STUDIES TO DETERMINE WAITING PERIODS FOR FEEDING TREATED LEAVES WITH COMMERCIAL INSECTICIDES TO TASAR SILKWORM LARVAE, ANTHERAEA MYLITTA D.
RAM KISHORE, RAKESH GUPTA
CENTRAL TASAR RESEARCH AND TRAINING INSTITUTE, RANCHI - 835303, INDIA.
B.C. PRASAD
CENTRAL TASAR RESEARCH AND TRAINING INSTITUTE, RANCHI - 835303, INDIA.
B.R.R. PRASAD SINHA
CENTRAL TASAR RESEARCH AND TRAINING INSTITUTE, RANCHI - 835303, INDIA.
*Author to whom correspondence should be addressed.
Abstract
Insecticides are widely used for the control of insect pests of field crops, However, their extensive use posses certain problems to non-target organism which includes beneficial insects. To determine the waiting periods of insecticides three concentrations of each of the chemical insecticides viz. endosulfan, quinalphos, monocrotophos, malathion, dichlorvos, dimethoate, methyl-parathion, cypermethrin and fenvalrate were applied individually to different bushes of Tasar food plants. Mortality of silkworm larvae was recorded by feeding treated tasar leaves. The results indicate that persistence toxicity of various insecticides tested ranged betvc!en 5-23 days. Application of 0.0P/0 concentration of Dichlorvos, Endosul fan, Quinalphos, Malathion, Dimethoate and Methyl-Parathion resulted in minimum persistence while toxicity persisted for a maximum duration when applied with 0.10% concentration of cypermethrin and fenvalrate.