Isolation and identification the fungi associated with broad bean aphid and testing their pathogenicity and using some of them as a biological agents against the insect

Abstract

This study aimed to isolate and identify the fungi associated with the broad bean black aphid Aphis fabae Scopolli . The pathogenicity of these fungi and the biological effect of some of them on the different insect instars were also studied . Nine species of fungi were isolated , they were Alternaria alternata, A. chlamydospora, A. niger, Beauveria bassiana, Cladosporium oxysporum ,Penicillium chrysogenum, P. compactum , Ulocladium atrum and sterile white mycelium. P. chrysogenum and A. Chlamydospora gave percent of high occurrence reached to 24.6 and 18.4 % respectively , while A. niger and white mycelium gave a less percentage of occurrence which were 3.07 and 1.5% respectively. The pathogenicity test indicated that B. bassiana and C. oxysporum were entomopathogenic fungi compared with the other isolated fungi , the mortality reached to 54.8 and 44.5% for tow fungi respectively.The fungal suspensions of these fungi in concentration of 1x 108 spores/ml led to kill the insect at mortality of 39.2 and 35.68% respectively. On the other hand , the exudates of these tow fungi in concentration of 100% revealed a high percent of mortality in nymphs and adults of aphid reached to 52.17 and 54.10 % respectively, while C. oxysporum exudate led to kill the nymphs and adults in percent of 55.5 and 50.6 % respectively .This paper is a part of Msc. Theses of the third author.