Pumpkin and squash-Seedcorn maggot

Delia platura

Pest description and crop damage The seedcorn maggot adult is a slender, light gray fly about 0.19 inch long. It looks much like a small housefly. The whitish eggs have slightly raised ridges running the length and width of the eggs forming tiny rectangles. Larvae are about 0.25 inch long, white to whitish yellow, cylindrical, and tapered, with the smaller end in front. Pupae are small brown capsules. The seedcorn maggot is abundant during or following a wet cycle, primarily in spring, and is most common in fields containing a high amount of residue from a previous crop or where manure has been spread. Seedcorn maggots burrow into seeds and developing embryos in the ground, damaging and destroying seeds and creating sites for rot. They may spread bacterial soft rot.

Management-biological, cultural, tactical

See:

Management-chemical control: HOME USE

  • bifenthrin (granular form)
  • zeta-cypermethrin

Management-chemical control: COMMERCIAL USE

Seed treatment

  • chlorpyrifos (Lorsban 30F) at 2.75 fl oz/cwt seed. Use as a slurry seed treatment prior to planting. Mix with seed, water, and a suitable methyl cellulose sticker as directed on the label. Pumpkin only. Toxic to fish. Oregon only.

Note: Pesticides may injure cucurbits. The possibility of injury is less when foliage is dry at time of application.