Increased mortality of Acanthoscelides obtectus by alkane-grown Beauveria bassiana

CRESPO R; JUÁREZ MP; DAL BELLO G; PADIN S; CALDERÓN FERNÁNDEZ G; PEDRINI N

Córdoba, Argentina

Congreso; XXXVII Reunión de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular; 2001

Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular

The effect of alkane-growth induction of the entomopathogenic fungus Beauveria bassiana on the ability to kill the bean weevil Acanthoscelides obtectus was tested. Adult insects were sprayed with an 0.01% Tween 20 aqueous suspension of 4 x 106 conidia/ml. The performance of fungi grown in complete agar medium containg glucose as carbon source (FS0) was compared to that of alkane-grown fungi (FS1). Mortality increased (p <0.05) from 22 ± 4.5% to 44 ± 11.4%  7 days after treatment with FS0 or FS1 respectively. The insect hydrocarbons were analysed by capillary gas chromatography (CGC), major components were saturated hydrocarbons, 27 to 29 carbons length. Oleic, linoleic and palmitic acids accounted for almost 88% of the fungal fatty acids. These results indicate that alkane supplementation  of culture media might be a tool to improve the virulence of  some mycoinsecticides.