Abstract: Effect of temperature (20, 25 and 30°C) and photoperiod (12:12, 14:10 and 16:8 h L:D) were studied separately on Trichogramma chilonis Ishii. As the temperature increased from 20 to 30°C, fecundity increased but longevity decreased. The maximum fecundity (12.73±1.01 eggs/female/day) and adult emergence was observed at 30°C. However, the least longevity of females (6.73±0.53 days) was observed also at 30°C and the maximum (10.08±1.21) was at 20°C, which was significantly higher compared with that at 25 and 30°C. Similarly, at 14:10 h L:D fecundity (9.92±0.13 eggs/female/day) and adult emergence was significantly higher compared with 12:12 and 16:8 h L:D photoperiod regimes. There was no significant differences among different photoperiod regimes tested with respect to longevity, though it was higher at 16:8 h L:D.