Evaluation of the behavioral response and conidium transmission by Tribolium castaneum in presence of the entomopathogenic fungus, Beauveria bassiana on different wheat cultivars

The side effects of pesticide usage to control the Tribolium castaneum include the pest resistance and the risk of pesticide residues in stored products. Therefore, one aim of this research was to evaluate the effect of wheat seed conditions or presence of B. bassiana on host selection by the flour beetle on three wheat cultivars including the Chamran, Chamran2 and Pishtaz (at 27±1ºC, RH 85±5% and darkness). The results indicated that the beetle was able to recognize and avoid the fungus. Also, the mean proportion of obtained adults from undamaged seeds (0.67±0.05) was significantly higher than that of damaged seeds without fungal infection (0.33±0.05). There was no significant difference between the mean proportion of obtained adults from undamaged and damaged seeds with fungal infection. The evaluation of seed conditions on the B. bassiana transmission during the beetle colonization showed the occurrence of the fungal transmission. During the colonization, there was significant difference between the mean number of sporulating-cadavers obtained from damaged and undamaged seeds for all three cultivars. For instance, the mean number of sporulating-cadavers on the Chamran cultivar for damaged and undamaged seeds was 37.25±0.85 and 40.75±1.25, respectively. The results declared that the flour beetle could distinguish the presence of the fungus; however, the seed condition (being damaged or undamaged) did not have any influence on the interaction between the beetle and the fungus. The fungus was transmitted properly among the colony and it declared the efficiency of the sporulating-cadavers that can be a remarkable reservoir in grain stores.