Pests and diseases of mushrooms

Below is some information about pests and diseases that affect mushroom crops in Queensland. For more information, contact the Australian Mushroom Growers Association.

Invertebrate pests

Arthropods

A variety of small fly and midge species are pests of mushrooms. The larvae feed on the fungal mycelium in the compost, but may also tunnel into the fruiting bodies.

A range of mite species may affect the mushroom crop. Some directly damage the fruiting bodies, some may attack the mycelium and some mites are predatory on other mites, fly eggs, nematodes or bacteria. Mite damage on the fruiting bodies often shows up as small cavities in the stem and cap similar in appearance to bacterial pit disease. Mycelium-eating mites can cause high yield losses. Mites are very small and easily transported on clothing and tools.

Springtails are commonly associated with compost and can damage the crop if present in high enough numbers. Slaters and millipedes may also cause damage to the fruiting bodies.

Nematodes

Nematodes will cause a loss in yield and brown, watery mushrooms and, in extreme cases, a soggy, smelly compost. Peat is a common source for nematodes and should be treated before use.

Diseases of mushrooms

Fungal diseases

Even though the mushroom itself is a fungus, it can in turn be affected by a range of fungal pathogens, which are listed in Table 1.

Table 1. Fungal diseases of mushrooms
Disease Other names Symptoms
Dactylium Cobweb, mildew White to pink, cobweb-like, fluffy mould
Diehlomyces Calves brains/ false truffle A competing fungus which produces brain-shaped fruiting bodies
Fusarium Damping off Mushrooms wither
Mycogone Wet bubble / white mould Dense white growth on gills
Papulaspora Brown plaster mould Brown plaster-like patches on casing
Scopulariopsis White plaster mould White plaster-like patches on casing
Trichoderma Green mould Dark green mould patches on casing spreading to lesions on stems
Verticillium Dry bubble / brown spot Brown irregular pitted areas on stems and caps. Distortion and splitting

Bacterial diseases

Pseudomonas (bacterial spot, bacterial or pit or brown blotch) cause yellow to brown blotches on the cap, which may exude sticky residues. Early symptoms are similar to verticilium.

Other diseases

A range of viral diseases attack mushrooms. Fruiting bodies that are either noticeably elongated or flattened, or gradually decreasing crops or flushes, should be examined. If viral diseases are suspected, seek professional advice on eradication.

Management

Maintaining high levels of hygiene will assist any pest management program by reducing the number of problems that are likely to occur. If an outbreak does occur, ensure that you correctly identify the pest or disease before taking any action.

Several chemicals are registered for use on mushrooms in Queensland. Contact your local chemical reseller or the Australian Mushroom Growers Association for details. Always read the label and follow the enclosed instructions carefully.

Last updated 10 December 2010