Biological control of key pest of jute, Spilosoma obliqua Walker (Lepidoptera: Arctiidae) - A case study

Surveys were conducted in intensive jute growing areas of West Bengal to collect information on natural enemies and other entomopathogens infecting jute hairy caterpillar Spilosoma obliqua (Lepidoptera: Arctiidae). The jute crop supports large number natural enemies of S. obliqua and entomopathogens. Among the braconid larval parasitoids, Meteorus spilosomae (Hymenoptera: Braconidae) and Protapantales obliquae (Hymenoptera: Braconidae) were the key mortality factors. The activity of these parasitoids was noticed from mid- May to mid-July during the cropping season. The parasitoid, P. obliquae is a gregarious, endoparasitoid specific to S. obliqua and parasitize to the extent of 38% up to third instar of larvae whereas M. spilosomae reported to cause up to 77% of parasitisation on S. obliqua under field condition. Bacillus thuringiensis and nuclear polyhedrosis virus were found be very effective with mortality of, 64 and 93% respectively. These parasitoids and pathogens can be used as potential bio-control agents against jute hairy caterpillar through conservation, augmentation and mass multiplication.