Seasonal incidence of insect pests on soybean in relation to weather parameters

An experiment was carried out at ICAR Entomology Farm at Umaim, Meghalaya in kharif season during 2011with the aim to study seasonal incidence of insect pests on soybean (Glycine max (L.) Merrill).Six insects species, viz., stem fly (Ophiomyiaphaseoli Tryon), soybean leaf folder (NacoleiavulgalisGuen.), white spotted flea beetle (MonoleptasignataOliv.), jassids (EmpoascakerriPurthi), aphids (Aphis glycines Matsumura) and southern green stink bug (Nezaraviridula Linn.) were recorded. Among them stem fly and soybean leaf folder were found to be major pests.The population level of these insect pests was fully observed during 2nd week after sowing with a peak during July and August. Correlation studies indicated that only stem fly and soybean leaf folder were significantly correlated with abiotic factors viz., the minimum temperature and rainfall that favoured the development of stem fly whereas sunshine hours for the leaf folder.