Relative toxicity of imidacloprid to Aphis gossypii Glover and Amrasca biguttula biguttula Ishida infesting okra

Abstract

Investigations were carried out to evaluate the sensitivity of neonicotinoids to Aphis gossypii and Amrasca biguttula biguttula under laboratory condition at PGI, MPKV, Rahuri during the year 2012-13. Evaluated insecticides differed in their persistence and index of persistence against both insects. The persistence of insecticides was assessed by exposing known number of aphids and jassids to pretreated leaves of okra. It was revealed that recommended dose of imidacloprid (25 g a.i/ha) persisted for 21 days against both aphids and jassids. However dimethoate, a conventional insecticide persisted for 11 days.