author(s)
Parul Suyal, Neeta Gaur, Rukesh Pramod KN and Ashish Devrani

abstract
Investigation was carried out during Kharif, 2017 at GB Pant University of Agriculture & Technology, Pantnagar, India to study seasonal incidence of insect pests and their natural enemies on soybean crop. The density of defoliators i.e. Spodoptera litura and Spilosoma obliqua increased gradually to a peak of 12.5 and 3.9 larva/meter row length during the last week of August and Thysanoplusia orichalcea with 6.1 larva/mrl during first week of September and exhibit positive correlation with maximum temperature and RH%. The peak density of sucking pest (Bemisia tabaci and Aphis gossypii) was observed during mid of August and exhibit positive correlation with maximum temperature, RH% and evaporation. Stem fly infestation persisted till maturity of the crop. Natural enemies i.e. Coccinella septumpunctata and Eocanthecona furcellata occurred during third week of August. Results revealed that temperature, relative humidity and evaporation act as limiting factor for population buildup of insect pests in soybean ecosystem.