Seed Bugs – All You Need To Know

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Seed bugs are massively common in North America, so if there is anything you want to know about these critters, this single resource will help you out.

Seed bugs are extremely common in North America, and unfortunately, they are almost all problematic. 

There are a large variety of seed bugs out there that share similar characteristics. 

This article covers these bugs in detail, including their types, habitat, lifecycle, diet, and so much more. Read on to learn more about this family of bugs.

What Are Seed Bugs?

Seed bugs and their kin are scientifically known as Lygaeoids, a group of insects in the Lygaeoidea superfamily

However, you might want to note that the term “seed bugs” doesn’t refer to a single insect species but several.  

All 15 insect families under the Lygaeoidea superfamily, including seed bugs and other related bugs like stilt bugs and big-eyed bugs, are known as Lygaeoids.

As their name suggests, seed bugs primarily feed on seeds by sucking out the juices. Some seed bugs are generalists with a variety of hosts. 

Others are specialist seed bugs, feeding only on a few specific species of plants. 

Seed bugs can be of various colors – reddish brown, black, tan, or bright orange and red areas contrasting darker colors.

Whitecrossed Seed Bug

Types of Seed Bugs

1.    Dirt Colored Seed Bug

The Rhyparochromidae family, or dirt-colored seed bugs, are a group of insects that primarily feed on seeds. A few species are insectivorous and prey on other insects. All bugs of this family are dark brown – much like soil. 

They feature large, red, and bulging eyes on the sides of their heads, while the wing coverings have a bronze tinge to them. 

Most seed bugs of this family visit flowering plants to feed on the seeds at the bases of flowers. However, they don’t cause much damage and hence aren’t deemed a pest.  

2.    Long Necked Seed Bug

This slender bug is a member of the Rhyparochromidae mentioned just earlier, i.e., they’re a dirt-colored seed bug too. 

However, the long-necked seed bug deserves special mention due to its distinct appearance and large population. This bug is very common in agricultural habitats, gardens, and lawns. 

Especially if you live in Kentucky, there’s a good chance that you might encounter long-necked seed bugs. These bugs mostly feed on the seeds of cotton and strawberry plants.

3.    Mediterranean Seed Bug

The Mediterranean Seed Bug is a species of true seed bug that’s quite common in both Europe and North America. Their appearance is rather unique, which makes it easy to identify them. 

This bug is characterized by a bold black triangle on its back, followed by three black patches behind it. An invasive species in North America, the Mediterranean Seed Bug overwinters together in large numbers. 

At the onset of spring, the adults and the larvae emerge and together feed on the same seeds and plants. Although they mostly prefer grass seeds, you can also find them on mint family plants.

4.    Elm seed bugs

The elm seed bug is a well-known invasive pest species native to Europe and the Mediterranean region. As its name indicates, this is a specialist seed bug known to feed on the seed of elm trees primarily. 

This bug is often confused with boxelder bugs – a different seed bug species. Although they don’t cause much damage besides destroying the seeds, they’re a major nuisance pest species. These bugs congregate in homes in large numbers during the winter months. 

Like stink bugs, they also release a foul odor similar to that of bitter almonds when threatened or aggravated.

Elm Seed Bug

5.    Western Conifer seed bug

Interestingly, the Western Conifer seed bug doesn’t belong to any of the Lygaeoid families. 

Despite its feeding habits and its name identifying it as a seed bug, it belongs to the family of leaf-footed bugs, Coreidae. 

Western conifer seed bugs are a serious pest due to the economic damage they cause in pine farms by destroying conifer seeds

In homes, they’re a nuisance pest known to congregate in large numbers and release a foul odor. While they aren’t capable of stinging, they can still hurt you with their proboscis.

The WCSB is a bug that smells like grass when you kill it, a unique thing that many people use to identify it.

6.    White Crossed Seed Bug

Also known as the ragwort seed bug, the white-crossed seed bug is easy to identify. Although the prominent X pattern on its back isn’t very uncommon, its color sets it apart from bugs with such patterns. 

Its back is neatly divided into areas of red and black by a white or pale yellow thin-lined X, which explains its name. 

Although white-crossed seed bugs prefer to feed on ragworts and groundsels, various other plants make suitable hosts too.

7.    Sycamore seed bug

The Sycamore seed bug is a species native to North America. Identified by the triangular plate at the back of their heads, these bugs are a shade of mottled brown. 

Sycamore seed bugs have an elongated body with a long proboscis. Feeding primarily on the sycamore plant and its seeds, this is a specialist seed bug. 

Apart from hindering the spread of sycamore trees by destroying their seeds, these bugs can also be a nuisance due to their large presence. 

They often appear in huge numbers on walkways and parks lined with sycamore trees.

8.    Milkweed Bugs (Small)

In case you wonder why we specified this bug as small, it’s because there are two different species of milkweed bugs. 

We’ll talk about the large one in the next section, but let’s cover the small milkweed bugs first. 

This is a very common and widespread true bug, known to feed on the sap of milkweed seeds, nectar, etc. Interestingly, milkweed bugs are omnivorous and also prey on caterpillars, flies, bees, and beetles.  

Small Milkweed Bug Nymph

9.    Milkweed bugs (large)

Growing to a length of 0.5 inches to 1 inch, these bugs are a larger species of the milkweed bug. Their prominent black and orange pattern not only renders them easily identifiable but also makes them one of the most beautiful true seed bugs. 

The pattern is different from the smaller species of milkweed bugs mentioned earlier. Large milkweed bugs have two orange triangles facing opposite sides on each forewing, divided by a black band in between. 

They have a similar diet as small milkweed bugs, with a preference for the common milkweed plant.

10.  Neortholomus scolopax

The Neortholomus scolopax is quite common, usually found in dry grassy areas. They’re of a mottled brown color, like the dirt-colored seed bugs. 

In case you’re wondering why we mention this seed bug only by its scientific name, it’s because this species does not have a common name. 

Neortholomus scolopax is a generalist seed bug that feeds on various host plant species.

Where Do Seed Bugs Live?

With so many species of seed bugs out there, it’s not surprising that they’re quite widespread across the continents. 

They’re extremely common all over the United States, with some seed bugs being native to North America and the rest being invasive species. 

You’re more likely to find them in prairies, old fields, and other such grassy open areas. 

Seed bugs are also common at the borders of grasslands and woodlands, with a mix of grasses and flowering plants.

Immature Seed Bugs

What Do They Eat?

The seed bugs cannot chew as they have piercing and sucking mouthparts rather than chewing mouthparts. 

Like the other members of the order Hemiptera, they pierce plant matter with their proboscis and suck out the juices. While seed bugs primarily feed on the juices from host plant seeds, leaves and flowers make suitable food sources for many species too. 

Not all of them are garden or agricultural pests, as some seed bugs feed on specific host species like elm or boxelder trees.

What is the Lifecycle of Seed Bugs?

The seed bugs mostly share a similar life cycle, although their overwintering habits may vary. Like other true bugs, they only undergo simple metamorphosis. 

Most of them are gregarious and overwinter in large groups, but some species are migratory and leave for warmer areas in the south during the cold months. 

The overwintering adults emerge again in spring to resume feeding and mate, eventually laying eggs after a while. The females tend to insert their eggs into plant tissue or lay them on host plants.

The Seed bug nymph emerges during late spring or early summer. They spend several weeks feeding on seeds and growing. 

Mediterranean Seed Bug

Larval seed bugs molt through five instar levels, growing more similar to the adults with each instar. Around late summer, the larvae are fully developed and pupate into adults.

Until the onset of fall, adult seed bugs are abundant and can be found feeding on plant matter. As the cold weather begins to set in, they seek refuge inside homes and other sheltered spaces. 

The cycle then repeats, with the adults reemerging in spring and laying eggs for a new generation of seed bugs.

Where Do They Lay Eggs?

Different seed bug species have different preferences in this matter. While some lay their eggs on plants, others prefer to lay eggs among soil and leaf litter. 

Again, some species, like the western conifer seed bug, lay eggs on pine cones or in the tissue of cone scales. With so many different types of seed bugs, it’s hard to point out a few specific egg-laying spots.

Do They Bite or Sting?

Don’t worry – as much of a nuisance as these bugs may be, they cannot sting or bite you. While the lack of chewing mouthparts prevents them from biting, seed bugs do not have stingers either. 

However, some seed bugs can hurt you in other, less serious ways – such as the western coniferous seed bug using its proboscis to poke.

Are They Poisonous or Venomous?

Seed bugs do not pose a threat by being venomous or poisonous either. 

While some seed bug species extract poisonous substances from their food and store the poison to deter predators, their poison isn’t potent enough to harm humans.

Western Conifer Seed Bug

Are They Harmful to Humans as Pests?

Most seed bugs are only nuisance pests that cause trouble by infesting homes in large numbers and/or spreading foul odors. 

They don’t cause much trouble as garden pests, thanks to their feeding habits. However, the western coniferous seed bug can have an economic impact due to the damage they cause in nurseries and plantations where pines are grown.

Can They Come Inside Homes?

Although this isn’t the case for every seed bug species, man seed bugs are notorious for infesting homes. 

Especially during the cold months, they seek warmer places to overwinter, and that is exactly what homes offer. It’s easy to find the gregarious seed bugs overwintering in your home in large numbers.

What Are Seed Bugs Attracted To?

Different seed bug species are attracted to different host plants. For example, you’ll usually find milkweed bugs around milkweed plants, while elm seed bugs mostly stay on or near elm trees. 

Generalist seed bugs have a variety of hosts, including grasses and flowering plants. During winter, indoor areas, wall vents, cracks, and crevices protected from the cold attract them.

Western Conifer Seed Bug

How To Get Rid of Seed Bugs?

Managing the seed bug population in your home isn’t very difficult. Manual removal is the easiest solution, after which you can either kill the bugs or release them outside. 

If there’s a large cluster of seed bugs in your home, a vacuum cleaner can be of help too. However, if it’s one of those stinky seed bugs, vacuuming can cause them to release the odor. 

For the same reason, don’t crush seed bugs when killing them – just drown them in a bowl of soapy water or flush them down the toilet.

Interesting Facts About Seed Bugs

Now that you’ve learned almost everything about seed bugs, here are some interesting facts that you should know:

  • Most seed bugs with contrasting colors of black and bright red or orange sequester toxins by feeding on toxic plants. Their bright colors are a symbol of their toxicity and ward off predators. This isn’t exclusive to seed bugs alone – it’s a rather common occurrence in the animal kingdom.
  • Many non-toxic seed bugs enjoy a different form of protection – camouflage. Their drab or tan colors help them blend into their surroundings.
  • A common characteristic shared by these bugs is the appearance of their hind legs. Each hind leg has a small but distinctly swollen area near the end.
  • Seed bugs don’t need to be exterminated as they aren’t major pests. Besides, these bugs are a colorful and important part of the ecosystem.
Mediterranean Seed Bug

Wrap Up

Seed bugs are rather harmless when it comes to their chances of hurting you or damaging your plants. 

However, if they start appearing on your window frames or inside your home, it’s a good idea to seal cracks and install window screens. 

Although the ability to emit foul odors is a common trait among seed bugs, a bug that smells like apples when killed might also be a brown marmorated stink bug

Hopefully, identifying seed bugs and keeping them out of your home will now be easier for you.

Thank you for reading!

Reader Emails

Over the years, our website, has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Bug of the Month: December 2006 – Western Conifer Seed Bug


Winter migration of these into my house What is this? It seems they come into my house located in Cumberland, Maine every winter. We also have them in Dover, NH but fewer. They seem to be some sort of harmless bug, maybe a form of grasshopper? Picture attached. Thanks Russell Hi Russell, This is a Western Conifer Seed Bug, Leptoglossus occidentalis. It is native to the Pacific Northwest, but has migrated east over the last century. They often enter homes in the fall. We have decided to make this our featured Bug of the Month for December.

Letter 2 – Western Conifer Seed Bug


Nasty looking bug in Florida..need help identifying
I found this nasty looking critter stationed on my patio window in Tampa, FL. He flies but apparantly not too well…I heard him crash into the window with a thud….about 1 inch long, 1/2 inch wide with legs similar to a big roach or preying mantis. It had distinctive eyes and a flat head….the bug itself was relatively flat but the head looked kinda like a shovel. Where the eyes were was completely flat and not round like most bugs. This guy was sand-colored with a shiny black patch on its back that almost looked seperate from the rest of him. He looked like he could pack a mean bit if I were to step on him or something. yick…nasty, nasty….
I’ve seen similar looking critters about 1/20th of this guys size, about the size of a roofing nail head in my house at times but this one was gigantic in comparison and much lighter in color….almost like the little critter’s, larger and meaner big brother or something. Those little critters however are jet black but have a similar flat head, so I would guess they are related somehow. They look like something right out of the stone age. Please help me identify this. My wife is now terrified of the patio. In the photo above, I got a lot of glare from the glass but you can really get a good look at this guy’s head and see how its triangular almost. His eyes are on either side of those points.
Buggy Tampa, FL

Hi Phil,
Your insect is one of the True Bugs, most probably the Western Conifer Seed Bug, Leptoglossus occidentalis, a member of the Big-Legged Bug Family Coreidae. We have more photos and information on our True Bug page.

Letter 3 – Nope, Western Conifer Seed Bug


I’m in Toronto, Ontario, Canada and this bug has been living in my apartment with me for quite some time. it seems quite content to just chill out on my rather large ivy plant, in the window. it’s moved about 6 inches in total in the last few weeks. i know it’s alive because it will move if i breath on it. here are some links to the photos I’ve taken of it. Is this a stink bug?

Dear Adrian,
You have a Coreid Bug or Leaf Footed Bug, so named because of the large rear legs on many species. More specifically, it is a Western Conifer Seed Bug, Leptoglossus occidentalis. They are plant feeders and are usually not noticed until they seek shelter in the home in the autumn so they can hibernate. They are plant eaters and are related to stink bugs, hence the foul odor they emit. There is no way to prevent them from seeking shelter, but they will not breed indoors. They just want to hibernate.

Letter 4 – Western Conifer Seed Bug


Bug in Western Mass.
Hi Bugman!
Your website is so helpful regarding other bugs. I have this bug that’s been coming into our dorms in Amherst, MA. It’s about an inch long, and it emitted a somewhat foul odor when we tried to kill it. I was told it was a stinkbug because of this, but it doesn’t look like any stinkbugs on your site. How do I keep them out??? They come in every night. Thanks from some curious UMass students,

Hi Stephanie,
This is a Western Conifer Seed Bug, Leptoglossus occidentalis. in the family Coreidae. Both Leaf-Footed Bugs and Stink Bugs are in the same order, Hemiptera, the True Bugs.

Letter 5 – Western Conifer Seed Bug


whats this bug HELP
We have 5 of these bugs within 2 days.. what are they please ! thanks

The Western Conifer Seed Bug, Leptoglossus occidentalis, often seeks shelter indoors to hibernate during cold winter months.

Letter 6 – Western Conifer Seed Bug


What kind of bug is this?
We have had several of these show up in our home within the last month. I am in Northcentral Indiana and have never seen any of these around before. They are very slow, and don’t seem to come out of any particular area. I have seen them in the sink, waterbowl, Lamps, heat ducts, and simply hanging out on the counter top. Light doesn’t seem to affect them either, except for the couple that were on the inside of our front windows during a cold day. Any ideas?

Hi Jay,
The Western Conifer Seed Bug, Leptoglossus occidentalis, is an invasive introduction from Europe that is spreading and becoming more plentiful.

Letter 7 – Western Conifer Seed Bug


Bloodsucking Conenose
I have tentatively identified this as a member of the Assassin Bug family, namely Triatoma Sanguisuga-"Bloodsucking Conenose" Could you please confirm or correct this identification. There have been several flying around the house lately. Thanks,
Hancock County, Maine-January 11, 2007

Hi Albert,
This is a Western Conifer Seed Bug and you need not fear getting bitten.

Letter 8 – Western Conifer Seed Bug


a couple of bugs
hi from Canada!
i’ve included two pics of bugs, one we’re pretty sure is a ‘green stink bug’ (we looked it up in ‘bugs of ontario’). … identifying the other one has been a bit of a chore. it was about 3-4 cm long. here it is seen on our screen door. we see them frequently in the summer months, most often perched on a wall outside or on the screen door and sometimes they find their way indoors and have to be evicted, usually i simply hold a margarine tub near them and brush them gently into it where they sit quietly while i move them outdoors. some of them can be quite large. thanks for any help you can provide,
D. Mitchell

Hi D,
Your mystery bug is our featured Bug of the Month for December, the Western Conifer Seed Bug, Leptoglossus occidentalis.

Letter 9 – Western Conifer Seed Bug


Bug help
I have been seeing these bugs in the house for a couple of years. They seem to come out in fall. I have tried to research this and as far as I can tell, this is either a shield bug/stink bug, or a wood borer. Do I need to worry about these guys? I do not find too many but maybe a couple a week. Thanks for the help, great website.
Chris Sihpol

Hi Chris,
Your letter and humorous image could not be more timely. A mere three hours earlier today, we got a request from Ann of The Boston Globe (see below) regarding information we could provide on the Western Conifer Seed Bug, Leptoglossus occidentalis. The Western Conifer Seed Bug is a True Bug in the order Hemiptera. The family is the Leaf Footed Bugs or Big Legged Bugs, Coreidae. Technically, they are not Stink Bugs, though they do give off a pungent odor if handled. Like many other Hemipterans, including Stink Bugs and Boxelder Bugs, the Western Conifer Seed Bug will enter homes in the fall to escape the cold, sometimes hibernating until spring. This tends to be a source of annoyment for many homemakers and is the reason for much of the publicity these insects generate. There is a wealth of information on the internet, including the PennState entomology site. The Western Conifer Seed Bug is native to the Pacific Northwest, but its range has been increasing in the east, perhaps due to global warming though interstate commerce is also a contributing factor. The Cornell Cooperative Extension claims: “This species was first described in 1910 from California”. BugGuide does not list any submissions from California on its map, but it does include the amusing disclaimer: “The following data is based on images submitted and identified by contributors. Range and date information may be incomplete, overinclusive, or just plain wrong.” We here at What’s That Bug? have not observed an increase in queries regarding this species this year. In past years, we would receive many identification requests per week while this year we have only gotten two images.

(11/03/2006) Boston Globe Article
Hi Daniel:
I’m writing a humorous story about the stink bugs that invade New England homes this time of year (Leptoglossus occidentalis). I was just curious how frequently you hear about this bug at whatsthatbug, like top 5 or top 10 most asked about? Anything interesting, humorous or artful about Western Conifer I can quote you on? It is a Californian bug, after all. Deadline is imminent, so I’d appreciate hearing from you soon if you are able. Have any photos of it we could run? Thanks,

Letter 10 – Western Conifer Seed Bug


Can You Identify this bug?
My friend who lives on Long Island photographed this bug in her backyard. We think it may be some kind of stink bug. Could you please give me some insight as to what type of bug it is as well as it’s habitat and behavior. Thank you for your time,

Hi Diane,
We haven’t posted a new photo of a Western Conifer Seed Bug, Leptoglossus occidentalis, in quite some time. This photo is quite good. There is so much information on our site and elsewhere on the web that we are confident you will have no trouble finding the information you desire now that you have a name.

Letter 11 – Western Conifer Seed Bug


Bug Picture
Can you tell me what this is? Scared crap out of me. Only saw one of them, flew into the light. Something I need to kill, or something safe? PS: Dumped this one outside after picture. Thanks, IOU one.

Hey Jeff,
You have given us a fabulous new idea. We love the way your Western Conifer Seed Bug, Leptoglossus occidentalis, integrates with the wood of your ceiling fan. We see the potential for product design here. This is an imported invasive species that is spreading in the northeast.

Letter 12 – Cambodian Seed Bug Nymph


A red bug
Hi I was wondering what bug this is. It was found in the Cambodian jungle close to one of the Anchor temples. Lots of trees and leaves on the ground. Quite hot and a bit humid at the time.Cheers

Hi Kjartan,
We can’t tell you a species or genus, but we can guess a family and know the order. This is a True Bug in the order Hemiptera and probably the family Lygaeidae, the Seed Bugs. It is an immature specimen.

Letter 13 – Whitecrossed Seed Bug


Art deco critter Hi. I’m in Maryland and scooped this little creature out of my pool yesterday. Can you tell me what it is? It’s about the size of a ladybird / ladybug. Thanks. Sharon. Hi Sharon, This is the first posting to our site of a Whitecrossed Seed Bug, Neacoryphus bicrucis, but we noticed another letter with the name in the subject header.

Letter 14 – Western Conifer Seed Bug


assassin bug, spp?
Hello Bugman : )
I was sooooo excited to find your website yesterday and immediately knew I had to email you this photo. I work at an outdoor science school in northern California (4,100′ elevation, just north of Yosemite) where we teach a class called "Life in a Log". We survey the forest floor for invertebrate life and are currently trying to make our own site specific ID book. Thus, I’m wondering if you know what species, or even genus, of assassin bug this is. Thanks so much for your help!! Your website is such a valuable tool – thanks for hosting it!!!! Cheers,
Traci Fesko
Sierra Outdoor School
Sonora, CA

Hi Traci,
Your insect is not an assassin bug, but a member of the Coreid Bug Family, the Western Conifer Seed Bug, Leptoglossus occidentalis. This Pacific Northwest Species has spread throughout much of the eastern U.S. in recent years.

Letter 15 – Long Necked Seed Bug


Long necked seed bug
I’ve had occasion to reference your site for tough little critters more than a couple of times, and thought I’d give something back. I found on true bugs page five the story of the dorm resident with an odd little discovery in the room. You went on to identify it as a long necked seed bug, and the silhouette resembles a bug I found and photographed in front of the house a little while ago (I left the porch light on to see if I could get any interesting moths to come looking). I thought I’d send along a clearer picture of one, if that is indeed what it is – I identified it as a true bug because of the mouthpart. I found the bug in central Maryland. Thanks for the information and enjoyment!

Hi Nat,
Thanks so much for providing our site with this much needed image of a Long Necked Seed Bug in the genus Myodocha. BugGuide has many images of this genus.

Letter 16 – Long Necked Seed Bug


Need help, friend is losing it in her dorm room!
I was asked by my friend to help her identify this bug she has been finding in her dorm room. Of course I sent her your site as it’s my new favorite site to look at and everything thinks I’m more of a nerd for it. However, she couldn’t find this bug and we can’t figure out what it is. Attached is a picture. Please help if you can, she’s going crazy and is about to have me drive out there over an hour away to get them out of her room and it’s midnight here. Thanks!!
Seth W. (located at UT Arlington, Arlington, TX)

Hi Seth,
Even though this photo is blurry, we have decided to post your letter for several reasons. First and foremost, we are concerned for your friend’s peace of mind. Living in a dorm must be a traumatic experience, and agonizing over an unknown insect might just raise her level of stress to a dangerous level, for both her and those near to her. Second, though the photo is blurry, the insect in question is distinctive enough in its silhouette to make identification easy. Third, this is a new genus for our site, though we cannot identify the exact species. Lastly, we are charmed that being thought of as a nerd for reading our site does not in the least bother you. Now that we have treated you to some of the inner workings of how me make posting decisions, we will identify your friend’s intruder. She has nothing to worry about. This Long Necked Seed Bug in the genus Myodocha will not harm her.

(06/17/2007) Thank you
My name is Christine and I was the friend in “Need help, friend is losing it in her dorm room!” emailed to you by my friend Seth. I want to thank you for identifying my bug as a long necked seed bug. I visited the link provided in your response and those pictures are exactly what my bugs look like. I really am greatful that you responded to him so quickly. After finding a cockroach (which, after looking at your site I believe to be an American Cockroach) in my bathroom, this one making it number 3 and then walking into my room to find roughly 15 of these small bugs I was going a little crazy. At first I thought they were slightly cute because it was almost as if they followed me where ever I went. This was only cute until I found a whole bunch of them. I lived with them until I couldn’t handle sleeping with them anymore and some of them had to move on. As for the cockroach he died this morning of natural causes (as far as I know). I had to have a chat with him when I first found him and after sharing the shower with him for a couple of days I was slightly sad to see him leave. This turned into a long message but the jist of it is thank you. I hope you have a great day
crazy in texas,

Letter 17 – Western Conifer Seed Bug


Western Conifer Seed Bug?
Hi! I love your site! I’ve used it to identify at least 2 crawlys in the house already. I found this guy today on a houseplant…I’ve seen them before, and until looking them up on your site I’ve been calling them the King Box Elder Bugs, although I doubt they’re related. Is this a Western Conifer Seed Bug? I’m in Salt Lake City, UT. Thanks!

Hi Pax,
The Western Conifer Seed Bug, Leptoglossus occidentalis, is native to the Pacific Northwest, but has migrated east. BugGuide shows a map that indicates sightings in Utah.

Letter 18 – Western Conifer Seed Bug


Conifer Seed bug
Howdy —
Thanks to your site, I don’t wonder what I found this time, but the picture is so vivid, I wanted to pass it along. I can’t get over the colors. Thanks again for your addictive site!
Tara B.

Hi Tara,
This is the time of year that the Western Conifer Seed Bug seeks shelter from the winter cold by entering homes. This Pacific West Coast native has spread east in recent years, and is firmly established in New England and vicinity.

Letter 19 – Western Conifer Seed Bug


Western Conifer Seed Bug I think Hi Dan and Lisa, Joanne from near Chicago, again. Could you confirm this is a Western Conifer Seed Bug? I didn’t get too close ‘cuz honestly, it was looking at me and freaking me out. I saw it near Oswego, Illinois. Thanks, and I’ve linked you an my Facebook page, too! Joanne Near Oswego, Illinois
Western Conifer Seed Bug
Western Conifer Seed Bug
Hi Joanne, Your identification of the Western Conifer Seed Bug, Leptoglossus occidentalis, is correct.  According to BugGuide’s data, the species has spread from the Pacific Northwest to fully half of the continental U.S.  Also known as the Pine Seed Bug, the Western Conifer Seed Bug is in the family Coreidae, the Big Legged Bugs or Leaf Footed Bugs, so named because of their unusually shaped hind legs.

Letter 20 – Western Conifer Seed Bug


Beetle-like bug Sat, Oct 11, 2008 at 2:11 PM Hi Bugman! I live in Northeast Illinois near the Wisconsin border, and I’ve noticed a “new” bug hanging aroung on my house, my deck, and some plants. I’ve never seen a bug like this, and I’m hoping you can tell me what it is. It has hair on it’s legs and around it’s head, and I’m pretty sure this bug can fly. Thanks! Tracy Spidyweber Midwest
Western Conifer Seed Bug
Western Conifer Seed Bug
Hi Tracy Spidyweber, This is a Western Conifer Seed Bug, Leptoglossus occidentalis.  Perhaps the reason it is a new species for you is that in the past decade, its range has greatly expanded from the Pacific Northwest.  This range expansion may be partially explained by climate changes, but human mobility and the ease of accidentally transporting unknown passengers is doubtless a contributing factor.

Letter 21 – Long Necked Seed Bug


Help I don’t know what this is Mon, Oct 13, 2008 at 8:45 PM I am trying to find out what this bug is. I discovered it underneath a flat board that was covering a broken basement window, the board fell off the house and when I picked it up this was underneath the board with others like it numbering around 25 – 60 of them, they scattered fast, seems to like dark moist places. It measures from front to back without including leg or antannae, 1 cm long. I am worried this may be some type of bug that is causing hidden damage to my home. Scott worried in Ohio Midwest, Columbus, OH
Long Necked Seed Bug
Long Necked Seed Bug
Hi Scott, The Long Necked Seed Bug, Myodocha serripes, is not damaging your home. According to BugGuide, the Long Necked Seed Bug “overwinters as adult in leaf litter or under bark of trees in woodlands” and is found in “Leaf litter in early spring; fields and artificial lights in summer.” Many True Bugs hibernate overwinter in aggregations, and your individuals found the board to be a fine substitute for the bark of a tree.  While it is not harming the home, it may be harming your strawberries, because BugGuide also indicates it feeds on the “Seeds of strawberry and st. johnswort. Sometimes a pest of strawberries. ” We believe your photo is a new species for our site.

Letter 22 – Western Conifer Seed Bug


beetle Thu, Oct 23, 2008 at 1:41 PM Hi Bugman! My 7 year old daughter saw this beetle(?) crawling on our wooden garage door, and we put it in a container to get a closer look. We’ve been hearing about invasive beetles, mainly japanese long-horned beetles, that have been doing extensive damage in Massachusetts. We looked up as much as we could online, and feel pretty confident that this is not a long-horn, but are curious if you can identify it. It’s quite beautiful! My daughter would like to bring it in to school to share, and as much info as you can provide would be greatly appreciated! Marcy Lee Lexington, Massachusetts
Western Conifer Seed Bug
Western Conifer Seed Bug
Hi Marcy Lee, This is not a beetle.  It is a True Bug in the order Hemiptera.  It is in the family Coreidae, the Leaf Footed Bugs.  It is a Western Conifer Seed Bug, Leptoglossus occidentalis, a species native to the Pacific Northwest that has greatly expanded its geographic range in recent years.  They are frequently noticed at this time of year when they try to enter homes to hibernate over the winter.

Letter 23 – Western Conifer Seed Bug


Unkown Household Bug Thu, Nov 20, 2008 at 4:42 PM We have encountered at least five of these bugs inside our house. They are always out in the open in a well lit room and do not run away with human presence. In searching the internet I would say they look a lot like the timberman beetle. Six legs, the back two distinctly larger (almost grasshopper shape). Long front antenna. The head protrudes from the front of the body. The body is about 1/2 inch long and the entire but is about 1 inch long. The coloring is brown with light brown patches (like the timberman beetle). We live in the western suburbs of Chicago and the bugs began appearing in November (after the first frost and when we started heating our house). The first four bugs were found in the second story bedroom but the last one was found in the ground floor kitchen. (we live on a slab). Kim Western suburbs of Chicago, Illinois
Western Conifer Seed Bug
Western Conifer Seed Bug
Hi Kim, This is a Western Conifer Seed Bug, Leptoglossus occidentalis.  The Western Conifer Seed Bugs are seeking shelter from the cold and they will not harm you, your pets or your home.

Letter 24 – Western Conifer Seed Bug


Is it a roach? Is it a moth? Is it a beetle? Sun, Dec 21, 2008 at 3:43 PM This bug was found in my kitchen yesterday terrorizing my mother. She had no idea what it was and it was flying around the kitchen so it seemed to freak her out. When it flies it looks just like a beetle but when it lands it doesn’t have many similar features of one. I went to catch it but it disappeared until later that night where I found it on the T.V. I quickly ran into the kitchen for a jar but it was gone when I came back. This morning I found it in the living room and caught it. I’ve been looking up the various insects that are known to my area and have come up with little to no answers. I’ve lived in Northern California all my life as well as my mother and we have never seen a bug like this one. It’s brown and spotted, it flies, has “muscular” legs, and seems to be relatively calm in the jar (it’s not freaking out like a moth would normally do in a closed brightly lit environment). Its head is pointed – not rounded like a roaches head and it doesn’t appear have a super hard exoskeleton – its back is protected by its wings. I’ve provided three angles in the pictures so hopefully I can find out what this bug is. 🙂 *note: The red marks on the glass are not from the bug. Kristy McKinleyville, California.
Western Conifer Seed Bug
Western Conifer Seed Bug
Hi Kristy, The Western Conifer Seed Bug, Leptoglossus occidentalis, is often noticed when it seeks shelter indoors at the onset of cooler weather.  This species is native to the Pacific Northwest, but it has increased its range dramatically over the past few decades.  It is now found throughout the Northeast as well as Canada.

Letter 25 – Western Conifer Seed Bug


What is the name of this insect and is it native to Wisconsin? Mon, Jan 5, 2009 at 8:06 PM Dear Bugman, We found this bug crawling slowly on our bathroom rug. It seems like some type of borer. I haven’t seen something like this before in Wisconsin, especially during the winter months. I brought it outside where it crawled slowly around for a bit on the snow and then I think it died. Mike Zussman Milwaukee, Wisconsin
Western Conifer Seed Bug
Western Conifer Seed Bug
Hi Mike, The Western Conifer Seed Bug, Leptoglossus occidentalis, is native to the Pacific Northwest, but in the past three decades, it has demonstrated major range expansion.  It is quite possible that an accidental introduction led to its proliferation in the Northeast.  According to BugGuide, it has been reported in over half the lower 48 states now, including Wisconsin.  Western Conifer Seed Bugs often seek shelter indoors when cold weather arrives, but they will not do any damage indoors.

Letter 26 – Western Conifer Seed Bug


Is it a beetle? They’re all over! October 11, 2009 I live in Ocean Twp, Monmouth County, New Jersey. These bugs showed up in September and are so abundant that you can’t walk outside without one flying into you. They are on my screens, in the pine trees, hiding in the mandevilla and skip laurel, walking on the patio, and of course… in my house (from the screen door that my 7 year old forgets to close). I’m concerned that they are going to destroy my recently landscaped yard, but I don’t know what they are or if they are harmful to vegetation. Even my landscaper isn’t familiar with them. As you can see, they have a pretty pattern on their body… browns, black and white. They fly and are in all different sizes in my yard. I’ve searched the internet to no avail to figure out that they are. Any help would be much appreciated. Michele in Wayside Ocean, Monmouth County, NJ
Western Conifer Seed Bug
Western Conifer Seed Bug
Hi Michele, Each autumn, we get numerous letters requesting that we identify the Western Conifer Seed Bug, Leptoglossus occidentalis.  This species often enters homes to hibernate.  It is a species native to the Pacific Northwest, but since the 1970s, there have been an increasing number of reports from Eastern North America, and the species has spread significantly, expanding its range for the past four decades.


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    Bugman aka Daniel Marlos has been identifying bugs since 1999. 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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Tags: Seed Bugs

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5 Comments. Leave new

  • Nice to finally know what this critter is! They enter our home every year about this time and they DO fly! Nice to know they’re harmless. I’ll let our current captives go.

  • I just caught something that looks JUST like this on my deck in FLORIDA! Wondering if this is actually what it is!

  • Does this have wings? It looks rather like the ones mostly in my attic. Some have appeared downstairs lately. They seem to jump rather than fly.
    Can I send you a foto of one I tried to kill neatly?

  • i think I may have been bitten by this Western Conifer seed bug. I still have the marks on my body. There is 3 marks in a line going Horizontal and 2 to the right going vertical. I have had these marks for over a month now. They were itchy at first but not now. I was taking antibiotics then a cream. Should I be concerned from this bite? Will cause a problem? Thanks for your help


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