This insect attacks the seeds of many warm-season vegetables planted early when soil is still cool and often damp. Germinating seeds are eaten before seedlings appear above ground. Particularly vulnerable are the seeds of bean, corn and sometimes melon and cucumber. Though pea is a cool-season vegetable recommended for early spring planting, the maggot will attack pea seeds if they take a long time to germinate because of saturated or cold soil. Young plants of cabbage, beet, onion, turnip, spinach, potato and radish occasionally may be nibbled as well.
Maggots burrow in seed, either causing failure to sprout, or producing a weak, sickly plant.
Additionally, the insect transmits a bacteria that causes soft rot. The primary way to control the seed corn maggot is simply waiting until soil is warm enough to allow quick germination and rapid growth. In additional, avoid the application of fresh manure directly to your garden soil. The decaying organic matter from fresh manure attracts the egg-laying adult stage of the maggot. You can use fresh manure, but only in fall.