Susceptibility of Epilachna Dodecastigma Weid. Adults to Some Modern Insecticides.

Eleven insecticides were screened under laboratory conditions against Epilachna dodecastigma Weid. (Coleoptera: Coccinellidae) attacking musk melon. On the basis of LC50 and LC90 values, phosalone, fenthion, quinalphos and phosphamidon were highly toxic (LC50 0.01 percent and LC90 0.04 percent) while trichlorfon en-dosulfan and leptophos were least toxic (LC50 0.02 percent and LC90 0.09 percent) and chlorpyrifos fenitrothion malathion were modrately toxic (LC50 0.01 but more than 0.016 and LC90 0.06 but 0.10 percent). When the persistent toxicities of field weathered residues of promising insecitcides were studied the decreasing order of merit was monocrotophos, phosphamidon, phosalone, fenthion, chlorpyrifos, fenitrothion, quinalphos and malathion.