Effect of orally administrated an organophosphorus insecticide (Malathion) on the sex ratio of Pimpla turionellae L.

In this study, the effects of 0.001, 0.010, 0.100, 0.500 and 1.000 ppm concentrations of malathion, an organophosphorus insecticide, on the sex ratio of Pimpla turionellae L. were investigated. None of the malathion concentrations which was examined did not negative effect on the total adult emergence. Diets which was contain 0.001, 0.010 and 1.000 ppm malathion significantly increased the total adult emergence. Although 0.010 and 0.100 ppm malathion increased the female emergence, higher concentrations of malathion (0.500 and 1.000 ppm) significantly decreased the female emergence. The 51.86 % female emergence rate in the control group decreased to 27.64% by decreasing to a rate of 46.68% in the group which was fed with the nutrition containing 1.000 ppm malathion. On the other hand, the most significant difference in the male emergence rate was observed in the group fed with nutrition containing 1.000 ppm malathion. The 48.16% male emergence rate in the control group increased to 72.36% by increasing to rate 50.23% in the group which was fed with the nutrition containing 1.000 ppm malathion. Key Words: Pimpla turionellae, Insecticide, Malathion, Sex ratio