University of Maryland Extension

Maryland Corn Earworm Moth Map

Andrew Kness
Maryland moth map screenshot

If you’re spraying non-GMO corn to manage corn earworm, then check out our new website for monitoring populations at There you’ll find up-to-date catch counts for pheromone traps located across Maryland. Just click on a pin to display the most recent 5-day total. These 5-day totals are used to calculate your recommended spray interval, which you can see by clicking “Spray Rate” in the top right corner of the page. This website also works on mobile devices.

If moth populations are high enough to warrant an insecticide application, be sure to use products that have efficacy and be sure to rotate modes of action in order to reduce the development of resistance. Some earworm populations are developing resistance to pyrethroids (Group 3A insecticides). Consult your local Extension Agent for more information, or reference the Mid-Atlantic Commercial Vegetable Production Recommendations for a list of effective insecticides. Always be sure to read and follow all pesticide labels before application. It should also be noted that GMO hybrids with the Vip3A protein provide nearly 100% control of corn earworm, which you may want to consider for future crops.

Maintained by the IET Department of the College of Agriculture and Natural Resources. © 2021. Web Accessibility

University programs, activities, and facilities are available to all without regard to race, color, sex, gender identity or expression, sexual orientation, marital status, age, national origin, political affiliation, physical or mental disability, religion, protected veteran status, genetic information, personal appearance, or any other legally protected class. If you need a reasonable accommodation to participate in any event or activity, please contact your local University of Maryland Extension Office.