Corn: Seedcorn Maggot (Delia platura)


Pub 812: Field Crop Protection Guide > Chapter 1: Corn > Seedcorn Maggot

Field Crop Protection Guide 2011-2012, Order 2011-2012 publication

Table of Contents

  1. Description
  2. Integrated Pest Management Options
  3. Related links...


Description

The seedcorn maggot is a small, yellowish-white, headless, legless larva. The body tapers to the front with two small mouth hooks protracting. The maggots burrow into germinating seeds and the below-ground parts of emerging seedlings, producing weak seedlings. The adults resemble a small housefly that is slender, light grey and approximately 5 mm in length.

Image 1. Seedcorn maggots are small, headless, legless larvae that burrow into germinating seeds and weaken the seedling.
Image 1. Seedcorn maggots are small, headless, legless larvae that burrow into germinating seeds and weaken the seedling.


Integrated Pest Management Options

Seed Treatment

Seedcorn maggot problems in corn are extremely rare in Ontario. Use seed treatments in high-risk fields where large amounts of manure, green manure or residue have been recently incorporated, in fields that are freshly tilled or when cool, backward emergence conditions exist.
For all seed treatments use full rate and ensure good coverage of seed.

 
Active ingredient diazinon + captan
Trade name Agrox B-2
Rate (product) 340 g per 100 kg seed
Comments Available as 2 kg container that will treat 600 kg of corn seed. Do not use on seed already treated with an insecticide. Seed within 1 month of treatment. Seed-applied insecticides can affect seed drop and final plant stands. Use talc or graphite according to planter recommendations to ensure planting accuracy.

 

 
Active ingredient diazinon + captan
Trade name Agrox CD
Rate (product) 200 g per 100 kg seed
Comments Available as a 600 g container that will treat 300 kg of corn seed. Use this product only on seed previously treated with captan or thiram. Seed-applied insecticides can affect seed drop and final plant stands. Use talc or graphite according to planter recommendations to ensure accuracy.

 

 
Active ingredient clothiandin
Trade name Poncho 250
Rate (product) 33.3 mL per 80,000 kernels
Comments For use in commercial seed treatment facilities only. Seed-applied insecticides can affect seed drop and final plant stands. Use talc or graphite according to planter recommendations to ensure planting accuracy. A 30-day plantback interval for cereal grains, grasses, soybeans and dried beans is required.

 

 
Active ingredient thiamethoxam
Trade name Cruiser 5 FS
Rate (product) 16.7-33.3 mL per 80,000 kernels
Comments For use in commercial seed treatment facilities only. Seed-applied insecticides can affect seed drop and final plant stands. Use talc or graphite according to planter recommendations to ensure planting accuracy. Do not graze or feed livestock on treated areas for 45 days after planting.

 


Soil-Applied at Planting Only

In-furrow application is safer to the applicator and non-target animals than T-band application.

 
Active ingredient tefluthrin
Trade name Force 3 G
Rate (product) 37.5 g per 100 m (328 ft) row
Comments In-furrow application only. Place directly in the seed furrow behind the plander disc openers.

 


Related links...

 


For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca
Author: OMAFRA Staff
Creation Date: 2 May 2011
Last Reviewed: 10 May 2011