Maggots in your soil are usually root maggots. You may be able to identify an infestation of root maggots without actually seeing the insect because of the presence of stunted or wilted plants. The best way to tell if maggots are the culprit is to look at the wilted plant's roots. If maggots are the problem, there will be either maggot larva present or roots that look eaten away or tunneled through.
This maggot is easily identified. It is yellowish-white and legless, between 1/4 and 1/3 inches long, with a tapered head and blunt rear end. If you find this creature in your soil, it needs to be destroyed. It is significantly destructive to young plants. The maggot tunnels into the sprouting seed and causes the plant to stop developing. It also bores into developed plants' roots and stems, causing the infected plant to rot and eventually die.
Get rid of infested plants immediately when you discover maggots. Maggot flies are attracted to dying plants. Do not compost these plants; dispose of them in the trash or burn them. At the end of the season, you should remove crop debris or plow it under immediately after harvest in order to avoid drawing maggot flies to your soil.
There are many effective organic options with which to fight the maggots in your soil. Beneficial nematodes or rove beetles feed on maggots and can be added to your garden. These insects can be purchased at any garden supply store. Diatomaceous earth, also available in any garden or farm store, can be dusted on your plants to repel maggots. Another easy natural maggot prevention method is to cover plants with floating row covers.
Chemicals may also be effectively used to fight your soil maggots. Apply liquid pesticides to your garden soil at the beginning of the season and soak the soil thoroughly. Be aware that beneficial insects may also be killed by the product application. Use only registered insecticides and read product labels very carefully because pesticide labels change frequently. If you have any questions on what insecticides or pesticides are registered and how to use them, contact your local university extension program.