Comparing the Efficacy of spirotetramat (SC 100) with Regular Insecticides against Onion Thrips, Thrips tabaci Lindeman

Onion thrips, Thrips tabaci is a key pest of onion in Iran. Several spraying per season are applied against it. Therefore, replacing regular pesticides with more efficient and low-risk ones is necessary. In this study, the efficacy of insecticides against onion thrips was studied in two provinces (Esfahan and Markazi). The study was conducted in a completely randomized block design with six treatments including Cypermethrin® EC 40% (0.5L per 1000L), Dichlorvos® EC 50% (2L per 1000L), Malathion® EC 57% (1. L per 1000L), a new insecticide, spirotetramat “Movento® SC 100” (0.72L per 1000L and 0.60L per100 L) and control, in four replications. Sampling was done one day before treatment, 3, 7 and 14 days after treatment. Number of thrips per 10 plants per plot was recorded and efficacy of the treatments was calculated using Henderson- Tilton formula. Data were subjected to analysis of variance, followed by Duncan test. Damage indices were compared using Kruskal-Wallis non-parametric test. Efficacy of the treatments were different in Esfahan; Movento (0.72 L/1000L) had the highest efficacy in three sampling dates after spraying 95%, 95% and 83% respectively); it was followed by Movento (0.60 L/1000 L) (88%, 88% and 79%). The efficacy of Dichlorvos, three days after the treatment (88%), was close to the efficacy of Movento. Damage index for Movento, seven days after the treatment, was the lowest. In Markazi, the efficacy of Movento was the highest, while no significant differences were detected among the treatments. In summary, the new insecticide spirotetramat (Movento® SC 10%), at a rate of 0.60 L /1000 L, had an acceptable control rate against onion thrips.