Toxic Effects of various Plant Extracts against the Rice Leaf Folder (Cnaphalocrosis medinalis Guenee) Pest

Abstract

Pests are responsible for global pre and post-harvest crop losses of approximately 20-50% potential production. The Rice leaf folder (Cnaphalocrosis medinalis guenee) is a predominant foliage feeder and one of the most destructive pests affecting in all the paddy field. The use of plant products or plant derived compounds as safe alternatives to Chemical insecticides in controlling insect pest. Totally 16 plants were collected from in and around Thiruvannamalai District. The fresh leaves were washed with tap water and then rinsed distilled water 10 gm of washed plant materials were taken into the morter and add 100ml of distilled water to prepare raw experimental solution. The rice leaf folder (Cnaphalocrosis medinalis guenee) were used in this experiment and collected from a paddy field in Cheyyar. In this study dealing with the anti-feedant effect of extracts was studied by leaf dip assay method. Fresh paddy leaves measuring 15cm length were dipped in the test tube. in each petridish, a total of 5 treated leaves with one leaf folder larva each petridish were taken. As the result of experiment 4 plant leaf extract is very effective in all over 16 plants. Finally, Melia azedarach, Abutilan indicum, Calotropis procera and Calotropis gigantea, showed 80-100% mortality.