Calocalpe undulata Contact Toxicity of Ten Insecticides to the Larvae1

Ten insecticides were tested against larvae of Calocalpe undulata (L.). The decreasing order of toxicity at LD50 was: bioethanomethrin, phenothrin, pyrethrins, phoxim, tetrachlorvinfos, mexacarbate, carbaryl, phosmet, DDT, and malathion. At LD90, the decreasing order of toxicity was the same, except that phoxim and tetrachlorvinfos switched positions. Malathion was not toxic at the highest dose level tested (500 μg/g body weight). When the response of C. undulata was compared with that of 4 other forest geometrid species, the data showed that pyrethroids were always the most toxic candidates whereas malathion was always the least toxic.