II. MATERIALS AND METHODS
The experiment was carried out at the Laboratory of Entomology, D.M. College of Science, Imphal during September to October 2012-2013. Material used and the technique employed during the course of investigation for conducting the experiments were presented here.
Insect culture
Parent stock of S. oryzae was obtained from infested
raw white rice brought from the local market of Implal- west. The adult rice weevil, S. oryzae were maintained on uninfected rice grain. 50 pairs of adult rice weevils were introduced into plastic jars containing 400g of rice. These plastic jars were then covered with muslin cloth to prevent insects escaping and to allow ventilation. After two weeks the adult were removed and left the rice medium until new adult emerged. These cultures were done under laboratory conditions at 20.6oc min, 29.3oc max temperature and 80.75% relative humidity .The cultures so maintained were used throughout the period of investigation. Preparation of native botanical powders
Fresh leaves of Melia azadarach, Perthenium hysterophorus, Phlogocanthus thyrsiflorus, Vitex trifolia, Zanthoxylum acanthopodium and Azadirachta indica were collected from the surrounding of D.M College campus. Afterward they were washed in running water. The plant materials were kept in shade for air- drying and then they were dried in the oven at 60oC to gain constant weight.