Determination of the entomopathogenic effects of different Bacillus species and Pantoea dispersa on agricultural and forest pests: host range study

A large diversity of pest species can be found in agricultural and forestry regions due to Türkiye’s various climatic and geographic characteristics. These pests can cause significant crop loss and economic harm. This study aims to determine the efficacy of the local entomopathogen Bacillus species bacteria against various agricultural and forest pests by investigating the mortality rates on Dendroctonus micans (Coleoptera: Curculionidae), Pieris brassicae (Lepidoptera: Pieridae), Thaumetopoea wilkinsoni (Lepidoptera: Notodontidae), Tenebrio molitor (Coleoptera: Tenebrionidae) and Galleria mellonella (Lepidoptera: Pyralidae), whereas the highest mortality rate (96%) achieved upon GAP2 (Bacillus subtilis) treatment on Pieris brassicae, GAP1 (Bacillus cereus), GAP9 (Bacillus thuringiensis) and GAP4 (Bacillus megaterium) isolates showed relatively lower mortality at rates of 86.7%, 82.6% and 82.6%, respectively. GAP1 achieved 78% mortality at the highest on Thaumetopoea wilkinsoni, while the maximum mortality of Tenebrio molitor was observed upon GAP9 treatment at a rate of 66.7%. GAP2 treatment on Galleria mellonella reached maximum 65% rate of mortality. Overall, in this study we showed that bacteria isolated from different pests and beneficial agents were effective on biological control of agricultural and forestry pests. The results obtained may have the potential to be developed and formulated. These findings highlight that isolates of GAP1, GAP2 and GAP9 have broad host distribution, in which utilization of these in development of preparations for biological control will be a useful approach to control agricultural and forestry pests.