Maggots may overwinter in the soil or hatch from eggs laid in spring. The maggot attacks germinating seeds or transplants, but is only a pest early in the season before the soil warms up.
Little damage is likely to occur once favorable growing conditions set in.
Seedcorn maggots are particularly damaging when residues of the previous crop have not thoroughly decayed before planting cucurbits. To reduce attractiveness of the field to egg-laying adults, disc or plow early in the season to incorporate residues from the previous crop and allow time for residues to completely decompose. Destroy weed growth. Avoid planting cucurbits after root crops or cole crops, including cabbage, cauliflower, broccoli, and brussels sprouts, and after fall tomatoes. The longer the germination, the greater the risk of infestation.