Climatic factors interference with the occurrence of Beauveria bassiana and <i>Metarhizium anisopliae</i> in cultivated soil

Abstract

Description of method and recommendation of laboratory and field procedures for the isolation of soil borne entomopathogenic fungi (specifically Beauveria bassiana and Metarhizium anisopliae) is presented. Baiting technique method was used for screening of occurrence of indigenous populations of entomopathogenic fungi. Totally, 2068 alive greater wax moth larvae (Galleria mellonella L.) were used to trap entomopathogenic fungi present in the soil. Site selected was the experimental farm of Assiut University; only 105 larvae were infected by entomopathogenic fungi representing 5.08% mortality. B. bassiana caused 85.71% of the mortality  represented by 90 isolates. M. anisopliae caused 14.29% of the mortality giving only 15 isolates of M. anisopliae. Data showed that B. bassiana seems to be the most economically important entomopathogenic fungi inhabiting soil cultivated with wheat and cotton plants. The highest number of the isolates was recorded during spring and autumn seasons. The relationship between the incidence of B. bassiana and M. anisopliae and the selected weather factors was statistically analyzed using multiple regression analysis.

Key words: Entomopathogenic fungi, Galleria mellonella, baiting technique, soil.