Intraction between Neem and Beauveria bassiana on survival of sawtoothed beetle (Oryzaephilus surinaemnsis) in laboratory conditions

The aim of this study was to evaluate application of Neem (Azadirachta indica) extract with Beauveria bassiana against sawtoothed beetle in the nutritional status of the dates. The compatibility between Neem and the fungus was evaluated based on mycellial growth and spore germination of B. bassiana by extract medium mixing method. The lethality of Neem extracts individually and in conjunction with B. bassiana in the adult and larval population were evaluated by dipping bioassay method. Studies revealed that mycelial growth and spore germination of B. bassiana in 250 µl/L concentration of Neem were 3.1 and 2.5% respectively less than control treatment. 50% decreasing in mycelial growth and spore germination was happened at 3679.4 and 1949.4 µl/L of Neem extract respectively. The highest Compatibility of B. bassiana was 76.89% recorded at 250 µl/L of Neem extract. The average of LC50 in larva and adult population for the fungus was 3.31×102 and 2.5×104 conidia/ml respectively and while with usage neem extract was 386.1 and 696.4 µl/L respectively. According to the results, usage both of Neem extract and Beauveria bassiana increases mortality rate of adult and larval population of sawtoothed beetle based on SR indeices with 1.57 and 1.98 reppectivaly. Combined usage of neem extract and fungus B. bassiana can increase performance and provide the final formulation as a means of pest management to store dates.