Herbal Preparations Of Ageratum Conyzoides And Nerium Indicum As Potential Insecticides Against Henosepilachna Vigintioctopunctata, A Polyphagous Pest Of Brinjal

Abstract

In the present study, solvent guided leaf extracts of Ageratum conyzoides (Goat weed) and Nerium indicum (Pink kaner) were evaluated on the Ist instar larvae of Epilachna 28 punctata Fab. to observe its growth inhibition, larval mortality, developmental period and adult emergence. 1% leaves extracts of both A. conyzoides and N. indicum showed 100 and 93.3±3.3% larval mortality respectively till emergence. Whereas 0.2 and 0.1% of A. conyzoides extract had shown only 33.3±6.7% larval mortality and that of N. indicum extract exhibited only 22.2±2.6 and 16.7±6.7% mortality when compared to control (13.9±4.6%). The leaf extract of A. conyzoides at 0.5% significantly increased the total developmental period (27.4±1.4 days) in contrast to control (22.8±1.3 days) and reduced adult emergence (40±5.2%). The LC₅₀ values of both the extracts had also been determined. During the development of hadda beetle, diapause condition and deformed adults were also noticed.