An Investigation of the Efficacy of two Iranian Isolates of Metarhizium anisopliae Against Russian Wheat Aphid, Diuraphis noxia (Hemiptera: Aphididae) under Laboratory Conditions

In this study, the effects of two Metarhizium anisopliae isolates, originally obtained from red palm weevil (Rhynchophorus ferrugineus) and a beetle (Parandra caspica), on adults of Russian wheat aphid Diuraphis noxia were studied under laboratory coditions. After a determination of the minimum & maximum concentrations, the adults were treated with conidial concentrations of 1×103 to 1×106 conidia/ml to determine the LC50 & LC90. DEMI001 proved to possess the lowest LC50 (1.7×103 conidia/ml) whilst DEMI002 the highest (2.5×106 conidia/ml). The lowest LT50 was obtained 1.75 days for DEMI001 at 1×105/5 conidia/ml. In a completely randomized block design, the mortalities caused by the isolates on the 6th & 10th days were as follows: on the sixth day and for the concentration of 106 conidia/ml, isolates DEMI001 (32.22%±6.92), DEMI002 (22.28%±4.39) and for the tenth day, the isolates DEMI001 (41.9%±6.42), DEMI002 (28%±4.78) were observed as significantly different.