Divisi
Carrot fly
Chamaepsila rosae · Insect
Photo: Emanuele Santarelli · CC BY-SA 4.0
Carrot fly (Chamaepsila rosae) is a small, low-flying fly whose maggots tunnel through the roots of carrots and their close relatives — parsnip, celery and parsley. The females are drawn by the scent of the foliage, strongest when the leaves are bruised during thinning or weeding, and lay their eggs in the soil at the base of the plant. The maggots that hatch mine down into the root, leaving rusty-brown tunnels that spoil the crop for sale and storage and open the way to rots.
Why it matters
Carrot fly is the pest that ruins your carrots from the inside. Its maggots bore rusty tunnels through the roots so they can't be sold, stored or eaten, and a bad attack can spoil up to 2 in every 5 roots (40%). You won't see the damage until you pull a root up — and once the maggot is tunnelling inside, no spray can reach it. That is why, with carrot fly, keeping the fly out is not just one option, it is the whole battle.
When to act
adult flies caught on yellow sticky traps, or first rusty tunnels seen when sample roots are lifted
This guidance is general, compiled from published agronomic references including FAO and CABI. Thresholds and timing shift with your crop, your variety and the season.
In much of the region a spray is simply called mushonga — medicine. But a chemical group you cannot name is one you cannot rotate, and a product you did not write down has no pre-harvest interval you can observe. Mushonga, and other farming words →
The full carrot fly field guide
- Identify it
- Scout for it
- Control it
15 field-guide sections in the app
The full guide to carrot fly — every symptom to check, how and when to walk your field looking for it, and the controls that actually work, ranked. Built into your crop plan, so you are told to look before it costs you a harvest.
Crops it affects
Frequently asked questions
How do I identify carrot fly?
The first thing you notice (above ground): scattered single plants whose leaves turn a dull red-bronze, then yellow, sometimes stunted or wilting in the heat of the day while the plants right around them stay green. Reddening in odd patches like this is your warning — the real trouble is hidden below, in the root.
When should I take action against carrot fly?
adult flies caught on yellow sticky traps, or first rusty tunnels seen when sample roots are lifted
How do I control carrot fly?
Prevent — cover the bed (your best defence). Put fine insect-proof mesh or fleece over the bed from the day you sow, tucked in and weighted down all round so no fly can creep under the edge. The females simply cannot reach the plants to lay — this is the single most reliable control a smallholder has against carrot fly. Because the fly flies so low, a mesh barrier about knee-to-waist high (60–75 cm) around a small bed works the same way, walling the low-flying females out.
Which crops does carrot fly affect?
Among the crops covered here: Carrot.
Catch it before it costs you a harvest
Divisi builds scouting into your crop plan — it tells you when to walk your field, what to look for at that stage, and what to do when you find it. Free for farmers, works offline.
Check what grows on your farm