سمیت سه حشره کش گرد بی اثر در حفاظت از گندم علیه حشرات بالغ شپشه آردTribolium confusum (Coleoptera: Tenebrionidae)

The use of phosphine fumigation has created serious health issues for the personnel involved in grain silos and storages. In addition the incidence of phosphine resistance developing in the relevant insects requires even stronger gas concentrations to improve the insecticidal efficacy of this gas. So that, this research Project was carried out to determine if a locally produced IDI could match the efficacy of established, effective IDI’s used in Europe and the Americas for stored grain protection. All three formulations tested were enhanced efficacy products based on Diatomaceous earth with all three maintaining their basic amorphous silica nature. These were SilicoSec (Biofa GmbH, Munsingen, Germany) Protect-It (Hedley Technologies Inc., Canada) and Dryasil (Iran) which were applied against adults of Tribolium confusum Jacquelin du Val in Wheat (Var. Chamran). The IDIs were applied at three dose rates, 100, 200 and 400 ppm with three replications and three sub-replications. Untreated wheat was served as control. The experiments were carried out at 27±1˚C and 60± 5% r.h. in continuous darkness. Adult mortality was counted after 2, 5, 7, 10 and 14 days of exposure. Progeny production was determined 60 days after the removal of the adults. The mortality of T. confusum increased with increasing dose level and time exposed to each concentration. Results indicated that SilicoSec® was more effective in controlling the adults than Protect-It® and Dryasil. So that, SilicoSec® caused 58.1% mortality 10 days after treatment with the highest dose rate (400 ppm) which increased to 83.5% after 14 days, while for two other IDIs approximately 41% mortality was reported at 10-d time interval when treated with 400 ppm and increased to 56.5 and 58.8% for Protect-It® and Dryasil, respectively. Progeny production was significantly suppressed by all three IDIs when compared with control. In the control 20.4 progeny was reported, while the number of progeny in the lowest concentration was 12.0, 15.0 and 12.4 for SilicoSec®, Protect-It® and Dryasil, respectively and decreased to 3.7, 5.9 and 5.2 with increasing concentrations to 400 ppm. The results for both insect mortality and progeny production indicated that SilicoSec® is marginally the more effective product. Dryasil and Protect-It® formulations generated results indicating that they had comparatively similar toxicity.