Evaluation of Some Microbial Pesticides Against Apple Stem Borer, Aeolesthes Sp. in Himachal Pradesh

Abstract

Apple stem borer, Aeolesthes sp. is a serious pest in apple orchards in Himachal Pradesh. For its suppression, microbial biopesticides viz., Beauveria bassiana, Beauveria brongniarti, Metarhizium anisopliae (5 x 107 conidia/gallery), Steinernema feltiae, Heterorhabditis bacteriophora (5000 infective juveniles (IJ)/ live gallery) and econeem plus (having 1% azadirachtin @ 0.5%) were evaluated. The experiment was conducted for two years during 2007-08 and 2008-09 at Temperate Horticulture Research station, Kotkhai, District Shimla. These biopesticides were compared with the recommended insecticides,dichlorvos (0.1%) and chlorpyriphos (0.04%) and control (emulsified water, 0.02%). Before applying the treatments, all the holes except one present in each branch were plugged with mud paste.The leftover hole was then cleared with the help of flexible aluminium wire and the treatment was given with the help of syringe. Thereafter, the leftover hole was also plugged with mud paste.To calculate percent mortality, the larvae which opened any of the holes in the branch or made new hole to push out the excreta were considered as live and those which remained closed throughout as dead. In this experiment, B. bassiana, B. brongniartii, M. anisopliae, H. bacteriophora, S. feltiae, econeem, chlorpyriphos, dichlorvos and control resulted in 33.3, 66.7, 37.5, 80, 20, 100, 100, 100 and 40 percent mortality during 2007-08 and 33.3, 33.3, 66.7, 33.3, 33.3, 66.7, 100, 100 and 0.00 per cent mortality during 2008-09 respectively. Among different biopesticides, M. anisopliae, B. brongniartii and cconeem plus were the best treatments resulting in 66.7 and 100 per cent mortality of stem borer larvae.