Comparison Between the Effect of Neem Oil and Neem Aqueous Extract on Tetranychus urticae Koch (Acari: Tetranychidae)

Abstract

The two-spotted spider mite, Tetranychus urticae Koch is one of the most important pests responsible for yielding losses for many crops. For several years, chemical control of mites has been extensively practiced; a major problem in the control of T. urticae is the response to develop resistance to many acaricides, and so, scientists make efforts to replace the chemical acaricides with natural acaricides, as a mean to reduce negative impacts to human health and the environment. In the search for control alternatives, this study aimed to evaluate the effect of neem essential oil and the aqueous neem extract against adult females of Tetranychus urticae under laboratory conditions. Also, LC 50 of each treatment was established and the obtained results revealed that the active essential oil of neem was more effective than the aqueous neem extract. LC 50 : 33.99 ppm and 260.30 ppm for neem oil and aqueous extract respectively. However, LC 90 value was 238.83 ppm and 1813.70 ppm for neem oil and aqueous extract, respectively.