Population growth potential of Bracon brevicornis Wesmael (Braconidae: Hymenoptera): A life table analysis

摘要

A laboratory experiment was conducted at the Biocontrol laboratory, Coconut Research Station, Aliyarnagar to study the life table parameters of Bracon brevicornis Wesmael, a parasitoid of the coconut blackheaded caterpillar, Opisina arenosella Walker on its established laboratory host, Corcyra cephalonica Stainton. Studies at 28.3±0.1 °C and 59.6±0.6% r.h. revealed that the net reproductive rate (R) of B. brevicornis was 39.52 females/female when reared on C. cephalonica larvae. The precise generation time (T) was 13.33 days. The intrinsic rate of natural increase (r) was 0.2758 which was slightly higher than the innate capacity for increase (r=0.2504). The weekly multiplication rate was 6.893 numbers while 1561.83 females could be expected in the F generation. Higher net reproductive rate, coupled with shorter population doubling time of B. brevicornis indicate the efficacy of the parasitoid as a suitable candidate for the management of coconut black headed caterpillar, O. arenosella, its intended host under field conditions.