Study on the effects of some Iranian isolates of the fungus Beauveria bassiana (Balsomo) Vuill. (Deuteromycotina: Hyphomycetes) on the bird cherry-oat aphid, Rhopalosiphum padi (Linnaeus) (Hemiptera: Aphididae), under laboratory conditions

摘要

 According to the importance of non-chemical controlling methods based on integrated pest managment, Beauveria bassiana was considered as a pathogen of the bird cherry-oat aphid, Rhopalosiphum padi..In this study, the pathogenicity effects of some Iranian isolates of B. bassiana against adult aphids were evaluated using the spray bioassay method. Seven isolates, including DEBI 001, DEBI 002, DEBI 003, DEBI 006, DEBI 008, DEBI 010 and DEBI 015, were cultured on the SDA medium and incubated under dark conditions at 25??C for 15 days. The minimum and maximum dosages of each strain was determined and then 5 different conidial concetrations were prepared based on the logarithmic distances Experiments were carried out based on RCD, and repeated 4 times and for each replicate 20 adult aphids were treated. The control aphids were treated with distilled water_tween 80. Treated aphids put in plexiglass cups in an incubator at 25?à2??C, and mortality was recorded daily for 5 day. Data were analyzed using SAS (6.2) and Curve Expert 1.4 to determine LC50 and LT50. The lowest and highest LC50 were recorded 0.06 and 119.26 Spore¨Mml, and the lowest and highest LT50 were recorded 2.08 and 4.57 days, both respectively using DEBI 015 and DEBI 001 isolates