author(s)
Kunal Bhattacharyya, Ayan Das, Bimal Mondal, Mainak Bhattacharyya and LN Mohapatra

abstract
Experiments on the seasonal incidence of some sucking pests in cotton and their correlation with abiotic factors was conducted at the Central Research Farm, Orissa University of Agriculture and Technology, Bhubaneswar during kharif 2016. Various sucking insects recorded on cotton during the period of study were leaf hopper, Amrasca biguttula biguttula Ishida., aphid, Aphis gossypii Glover., whitefly, Bemisia tabaci Gennadius. and mealybug, Phenacoccus solenopsis Tinsley. Among the sucking pests leaf hopper was found to be the dominant pest and its peak population (4.70 nos/leaf) was observed during 39^th SW (Sep.24-30). Maximum activity of whitefly (4.50 nos/leaf) and aphid (11.58/leaf) was observed during 39^th SW (Sep.24-30) and 34^th SW (Aug. 20-26), respectively. Mealybug was active from the 30^th SW (July 23-29) to 52^nd SW (Dec. 24-31) with highest incidence during 47^th SW (Nov.19-25) with 26.35 per cent branch infestation. Among the natural enemies, various predators viz., ladybird beetle, Menochilus sexmaculata Fabricius., green lacewing, Chrysoperla carnea Stephens and one species of spider were recorded during the period of study. Peak activity of ladybird beetle (2.75/plant) and spider (2.68/plant) was recorded during 39^th SW (Sept. 24-30). The other predator green lacewing was active throughout the crop growth period with its peak occurrence 1.30/plant during 41^st SW (Oct. 8-14). The abiotic factors such as maximum temperature, minimum temperature, evening relative humidity and rainfall had a positive effect on the leafhopper, whitefly and aphid population. Mealybug incidence showed negative correlation with minimum temperature, evening relative humidity and rainfall.