In vitro evaluation of biorationals and their mixed compounds against the melon aphid Aphis gossypii Glover

Abstract

In recent days sucking pests are getting more attention due to their efficiency to withstand the chemical pesticides by various mechanisms like resistance and resurgence. Usage of chemical pesticides can be reduced by using the biorational pesticides. Biorationals are any type of insecticides active against pest populations, but relatively innocuous to non target organisms and therefore, helpful in biological control. Here some of the biorationals and their mixers are tested against aphids (Aphis gossypii Glover) under laboratory condition in order to find the best biorational pesticide and their combination which leads maximum mortality of aphids and could serve as a better alternative for the chemical pesticides. Four botanicals {Neem seed kernel extract (NSKE), Pongamia seed extract (PSE), Custard apple seed extract (CASE) and Asafoetida}, two entomopathogenic fungi (Beauvaria bassiana and Lecaenicillium lecanii), one organic oil product {Agricultural spray oil (ASO) @ 2ml/l} and five combinations of them has been tried. Among the combinations tested, Agricultural spray oil + Custard apple seed extract + Pongamia seed extract + Neem seed kernel extract (2:1:2:2) @5% has given higher cumulative mortality (100%) after 72 hrs of treatment. And the most efficient entomopathonenic fungus against A. gossypii was Lecaenicillium lecanii IOF 1 strain which gave the mortality percent of 83.40. The steps, results and the future aspects of the study are discussed briefly in this paper.