Efficacy of Synthetic Insecticides against sucking insect pests in cotton, Gossypium hirsutum L.
Sathyan T, Murugesan N , Elanchezhyan K, Arockia Stephen Raj J, Ravi G
A field experiment was conducted to evaluate synthetic insecticides against the sucking insect pest’s viz., leafhopper, aphid, whitefly and thrips of cotton at Agricultural College and Research Institute, Killikulam, Tuticorin District, Tamil Nadu, using cotton variety SVPR 2 during 2014 - 2015. The incidence of leafhopper, A. devastans on the plants treated with synthetic insecticides ranged from 1.30 (Diafenthiuron 50 WP) to 13.45 (Quinalphos 25 EC) numbers per three leaves. The insecticidal sprays reduced the aphid population from 20 (Flubendiamide 20 WG) to cent per cent (Diafenthiuron 50 WP, imidacloprid 17.8 SL, thiamethoxam 25 WG, triazophos 40 EC, carbosulfan 25 EC and chlorpyriphos 20 EC) over untreated check. Fipronil 5 SC was the most effective insecticide (3.15/3 leaves) with 83.06 per cent reduction in thrips population compared to the mean of untreated check (18.60/3 leaves). The incidence of whitefly, B. tabaci on the plants treated with synthetic insecticides ranged from 0.40 (Fipronil 5 SC) to 6.40 (Phosalone 35 EC) numbers per three leaves.