Western conifer seed bugs in Michigan, the big fall bug that isn't a kissing bug

In August 2026, a Detroit homeowner snapped a photo of a big bug, and Google said "kissing bug." So they asked MSU Extension. The answer: a seed bug, and harmless. If you're in the same spot, don't panic. Here's how to tell.

What is this big bug on my window?

Check the back legs first. Flat, leaf-like flares mean a western conifer seed bug. It's brown on top and about 3/4 inch long, MSU says. The flare sits partway down each back leg. The Montreal Insectarium calls it a leaf-footed bug. You may also see a thin white zigzag across the middle of the wings. Penn State says it can be darker, or not there at all.

When it flies, you'll hear it. MSU says the loud buzz sounds like a bumble bee. Outside, MSU says, it feeds mainly on the seeds and young cones of conifers.

Western conifer seed bug or kissing bug: how do you tell?

Look at the head and the back legs. A kissing bug has a thinner head, Minnesota Extension says, and its legs are thin, with no leaf-like flares. Ohio State points to the cone-like shape at the front of its head. The seed bug's head is wider, and you can't miss those flat flares.

If you mixed them up, you're not alone. Minnesota says they're a similar color, size and shape. In Chile, researchers got 74 bugs sent in as kissing bugs in 2018 and early 2019, and 63 of them were western conifer seed bugs. That's 85%.

Look-alikes

Western conifer seed bug or kissing bug?

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Western conifer seed bugLeptoglossus occidentalis

vs

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Kissing bugEastern bloodsucking conenose

How to tell a western conifer seed bug from a kissing bug

Look at	Western conifer seed bug	Kissing bug
1Head	Wider	Thinner, with a cone shape at the front
2Back legs	A broad, flat, leaf-like flare on each	Thin, with no leaf-like flares
3Wings and edge	A thin white zigzag across the wings; it can be faint or missing (barely there on this one)	Orange or red stripes around the edge of the body
4Food	Seeds and young cones of conifers, like pines	Blood, from animals or people

Are there kissing bugs in Michigan?

They haven't been reported here. MSU said in August 2026 that kissing bugs aren't found in Michigan and occur naturally in the southern US. The CDC's map of states that have reported them leaves Michigan out. Ohio, Indiana and Illinois are on it. Texas A&M says kissing bugs are found in 29 states, and are probably rare in Indiana and Illinois, where they've only been found a few times.

Ohio does have its own kissing bug. Ohio State has had reports mostly from counties in the south of the state, and it says there's been no reported case of Chagas disease caught in Ohio. You may have seen a 2019 headline saying a kissing bug was "confirmed in Michigan." The CDC's map doesn't back that up.

We checked iNaturalist, too, where people post bug photos and others confirm them. It has zero confirmed kissing bug sightings from Michigan, against 5,155 across the US, as of October 13, 2026. That's not proof, but it lines up.

Which fall bug is it?

Not sure which bug you've got? Two questions usually sort it out.

Why are western conifer seed bugs in my house?

They want a place to spend the winter. Out West, MSU says, they hide under pine bark, in dead Douglas firs, even in hawk and rodent nests. When it turns cold, they may come into buildings, too. Minnesota says the search starts as the weather cools in September.

They like the sunny sides of your house. They get in through cracks around your windows, doors and siding. The same sunny walls draw Asian lady beetles and cluster flies. If you see one in January or March, it came in last fall, Minnesota says.

Our own count shows the timing: September and October bring far more sightings than any other month.

Are western conifer seed bugs harmful?

Not to you or your house. MSU says it doesn't bite or sting. The Montreal Insectarium says it doesn't harm people or animals and doesn't carry disease. It can't breed indoors, because it needs its host plant to lay eggs on. It doesn't cause damage, but it may give off a bad smell if you bother it.

Here's the honest part. Penn State says they don't generally bite people. Researchers in Chile say one can give a painful bite, but it doesn't spread disease.

How do you keep them out, and when should you call?

Inside, vacuum them. Outside, the work happens in September. Here's what helps:

• Vacuum the ones inside. MSU says a vacuum works pretty well on these slow bugs.
• Fix the easy gaps. Penn State lists loose screens, windows and doors, gaps around frames and soffits, and unscreened chimneys and vents. That's a job for you or a contractor.
• Know the limit. Caulk may work on older homes with clapboard siding, MSU says, but no amount of it will keep them out of a house with vinyl siding.
• Time the outside. MSU says treating the outside walls in September, especially the south and west sides, when the first bugs gather, can help cut how many get in.

Minnesota Extension goes further. Since only a few usually get in there, it says spraying the outside isn't practical or needed. Honestly, if you see a handful each fall, vacuum them and move on.

Call us if they come back in numbers every fall, or you can't tell where they're getting in. We treat the outside walls where they gather, timed for September, and walk you around the gaps we find so you can get them fixed. We don't seal or caulk. See our stink bug control page.

Common questions

About this page

Nick Russler, Owner, Honorable Pest Control

License #C003210606

Nick wrote this. The facts come from the sources below, checked on October 13, 2026. The sightings are our own count of iNaturalist posts, so they show when people spot the bugs, not how many there are. Look-alike photos: Daslexia and Robert Webster (xpda.com), CC BY-SA 4.0, via Wikimedia Commons, cropped, with our labels added. We're not doctors, so call yours about a bite that worries you. See something wrong? Tell us and we'll fix it.