Biometrics and Reproductive Behaviour of Meteorus spilosomae Narendran and Rema, an Important Parasitoid of Spilosoma obliqua Walker (Lepidoptera: Arctiidae), a Pest of Mulberry

The biology and morphometrics of Meteorus spilosomae Narendran and Rema (Hymenoptera: Braconidae), a solitary larval endoparasitoid of Bihar hairy caterpillar, Spilosoma obliqua Walker (Lepidoptera: Arctiidae) were studied under laboratory conditions. The life cycle comprised of egg, three larval instars, pupa and an adult stage. The average duration of the life cycle was 33.73 days at 19 ± 1°C, 70-75% RH; 23.73 days at 24 ± 1°C, 75-90% RH and 20.21 days at 29 ± 1°C, 70-85% RH. Males are polygamous and females are monandrous. M. spilosomae is an arrhenotokous species. The total number of eggs laid ranged from 153 to 270, with an average of 213 ± 53.42. Sex ratio is female-biased, and male to female sex ratio was 1: 1.22 at 19 ± 1°C, 1: 1.24 at 24 ± 1°C and 1: 1.38 at 29 ± 1°C. The average number of female progeny was higher than males from the 1st to 7th day at 29 ± 1°C. On the 8th day, only female progeny emerged. Among the various food evaluated, the average longevity of mated males and females was highest when fed on 50% sucrose (19.6 and 29.7 days, respectively), while with no food the longevity was 1.8 and 2.2 days, respectively.