author(s)
Subhashree Priyadarshini, Soumita Pal and Sunil Kumar Ghosh

abstract
Screening of chilli varieties against thrips, population dynamics of thrips (Scirtothrips dorsalis Hood) and their sustainable management by using some new molecules were worked out in the present study during 2016 at District Seed Farm (AB Block) of Bidhan Chandra Krishi Viswavidyalaya located at Kalyani, Nadia, West Bengal. The mean population of thrips was recorded to be lowest in Bhanger variety i.e. 2.13 thrips/ three leaves followed by Bullet and Jhumko with mean as (2.71 and 2.87 thrips/ three leaves) respectively. Peak population of thrips was recorded to be in 18th standard week i.e. 12.58/three leaves when the average temperature, relative humidity and weekly total rainfall were 31.2 0c, 66.79% and 17.8 mm respectively. Correlation studies between thrips population and weather parameters revealed that population of thrips showed significant positive correlation with average temperature, maximum and minimum temperature and a significant negative correlation with maximum relative humidity while non-significant positive correlation with temperature difference and non-significant negative correlation with relative humidity (minimum and average) and weekly rainfall. Peak population was recorded to be 28.55/three leaves, when the average temperature, relative humidity and weekly total rainfall were recorded to be 31.040C, 74.29% and 71.1mm respectively. The treatment Imidacloprid 17.8% SL @ 25 a.i. g/ha was rendering satisfactory result against chilli thrips.