Tolerance of copper by entomogenous fungi and the use of copper-amended media for isolation of entomogenous fungi from soil

Abstract

The growth of several entomogenous fungi, as well as some common soil fungi, was tested on malt extract agar containing different concentrations of Cu. The most tolerant species were Cordyceps militaris and Paecilomyces farinosus (LD50 values > 400 mg Cu l−1). Verticillium lecanii, Beauveria bassiana and Metarhizium anisopliae were also tolerant, while fungi attacking nematode cysts (Verticillium chlamydosporium and V. suchlasporium) were less tolerant. All other fungi tested, except Aureobasidium pullulans, were not tolerant to Cu. B. bassiana and P. farinosus could easily be reisolated from conidia-inoculated soil using agar media containing Cu.