Influence of grain type on the susceptibility of Tribolium confusum adults to three diatomaceous earth formulations

Insecticidal efficacy of three diatomaceous earth (DE) formulations, DEBBM, DEA and F2 was evaluated on three different wheat cultivars, Chamran, Verinak and Behrang, against Tribolium confusum Jacqueline du Val. DEs were applied at the rates of 100, 200 and 300 mg/kg. Bioassays were carried out on wheat at 27 ± 1 °Cand 55 ± 5% RH in continuous darkness. Mortality of adults was counted after 2, 7 and 14 days of exposure. Adults of T. confusum were the most susceptible to DEBBM in Behrang. So that DEBBM concentration of 100 mg/kg after 7 days of exposure caused 98% mortality which reached 100 after 14 days. Therefore, Behrang was the most tolerant cultivarto T. confusum infestations. Furthermore, DEBBM was more effective than the other two testedformulations.