Relative Toxicity of Some Modern Insecticides against the Pink Bollworm, Pectinophora Gossypiella (saunders) and Their Residues Effects on Some Natural Enemies

Toxicity of three modern insecticides (chlorantraniliprole, thiamethoxam and spinetoram) was examined against the first instar larvae of Pectinophora gossypiella (Saunders). The field rate and other two concentrations were used. The results showed that thiamethoxam was the most effective insecticide followed by chlorantraniliprole and spinetoram. The LC50,s were 8.9, 13.9 and 19 ppm for thiamethoxam, chlorantraniliprole and spinetoram, respectively. The residual effect of these insecticides was tested against some natural enemies such as green lacewing, Chrysoperla carnea, seven-spotted ladybug, Coccinella septempunctata and trichogramma wasps, Trichogramma evanescens. The results showed that all tested insecticides were less toxic to the second instar larvae of C. carnea larvae. The percent of mortality with the highest concentrations ranged from 40 to 43.3%. Thiamethoxam and chlorantraniliprole were most toxic to the second instar larvae of C. septempunctata. Spinetoram was the most toxic against the larvae of T. evanescens. The results recommended that chlorantraniliprole was the most suitable insecticides for control of pink bollworm larvae and less toxic to C. carnea and T. evanescens larvae. So, it can be used when the population density of C. carnea and T. evanescens larvae in peak safely. Spinetoram can be used against the pink bollworm larvae during the C. septempunctata population in peak safely.