• Adults emerge from overwintering pupae in spring.
• Eggs are laid at the base of carrot and parsnip plants.
• Larvae hatch and feed inside roots for several weeks.
• Pupation occurs in the soil, producing two to three generations per year depending on climate.
• Overwintering occurs as pupae in soil.

Larvae feed inside roots, leaving brown tunnels that often become infected with secondary rot organisms. Damaged carrots and parsnips show stunted growth, discoloration, and are unsuitable for fresh market sales. Severe infestations can cause significant yield losses and make entire harvests unmarketable.

• Use crop covers or barriers to prevent egg-laying near seedlings.
• Rotate susceptible crops with non-host plants to reduce soil populations.
• Avoid thinning carrots during peak egg-laying, as plant odors attract adults.
• Monitor adult activity with sticky traps to time interventions.

The most effective and sustainable way to control carrot fly is by applying beneficial nematodes. These microscopic organisms naturally occur in the soil and specifically target carrot fly larvae. Once applied, they actively search for larvae, penetrate them, and release symbiotic bacteria that kill the host within days. After reproduction inside the larvae, new nematodes are released into the soil to continue the control cycle.

Koppert offers Capirel (Steinernema carpocapsae), a beneficial nematode product highly effective against carrot fly larvae and pupae.

For best results:

• Apply Capirel when larvae are present in the soil, usually following adult flight and egg-laying peaks.
• Ensure soil is moist before, during, and after application to allow nematodes to move and infect larvae.
• Apply in the evening or on cloudy days to avoid UV exposure.

With correct timing and application, Capirel provides a safe, natural, and effective solution to protect carrots and other root crops from carrot fly damage.