[The control of storage mites in the mycological laboratory]

Mycological cultures in the laboratory are threatened by storage mites who feed on fungi and cause contamination by transferring bacteria and fungi from culture to culture. To eliminate mites from fungal cultures without damage to the fungi themselves several chemical and physical procedures were tested. The following substances were added to Sabouraud glucose (2%) agar at concentrations of 0.1 and 1.0%: gamma benzene hexachloride (lindane), N-ethyl-o-crotonyltoluide, pyrethrins, dieldrin N,N-diethyl-m-toluamide, benzyl benzoate, and--as popular household remedies--Eau de Cologne, neutral soap and garlic. The media were inoculated with 4 dermatophytes (T. rubrum, T. mentagrophytes, M. gypseum and E. floccosum). Two to three weeks later the fully grown cultures were contaminated with mites and their eggs. In other test series, mite infested cultures were exposed to heat (40 degrees C and 60 degrees C) or cold from -12 degrees C to -28 degrees C over different periods of time. Finally, the protective value of sealing culture dishes with adhesive tape was investigated. The most useful method to control mite infestation in fungal cultures seemed to be exposure to heat over a short time.