Evaluation of insecticide efficacy, safety and economics for managing chilli thrips, Scirtothrips dorsalis (Hood) (Thysanoptera: Thripidae)

Abstract

The present investigation was conducted during 2021 and 2022 at the Department of Entomology, Dr. YS Parmar University of Horticulture and Forestry, Nauni, Solan, to evaluate the bioefficacy of five insecticides against chilli thrips, Scirtothrips dorsalis, and their effects on coccinellid populations. The efficacy of the insecticides was assessed based on thrips incidence, abundance of coccinellids (immature and adult stages), and marketable fruit yield in treated and untreated (control) plots. The results revealed that cyantraniliprole 10.26% OD applied at 60 and 120 g a.i./ha provided the highest suppression of thrips, followed by imidacloprid 17.8% SL at 25 and 50 g a.i./ha. Moderate efficacy was recorded with spirotetramat 15.31% OD (60 and 120 g a.i./ha) and fenazaquin 10% EC (125 and 250 g a.i./ha), whereas flubendiamide 20% WG (50 and 100 g a.i./ha) was the least effective against S. dorsalis. The highest coccinellid populations were recorded in plots treated with flubendiamide and cyantraniliprole, while the lowest populations occurred in imidacloprid-treated plots, indicating its comparatively greater adverse effect on these beneficial insects. Cyantraniliprole applied at 60 and 120 g a.i./ha also produced the highest marketable yield during both cropping seasons. Overall, cyantraniliprole demonstrated superior efficacy against chilli thrips while exerting relatively lower adverse effects on coccinellids, making it a promising option for sustainable chilli pest management.