Call for volunteers! Help us monitor for adult corn rootworms in 2025

Western and northern corn rootworms are serious corn pests in Iowa and the Corn Belt. These pests readily adapt to management tactics, especially in continuous corn production. The larvae consume corn roots, thereby reducing nutrient and water uptake and causing stalk lodging. The adults also feed on above-ground parts of the plant, including silks and pollen, which may interfere with pollination.

The regional rootworm trapping network enters its sixth year in Iowa. We will be monitoring corn rootworm adults throughout Iowa to get a sense of how populations vary across the state, both in numbers and in species composition (ratio of westerns to northerns). Since this is a huge undertaking, we are asking for volunteers to monitor sticky traps this summer. We will compile data and report findings later this year.

Want to be a volunteer trapper?

If you are interested in volunteering to set up and monitor traps for corn rootworm or would like additional information, send an email to bugtraps@iastate.edu by June 20, 2025. Please include your contact information and mailing address in the email. As part of the Iowa corn rootworm monitoring network, we provide traps to each cooperator to monitor one transect for four weeks. Traps are provided at no cost to the cooperators in 2025.

Traps and a protocol will be mailed to you in late June or early July. It can take over a month for the emergence of adult corn rootworms to be complete, depending on degree day accumulation, but we aim to capture peak emergence through our network. Trapping will likely begin during the second week of July.

If a cooperator is interested in continuing to monitor after the four weeks are up or wants to place more traps in their field, or if our free traps run out, additional traps may be purchased from several retailers. Details on where to purchase sticky traps can be found on the Corn Rootworm IPM website. To learn more about the Regional Corn Rootworm Monitoring Network and corn rootworm and see summaries of previous trapping seasons, visit our website.

Regional network

For the fourth year, we have partnered with extension, government, and industry personnel in several U.S. states and Canadian provinces to synchronize our data collection efforts and provide a regional perspective on corn rootworm activity. This partnership allows our cooperators to enter their data into an online database called Survey123. This is a web-based data entry system that cooperators can use for free without creating an account. It allows cooperators the autonomy to enter their own data, and the data will be used for live mapping of rootworm populations that will be publicly available on a webpage.

More information on Survey123 will be provided via email in late June, and you can opt in at that time. If you participated in the trapping network in the past, the data entry protocol is similar, and you will be able to reuse those sites. Cooperators are not be obligated to use the application to enter data; people can email their data to bugtraps@iastate.edu, which will be kept for our use only or we could enter the data online for you if you wish.

How can this help farmers?

Aside from providing data to us, we hope these traps provide the volunteer valuable insight for their field or a client’s field and that this information can be used by farmers, crop consultants, and agronomists who make better management decisions. High adult activity may be concerning and indicate issues for the following growing season. It should be noted that four traps per field is a small sample and will not completely represent adult activity in that field. Implementing multiple transects is ideal for understanding adult density, so use caution when making management decisions based on a single transect.