Role of temperature and hosts ( Sitotroga cereallela and Corcyra cephalonica ) egg age on the quality production of Trichogramma chilonis

摘要

The present study was conducted for efficient and quality production of the stingless wasp, Trichogramma chilonis Ishii with respect to rearing temperature and host egg age of the angoumois grain moth, Sitotroga cereallela (Olivier) and the rice meal moth, Corcyra cephalonica (Stainton) on its biology. Maximum parasitism was observed 95.7 and 84.3% at 28 °C, while minimum parasitism was 61.3 and 39.6% at 32 °C on S. cereallela and C. cephalonica eggs, respectively. The most favorable temperature was 28 oC on which maximum parasitism and adult emergence were obtained from S. cereallela eggs. Maximum parasitism was observed 97.4 and 79.4% in 2 h old, while minimum parasitism was 24.6 and 17.3% in 72 h old eggs of S. cereallela and C. cephalonica eggs, respectively. Parasitism by T. chilonis decreased with increasing host eggs age. Maximum adult T. chilonis emergence was 98.2% in 2 h old eggs, while minimum emergence was 21.5% on 72 h old eggs of S. cereallela. Adult T. chilonis longevity on the host eggs of different ages of female wasp was non-significantly different to each other except the 2 and 12 h old eggs which were significantly different from rest of the treatments in both hosts’ eggs of different ages. Maximum female longevity was 4.0 d on 2 h fresh eggs C. cephalonica, while minimum was 3.0 d on 24–48 h old S. cereallela eggs. The female ratio for different host eggs age was almost non-significant to each other except 2 h old eggs with maximum number of female (64). The results showed that T. chilonis preferred young eggs when offered older eggs, simultaneously.