Management of an emerging pest, Tetranychus urticae Koch (Acari: Tetranychidae), with pesticides in eastern Ethiopia

Abstract

Outbreak of two-spotted spider mite, Tetranychus urticae Koch, happened on potato (Solanum tuberosum L.) in eastern Ethiopia in 2014 and effective pesticides as part of IPM practice were sought from greenhouse and laboratory experiments at Haramaya University, Ethiopia. The objective of the study was to identify pesticides with the highest efficacy against the mite. Potatoes infested with mites were used in the efficacy trial. Treatments, 9 pesticides and a control, were applied 2 times at weekly intervals. Mites per leaf before and after each spray were counted. Promising pesticides were further screened with leaf-disc spray, and dip methods. Adult mortality was recorded after 24 and 48 hours. Chlorantrniliprole + Lambda-cyhalothrin, Amitraz, Profenofos, Profenofos “Q” 720 g l-1, and Paraffin oil showed superior efficacy on eggs and mobile stages; though Paraffin’s efficacy became clear 14 days later. Paraffin had the lowest mortality in leaf-disc sprays, but better mortality in the leaf-disc dip. This was attributed to complete wetting by the latter. Chlorantrniliprole + lambda-cyhalothrin, Profenofos, Profenofos “Q” and Paraffin were identified as promising pesticides for the two spotted spider mite management on potato.

Key Words:   Pesticides, potato, two spotted spider mite