Genetic Improvement in an Egg Parasitoid T. chilonis for Tolerance to Pesticides

Bioassay tests in the laboratory were conducted to study the susceptibility of adult T. chilonis to different concentrations of endosulfan. The newly emerged F₁ progeny were subjected to increased concentration of endosulfan. It was found that after the treatment of adult T. chilonis with endosulfan for 15 generations, the LC₅₀ values of endosulfan increased by 13.27% from 0.0437% of base colony (susceptible) to 0.0495% of selected F₁₅ colony (tolerant). To study the mode of inheritance, the programme of back crossing was undertaken. LC₅₀ values of back cross progeny obtained was 0.0476% which was intermediate between susceptible (S) colony (LC₅₀ 0.0437%) and F₁₅ selected (R) colony (LC₅₀ 0.0495%) indicating that the gene for endosulfan tolerance is completely dominant.