. The latter method, adult emergence, should be employed as the criterion for evaluating insecticides against third-stage larvae. The four insecticides providing the greatest mortality of the two larval age classes (first and third stage) were: SD 52618 85W [4H-1,3-thiazine,5,6-dihydro-2-(acinitromethyl)]; methamidophos 4E; methyl parathion 2E (microencapsulated) + permethrin 3.2E; and methyl parathion 2E (microencapsulated.)