Mushroom mite

The mushroom mite (lat. Histiogaster fungivorax) belongs to the order Acariformes and the family Acaridae. It is a microscopic pest with an oval, slightly flattened body, characterized by a white or yellowish-transparent color and a shiny chitinous shell.

Adult specimens typically reach a size of no more than 0.2–0.4 mm, making them almost impossible to detect with the naked eye without the use of a magnifying glass or a microscope. The mite has four pairs of legs that allow it to move actively across the substrate.

Special attention should be paid to the hypopus, a specialized developmental phase in which the mite acquires increased resistance to adverse environmental conditions. In this form, the pest can travel by clinging to insects or humans.

The biology of the mite is inextricably linked to the presence of mycelium. Reproduction occurs rapidly, especially in conditions of high humidity and temperature, allowing the colony to colonize large areas of substrate in a very short time.

The pest's life cycle includes the egg, larva, protonymph, deutonymph, and adult stages. Optimal conditions for development are temperatures around +20…+25°C and high air humidity.

The main targets of infestation are crops grown in protected ground, particularly various types of edible mushrooms such as champignons, oyster mushrooms, and others. The mite actively feeds on fungal hyphae.

In addition to fungal crops, the pest is capable of damaging stored cereal seeds, legumes, and processed food products if they show signs of fungal infection or have high moisture content.

In agricultural production, this mite poses the greatest threat to mushroom farms, where it can destroy mycelium during the incubation stage or throughout the fruiting period.

Damage is caused not only by direct consumption of the mycelium but also by the transmission of spores of pathogenic molds, which increases the infection load within the greenhouse environment.

During mass reproduction, mites can damage the fruit bodies of mushrooms themselves, boring tunnels into them, which causes the final product to lose its market value entirely.

The first sign of infestation is a slowing down of mycelium growth; the mycelium becomes loose and develops a specific unpleasant odor, often resembling rot or mustiness.

A whitish or yellowish film may appear on the surface of mushroom blocks or substrate. This is often mistaken for mold, but closer inspection reveals clusters of moving, microscopic dots.

When fruit bodies are infested, small indentations and brown spots appear on the stems and caps of the mushrooms, which gradually enlarge and darken due to the ongoing decay process.

Another characteristic signal is the rapid breakdown of the substrate structure, which turns into a shapeless, sticky, foul-smelling mass unsuitable for further mushroom growth.

If there is an unexplained general decrease in yield in the cultivation facility, it is necessary to perform a microscopic analysis of substrate samples to identify the presence of mites.

The foundation of effective control is strict production hygiene: disinfecting facilities, equipment, and containers before initiating a new cultivation cycle using specialized acaricides.

Thermal treatment of the substrate (pasteurization) is the most effective way to eliminate mite eggs and adults, as the pest is highly sensitive to high temperatures.

It is necessary to control the microclimate: avoid stagnant air and over-moistening of the substrate, as mites develop significantly faster in conditions of excessive moisture.

The use of biological control agents, such as predatory phytoseiid mites, can provide excellent results within integrated pest management (IPM) systems for mushroom farms.

• Regular inspection of mushroom blocks.
• Use of high-quality spawn and substrate.
• Prompt removal of infested mushrooms from the greenhouse.
• Sealing of facilities to prevent pests from entering from outside.