DOI: 10.36347/sjavs.2015.v02i01.007

Pages: 31-37

The date horn beetle Oryctes elegans Prell is one of the most important palm pest in many parts of the world and Iran. The aim of this study was to compare different bioassay methods for assess the pathogenecity of fungal B. bassiana, B. brongniartii and M. anisopliae on beetle larvae of the date horn beetle O. elegans. Five logarithmic doses including 5×107, 108, 5×108, 109, 5×109 spores/ml for immersion method, 108, 5×108, 109, 5×109 and 1010 spores/ml for oral method and 106, 5×106, 107, 5×107, 108 and 5×108 spores/ml for injection method had been used respectively. The results showed that M. anisopliae and B. bassiana with LC50 equal to 5.69×108 and 1.53×109 spores/ml on immersion method, M. anisopliae and B. bassiana with LD50 of 8.17×108 and 2.12×109 spores/ml and M. anisopliae and B. bassiana, with LC50 equal to 1.07×106 and 4.9×107 spores/ml had the highest and the lowest mortality rate based on immersion, oral and injection method respectively. The lowest LT50 occurred in concentration of 5×109, 5×108 and 1010 spores/ml of M. anisopliae equivalent to 3.61, 6.41 and 3.24 days based on immersion, oral and injection method respectively.