Seedcorn maggot

Definition

The larval stage of Delia platura, a small anthomyiid fly that burrows into germinating seeds and seedlings of corn, beans, and other crops, causing stand reduction and economic damage in cool, wet spring soils. The maggot is pale, legless, and tapered, reaching about 7 mm before pupation; adults resemble small gray house flies. The species is holarctic and among the most widespread seed-feeding dipteran pests of row crops.

Etymology

From 'seedcorn' (seed planted for crop production, especially maize) + 'maggot' (larva of a dipteran fly), referring to the larva's habit of infesting planted seeds.

Example

In the Midwest United States, seedcorn maggot damage is most severe when fields are plowed green manure or cover crops shortly before planting, as decaying organic matter attracts egg-laying females; economic thresholds often trigger preventive seed treatments with neonicotinoid or organophosphate insecticides.

Synonyms

• bean seed fly larva

Related Terms

• Delia platura
• Anthomyiidae
• root maggot
• seedling pest
• Integrated Pest Management
• Economic threshold

Usage Notes

The term refers specifically to the larva, though it is often used metonymically for the species Delia platura. Contrast with cabbage maggot (Delia radicum) and onion maggot (Delia antiqua), related congeners with narrower host ranges. Damage is often mistaken for poor seed quality or soil-borne pathogens; diagnostic confirmation requires excavating seedlings to find the characteristic white larvae feeding on the cotyledons or below-ground stem.