Toxic and repellent effects of Prunus laurocerasus L. (Rosaceae) extracts against Tetranychus urticae Koch (Acari: Tetranychidae)

Abstract

The toxic and repellent effects of leaves, flower and seed extracts of Prunus laurocerasus L. (Rosaceae) were investigated against Tetranychus urticae Koch (Acari: Tetranychidae) under laboratory conditions. Extracts at three different concentrations (1 %, 5 % (v/v), 10 % (w/v)) for ovicidal and repellent effects against eggs and adult females, respectively and at five different concentrations (1 %, 2.5 %, 5 %, 7.5 % (v/v), 10 % (w/v)) for the contact toxicity against female adults were evaluated. The results showed that seed extract was the most effective compared to flower and leaf extracts. It was found that at 5 % and 10 % concentrations of seed extract, the repellent effects were 92 % and 100 %, respectively within the first 72 hours. At 10% concentration of seed extract, the ovicidal and adulticidal effect were 96.56 % and 100 %, respectively. Moreover, further concentration response trials showed that LC50 and LC90 values for the contact toxicity of seed extract on eggs and adult females were LC50=4.5 %, LC90=9.4 % and LC50=2.9 %, LC90=9.1 %, respectively. The result indicated that seed extract of P. laurocerasus has good potential to be used to control T. urticae. However, the impact of these extracts on natural enemies of T. urticae should also be needed further studies.