Conidia of the nematophagous fungus Drechmeria coniospora adhere to but barely infect Acrobeloides buetschilii

Abstract

Conidia of the endoparasitic fungus Drechmeria coniospora were able to adhere to the nematode Acrobeloides buetschilii; approximately 70% of the nematodes were carrying spores 16 h after their addition to the fungal culture. Young nematodes were preferentially affected; adhesion mainly took place in the head region of the animal. Full infection, characterized by colonization of the nematode body and production of conidiophores and conidia, was observed, albeit at low frequencies. In case of failure, a second adhesive knob was often formed on the germinated spore. The low frequencies of infection are not related to a loss of virulence, due to prolonged in vitro culturing of the fungus. Fresh spores, obtained from cultures which were passed several times through the host, did not show higher infection frequencies.