Le Mars, Iowa Pest Guide

Updated 2026-10-22 · By Kasey, Waukee, Iowa

• Plymouth County
• Western Iowa
• 4 listed companies
• 12 sources

Le Mars is the county seat of Plymouth County. It sits on the Floyd River northeast of Sioux City and is part of the Sioux City metropolitan area, and its population was 10,571 in the 2020 census. Le Mars is the home of Wells Enterprises, maker of Blue Bunny ice cream, and calls itself the "Ice Cream Capital of the World."

This page pulls together the pest issues Le Mars homeowners tend to run into, local places to get help, and how to check that a pest company holds a current Iowa license.

What Le Mars homeowners see through the year

These seasonal patterns come from ISU Extension, which covers the whole state:

• Ants (spring). Wet springs bring busy soil-nesting ants and mounds in lawns. ISU's advice is usually to rake or hose the mounds flat. Our Iowa ant guide covers ants indoors too.
• Yellowjackets (late summer). Colonies grow from a single spring queen to as many as about 5,000 wasps by Iowa State Fair time, ISU says. If you find yellowjackets indoors after a frost, ISU says they almost always come from a nest inside a wall. Read wasp nest removal before you go near one.
• Fall invaders (September-October). ISU says boxelder bugs, Asian lady beetles and stink bugs can't reproduce indoors and are mostly a nuisance. Exterior treatments only help if they're applied before the insects move in.
• Mice (fall). Native deer mice and white-footed mice look for winter shelter in homes, ISU says. Our guide on mice in your Iowa home covers sealing, trapping and safe cleanup.

Emerald ash borer in Plymouth County

Plymouth County does not appear on the state's 2022 list of confirmed emerald ash borer sites. IDALS announced in October 2024 that the beetle had been confirmed in all 99 Iowa counties, so Le Mars-area ash trees should be treated as at risk. IDALS says an infested tree is typically killed within two to four years. Signs include canopy thinning, leafy sprouts from the trunk, S-shaped galleries under the bark, bark splitting, woodpecker damage and 1/8-inch D-shaped exit holes. If you own ash trees, talk with a qualified tree care professional.

Local help in Le Mars

• County Extension office: ISU Extension and Outreach Plymouth County lists its office at 251 12th Street SE, Le Mars, IA 51031 (phone 712-546-7835). Extension offices are a good first stop for research-based yard, garden and pest information.
• Insect identification: the ISU Plant and Insect Diagnostic Clinic in Ames identifies insects mailed in by Iowans. Check its page for current forms and fees.
• Ticks: ISU's Medical Entomology Laboratory offers a free tick identification service by mail. It identifies the tick but does not test it for disease.
• Mosquitoes: the same ISU lab has run Iowa's mosquito surveillance program for about 50 years with state health partners, monitoring West Nile virus and mosquito numbers. Current data is on the Iowa Mosquito Surveillance website linked from its page.

Guides for Le Mars homeowners

• Ant Exterminator Near Waukee: What to Expect and How to Choose a Pro
• Bed Bug Signs and What to Do in the Des Moines Metro
• Boxelder Bugs in Iowa Homes
• How to Get Rid of Ants in Iowa
• Mice in Your Iowa Home This Fall
• Wasp Nest Removal Near Waukee, Iowa

How to check a pest company's license in Le Mars

Iowa requires anyone in the business of applying pesticides to another person's property to be licensed and certified by the state. To check a company:

1. Open the IDALS license lookup and choose Search By Company/License.
2. Type part of the company's name, or pick the county PLYMOUTH - 75 to see every company registered there.
3. Check that the expiration date is in the future. Expiration dates in the lookup fall on December 31.

When we searched Plymouth County on 10/22/2026, the lookup returned 87 company records. That count includes every license type (lawn care, agriculture, golf courses and pest control) and some expired records, so narrow it down by name. A company is listed under the county of its own address, so a company that serves Le Mars may be listed under a neighboring county. Our guide on choosing a licensed pest pro has a checklist of questions to ask.

Frequently asked questions

What county is Le Mars in?

Le Mars is in Plymouth County, Iowa. The county matters for two things: which ISU Extension office is closest, and which county to choose in the IDALS license lookup.

Has emerald ash borer reached Le Mars?

Plymouth County isn't on the state's 2022 site list, but IDALS confirmed EAB in all 99 Iowa counties in October 2024.

How do I know a pest company in Le Mars is licensed?

Search the company's name in the IDALS lookup and check that the expiration date hasn't passed. A company saying it's licensed is not the same as a current state record.

Is the Plymouth County Extension office in Le Mars?

Yes. ISU Extension and Outreach Plymouth County lists its address as 251 12th Street SE in Le Mars. Its phone number is 712-546-7835.