Seedlings of onion variety Agrifound Light Red were transplanted in bed size of 3.0m x 1.5m at 15cm X 10cm spacing in
a randomized block design with 4 replications. The treatments evaluated were NSKE @ 4.0%, Neem seed powder @ 6.0. %, Fipronil @ 1.5 ml/lit, Imidacloprid @ 0.3ml/lit., Spinosad @ 1.0 ml/lit. with an unsprayed plot serving as control. Identified botanical preparations and insecticides were applied at appearance of the thrips on thirty days after transplanting (DAT) and subsequently two applications were made using high volume sprayer at 15 days interval. All other agronomical practices were performed as per need in all the treatments. The crop was harvested afterattaining the maturity. The total number of thrips larvae per plant was counted visually from 10 randomly selected plants of each plot at 4 and 14 days after each spray and expressed the mean as number per plant. Adults were not recorded because they move between plots and their presence does not always reflect the efficacy of the treatment. The cost benefit ratio was also worked out and data of two consecutive years i.e. rabi 2007-08 and 2008- 09 were pooled, analyzed statistically.