Toxicity Assessment of Certain Insecticides Against the Onion Thrips, Thrips Tabaci Lindeman (Thysanoptera: Thripidae) on Onion Crop Under Field Conditions

Abstract

Onion is one of the most significant vegetable plants that cultivated on large areas in Egypt. The onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae) is the most destructive insect pest causes significant damage to seed heads and reduce onion seed crop production about 50% annually. The combinationof Thiamethoxam + Abamectin has been recommended to control T. tabaci in Egypt. Herein, we evaluated the toxicity of eight selected insecticides [Abamectin (1.8% EC), Lufenuron (5% EC), Thiamethoxam (18.6% SC), and Thiamethoxam + Abamectin (18.6 EC+1.8% EC), Lambda-cyhalothrin+ Abamectin (5% EC+1.8% EC), Carbosulfan (20% SP), Lambda-cyhalothrin (5% EC) and Bacillus thuringiensis kurstaki (4.6% EC) against T. tabaci under field conditions. The results were recorded after 1, 2, 3, 7 and 14 days. Among all tested insecticides, the combination of Thiamethoxam + Abamectin was more potent to T. tabaci than separate application of Thiamethoxam or Abamectin solely, While, Lufenuron and Bacillus thuringiensis kurstaki were the least toxic insecticides. These insecticides mixtures gave promising results in controlling the onion thrips, T. tabaci.

Keywords

• thrips tabaci
• onion
• toxicity
• insecticides
• seed crops