Effects of Biological Insecticides on Predatory Spider’s Population in Rice Field

Copyright © 2015 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT: The study was conducted to compare the effects of different biological insecticides: extracts of Azadirachta indica and Eucalyptus globulus, and Spinosad on spider’s population in a rice field at an agricultural farm in tehsil Daska of district Sialkot-51310, Pakistan. Spiders, as natural enemies play an important role in keeping pest population under control by not only feeding on pests but also limiting the availability of habitats open to pests by occupying various microhabitats in an agricultural ecosystem. The experiment was laid in randomized complete block design (RCBD) with three replicates. Biological insecticides including two botanical (extracts of Azadirachta indica and Eucalyptus globulus) and one microbial (Spinosad) were applied to the rice crop. The spider’s population was counted after one, three and seven days from insecticide application. After one day from insecticide application, the reduction in spider’s population was 42.18%, 36.68 % and 33.38% with Spinosad, A. indica (20 % conc.) and E. globolus (20 % conc.) respectively. The trend of reduction of spider’s population decreased with time from one to seven days. Spider’s population showed significantly higher resistance to botanical than microbial insecticide