Three Pests That Affect the Carrot

Carrot Rust Fly

• Keep your eye peeled for carrot rust flies from late May through the end of June, and then again from late July through the end of September. You can recognize these shiny, black flies by their red heads and long, yellowish legs. Carrot rust flies will lay their eggs in the soil surrounding your young carrots. As the eggs hatch, the larvae will feed on the root hairs until their third molt. At this point, they will burrow into your carrots to complete their development into adult flies. You can tell your carrots have been infested if they have yellow foliage and especially hairy roots. You should also be able to see black feeding tunnels in the lower portion of the roots.

Carrot Weevil

• Carrot weevils are dark brown snout beetles that lay their eggs directly in carrots at the first true leaf stage. Each female will lay two or three eggs in a cavity at the crown of a carrot, then seal the cavity with a black substance. After the eggs hatch, the larvae will burrow deeper into the carrot's root. You can tell that your carrot has been hit by carrot weevils if the foliage wilts and there are black tunnels in the carrot's crown. These are the larvae's feeding tunnels.

Aster Leafhopper

• Aster leafhoppers are very small, slender, greenish-black, winged insects that will feed on a wide range of cultivated plants and weeds. They are active throughout the spring and summer, and a single summer can see five generations of this pest. Look for Aster leafhoppers around your carrots from early May through late July. Aster leafhoppers will eat your carrots, and some of them carry a mycoplasma-like organism called AY-MLO, or aster yellows. AY-MLO will cause the roots of your carrots to grow thick, black hair and the foliage on your plants will turn yellow.

What You Can Do To Fight Pests

• Monitor your garden for carrot rust flies and aster leafhoppers by hanging a few sticky traps around your carrots. Both types of flying insect will get stuck to these traps, and you will get a good idea of whether you have a problem in your garden. You can monitor the presence of carrot weevils with wooden-plate traps. Once you detect the presence of any type of pest, remove the affected carrots immediately. This is especially important if the carrots have been exposed to AY-MLO. All three types of pest can be treated with commercial garden pesticide. You can also discourage pests by removing any weeds from your garden.