Evaluation of Pathogenicity of Metarhizium anisopliae against Green Peach Aphid

Metarhizium anisopliae, is one of the most famous soil inhabitant entomopathogenic fungi, has a virulence potential on plant pests and animals. The green peach aphid, Myzus persicae, exists in all over of the Iran and causes damages to peach trees, citrus, vegetables and ornamental plants grown in greenhouses. The aim of this study is checking peach aphid mortality by Metarhizium anisopliae. Two strains of Metarhizium anisopliae, namely M1 and A3 available by Department of applied microbiology of Tehran organization of Academic Center for Education, Culture and Research (ACECR) were used in this study. Bioassay test against peach tree aphids was done in 18 cm diameter Petri dishes with three gradient suspensions consisted of 1×103, 1 ×105 and 1 ×107 conidia ml−1 and 14: 10 h of dark: light photoperiod in ambient temperature for 9 days. The least amount of LC50 determined for A3 with concentration of 6.5×105 conidia/ml and the best LT50 for A3 with concentration of 1×107 conidia ml−1 was 3.82 days. The least LT50 for M1 with concentration of 1×107 conidia ml−1 was 5.51 days.