EVALUATION OF THE TOXICITY OF O, O-DIETHYL-THIONO PHOSPHORIC ACID O [QUINOXALYL (2)] -ESTER (SANDOZ INSECTICIDE-6538) TO INSECT PESTS - P GOPINATHAN NAIR; M R G K NAIR (AGRICULTURAL COLLEGE AND RESEARCH INSTITUTE VELLAYANI DIVISION OF ENTOMOLOGY, 1970)