Mortality Effects of Indoxacarb and Thiodicarb On Trichogramma brassicae Bezdenko (Hym.: Trichogrrammatidae)

Through identifying the role of natural enemies in pest control and developing their application, it is expected that particular attention will be paid to the adverse effects of pesticides on natural enemies, especially removal or reduction of their activities. Among all the popular natural enemies in the world, Trichogramma</em> bees bears a special importance in terms of efficiency, mass production technology, application scope, adaptability in different climates, and the ability to grow on the intermediate host. This paper tends to investigate the effects of different doses of 250, 500, 750 and 1000 ppm of pesticides including inodxacarb, thiodicarb and a combination of both on mortality of Trichogramma brassicae</em> Bezdenko, in laboratory conditions (25±1°C, 70±10% relative humidity and 16L:8D). Results showed that each of pesticides and combination of both, compared with the control (water), caused a significant increase in mortality and, with increasing doses, their lethal effects became more severe. Regarding this, indoxacarb pesticide had the least amount of mortality, which in this regard, had a significant difference with the other two treatments. At the highest concentration for 24, 48, and 72 hours after exposure, mortality rate was calculated as 29.6, 30, 55.56% for indoxacarb, 33.33, 81.48 and 96.30 % for thiodicarb, and 56.67, 96.3, and 100% for combination of both pesticides, respectively. Comparison of the mortalities of two insecticides and combination of both showed that there was no significant difference between the mortality rates of the combination of indoxacarb+thiodicarb and the sole use of thidiocarb. However, indoxacarb showed significant difference. According to the results, inodexacarb has the lowest mortality rate in the direct application on T. brassicae</em>.