Onion is considered as one of the most important vegetable crops produced on large scale in Ethiopia. Onion thrips, Thrips tabaci is a pest of economically important crops of onion (Allium cepa) and causes significant yield loss globally. The present study was aimed to evaluate the efficacy of insecticides for the control of Thrips tabaci on yield and yield component of onion. The experiment was laid out as a randomized complete block design with four replications. The study was conducted on farmer’s fields at three districts of West Shoa Zone, Oromia Regional state, Ethiopia during October 2018 to March 2019. The Experiment was conducted on farmers’ field at two different districts of West Shoa Zone, Oromia Regional state, Ethiopia, such as Ambo and Toke Kutaye districts. After the infestation of thrips pre and post spray and yield parameters were taken. The tested insecticides caused mortality of onion thrips at various degrees of significance over untreated control. The result of the research revealed that the Sivanto Energy EC 85 at rate of 1200ml ha-1 gave promising mortality percent and significantly (P < 0.05) different from untreated control. Sivanto Energy EC 85 insecticide has effective percent mortality to control onion thrips, in open field conditions. Therefore, Sivanto Energy EC 85 insecticide is recommended at a rate of 1200ml ha-1 to control onion thrips on onion field conditions.

Keywords: Efficacy, Infestation, Insecticide, Onion, Thrips tabaci, Yield