The Pathogenesity of Beauveria bassiana on Larval and Adult Stages of the Sawtoothed Beetle Oryzaephilus surinamensis Reared on Different Date Cultivars.

Beauveria bassiana (Balsamo) Vuillemin (Deut.، Moniliaceae) isone of the fungus biocontrol agents of saw toothed beetle Oryzaephilus surinamensis L. (Col.، Silvanidae). Fungi pathogenesis was investigated on larval and adult stages of pest on three date cultivars-Sayer، Zahedi and Deiri-under laboratory conditions (temperature 25±2ºC، relative humidity 60% and Photoperiod 12D: 12L). In adult، the minimum lethal concentaration for 50% (LC50) 2. 46x104 conidia/ml was obtained on Zahedi and maximum 3. 69x104 Conidia/ml on Deiri. In larvae، the minimum LC50 3. 31x103 conidia/ml was obtained on Sayer and the maximum 6. 29x103 conidia/ml on Deiri. The minimum time for 50 present mortality (LT50) was 4. 68 and 6. 68 days for larval and adult of Sayer، respectively. The maximum LT50 was 6. 62 and 7. 07 days for larval and adult stages of Deiri، respectively. It is concluded that the recommendation of the effective dose of Beauveria bassiana depends on the insect-host stage and the media that host reared on it.