Comparison between Toxicoiogicai and Biological Efficiency of some Aromatic Oils and other Compoundes on Two Spotted Spider Mite

Abstract

Control of the two spotted spider mite, Tetranychus urticae(Koch) using the conventional acaricides resulted in many problems . So, this study was carried out to evaluate the toxicity of certain alternative pesticides against this pest ,T. urticae as well as some biological aspects under laboratory conditions using two aromatic oils (Basil and Carnation) .one natural oil (Nat-1) and one conventional acaricide (Helbstar). The results indicated that Helbstar was the highest toxic compound to adult females of T. urticae followed by Nat-1 with Lc50 values of 1686.5 and 2861.5 ppm, respectively while Basil was the least toxic one with Lc50 value of 5990.4 ppm . The population showed more homogeneity in its response to the aromatic oils (Basil and carnation). Also, the results showed that the Helbstar caused the highest reduction in egg deposition with a mean number of 1.0 egg / day followed by Nat-1 with a mean number of 4.45 eggs / day , while Carnation was the lowest one with a mean number of 11.85 egg / day. The egg hatchability decreased with the increase of egg age at treatment by Basil , while in treating 1,2 and 3 day old eggs , the highest reduction in hatchability was found for Nat-1 , Helbstar and Carnation, with 100% reduction in hatchability at the three ages .Thus, the obtained results are of a great importance as they are taken into account in planning programs of integrated pest management.