UC IPM Online UC ANR home page UC IPM home page

UC IPM Home

Search

SKIP navigation

Home & garden
Agriculture
Natural environments
Exotic & invasive

Weather data & products
Degree-days
Interactive tools & models

Publications & more
Workshops and events
Training programs
Pesticide information

Grants programs
Funded-project results


 

How to Manage Pests

Pests in Gardens and Landscapes

Corn earworm—Helicoverpa zea

Larvae have distinct stripes along sides and many short, whiskerlike spines over the body surface. Body color varies.

Identification of species | Life cycle

Damage

Larvae eat through kernels of ears and leave frass. The pest feeds on the developing tassels in the whorls of the plant. Damage is usually limited to the first 2 to 3 inches of the ear.

Solutions

Corn early planted is not as seriously affected as is late corn. Consider not treating, and cut off damaged ends of corn at harvest. Applying a few drops of mineral oil with a medicine dropper to silks just inside each ear 3 to 5 days after silks first appear may be effective. Applications of insecticides, such as spinosad must be applied on silks within 3 days after first silks appear and at 3-day intervals until silks turn brown. Bacillus thuringiensis, a biological insecticide, may be dusted on silks every 3 days after 5 to 10% silk formation for partial control. Destroy culls and plants immediately after harvest. General predators and Trichogramma or Hyposoter parasites have limited impact.

Cornworm larva
Earworm larva feeding in tomato fruit
Feeding on tassels
Feeding on tassels

Feeding on kernals
Feeding on kernals


Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2008 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See How to manage pests, or in the U.S., contact your local Cooperative Extension office for assistance. /PMG/GARDEN/VEGES/PESTS/cornworm.html revised: January 17, 2008. Contact webmaster.