Effect of temperature on the development of two pupal parasitoid species of Xanthopimpla Saussure (Hymenoptera: Ichneumonidae) on Sesamia inferens Walker

The biology of two pimplini parasitoids viz., Xanthopimpla flavolineata and X. stemmator were investigated in the laboratory by using the pupae of Sesamia inferens Walker. The host insect pupae were collected from the field and maintained in the laboratory for rearing the pimplini parasitoids. The results showed that the developmental period of X. flavolineata was 33.87 ± 0.18 and 18.54 ± 0.15 days, and X. stemmator was 36.08 ± 0.16 and 18.95 ± 0.19 days under 20°C and 28°C, respectively. The morphometric studies of two pimplini parasitoids showed that X. stemmator was larger than X. flavolineata in all the life stages. The longevity of X. flavolineata males and females was 21.09 ± 0.14 days for males and 34.53 ± 0.26 days for females when fed with 50 per cent honey at 20°C., while X. stemmator males and females survived for 26.94 ± 0.22 days and 38.90 ± 0.25 days. At 28°C, the lifespan of X. flavolineata male and female was 16.17 ± 0.09 and 26.55 ± 0.13 days, respectively, while in X. stemmator, it was 17.47 ± 0.16 and 27.08 ± 0.17 days in male and female, respectively, when fed with 50 per cent honey. Thus, females lived longer than males when fed with honey (50%) solution as a food source followed by sucrose (50%). From the results, it is concluded that the temperature and developmental period are inversely proportional and these details can be integrated into the development of a standardized mass-production technique for both parasitoids.