Impact of Weather Factors on Succession and Incidence of Insect Pests in Soybean Glycin max L.

Soybean Glycin max L. is economically the most important crop in the world, providing vegetable protein for millions of people and ingredients for hundred of chemical products. It is severely infested by dozen of insect pests on different plant parts throughout its growth stage. The Present study was carried out at Rajmata Vijayaraje Scindia Krishi Vishwa Vidhyalaya- Zonal Agricultural Research Station, Morena (M.P.) to find out the impact of weather factors on incidence of insect pests and their natural enemies of soybean. Eight species of the insect pests and one species of natural enemy was observed during the cropping season. The activities of Aphis gossypii, Bemisia tabaci, Empoasca kerri, Spodoptera litura, Chrysodeixis acuta, Melanagromyza sojae, Obereopsis brevis, Nezara viridula and Coccinella septempunctata was observed from the last week of July to second week of October. The population of Aphis gossypii (2.20/ Three leaves), Bemisia tabaci (1.98/ Three leaves), Empoasca kerri (3.25/ Three leaves), Spodoptera litura (8.15 larvae/mrl), Chrysodeixis acuta (3.00 larval/mrl), Melanagromyza sojae (5.20 percent), Obereopsis brevis (4.80 percent/ plant), Nezara viridula (5.35/ mrl) and Coccinella septempunctata (1.40/plant) reached peak from 31st to 35th Standard Meteorological Week. Abiotic factors was affected the population of insect pests and natural enemies. Temperature (maximum), relative humidity and rainfall were positively influence the activity Aphis gossypii, Bemisia tabaci, Empoasca kerri, Spodoptera litura, Chrysodeixis acuta, Obereopsis brevis, Nezara viridula and Coccinella septempunctata. While maximum temperature was negatively influenced the activity of Melanagromyza sojae.