Characterization of a new isolate of Beauveria bassiana in Algeria and evaluation of its pathogenicity against the cowpea aphid ( Aphis craccivora Koch)

Background The cowpea aphid, Aphis craccivora Koch (Hemiptera: Aphidiidae) is a polyphagous aphid species that causes various damage on different crops. The conventional method of controlling this pest is the use synthetic insecticides that threaten both the environmental safety and human health. Moreover, it contributes to the emergence of insecticide-resistant generations. Hence, relying on Entomopathogenic fungi (EPF) remains one of the most safe and effective alternative solutions to control insect pests. For the mentioned reasons, the EPF, Beauveria bassiana was isolated and characterized; besides, its efficiency against adults’ A. craccivora was evaluated both in the laboratory and in the greenhouse. Results A new isolate of B. bassiana was isolated from collected cadavers’ insects associated with the population of A. craccivora in a rural area in the Northwest of Algeria. This isolate was identified on the basis of its morphological and molecular characteristics and was referred to as B. bassiana BBAA. The enzymatic activities of this isolate revealed a high production of chitinase, protease and lipase, without any production of amylase. The use of different concentrations of B. bassiana BBAA conidia against A. craccivora led to a high mortality rate, ranging from 64 to 74% mortality on the seventh day post-treatment in vitro and 58 to 70% in greenhouse. Conclusion Virulence and enzymatic activities produced by B. bassiana BBAA demonstrated the necessity to exploit entomopathogenic fungi (EPFs) in pest control.