Back to top

Section 26.6.3: Seedcorn Maggot

Delia platura

Time of concern: Late April through June. Seed sprouting through emergence
Key characteristics: Adult flies are slender, 3/8 inch long, and grayish black in color. Maggots are yellowish white. Infested seeds and other plant parts are hollowed out. Damaged plants are weak and may not develop. Stand may be poor. 

Management Option Guideline
Scouting/thresholds

No thresholds have been established.

Fresh Market Sweet Corn IPM Scouting Procedures

Natural enemies

Predators, parasitoids, and pathogens, including nematodes help suppress infestations. Use Natural Enemies of Vegetable Insect Pests for identification of natural enemies.

Resistant varieties No resistant varieties are available.
Site selection Root maggot adults prefer soil with decomposing organic matter. Incorporate crop or cover crop residues well before planting and allow 2-3 weeks between incorporation and planting.  Do not spread manure directly before planting. Avoid low, wet areas. The threat of seedcorn maggot diminishes greatly if the crop is planted after the third week in June.
Seed selection/treatment Buy treated seed or use an insecticide at planting.
Note(s) Shallow planting and other means to speed up germination and emergence will reduce damage.
Crop rotation,
Postharvest, and

Sanitation
These are not currently viable management options.
Pesticides Cornell Integrated Crop and Pest Management Guidelines for Commercial Vegetable Production