What Do Ground Beetles Eat: A Quick Guide to Their Diet

Ground beetles are a fascinating group of insects that play a vital role in keeping our gardens and agricultural fields healthy. With over 34,000 species worldwide and hundreds found across the Midwest, these creatures are not only diverse but also extremely important to our ecosystems source. As you read on, you’ll learn about their dietary habits and the benefits they bring to our environment.

Most of these beetles are predators, feeding on a variety of different prey to maintain the balance of our ecosystems. Some common food sources for ground beetles include cutworms, ants, maggots, earthworms, slugs, and other beetles source. You may not often spot them as they are mainly active during the night, but rest assured that they are diligently working to control pests in your garden.

Keep in mind that ground beetles do not harm people or pets, and they also don’t damage your household belongings. In fact, their presence is beneficial as they act as natural pest controllers, helping to keep the populations of various insects in check source. So, the next time you see a ground beetle in your garden or yard, you can appreciate the valuable work they do in helping to maintain a balanced ecosystem.

What are Ground Beetles

Ground beetles are a diverse group of insects that belong to the family Carabidae. They are prevalent in agricultural and garden settings and are considered important predators. With over 34,000 species worldwide, ground beetles come in various sizes, ranging from less than ¼ inch to over 1½ inches long.

These beetles have distinct features, such as their elongated body consisting of a head, thorax, and abdomen. They are generally flat and have long legs. Their wings, known as elytra, are hard and often metallic in color. Ground beetles can be brown or black, and their iridescent appearance can display different colors in varying angles of light. To help you better understand ground beetles, here’s a comparison table:

Ground beetles have antennae that allow them to detect their prey. Their powerful jaws, or mandibles, enable them to capture and devour many soil-dwelling insects. So, if you happen to spot these intriguing creatures in your garden, don’t worry, as they are beneficial to the ecosystem by naturally controlling pest populations.

Diet of Ground Beetles

Ground beetles are incredibly versatile in their diet, making them an essential part of our ecosystem. Depending on the species, they can either be carnivorous or omnivorous. We’ll go through some of the main components of their diet, making it easier for you to understand what ground beetles eat.

One of the primary sources of food for ground beetles is other insects. They enjoy munching on a variety of insects, some of which are considered pests. For example, they prey on caterpillars, aphids, and slugs, effectively controlling their population and benefitting gardens and agricultural fields.

In addition to insects, ground beetles sometimes consume seeds and plants. Although this may sound counterintuitive, it actually plays a crucial role in maintaining a balanced ecosystem. By eating seeds and plants, along with other insects, they act as nature’s clean-up crew, helping to prevent overgrowth and maintaining overall environmental health.

A significant portion of a ground beetle’s diet consists of worms as well. In particular, they often feed on soft-bodied prey like slugs and earthworms. This helps control the populations of these creatures in gardens, as they could otherwise damage plants and become a nuisance.

Here’s a brief comparison table for easy reference:

In conclusion, ground beetles play a vital role in controlling the population of various insects, worms, and other organisms. Their diverse diet helps create balance in the ecosystem, making them an essential component of a healthy environment. So next time you spot a ground beetle, remember the important work they do and appreciate their contribution to maintaining our ecosystem.

Hunting and Feeding Behavior

Ground beetles are fascinating creatures that play a crucial role in controlling various pests. As predators, they are quite active and hunt for food primarily at night, which makes them nocturnal animals. They typically use their strong mandibles to capture prey and consume an assortment of insects, such as cutworms, ants, maggots, earthworms, slugs, and other beetles ¹(https://hortsense.cahnrs.wsu.edu/fact-sheet/predatory-beetles-ground-beetles/).

Their movement is swift and efficient as they navigate through various habitats. While some species can fly, most ground beetles prefer to stay close to the ground and rely on their speed and agility to catch prey. This behavior helps them to avoid becoming prey themselves.

Ground beetles are a perfect example of beneficial insects that can help maintain a healthy garden ecosystem. Here are some of their characteristics:

• Predators that hunt pests
• Nocturnal and active hunters
• Strong mandibles to catch prey
• Swift movement and some can fly

In summary, ground beetles are crucial predators in gardens and agricultural settings. Their nocturnal hunting behavior, strong mandibles, and swift movement make them efficient at reducing pest populations, ultimately contributing to a healthier environment. Keep in mind that maintaining a welcoming habitat for them can help you keep your garden healthy and thriving.

Habitat of Ground Beetles

Ground beetles thrive in a variety of habitats. Some common places you can find them include:

• Soil: Most species live in soil cracks and crevices, where they can easily hunt their prey.

• Rocks and logs: They can be found under rocks, logs, and debris, providing protection from predators and extreme weather conditions.

• Mulch, forests, and gardens: These beetles also reside in mulch, forests, and gardens, which offer plenty of food sources and hiding spots.

• Trees and weeds: Some species prefer living on trees or amidst tall weeds and grasses.

• Fields: Agricultural fields are another common habitat for them as they can find plenty of pests to feed on.

Ground beetles mainly prefer outdoors but might occasionally wander indoors. However, they are not a threat to your indoor space.

It is helpful to have a diverse habitat with different elements such as stones, boards, or containers. These features can serve as hiding places for ground beetles while also providing safe zones during unfavorable weather conditions. Moreover, sandy areas with cracks and crevices are more suitable for them.

To summarize, ground beetles adapt to a wide variety of habitats, ranging from soil and rocks to forests and fields. Providing a mix of these elements in your outdoor space can encourage their presence, bringing valuable pest control benefits.

Seasonal Activity

During the Spring, you’ll find that ground beetles become more active as the weather warms up. They emerge from their winter hibernation in search of food, which primarily consists of other insects, larvae, and slugs. As daylight increases, these nocturnal insects take advantage of the longer nights to hunt for their prey.

Summer is the peak time for ground beetle activity, as they enjoy the warm weather conditions and plentiful food supply. You’ll likely spot them in your garden or grassy areas where their prey is abundant. Keep in mind that they are most active during the night, so you may not see them often during the day.

In the Fall, as the days get shorter and temperatures begin to drop, ground beetles start to prepare for their winter hibernation. They do this by finding sheltered spots like leaf piles, wood piles, and under rocks. Keep an eye out for them on mild evenings, as they still hunt for food, but their activity reduces as temperatures continue to get colder.

Ground beetles are sensitive to lighting and prefer dark, hidden areas to rest during the day. However, they are drawn to artificial light sources at night, which can sometimes make them more visible if you have outdoor lights on.

To recap, ground beetles follow a seasonal pattern of activity:

• Active during Spring, with increased hunting at night
• Peak activity in Summer, making the most of warm weather and food abundance
• Reduced activity in Fall, preparing for winter hibernation
• Sensitive to lighting, preferring dark areas during the day but drawn to artificial light at night

By understanding their seasonal behavior, you can better appreciate the role these beneficial predators play in your garden ecosystem and support their presence by providing shelter and a suitable habitat.

Ground Beetles in North America

In North America, ground beetles (Carabidae) are a diverse group of arthropods that play a significant role in controlling pest populations. They are mainly found in agricultural and garden settings, where they prey on various types of pests. For example, some ground beetles help control the population of the notorious Colorado Potato Beetle.

Most ground beetles are small to moderate in size, ranging from 1/8 to over 1½ inches long, and are often black or brown-colored with iridescent features. They are primarily nocturnal and dwell in soil and detritus. Their diet includes cutworms, ants, maggots, earthworms, slugs, and even other beetles, making them valuable in pest control services.

A notable subfamily within the Carabidae family is the Cicindelinae, also known as tiger beetles. These beetles are voracious predators and are typically found in sandy or muddy habitats. Tiger beetles hunt various insects and are known for their incredible speed as they chase prey on the ground.

Another fascinating group of ground beetles are the Bombardier Beetles. They have a unique defense mechanism that allows them to produce and release hot, noxious chemicals to deter predators. This impressive and rare bombardier ability adds to the intricacy of ground beetles’ functionalities in their ecosystems.

The diverse species of ground beetles found in North America are worthy of appreciation for their essential contribution to maintaining balance within their respective environments. By feeding on pests in gardens and agricultural fields, they help reduce the need for chemical pesticides. So next time you come across a ground beetle, remember the vital role they play in maintaining a healthy ecosystem.

Ground Beetles and Ecosystem

Ground beetles play a crucial role in maintaining the balance in various ecosystems. They are considered beneficial insects due to their predatory nature, helping in biological control of pests in agricultural settings and gardens.

Pros of Ground Beetles in Agriculture:

• They feed on a wide range of prey, such as cutworms, ants, maggots, earthworms, slugs, and other beetles, providing valuable pest control services in farms and gardens.
• Their presence in agricultural systems contributes to the reduction in the use of chemical pesticides, promoting a more sustainable and eco-friendly farming approach.

Cons of Ground Beetles in Agriculture:

• Some species might occasionally feed on the seeds of certain plants, but the benefits of their pest control outweigh this minor drawback.

By living in the soil and detritus, ground beetles become essential components of the ecosystem. Their larvae, with distinct curved mouthparts, also reside in leaf litter or topsoil, helping in breaking down organic materials and recycling nutrients.

To ensure a thriving ecosystem and promote beneficial interactions between ground beetles and your farming or gardening practices, consider the following suggestions:

• Provide shelter for the beetles by maintaining a layer of leaf litter or mulch.
• Avoid excessive usage of chemical pesticides that may harm ground beetles or their larvae.
• Establish native plant species or insectary plants to support and attract ground beetles to your agricultural landscape.

By encouraging a healthy population of ground beetles in your garden or farm, you will see the positive impact they have on pest control and overall ecosystem health.

Life Cycle of Ground Beetles

The life cycle of ground beetles goes through four main stages: eggs, larvae, pupae, and adults. Let’s briefly discuss each stage, so you understand their characteristics and roles in the life of these helpful insects.

• Eggs: Female ground beetles lay their eggs in soil or among plant materials. These eggs take about 7 to 10 days to hatch, depending on the environmental conditions¹.

• Larvae: Upon hatching, young ground beetles emerge as larvae. This is the stage where they actively feed on various small insects, such as cutworms, maggots, and other beetles, helping to control pests in gardens². They are also known to consume earthworms, ants, and slugs³.

As they grow, ground beetle larvae molt several times before reaching their next stage. The larval stage can last anywhere from a few weeks to several months, during which they contribute to the ecosystem by preying on harmful pests.

• Pupae: After the larval stage, ground beetles enter the pupal stage. This is when they undergo a remarkable transformation, developing into their adult form. Pupation can take place in soil or under debris, where they remain hidden and protected from predators.

• Adults: Finally, ground beetles emerge as fully-formed adults. They are nocturnal creatures, actively foraging for food at night while hiding under rocks, logs, leaves, or other debris during the day⁴. Adult ground beetles continue to serve as essential predators, feeding on various small insects and contributing to natural pest control.

In general, ground beetles live for about a year, with some species living longer than others. Throughout their life cycle, these insects play a crucial role in maintaining the balance of garden ecosystems and helping to control potential pest outbreaks⁵.

Ground Beetles and Pest Control

Ground beetles are often found in agricultural and garden settings, where they play a crucial role in controlling pests. These nocturnal insects are known to feed on a variety of pests such as cutworms, ants, maggots, earthworms, slugs, and other beetles, making them valuable allies in pest control ¹.

The presence of ground beetles can help you avoid relying on harmful pesticides and insecticides, which can harm the environment and disrupt the balance of your garden ecosystem. Instead, they offer a natural solution to common pest infestations ².

To encourage ground beetles in your garden or agricultural setting, you should:

• Provide a protective habitat for them by maintaining leaf litter and debris on the ground.
• Avoid using chemical pesticides and insecticides that might harm the beetle population ³.

Here are some pros and cons of using ground beetles for pest control:

Pros:

• Effective predators of common garden pests.
• Chemical-free, environmentally friendly solution.
• Reduces the need for pesticides and insecticides.

Cons:

• Takes time to establish a healthy ground beetle population.
• May not be effective against all types of pests.
• No guarantee of complete pest elimination.

In conclusion, ground beetles serve as a natural and eco-friendly method of pest control, helping to maintain the balance in your garden or agricultural area. By providing a favorable habitat and avoiding chemical treatments, you can encourage the growth of these helpful insects and benefit from their predatory behavior.

Interaction with Other Species

Ground beetles interact with various other organisms, including ants, birds, humans, snails, spiders, invertebrates, and caterpillar hunters. In many cases, these interactions involve the ground beetles preying on other species.

For example, ground beetles are known to prey on snails, caterpillars, and invertebrates such as cutworms, maggots, and other beetles ¹. They can be beneficial predators in gardens since they help control pest populations.

On the other hand, ground beetles can be prey for birds and spiders. Birds often rely on ground beetles as a food source, while some spiders may capture them in their webs or hunt them on the ground.

In terms of their interaction with ants, certain ground beetle species mimic ants in appearance or behavior. This mimicry helps the beetles avoid being attacked by ants or other predators.

Humans generally have a positive relationship with ground beetles, as they can provide valuable pest control services in gardens. However, sometimes, they may also be considered a nuisance, especially if they find their way indoors.

Remember to treat these insects with respect and avoid disturbing their natural habitats. By understanding their role in the ecosystem, you can appreciate their contributions to maintaining a balanced environment.

Unique Ground Beetle Specimen

Meet the Bombardier Beetle, a fascinating specimen within the Coleoptera family. This particular ground beetle has a unique and intriguing defense mechanism.

When threatened, it can:

• Mix chemicals within its abdomen
• Produce a boiling hot, noxious spray
• Aim the spray at predators with surprising accuracy

Another fascinating aspect of the Bombardier Beetle is its diet. Like most ground beetles, it is a predator that consumes a variety of prey, such as:

• Cutworms
• Ants
• Maggots
• Earthworms
• Slugs
• Other beetles

Here’s a comparison table for the Bombardier Beetle and a typical ground beetle:

By understanding the habits and features of these unique beetles, you can appreciate their role in natural pest control and ecological balance. Remember to treat your garden and its inhabitants with care to maintain a healthy ecosystem.

Reader Emails

Over the years, our website, whatsthatbug.com 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 – Snail Eating Ground Beetle with Prey

Subject:  Beetle eating banana slug Southeast Alaska
Geographic location of the bug:  Juneau, AK
Date: 10/22/2017
Time: 02:03 PM EDT
Hi there! I see these beetles wandering the ground and on and under rotten logs all over Southeast Alaska and the rainforests of the Pacific Northwest (WA, OR, British Columbia) and I have not been able to ID them! They have these wonderful purpleish abdomens and are maybe an inch long or less. This one was found with a baby banana slug in its jaws! What is it?
How you want your letter signed:  Thanks! -Mike J

Dear Mike,
Your image is gorgeous.  We have several images on our site of Snail Hunters or Snail Eating Ground Beetles in the genus Scaphinotus, but your image is the only one showing its preferred prey.  According to BugGuide:  “55 spp. in 9 subgenera total, all in our area.”  Several species are known from Alaska, including Scaphinotus angusticollis which is pictured on BugGuide and Scaphinotus marginatus which is also pictured on BugGuide.  Both species look very similar to your individual and we are not confident enough to provide an exact species identification for you.  According to Bugs of the Month:  “Scaphinotus angusticollis is large (satisfyingly so) and black, with a beauteous purple or greenish sheen in sunlight. The thorax is peculiarly shaped, turned up at the outer edges (a bit like a satellite dish), the legs are quite long and slender and the head is distinctly narrow and elongate. Truly the Afghan hound of the carabid world. The narrow head is an adaptation to eating snails from the shell. Now there are shelled snails in forests around these parts, but with forest clearing and the introduction of non-native pests, shelled snails are less frequent and slugs abound.”

Letter 2 – Lace Bugs and Ground Beetle

Two Unknown Bugs
Hi Bugman, I have two bugs that I have been trying to identify but cannot. The little winged ones were found at the underside of tree leaves and the beetle was found in our garden. We live in British Columbia, Canada
Thanks!
Cheryl

Hi Cheryl,
Your small bugs are Lace Bugs in the Family Tingidae. This is the first entry we have gotten for our site. We are seeking an opinion from Eric Eaton on the beetle. Here is Eric’s response: “The lace bugs are almost certainly in the genus Corythucha. Host plant information really helps in identifying them to species. The beetle appears to be a species of Carabus, but not one I’m familiar with. Definitely a ground beetle, and in the same tribe with Carabus if that is NOT the genus. Eric”

Update: (05/19/2007) A further identification for you
Hey there! Love the site. I noticed on your main page that Cheryl from British Columbia sent you images of lace bugs and a mystery ground beetle. Her beetle looks remarkably to me like a specimen I snapped a shot of last week on the other side of the country, just north of Toronto, Ontario. I think her mystery beetle is Carabus granulatus, an introduced species from Europe. Here’s a link to my picture as posted on bugguide.net: http://bugguide.net/node/view/109257
Dave Kleiman Thornhill, Ontario, Canada

Letter 3 – unknown Ground Beetle identified as Pasimachus punctulatus

Help Identify this beetle, pretty please!!
Dear Bugman,
As an avid buglover since birth, I have captured and played with my fair share of creepy-crawlies. But I have never encountered such a bloodthirsy, savage critter such as this! I found him in Eastern Kentucky. He’s all black, with a purpleish blue outline around his body (one of the pictures shows this very well). I had a cage with 2 Bess Bugs (patent leather beetles) and a rather large Millipede in it, and the three seemed to be getting along fine. Then, I found this fella under a log (where I found he others) and was impressed. Since I found them all in the same place, I figured they could co-habitate. Unfortuantely, this guy must have been hunting when I found him, because the day after I put him in with the others, I went to check on them, and to my horror, BOTH Bess Bugs AND the Millipede had been cut into pieces. I swear, this sucker ate more than 4 times his own weight overnight, (each of the Bess Bugs were slightly larger than him, and the Millipede was almost 3 times his length) then proceded to bury himself in the dirt I had in the cage. From now on, I’ll be much more careful about who I room together, but please help me in identifying this little monster.. I was NOT happy that he ate my buddies! Thanks a bunch,
Sam

hi Sam,
This is some species of Ground Beetle, and we believe it is in the tribe Carabini, but we are not convinced it matches specimens posted to BugGuide in the genera Carabus nor Calosoma. It seems similar to the European Ground Beetle, Carabus nemoralis, but the elytra are different. We will contact Eric Eaton to see if her recognizes this spectacular specimen.

Update: (06/18/2008)
Hi, Daniel:
The big, fierce ground beetle is in the genus Pasimachus, and is probably Pasimachus punctulatus. They are highly beneficial predators of cutworms and other pest insects. We would love to have this image over at Bugguide, where the guide page for this species is currently without any images at all.
Eric

Letter 4 – Snail Eating Ground Beetle

Oregon beetle, what is it?
Hi,
I live in Eugene, Oregon and on a recent trip to the coast we were hiking in a mixed (mostly pine) rain-forest on the western side of the coast range we kept seeing these long-legged black beetles with a vivid purple edging around the body. I am curious what these are and whether they are native or invasive. … I’d really appreciate some help identifying this as I can’t find one that looks like it online anywhere. Thanks,
Brian Jones
PS- My picture shows as copyrighted on the page, but please feel free to post it on your site or wherever you’d like

Hi Brian,
We thought this ground beetle resembled the Narrow Searcher, Calosoma externum, pictured on BugGuide, but that is an eastern species. We requested Eric Eaton’s assistance and he wrote back: ” Daniel: Sorry, you are way off. This is a specimen of Scaphinotus angusticollis, one of the snail-eating beetles. Very common. The protruding jaws, narrow ‘neck,’ and long, gangly legs help set the genus apart from most other ground beetles (family Carabidae). Eric “

Letter 5 – Minute Yellow Tailed Ground Beetle: Miotachys flavicauda

Very small insect – identified
July 20, 2009
After looking at it more closely and determining that it is a beetle, and after browsing about 130 pages at BugGuide, I think I have identified these as Mioptachys flavicauda. Thanks for your great site!
Duff Means
Sterling, VA

Dear Duff,
We know how ponderous it can be sifting through countless pages on BugGuide (the most awesome North American insect and arthropod identification website) in an attempt to identify an unknown submission.  There is a real sense of accomplishment when we finally arrive at the end of an identification quest.  We don’t want your work to go unrewarded, and though we cannot offer you any tangible compensation, we do want to post the fruits of your labor on our site.  Thanks for contributing a new species to What’s That Bug?, Miotachys flavicauda, a minute  Yellow Tailed Ground Beetle.

Letter 6 – Ground Beetle from Madagascar is possibly Crepidopterus descorsei

Beetle question
December 21, 2009
Hi Bugman,
I am sending a photo of an insect which I am guessing is a beetle, perhaps a stag beetle. The insect was found at Berenty which is a private reserve west of Fort Dauphine, in the southeast of Madagascar, It was found in the leaf litter and is quite large. I was impressed by those mandibles!
Diana B.
Berenty Private Reserve, South Madagascar

Hi Diana,
The large mandibles are characteristic of Stag Beetles, but your specimen lacks clubbed antennae.  The threadlike antennae indicates this is some species of Ground Beetle in the family Carabidae, though we are uncertain of the species.

Letter 7 – Ground Beetle

grade school garden project needs help
April 18, 2010
We found this beetle outside our school and our teacher asked us to identify it as dangerous or not. He thinks it may kill trees. We have looked far and wide in other resources and can’t tell for sure. We think it may be a type of ground beetle? It is dark brown, with iridescent sheen and a pock-marked back. No stripes. Purple flares from the midsection. Narrow head. Thicker thighs, skinny lower legs. 3/4 of an inch long. Any ideas?
Matilda, grade 2
upstate New York

Dear Matilda,
You are correct that this is a Ground Beetle in the family Carabidae.  Ground Beetles are beneficial predators.  Often identifying them to the species level requires an expert’s examination.

Eric Eaton provides a species identification
Daniel:
The ground beetle from upstate New York on April 18 is almost certainly Carabus nemoralis, a flightless predator of mostly caterpillars and other soft-bodied invertebrates.
Eric

Letter 8 – Ground Beetle

Small metallic green beetle – Agonum sp?
Location: North Carolina
December 4, 2010 10:51 pm
Hi there,
I caught this fellow in a Berlese funnel for my entomology class – it’s pretty small, probably 8 mm long. I’m thinking it’s a Agonum sp., but is there a more accurate ID?
Thanks!
Signature: Beginner entomologist

Dear Beginner entomologist,
We find Ground Beetles to be particularly challenging to identify, but we will give this a try.  In the meantime, perhaps one of our readers will be able to provide an answer.

Ed. Note: We do not believe this is Agonum based on BugGuide’s images.

Letter 9 – Ground Beetle from China

Metallic Ground Beetle From China
May 3, 2011
Hello Bugman,
I spotted this beautiful baby on a bug hike last week. She (or he) was running, quickly, along a dry, concrete drainage ditch around 2:30 in the afternoon. The area where I was hiking is right at sea level. My guess is it’s some kind of ground beetle; a caterpillar hunter, maybe. But I am having trouble narrowing it down to species, especially because there seem to be very few online insect ID resources for amateurs for China and Eastern Asia. And, for obvious reasons, my Kaufman guide to North American insects can only take me so far. I would very much appreciate any help you can give. I did look through the Carabidae of the World website but did not have much luck. Thank you so much!
Best,
Marian Lyman

Hi Marian,
You are positively correct that this exquisite little metallic beauty is a Ground Beetle.  Your photos have exactly the kind of details that should enable an expert with the correct resources to key it out to genus or even species level.  Maybe Mardikavana will be able to assist us with this identification.

Comment
This beauty is most likely Carabus lafossei or some related species.
http://www.flickr.com/photos/kqedquest/3256354127/

Letter 10 – Ground Beetle

What kind of beetle?
Location: Corrales, NM
June 13, 2011 12:17 pm
Hi,
These beetles were found in my office in Corrales, NM in June.
Can you help identify them?
Signature: Concerned

Dear Concerned,
You have no need to be concerned about this beautiful Ground Beetle in the genus Pasimachus, which is most probably Pasimachus californicus, based on the photos and range listed on bugGuide.  Adults and larvae feed on caterpillars, so it probably just wandered into your office accidentally.  The genus page on BugGuide indicates a common name Fierce Ground Beetle.  If carelessly handled, they might pinch, but the bite has no venom.  Your other smaller Ground Beetle is also of no concern.  Since you submitted three different identification requests, the only species that you might have some concern about is the female Cockroach carrying an ootheca or egg case.  The Ground Beetles are considered beneficial, but again, there presence in your office is puzzling.  Since this genus is incapable of flight, according to BugGuide which states:  “Large, extra-robust, flightless ground beetles (elytra fused into rigid shell). Huge jaws, head, pronotum. Some have blue margins. Typically run about under or on leaf litter in forests”, we would eliminate the possibility that they were attracted to lights, which is often the reason large beetles enter homes.

Letter 11 – Ground Beetle

Subject: Ground beetle (Pasimachus sp.)
Location: New Braunfels, Texas
July 1, 2013 10:53 pm
Hi bugman,
I came across three of these beetles yesterday (Monday 07/01/13) and thought you might like a pic of one. Until I found these three beetles I had never heard of Pasimachus, even though I have loved insects and have avidly hunted for them since I could walk (I am now 27). I am so happy to have found these as they are pretty freakin awesome. I hope you enjoy the photo as much as I enjoy visiting your website multiple times a day.
Thank you for all the awesomeness you provide!
Signature: Michael

Hi Michael,
Thank you for sending in your photo.  We haven’t posted a photo of a Ground Beetle in the genus Pasimachus in a few years.  We don’t feel too confident attempting a species identification.  Several members of the genus have blue margins like the one in this image from our archives.  According to BugGuide, they are:  “Large, extra-robust, flightless ground beetles (elytra fused into rigid shell). Huge jaws, head, pronotum. Some have blue margins. Typically run about under or on leaf litter in forests” where they eat caterpillars and other larval insects.

Letter 12 – Marsh Ground Beetle

Subject: Nunavut bug
Location: Rankin Inlet, Nunavut, Canada
June 28, 2015 8:21 pm
Hi, this is a picture a friend took of a bug in Nunavut, far north of Canada. I’m not sure anyone can identify it, as it seems to be sparkling with wetness of some kind.
Signature: Margaret B.

Dear Margaret,
Initially we thought this might be a Tiger Beetle, and we knew it looked familiar, and we had a vague memory from long ago of receiving an image of a similar looking beetle, and though it was related to the Tiger Beetles, it was actually classified differently.  Well, we eventually found this image of a Marsh Ground Beetle in the genus Elaphrus in our archives, and we believe your individual looks very similar.  This image of Elaphrus americanus from BugGuide looks very similar.  According to BugGuide, it is found:  “From the arctic treeline south to central British Columbia and east to Newfoundland. Along the pacific coast from British Columbia to southern Oregon, eastward across southern British Columbia to southwestern Alberta, south to northeastern Oregon, central Idaho and central Colorado.”

Letter 13 – Unknown Ground Beetle from Congo may be Craspedophorus species

Subject: Ground beetle
Location: Bomassa, Republic of Congo
November 11, 2015 11:56 pm
I live in northern Congo and regularly come across interesting insects, some of which are probably little known or unknown to science.
I try to identify many of the arthropods I see here via iNaturalist, but many can use a lot of extra help – always appreciated!
Feel free to contact me at: naftalihonig@gmail.com
Signature: Naftali

Dear Naftali,
We agree that this is a Ground Beetle in the family Carabidae, but at this time we are unable to provide you with a more specific name.  Perhaps one of our readers will provide a comment.

Via iNaturalist a good bet seems Craspedophorus sp.
There are many spp. though…

According to a published paper we found, that genus is from Australia and Asia, but in Google Books Taxonomy, Phylogeny, and Zoogeography of Beetles and Ants online, it indicates:  “The carabid genus Craspedophorus, with over a hunderd species distributed through tropical Africa, Madagascar, Asia, and Australia is notable partly because of its usual dorsal color pattern, which consists of four yellow or orange spots on a blackish elytral background.  The spots are normally at or near the lateral margins of the elytra, two on each elytron, and when they are extensive, the dark background has even been described as forming a cross.”  Colnect indicates one species is pictured on a stamp from Portuguese Guinea.  The first species pictured on Carabidae of the World , Craspedophorus abnormis, is reported from “Democratic Republic of the Congo, Tanzania, Zimbabwe, Zambia,” but alas, there is no image.  We believe you have discovered the correct genus.

No way to undercover (or name?) the species? I am just near the trinational border Cameroon-Congo-CAR…on the Congo side.