The efficacy of nematophagous fungi on predaceous nematodes in soil compared with saprophagous nematodes in mushroom compost

Abstract

The predaceous efficacy of five nematophagous fungi was investigated against the predaceous soil nematode, Butlerius sp., and the saprophagous nematode, Panagrolaimus sp., during the cultivation of the commercial mushroom, Agaricus bisporus. Two isolates, Arthrobotrys oligaspora and Dactylaria scaphoides, produced three dimensional adhesive networks in the isolation of other predatory organs, while Dactylaria dasguptae, an unidentified Dactylella species and the egg-parasitizing fungus, Dactylella oviparasitica, produced both networks and detachable knobs in the presence of nematodes under our experimental conditions. Preliminary studies in soil microhabitats proved A. oligospora and the unidentified Dacylalla species to be potentially effective biological control agents, immobilizing 80% of the total nematode population. However, during the cultivation of A. bisporus, the most biologically effective fungus, Dactylaria dasguptae, reduced the nemtode population by 35%. There is some evidence to suggest that saprophytic nematophagous fungi would make effective biocontrol agents.