Humpbacked fly Megaselia picta

Systematic position. Megaselia picta belongs to the order Diptera and the family Phoridae. Commonly referred to as humpbacked flies, these insects are characterized by a pronounced arch of the thorax. This specific species is globally recognized in entomology as a significant pest associated with decaying organic matter and high-moisture environments, frequently infiltrating agricultural facilities.

Affected crops. This species poses a major threat to intensive agriculture, particularly in mushroom production where it damages mycelium and sporocarps. Furthermore, it is a known pest in greenhouse vegetable cultivation, affecting cucumbers, tomatoes, and other crops. It also targets ornamental plants, nursery seedlings, and stored organic agricultural products that provide suitable nutrition for larvae.

Biology and life cycle. The life cycle comprises egg, larval, pupal, and adult stages. The flies are highly prolific, particularly in stable, warm, and humid indoor conditions. Females lay eggs on decomposing organic material or damaged plant tissues. Larvae develop rapidly, consuming organic matter and often invading the healthy tissues of seedlings or host plants, leading to rapid decay and poor crop establishment.

Damage patterns and economic impact. The primary economic impact stems from larval feeding, which destroys root systems, stems, and fruits, resulting in stunted plant growth or total crop failure. In the mushroom industry, their presence causes direct loss of yield and quality. Additionally, Megaselia picta is a vector for various plant pathogens, meaning their presence often initiates secondary bacterial or fungal infections in compromised plant tissues.

Control measures. Integrated pest management strategies are essential for controlling Megaselia picta:

• Strict sanitation protocols to remove decaying organic matter which acts as a breeding site.
• Installation of yellow sticky traps to monitor and reduce adult fly populations.
• Heat sterilization or chemical treatment of growing substrates before planting.
• Biological control using entomopathogenic fungi or nematode-based products applied to the soil.
• Consistent air ventilation and humidity management within greenhouses to discourage fly activity.