| Abstrakt: |
Cereals, as the major and important sources of food for humans, are usually stored in warehouses until consumption so they may be attacked by stored products pests. Therefore, it is necessary to prevent the economic damages of such pests as the main issue. One of the important pests of cereals, especially wheat, is the wheat weevil, Sitophilus granarius. In the current study, the sole and combined effects of phosalone, lambda-cyhalothrin and Beauveria bassiana, were studied on wheat weevil. Bioassays of the insecticides were carried out by contact residue exposure method, while B. bassiana bioassay was done by immersion method. Mortality of the adult treated by insecticides was recorded after 24 hours, while the exposure time was 10 days for B. bassiana. Also, the combined effect of the insecticides and the isolates of fungus B. bassiana were evaluated on adult insects. The LC50 values of phosalone and lambda-cyhalothrin were 2.82 and 0.22 µg a.i./ml, respectively, while the LC50 values of OZ1 and OZ2 isolates of B. bassiana were reported to be 9.3×104 and 9.03×104 conidia per ml, respectively. Results of the combined effect of insecticides and B. bassiana isolates showed that phosalone and lambda-cyhalothrin were synergistic for B. bassiana lethality against S. granarius. In general, it can be concluded that the initial treatment with low concentrations of phosalone and lambdacyhalothrin significantly enhances the killing effect of B. bassiana. [ABSTRACT FROM AUTHOR] |
