- Carrot flies are a major pest of the whole carrot family. The main host plant is carrots but they also attack celery, celeriac, parsnips and parsley.
About Carrot fly
- Adult carrot flies are part of a group known as stilt-legged-flies. They have long orange legs, a black body and a red/brown head. They're about 4-5mm long and poor fliers.
- The larvae of the carrot fly are the major cause of plant damage.
- They are maggot-like in appearance, growing to about 10mm in length and are creamy yellow in colour.
- Carrot fly pupae are brownish yellow in colour and are found in the soil.
- Carrot fly larvae often cause widespread damage since they move through the soil feeding on different roots.
- Adult carrot flies overwinter below ground and emerge in the spring to mate.
- The first generation of eggs are laid into the soil surrounding the host plants.
- A second generation emerges in July and August. It's this generation that overwinters in the soil.
- Occasionally there can be three generations a year if environmental conditions are favourable.
- If carrot or parsnip canker spores are present within the soil, they can often infect the areas where carrot root fly larvae have been feeding. This causes a rust colouration of the affected areas.
Products containing the following chemical ingredients are all effective on Carrot fly
- There are no approved insecticides currently available to amateur gardeners.
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
- Regular checks for damage or infestation.
- Crop containment, for example, covering plants with a fleece barrier.
- Choose growing sites that are fairly open and exposed.
- Remove damaged plants to reduce the smell of carrot which attracts the flies.
- Companion plant with strong smelling plants to mask the carrot smell, such as onions.
- Avoid sowing susceptible plant seed during the early spring and late summer when carrot flies will be laying eggs.
- Thin seedlings in the evening when adult flies are less active and then destroy all thinned plants.
- Firm the soil around the plants after thinning as this deters the flies from laying eggs.
- Check the crop regularly for signs of infestation and promptly remove any affected plants.
- Grow less susceptible varieties, such as 'Fly Away' and 'Resistafly', which are low in phenolic acid.
- During the winter, thoroughly fork through the soil where susceptible plants will be grown. This should expose overwintering carrot flies to frosts and predators.