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

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 LC 50 and LC 90 values for the contact toxicity of seed extract on eggs and adult females were LC 50 =4.5 %, LC 90 =9.4 % and LC 50 =2.9 %, LC 90 =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.