Biology of Spilosoma obliqua Walker and seasonal incidence of soybean pests

摘要

Soybean is important oilseed and pulse crop. It contains20% edible oil and 40% protein. It also helps inmaintaining soil fertility and fixes atmospheric nitrogen.Due to its proteineous nature and introduction of highyielding varieties, many of the pests started attacking andcausing immerse damage to the soybean crop resultingreduction in yield. Considering the extent of damagecaused by different pests, several workers found thelosses in the yield of soybean to the extent of 37% andinfestation to tune of 5 to 78% (Singh et al., 1990). Amongvarious pests of soybean, Spilosoma obliqua Walker is themost important pest. Infestation of S. obliqua during initialpodding of late sown crop resulted in yield losses of about80%, whereas, infestation at an advanced stage resultedin satisfactory seed development, but a reduction in seedsize by about 40 % (Ram ef al., 1989). Keeping this inview, the present study was undertaken to study thebiology of S. obliqua and the seasonal incidence ofdifferent soybean pests by correcting them with differentecological conditions so that appropriate control measurescan be taken during the right period of time was studied.