Coproica ferruginata

Coproica ferruginata is a small fly belonging to the Sphaeroceridae family within the order Diptera. These flies, often referred to as lesser dung flies, are typically 1.5 to 2 mm long and possess a brownish-rust color. While they are primarily known as decomposers of organic matter, they are recognized in greenhouse horticulture as opportunistic pests that can thrive in environments rich in decaying vegetable matter.

The pest primarily targets vegetable crops grown in greenhouses, especially those cultivated in peat-based substrates or composts. The presence of Coproica ferruginata is usually an indicator of poor cultural practices, such as overwatering, lack of proper drainage, or accumulation of decaying plant waste. Young seedlings are particularly vulnerable to larval activity if the substrate becomes waterlogged.

The life cycle of this fly is rapid and dependent on humidity and temperature. Females lay their eggs in moist, decaying organic material. Larvae emerge and feed on organic decay, but they can easily shift to feeding on the soft tissues of roots and stems if they are in close contact. This ability to transition from saprophagous to facultative parasitic behavior makes them a concern in intensive greenhouse operations.

Damage caused by Coproica ferruginata often manifests as stunted growth, yellowing of leaves, and wilting of the crop. Larvae feed on the epidermis and cortical tissue of roots, which serves as an entry point for secondary fungal pathogens such as Pythium and Fusarium. The resulting root rot often obscures the original cause of the infestation, leading to improper diagnosis.

Effective management requires a combination of sanitation and environmental control strategies:

• Improving drainage and irrigation management to prevent substrate sogginess.
• Sanitizing the greenhouse facility to remove any accumulation of decaying plant material.
• Using yellow sticky traps to monitor and reduce the population of adult flies.
• Implementing biological controls, such as beneficial nematodes, to target larvae in the substrate.
• Ensuring proper ventilation to lower ambient humidity levels within the greenhouse.