Avoid The Scorn Of Seedcorn Maggots

Photo by Whitney Cranshaw
Photo by Whitney Cranshaw, Colorado State University

Pest Specs

The seedcorn maggot (Delia platura Meigen) or bean seed fly is a small fly closely related to the cabbage maggot and the onion maggot. It is a sporadic pest on germinating seeds of corn and many other agronomic and horticultural plants.

Identification

The pest is cosmopolitan occurring on all continents except Antarctica. Seedcorn maggots damage newly planted seeds by feeding on seed contents, often leaving empty seed shells and preventing germination. Seedlings that germinate despite the damage are spindly, with few leaves, and die before maturation. Usually a small percentage of the seedlings get infested by this insect. But in severe cases, as much 30% to 60% plant loss may occur in the field.
The adult seed corn maggot is a brownish-gray fly with three stripes on its back. They resemble a small house fly but are about half the size and hold their wings crossed over the abdomen at rest.
The legless larvae maggots are dirty white with a yellow tint, legless, cylindrical, and tapered in shape. Fully grown maggots are about ¼-inch long and have a pointed head with two black mouth hooks. The abdomen is blunt with two brown to black spiracles at the posterior end.
This pest is associated with organic matter such as manure and plant residues. Seedcorn maggot activity increases during years when conditions are cool and damp and seeds germinate slowly. They may be more common in reduced-tillage systems as the decaying organic matter from crop residues is an ideal ovipositional site for the insect.

Survival And Spread

The flies mate within a few days after emerging, and each female lays an average 270 eggs in soil high in decaying organic matter and/or on seeds or plantlets in moist soil. Females lay eggs near food sources and tend to deposit more eggs near the base of newly emerged seedlings. The eggs are white, deposited in loose groups among organic debris and around plant stems near the soil surface.

The larval period lasts nearly 21 days and the maggots develop over a wide temperature range. They complete their entire development within the soil by burrowing into and feeding on seeds or emerging cotyledons. Larvae also can survive as soil saprophytes.
The insect can pass through up to five generations per year in the South, and adults are common in the fall, early winter, and spring seasons. However, few are seen in mid-summer as they appear to be intolerant of high temperatures. Since much of the life cycle is spent protected underground, the seedcorn maggot does not appear to have many natural enemies.

Management Methods

Preventative measures include late planting, shallow planting, higher seeding rates, well-prepared seedbed, and turning undercover crops early, which renders fields less attractive to egg laying.
Insecticidal seed treatment is the cheapest and most effective treatment for the control of seedcorn maggots. Granular insecticides also can be used for control.
Consult UF/IFAS recommendations for currently labeled insecticides for seedcorn maggot control.

Topics: , ,

Leave a Reply

Crop Protection Stories

Insect ControlFlorida Vegetable Growers Gain Access To New Nematicide
November 20, 2014
Methyl bromide alternative Nimitz approved for use on tomatoes, peppers, okra, eggplant, cucumber, watermelon, cantaloupe, and squash. Read More
Apples & PearsFall Sprays For BMSB Can Cause San Jose Scale Flare Up
November 18, 2014
Penn State University research entomologist says prevention is best control option for devastating pest. Read More
Insect Control5 Sweet Corn Pests Florida Growers Need To Guard Against
November 13, 2014
These foes can take a bite out of yields and quality. Read More
Disease ControlPH-D Fungicide Now Available For Additional Crops In California
November 11, 2014
Arysta LifeScience receives supplemental label for fungicide for The Golden State. Read More
Disease ControlNew Mechanism Developed To Prevent Tomato Wilting
November 3, 2014
The mechanism aids in the resistance and susceptibility of a fungus associated with wilt. Read More
CEU SeriesCEU Series: Pesticide Labels Are A Must-Read
November 1, 2014
Be cued into what's on the container as well as safety data sheets. Read More
Crop ProtectionThe Unlikely Parallel Between Human And Plant Health
October 31, 2014
One of the notable national developments in the summer of 2014 was the unexpected occurrence of serious respiratory infections in Read More

The Latest

Crop ProtectionThe Unlikely Parallel Between Human And Plant Health
October 31, 2014
One of the notable national developments in the summer of 2014 was the unexpected occurrence of serious respiratory infections in Read More
CitrusUSDA To Provide $4 Million For Honey Bee Habitat
October 29, 2014
The funds will go toward helping growers implement conservation practices to improve honey bee health. Read More
CitrusEPA Launches Program To Reduce Pesticide Drift
October 22, 2014
The voluntary star-rating program aims to protect people, wildlife and the environment. Read More
Crop ProtectionTool Helps Track Insects On The Move At Night
October 1, 2014
Signals collected by the National Weather Service’s Doppler radar network may serve as an early warning system to track corn earworm, a major pest in sweet corn. Read More
Crop ProtectionCalifornia To Ban Some Pesticides In San Joaquin Valley
September 24, 2014
Chemistries with high Volatile Organic Compounds are used on pistachios, almonds, walnuts, grapes, and citrus crops. Read More
Crop ProtectionBagrada Bug On The Move In California
September 16, 2014
Find out more on management tactics and what counties are impacted by this invasive pest. Read More
Crop ProtectionNimitz Nematicide Receives EPA Approval
September 12, 2014
New product from Adama has a unique mode of action and is approved for use on a variety of vegetables. Read More
Crop ProtectionGiant Snail Threat Spreading In South Florida
September 10, 2014
Dangerous invasive pests found well outside Miami-area hot zone. Read More
Crop ProtectionStockton’s Timorex Gold Biofungicide Receives EPA Reg…
September 9, 2014
This broad spectrum fungicide can be used in rotation or in a tank mix. Read More
CitrusFMC Acquires Cheminova
September 9, 2014
Transaction expected to close in early 2015. Read More
Crop ProtectionBayer Opens Worldwide Biologics R&D Center In Calif…
September 5, 2014
$80 million facility will also be used to develop vegetable seed. Read More
Crop ProtectionHow To Control Corn Earworm, European Corn Borer In Swe…
September 5, 2014
Monitor traps, plant varieties with good husk cover, and rotate modes of action to avoid resistance. Read More
Crop ProtectionMost Fresh California Produce Has Little/No Detectable …
September 4, 2014
State Department of Pesticide Regulation finds that 95% of produce was in compliance. Read More
Crop ProtectionGetting To The Root Of Good Soil Health Requires Some D…
August 21, 2014
Dave Gilliam of Horticultural Alliance says more citrus growers are paying attention to what's happening below the ground in their groves. Read More
Crop ProtectionBioConsortia Inc. Bolsters Executive Team
August 18, 2014
Industry veterans Christina Huben and Dr. Susan Turner bring experience to plant biotechnology firm. Read More
Crop ProtectionCover Crop Solutions Offers New Three-Way Cover Crop Mi…
August 13, 2014
A fast-growing cover crop mix needs 45 to 60 days of growth in warm conditions. Read More
Crop ProtectionBiopesticides Vs. Traditional Agrochemicals
August 4, 2014
To effectively control pests, understand how the products work and know the biology of insect pests. Read More
Crop ProtectionFrench Crop Protection Firm Acquires Fine Holdings Ltd.
August 4, 2014
De Sangosse group seeks to bolster its business with purchase of plant growth regulator specialist. Read More