Western Conifer Seed Bugs in Your Home? Try These Removal Strategies

folder_openHemiptera, Insecta
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As fall approaches, you might be surprised to find some uninvited guests in your home — the western conifer seed bug (WCSB). These herbivorous insects are native to western North America, but have spread eastward since the 1950s. They feed on conifers, including various pines, spruces, hemlocks, and Douglas fir. While their feeding habits don’t impact the health of trees, these bugs can become a nuisance when they invade homes seeking warmth and shelter during the colder months.

You may find these reddish-brown bugs, approximately 3/4 inch long, with a white zig-zag pattern on their wings, hanging around your windows or crawling on your walls. Although they may appear threatening, WCSBs are harmless to people, pets, and your home’s structure. But, nobody wants these uninvited guests overstaying their welcome. So, how can you deal with a western conifer seed bug infestation in your house? In this article, we will discuss some simple yet effective methods to keep these bugs at bay and prevent future infestations.

Understanding Western Conifer Seed Bugs

Identifying Characteristics

The Western conifer seed bug (Leptoglossus occidentalis) belongs to the family Coreidae. These insects have some distinguishing features that set them apart from other insects:

  • Body length: They are about 3/4 inch (19mm) long.
  • Wings: Their wings have a mottled dark brown color, with a faint white zigzag line across the center.
  • Hind legs: They have flattened, leaf-like hind legs.
  • Antennae: Long and thin.

They are often confused with the brown marmorated stink bug, but the Western conifer seed bug is longer and narrower. You can easily identify them by their distinct piney odor when handled.

Life Cycle

The life cycle of Western conifer seed bugs involves several stages:

  1. Eggs: Adult females lay chains of tiny eggs (less than 1/10″) on conifer needles.
  2. Nymphs: After hatching, the nymphs go through five developmental stages. They start out as orange and gradually turn darker as they mature.

When fully grown, the insects are strong fliers, capable of covering significant distances.

Habitat and Range

Western conifer seed bugs are native to western North America, where they feed on conifers such as pines, spruces, hemlocks, and Douglas firs. Their feeding does not impact the health of the trees, but they can be annoying when they invade homes during the fall.

The insects’ range has expanded dramatically since the 1950s. They are now found throughout the United States, including in the eastern part of the country. The bugs have also been reported in countries like Turkey, Chile, and Japan, demonstrating their adaptability to different environments.

To keep them out of your home, it’s essential to seal any exterior cracks and equip foundation and attic vents with tight-fitting screens during warmer months. If you find Western conifer seed bugs indoors, consider vacuuming them up as a safe and effective removal method.

Why They Invade Homes

Seasonal Changes

Western conifer seed bugs seek refuge in homes due to seasonal changes. As fall approaches, the temperature drops, and these bugs start looking for warm places to overwinter. Your home can provide the perfect shelter for them to survive the cold months.

During spring, overwintering insects like western conifer seed bugs emerge from their hiding places. You might notice them in your house as they attempt to leave and return to their natural environment.

Searching for Food

These bugs feed on conifers such as pines, spruces, hemlocks, and Douglas firs during the warmer months. However, when fall arrives, their food source may become scarce. Consequently, they search for new food sources and often end up in your home.

When they invade your house, remember that they are not harmful to you or your property. As overwintering insects, they don’t build nests or cause structural damage; they only seek shelter. Therefore, it’s essential to maintain your home’s cleanliness and take preventive measures to keep them at bay.

To avoid future invasions, consider these steps:

  • Equip foundation and attic vents with tight-fitting screens
  • Seal any exterior cracks
  • Regularly vacuum your home, especially in areas where you found the bugs

By taking these measures, you can make your home less inviting for western conifer seed bugs and other overwintering insects during the fall and spring seasons.

Impact of Infestation

Homeowners may experience some issues when western conifer seed bugs find their way indoors. These insects tend to be attracted to the warm interiors of homes, and as temperatures drop, they may begin to enter your home in search of a place to overwinter.

Although western conifer seed bugs do not cause any significant damage to homes or plants, they can be quite a nuisance. They are often confused with stink bugs, which is another type of insect that produces a strong odor when disturbed or crushed. While the odor emitted by western conifer seed bugs is not as strong as that produced by stink bugs, it can still be unpleasant.

Additionally, these home invaders do not reproduce indoors, and they are not known to bite or transmit diseases. The infestation is mainly about the annoyance caused to the homeowner.

Here are some general tips to help manage western conifer seed bug infestations in your home:

  • Seal any cracks or gaps in your home’s exterior to prevent bugs from entering.
  • Install or repair window screens to keep bugs out.
  • Vacuum up any bugs you find indoors and dispose of them outside.
  • Avoid using insecticides, as these chemicals can be harmful to beneficial insects and may not be effective for controlling western conifer seed bug infestations.

Remember to stay calm and patient when dealing with these pesky intruders. By taking these simple preventive measures, you can minimize the impact of western conifer seed bug infestations in your home.

Prevention Strategies

House Insulation and Repair

To prevent western conifer seed bugs from entering your home, take steps to improve your house insulation and repair. One method is to inspect your windows, doors, and window frames for any cracks, and then seal these openings with caulk. Keep an eye on the siding, fascia, eaves, and soffits as well, as these areas can also harbor crevices where bugs can sneak in.

Examine your home’s foundation, looking for any entry points that might need attention. Filling these openings will not only help with bug prevention but also improve your home’s overall insulation.

Effective Use of Screens and Traps

Installing screens on your windows and doors can significantly reduce the chances of western conifer seed bugs finding their way into your home. Ensure gaps are small enough to prevent them from squeezing through.

Traps are also an option for controlling and reducing the population of these bugs. Sticky traps can be placed near doors, windows, or areas where you have spotted them before. Remember to replace traps regularly for maximum effectiveness.

In summary:

  • Inspect and seal cracks, openings, and crevices around windows, doors, siding, fascia, eaves, and soffits.
  • Caulk and repair any gaps or entry points in your home’s foundation.
  • Install screens on windows, doors, and other openings.
  • Use sticky traps near doors, windows, and other points of entry to capture bugs.

By following these prevention strategies, you can help keep your home free from western conifer seed bugs and maintain a comfortable living environment.

Removal Techniques

Non-Chemical Methods


One simple method to remove western conifer seed bugs from your house is by using a vacuum cleaner. This can help you quickly and efficiently capture these pests without harming them or your environment. Simply aim the vacuum hose at the bugs and suck them up.

Soapy Water

Another non-chemical option is to use a mixture of soapy water to kill and remove the bugs. Fill a spray bottle with water and a few drops of liquid dish soap, then spray it directly on the bugs. The soapy mixture will suffocate the bugs, making them easier to remove.

Chemical Methods


If the infestation is severe, you may consider using pesticides. Many common household insecticides can be effective in controlling western conifer seed bugs. However, take caution when using chemical pesticides and follow the label instructions. Its best to call a local pest control company to help if you feel you need to use chemicals.


Permethrin is an insecticide that can be used against western conifer seed bugs. This chemical can be applied as a spray or dust to the areas where the bugs are found, helping to eliminate the infestation.

Bug Zappers

Although not the most effective method, bug zappers can sometimes help control western conifer seed bug populations. Position the zapper in areas where the bugs are most commonly seen. Keep in mind, however, that bug zappers will also attract and kill other insects, including beneficial ones.

To determine which method is best for you, here’s a comparison table:

VacuumingNon-toxic, safe for the environmentMay not eliminate entire infestation
Soapy WaterNon-toxic, inexpensiveTime-consuming, may require multiple sprays
PesticidesEffective, fast-actingToxic to humans and the environment
PermethrinEffective, long-lastingToxic to humans, pets, and the environment
Bug ZappersEasy to use, covers large areaKills other insects, not the most effective

By understanding these removal techniques, you’ll be able to make an informed decision on how to deal with the western conifer seed bugs in your house.

Dealing with Dead Bugs

If you find dead western conifer seed bugs in your house, don’t worry, they won’t sting you. Follow these simple steps to clean them up and prevent odors:

  1. Vacuum them up: Use a vacuum cleaner to easily dispose of the dead bugs. Make sure to empty the vacuum bag or container into an outdoor trash can to avoid unpleasant odors.
  2. Wear gloves for manual removal: If you prefer picking up the bugs by hand, use a pair of gloves to protect against any potential allergens or irritants. Dispose of the bugs in an outdoor trash can.

Here are some key points to remember:

  • Western conifer seed bugs don’t sting or bite
  • They may release a foul odor when disturbed or crushed
  • Regular cleaning can help prevent accumulation of dead bugs

By following these steps, you’ll be able to effectively deal with dead western conifer seed bugs in your home. Remember to always dispose of them outside, and keep your home clean to avoid any unwanted smells and future invasions.

Interactions with the Tree Ecosystem

Types of Trees They Infest

The Western Conifer Seed Bug is known to infest various types of conifer trees. Some examples include:

  • Pines
  • Douglas firs
  • Hemlocks
  • White spruces

These insects have a sap-sucking mouthpart allowing them to feed on the seeds within pine cones, potentially impacting the reproductive success of the trees.

Their Role in the Ecosystem

Despite being considered a tree pest, the Western Conifer Seed Bug’s impact on the overall health of conifer trees is minimal. While their feeding can cause some damage to individual seeds, they do not pose a significant threat to the trees themselves. In fact, the presence of these bugs can contribute to the ecosystem by providing a food source for predators such as birds.

Remember, it is essential to maintain a balance between managing tree pests and preserving the ecosystem. With that in mind, although the Western Conifer Seed Bug may cause minor disruptions, its overall role as a participant in the ecosystem is vital.

Western Conifer Seed Bugs and Other Insects

Similar Insects

Western conifer seed bugs (WCSB) belong to the leaf-footed bug family Coreidae, and they can sometimes be mistaken for other household pests. Here are some similar insects to help you identify WCSB:

  • Assassin bugs: These insects have a narrow body and a distinct curved beak. Unlike WCSB, they are predators that feed on other insects.
  • Kissing bugs: Triatominae, also known as kissing bugs, feed on blood and can transmit Chagas disease. They are brown, wingless, and have a rounded abdomen.
  • Wheel bugs: A member of the assassin bug family, wheel bugs have a prominent spiked crest on their back. They also prey on other insects.
  • Brown marmorated stink bugs: These pests are shield-shaped, have a marbled brown color, and release an unpleasant smell when threatened. They are different from WCSB due to their shape and smell.

Natural Predators

A variety of predators can help control the WCSB population. Recognizing them can be useful in controlling pest infestations. Some natural predators include:

  • Spiders: Various species of spiders prey on WCSB and other insect pests.
  • Praying mantises: These large, distinctive insects are well-known for their predatory behavior, including feeding on WCSB and other insects.
  • Birds: Some birds, such as blue jays and woodpeckers, feed on WCSB, helping to regulate their numbers.

By understanding the differences between WCSB and other insects, you can identify and manage pests more effectively. A combination of natural predators and other control methods can help keep your home free from unwanted insect infestations. Remember to stay informed and maintain a proactive approach to pest control.

Health and Safety Concerns

You might be worried about the presence of western conifer seed bugs in your home. It’s natural to have concerns, especially regarding potential bites, disease, and whether they are harmful. Here are some key points to help ease your mind:

  • Bite: Thankfully, western conifer seed bugs do not bite humans. Although they have piercing mouthparts that help them feed on conifer seeds, you won’t have to worry about them biting you or your family members.
  • Harmless: These bugs are generally harmless to humans and pets. They are considered more of a nuisance than a threat, primarily because they tend to seek shelter in buildings during the colder months. Nevertheless, they won’t damage your home or possessions.
  • Disease: There are no known diseases associated with western conifer seed bugs. They don’t transmit any illnesses to humans or pets, so you can rest easy knowing they won’t cause any health issues.
  • Bodies: When you find dead western conifer seed bugs in your home, dispose of them promptly. This can help minimize any potential allergens caused by their bodies. Remember, they are not harmful, but it’s always good practice to keep a clean environment.

To sum it up, western conifer seed bugs are mostly harmless and pose minimal health and safety concerns. However, it’s essential to maintain a clean living space and dispose of any dead bugs to avoid further issues.


  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

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  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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Tags: Seed Bugs

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35 Comments. Leave new

  • I wanted to comment on this bug. I live in Ct as well in an apt complex and my apt has tons of them in there. They fly and are near windows and tend to go near the lamps. I complained to the apt office several times they told me that their is nothing to get rid of them with and they would have to seal up cracks and any a/c units. They come in near winter and come from pine trees. I hate them any other assistance on this would be great.

  • I’m also from CT and am experiencing my first fall with these bugs. The first one I found in my bathroom late at night, it got a trip down a toilet, but not before spraying that awful smell. I didn’t bother to find out what it was then.
    Tonight I had another encounter, though this one was unseen. My boyfriend and i were watching tv and all of a sudden we heard an insect thrashing around. Then the smell hit me, and I instantly recognized it. Boyfriend didn’t smell anything, so I tried to describe it. It smelled like an unripe banana peel, and he recognized it then. Decided to find out what it was this time, and after a bit of googling I found out it was this guy.
    Just wish I knew where tonight’s invader went. Now I know its not harmful, but I’d rather not have it getting spooked and spraying regularly.

  • I live in Strafford County New Hampshire. We live on a river and are surrounded by pine trees. This year, much more then past years, we are experiencing a pest problem with the Western Conifer Seed Bug. What is effecting them this year particularly, AND what is that pungent smell they emit when you disturb them?
    Thanks ahead!

    • Insect populations move in cycles. This is just a year when the Western Conifer Seed Bugs are plentiful. Many Hemipterans, not only Stink Bugs, can emit odors.

  • Have identified several of these in my neighborhood of Jackson, NH.

  • I caught one of these Western Conifer Seed Bugs on my Jade Plant. Creemore, Ontario, Canada (close to Georgian Bay). Strange thing to find in my house in the middle of winter.
    Your site is a great source for insect identification.

  • I found one of these guys on one of my flowers and took a picture of it. I live in Northern Ohio and have lived here for 56 years and have never seen one before. I do have several pine trees around in the neighborhood. Love your site! I have been here a few times to identify critters. I was going to post a picture I took of him, but am not sure how to do it

  • I have had these in my home every Spring and every Fall for the last 4 to 5 years. I am invaded with them. They are everywhere and do find them in my hair or on me at times. The most frightening of was on one morning I was awakened with a pinkish one on the edge of my mouth. I had to pull to get it off and it left a big blister-like sore that took a week to heal. I wished I could get them out of my home. I catch them and keep them in a covered jar until they have expired. So, I do not think they are harmless. Sorry to disagree….my personal opinion.

    • I’m truly sorry of your experience with this bug.
      I do have them also in the winter season…but maybe one
      at the time. I never had a problem with it.

      The blister on your month could be also cold sore…
      since this bugs do not bite.

    • I’m truly sorry of your experience with this bug.
      I do have them also in the winter season…but maybe one
      at the time. I never had a problem with it.

      The blister on your month could be also cold sore…
      since this bugs do not bite.

  • how can I discourage the Western Conifer Seed Bug from hibernating inside my house?

    • If you want to keep Western Conifer Seed Bugs from entering your home, you need to understand why they are entering and how they are gaining access. They enter homes to provide shelter from the elements, and they are able to enter homes through cracks in the foundation, gaps in windows and doors, and even simultaneously as people come and go through open doors. You can make your home inhospitable by keeping the indoor temperature the same or lower than the outdoor temperature, though that would not help much for the human inhabitants. You can have your house hermetically sealed, but that could get costly. You will most likely never be able to keep them out with 100% assurance, but you can at least weatherproof your windows and doors and check for cracks in the foundation. That will have the added benefit of keeping your heating and cooling costs down.

  • How does this bug enter your home? Can they come up through the drains. [Most of the ones I find are near the kitchen of bathroom sink.]

    Do they do damage to coniferous trees?

    • We are relatively certain that Western Conifer Seed Bugs do not enter homes through drains. They do not harm trees, but they will affect the viability of the cones. According to the Penn State Entomology website: “This true bug of the family Coreidae feeds mainly on the seeds and developing cones of several species of conifers and their respective hybrids.”

  • How does this bug enter your home? Can they come up through the drains. [Most of the ones I find are near the kitchen of bathroom sink.]

    Do they do damage to coniferous trees?

  • margaret hardy
    April 26, 2014 1:28 pm

    I can back these people from New England with regards to this bug. I have a jar that I capture these bugs in and they are definitely this bug! I can submit a pic of five of them. They are gross, and if you step on them they smell bad!!!

  • I have been finding a lot of Western Conifer Seed Bugs inside my home in Mid Michigan area October and they scare me to death, do they bite? what is their purpose in my yard, why are they trying to get into my home? How do I get rid of them?? Any info will be helpful, thank you.

    • Western Conifer Seed Bugs, an invasive species in Michigan, do not bite. They enter homes to hibernate when the weather cools. We do not offer extermination advice.

  • I have found a couple of these bugs in my house in upstate NY this weekend. I scooped them up with a paper towel and placed them outside- don’t like to kill anything unless it’s a parasite or super destructive like EAB. And yes they fly.

  • Have been removing a number of these beetles from inside, the basement mostly and now in the kitchen. Our home is surrounded by Norway Spruce with large cones. Anything we can do to make their visit less desirable? We also get the stink bug in early fall. I also meant to comment we live near Toronto ON

  • I keep finding more of these bugs in my house. I am freaking. Someone told me it’s a kissing bug? Maybe you can help. Thank you very much

    • Western Conifer Seed Bugs are classified in the same order as Kissing Bugs, so they share some similar anatomical features. Western Conifer Seed Bugs do not pose a threat to humans.

  • I love these guys so much. They make wonderful photography subjects because they are so beautiful and cooperative.

  • Mr. Bug Man, does the Western conifer seed bug have a dangerous bite if disturbed. my wife was bitten by one and it was very painful

    • To the best of our knowledge, other than pain, the bite of a Western Conifer Seed Bug would not be considered dangerous.

  • I’m concerned that what I think are the conifer seed bugs are kissing bugs which I’ve read can spread disease. Twice I’ve awoken to one crawling on me. How do I tell the difference? They were ALL OVER the outside of my house this past fall and have gotten into the house. I’m still finding them but not in such numbers. They make a buzzing noise when flying and stink when I squish them. Can you help me to correctly identify them?

    • Excellent images of Kissing Bugs can be found on BugGuide. To alleviate your fears, you should take specimens to your local natural history museum for identification.

  • Clark Gent Pretty Face
    March 29, 2018 11:39 pm

    My God they are so ugly! most ugliest most eerie looking bug I have ever seen!

  • Clark Gent Pretty Face
    August 17, 2018 6:13 pm

    That’s a bug that has nothing to be vain about. lol

  • I have lived in NE my entire life (over 40) and I have not come across these until this year and I have found about 20 of them so far in and around our house this fall. Do these bugs cause any damage (e.g., like the powder post beetle etc.)? Thank you!

  • I found one in my bathroom also on the toilet, however, I live in the UK so totally baffled how it got here. I’d been in the bathroom a lot that day doing repairs & it just appeared after I left the room.

  • I have seen these outside but not in the house.


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