The appearance of insects on garden vegetables is a nightmare for many gardeners, and some infestations are worse than others. Root maggots are some of the worst pests that you can have. Infecting cabbage, broccoli and other cole crops, the maggots dig in and eat the roots, which effectively destroys the entire crop. Rid yourself of these maggots before they kill your vegetables.
Run your hands up and down the plants as well as the surrounding soil. Crush any eggs (they look like grains of rice) you find to prevent the bugs from hatching. You may find eggs if it's early in the season.
Set up sticky insect traps in your garden to capture any flies that have grown from the maggots. If you catch them early enough, they will be unable to lay eggs to propagate the maggot population.
Coat the surrounding soil with diatomaceous earth, a naturally occurring soil that can kill maggots in their early stages. Lay a 2- to 3-inch layer of this soil (available from garden centres and nurseries) around your plants to kill the maggots.
Cover the soil around the base of the infected plants with floating row covers, available from garden centres and nurseries. Staple the covers to wooden stakes spread throughout your garden; be sure the edges are completely sealed. Row covers will prevent the maggots from emerging from the soil to feast on your plants or to lay their eggs, effectively eliminating the population in one season.
Consult a local extension service, or professional garden centre or nursery, for details regarding chemical control of root maggots. Many chemicals are available only to professionals, while some areas have strict limitations on what you can use to treat bugs. Crop rotation will help to limit or eliminate the root maggots. Because you rotate your crops, the maggots won't have anything to eat after a single planting season, and thus will die off. Natural predators such as nematodes can also help control maggot populations. Consult with a local extension service or nursery about safely introducing these tiny creatures into your garden.