Residual Efficacy of Beauveria Bassiana and Diatomaceous Earth on Wheat Grain against Red Flour Beetle, Tribolium Castaneum (Herbst)

Laboratory bioassays were conducted to assess the efficacy of each entomopathogenic fungus, Beauveria bassiana (Bb), and diatomaceous earth (DE) and their combinations against the red flour beetle, Tribolium castaneum (Herbst) (Tenebrionidae: Coleoptera) on stored wheat (Triticum aestivum L.). The results indicated that the highest concentrations of Bb and DE in their combinations were more effective in suppression of red flour beetle. After a nine-month storage period, the Bb۲+DE۲ treatment achieved the highest level of adult mortality (۷۶.۶۱%). In contrast, the Bb۱ treatment alone demonstrated the lowest mortality rate (۱۶.۳۳%). Minimum grain damage (۲۳.۳۶, ۲۵.۶۹, ۳۱.۵۷, ۳۳.۴۵, ۴۱.۹۳, ۴۲.۵۷, ۴۶.۷۳, and ۴۷.۶۳%) was observed on Bb۲+DE۲, Bb۲+DE۱, Bb۱+DE۲, Bb۱+DE۱, DE۲, DE۱, Bb۲, and Bb۱, respectively, with the minimum weight loss after ۹ months of storage. It has been clearly observed that seed germination was not affected adversely in any treatment during ۹ months of storage. Moreover, during the storage period (≈nine months), the Bb۲+DE۲ was the most powerful combination reduced grain damage and weight loss, resulting in germinating by more than ۷۵% compared with untreated grains by only ۲۴%. The study highlighted that the combination of Bb and DE has residual efficacy leading to long-term protection of wheat against red flour beetle.

کلیدواژه ها:

biological control ، Diatomaceous Earth ، Grain storage ، Insect pathogenic fungi ، Red flour beetle ، Tribolium castaneum