Abstract
Population growth of Histiogaster sp. was observed on three well-known Imperfect fungi (Aspergillus oryzae, A. niger and Fusarium oxysporum), five popular Basidiomycetes (commercial mushrooms of Lentinus edodes, Pholiota nameko, Pleurotus ostreatus, Flammulina velutipes and Grifola frondosa) and an important mushroom pest fungus (Hypocrea nigricans). The mites showed steady population growth on most of the Imperfect fungi and on H. nigricans. Hypocrea nigricans and A. niger, among those, provided a high growth rate of the mite population. In Basidiomycetes, the mites showed a high growth rate on F. velutipes, but no sign of growth was observed on L. edodes. The mites grew well at 25°C and 30°C but did not grow at all at 15°C. When mite density reached a high level they started to crawl off the culture and escape. Escaping mites most frequently reached a fresh nearby plate of H. nigricans, where they established well. Some mites, mostly in hypopi stage, even moved to a PDA plate without any fungus. This suggests that this mite species may become a serious pest for culturing fungi.
