ABSTRACTSeven species aggregates ofTrichodermaandGliocladium virenswere isolated from roots ofPhellinus weirii-infested Douglas-fir stumps fumigated with chloropicrin, Vorlex, or methylisothiocyanate, or left untreated. Most commonly isolated wasTrichoderma viride, followed byT. hamatum, T. citrinoviride, G. virens, T. polysporum, T. saturnisporum, T. harzianum, andT. longibrachiatum.Roots from chloropicrin-treated stumps were more frequently colonized than those from untreated stumps, althoughT. citrinoviridewas more frequently found in untreated stumps.