Effects of the Entomopathogenic Fungi, Beauveria bassiana and Metarhizium robertsii , on the Physiological and Behavioral Traits of the Northern Red-Backed Vole ( Myodes rutilus , Rodentia, Cricetidae) under Stressful Conditions

An experiment aimed at revealing the consequences of adding two species of entomopathogenic Ascomycetes, Beauveria bassiana and Metarhizium robertsii , to grain fodder showed that northern red-backed voles that received M. robertsii conidia in their food for 15 days had higher levels of triglycerides, glucose, and peroxidase in the blood; differed from other animals in social behavior patterns; and demonstrated significantly less emotionality in an open field test than control animals. The voles fed fungal conidia showed a trend towards reduced survival in captivity compared to controls. These data indicate the significant impact of entomopathogenic fungi on the metabolism, behavior, and lifespan of nontarget mammals.