Mushroom phorid fly

Systematic position. The mushroom phorid fly Megaselia bovista belongs to the order Diptera and the family Phoridae. These small flies are easily recognized by their arched thorax, which gives them a distinctive humpbacked appearance, and their habit of running erratically on surfaces.

Host crops. The primary hosts for this pest are cultivated edible mushrooms, particularly Agaricus bisporus (button mushrooms) and Pleurotus species (oyster mushrooms). They are considered major pests in professional mushroom houses where they thrive on mycelium and decaying organic matter.

Biology and life cycle. The life cycle of Megaselia bovista is rapid, highly dependent on ambient temperature and humidity. Adult females lay eggs on the mushroom compost or directly on the developing fruit bodies. The resulting larvae tunnel through the stalks and caps of the mushrooms to feed, eventually pupating within the substrate.

Damage and economic impact. The larval stage is responsible for all significant damage. As they bore into the mushroom tissue, they create a network of tunnels that causes the fruit body to degrade rapidly. This renders the mushrooms unmarketable and susceptible to secondary bacterial infections, leading to substantial yield losses.

Control measures. Integrated pest management (IPM) is essential to minimize populations of Megaselia bovista:

• Heat treatment (pasteurization) of mushroom compost to eliminate larvae and pupae.
• Sealing mushroom houses with fine-mesh screening to prevent adult fly entry.
• Use of yellow sticky traps to monitor and reduce the adult population.
• Maintaining strict hygiene by removing and disposing of infested debris promptly.
• Implementing rigorous cleaning protocols between cropping cycles to break the life cycle.