Field Evaluation of Biorationals and Chemical Insecticides against Thrips parvispinus (Karny) (Thysanoptera: Thripidae), in Chrysanthemum

Abstract

Field study was conducted to evaluate the efficacy of biorationals and chemical insecticides against black thrips, Thrips parvispinus (Karny) on chrysanthemum. Thrips population ranged from 15.33 to 13.89/flower before spraying. The efficacy of seven biorationals and seven chemical insecticides were evaluated against black thrips under field conditions. The application of pongamia soap @5g/lit and Spinosad 45% SC @ 0.2 ml/lit reduced the thrips incidence significantly among the biorational and chemical insecticides respectively. The mean per reduction of thrips incidence in pongamia soap @ 5 gm/lit application was 74.90%. This was followed by neem soap @ 5g/lit (72.25%), azadirachtin @10000ppm (71.10%), Beauveria bassiana (66.76%), Isaria fumosorosea (64.93%), Lecanicillium lecanii (63.72%), and Metarhizium anisopilae (62.46%). Among the chemical insecticides Spinosad 45%SC @ 0.2 ml/lt. stood first in the order of efficacy with 80.2% reduction in thrips population. The order of efficacy of chemical insecticides against black thrips in chrysanthemum are spinetoram 11.7%SC (76.245%) > cyantraniliprole 10%OD (73.92%) > fipronil 5% SC (72.24%) > thiamethoxam 25% WG (70.79%) > dinotefuran 20% WG (69.80%) > tolfenpyrad 15% EC (68.02%). The effective biorational and chemical insecticide can be included as a component in the Integrated pest management of thrips complex in chrysanthemum. The rotation of effective compounds will reduce the resistance development against insecticides in thrips associated with chrysanthemum and also reduces the thrips infestation.