Acaricidal effect of new botanical pesticide, Dayabon on Tetranychus urticae (Acari: Tetranychidae) and its predator, Stethorus gilvifrons (Coleoptera; Coccinellidae)
عنوان دوره: دومین کنگره بین المللی حشره شناسی ایران
نویسندگان
چکیده
The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most important pests with a wide host plant range that it causes severe damage to many crops both in the field and in greenhouse. The predatory ladybird beetle, Stethorus gilvifrons (Mulsant) (Coleoptera: Coccinellidae) is a predator preying on different life stages of two-spotted spider mites and it has been well documented as an effective biocontrol agent of T. urticae. Integration of natural enemy and pesticide should be considered in the integrated pest management (IPM) programs. Therefore, this study aimed to investigate the toxicity of five logarithmic concentrations from 10000 to 3000 ppm of Dayabon (SL 10%) on the second nymph of T. urticae as well as the toxicity effects on the adult of S. gilvifrons at 4000, 6000 and 8000 ppm. Dipping the leaf discs method was used to investigate the lethal effect of Dayabon and the mortality was recorded 24 h. after treatment. The experiment was conducted in a standard environmental condition at 25±2ºC, 70±5% RH and photoperiod of 16:8 h. (L:D). The percent mortality of T. urticae was 93.70, 77.12, 55.71, 43.41 and 16.03 at 10000, 7500, 5500, 4000 and 3000 ppm, respectively. However, the percent mortality on the adult of S. gilvifrons was 4.76, 9.52 and 19.05 at 4000, 6000 and 8000 ppm respectively. The lethal concentration to cause 50% and 90% mortality (LC50 and LC90) of Dayabon on the two-spotted spider mite were 4879 ppm and 9414 ppm, respectively. According to the results, Dayabon may be a suitable choice for controlling two-spotted spider mite. Also, the mortality of S. gilvifrons adults was no more than 19.05% at 8000 ppm.
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