Lesser dung fly

Borborus hamatus (now commonly associated with the genus Copromyza, family Sphaeroceridae, known as lesser dung flies) is a small dipteran insect. These flies are primarily saprophagous, meaning they thrive on decaying organic material, but they can become significant pests when they invade greenhouse environments and damage young seedlings.

The species poses a particular threat to germinating seeds and young vegetable crops. In agricultural settings, they are often found in soils enriched with fresh manure or compost that has not been properly decomposed, as well as in areas with poor drainage that promote fungal growth and organic rot.

The biology of Borborus hamatus is intrinsically linked to moisture-rich environments. The adult flies lay eggs in moist soil containing organic waste. Once hatched, the larvae feed on the decaying matter, but in high-density populations, they will aggressively attack the succulent tissues of germinating seeds and seedling roots, leading to plant mortality.

Damage caused by these larvae is characterized by the sudden wilting and death of young seedlings. Because the larvae tunnel into the hypocotyl and roots, the plant stops growing and eventually collapses. This process is frequently compounded by the introduction of bacterial soft rot pathogens by the larvae during feeding.

Effective management requires a combination of hygiene and environmental control to break the life cycle of the pest. Key strategies include:

• Ensuring complete composting of organic fertilizers before application to the soil.
• Maintaining proper greenhouse hygiene by removing all crop debris promptly.
• Regulating irrigation to avoid soil waterlogging and stagnant conditions.
• Using sterile soil mixes for starting seeds.
• Applying biological control agents or targeted insecticides if monitoring indicates high adult fly presence.