Comparative evaluation of indigenous entomopathogenic fungal isolates and three commercial entomopathogenic fungal products against the rice weevil, Sitophilus oryzae L. and the confused flour beetle, Tribolium confusum du Val.

In the present study, a total of 17 indigenous entomopathogenic fungal (EPF) isolates (Beauveria bassiana (Bals.) Vuill. – 14, Clonostachys rosea (Link) Schroers – 2, Isaria farinosa (Holmsk.) Fr. – 1) obtained from soil samples collected from Antalya province (southwestern part of Turkey) and three commercial EPF products [i.e. Priority® (Paecilomyces fumosoroseus), Nibortem® (Verticillium lecanii) and Nostalgist® (Beauveria bassiana)] were evaluated for their efficacy against the 7–10-day-old adults of Sitophilus oryzae L. (Coleoptera: Curculionidae) and Tribolium confusum du Val. (Col.: Tenebrionidae) under laboratory conditions. All the isolates and products were tested at 1 × 107 conidia/ml suspensions against the both insect species. The results from the single-dose pathogenicity assays showed that three B. bassiana isolates (BbDm-1, BbKp-1 and BbMp-1) caused mortalities 96.7%, 100% and 93.3% in S. oryzae, and 100%, 100% and 96.7% in T. confusum, respectively, 14 days after inoculation whereas all three commercial products achieved mortalities ranging from 56.7% and 63.3% in S. oryzae and from 56.7% and 66.7% in T. confurusum. In addition, the results from molecular phylogenetic analyses based on the ITS region sequence indicated that the three effective B. bassiana isolates (BbDm-1, BbKp-1 and BbMp-1) showed a high similarity (99%) with other B. bassiana isolates in GenBank. Overall results suggest that these three B. bassiana isolates have potential for management of S. oryzae and T. confusum.