Persistence of Early-Season Treatments for Control of Colorado Potato Beetle,Leptinotarsa decemlineata(Say), Attacking Field Tomato

Abstract

ABSTRACT The relative persistence of early-season treatments for control of Colorado potato beetle, Leptinotarsa decemlineata (Say) attacking field tomato, Lycopersicon esculentum, in southwestern Ontario, Canada, was compared by laboratory bioassay of field-collected foliage. Both mortality and feeding damage by introduced adult Colorado potato beetle (CPB) were recorded after 72 hours. Four methods of insecticide application (pre-plant foliar [PRF]); post-plant foliar [POF]; pre-plant drench [PRD]; and, planting water [PW]) were compared with commercial control programs. At an arbitrary acceptable threshold for percent mortality/damage reduction of 70%, the order of effectiveness in 1996 was: imidacloprid-PW > imidacloprid-PRD > imidacloprid-POF = cypermethrin-POF, Imidacloprid-PRF did not provide acceptable control of adult CPB. No residues of imidacloprid were detected in ripe tomato fruit following any application or in soil after fall cultivation following PRD-application. Relevance of results to po...