Do Darkling Beetles Bite? Debunking Myths and Facts

Darkling beetles are among the most common beetles found across various environments. They can be identified by their dark color, slow movements, and the distinct shapes and textures of their abdomens depending on the species. One of the main questions that people have about these insects is whether they are capable of biting humans or causing harm.

While darkling beetles possess biting and chewing mouthparts, they are primarily scavengers that feed on dead or decaying materials such as wood, fungi, clothing, and stored foods. This nocturnal lifestyle leaves many wondering if darkling beetles would pose a threat by biting humans. Based on their feeding habits, it is not common for darkling beetles to bite, nor do they actively seek out humans for this purpose.

Of course, it is essential to remember that there are several species of darkling beetles, and their behavior may vary. While bites are rare, it is still wise to exercise caution if you come across these insects and avoid handling them. In general, darkling beetles are not considered dangerous to humans, but it is best to treat them with respect and give them space to thrive in their natural habitats.

Darkling Beetle Overview

Characteristics

Darkling beetles belong to the Tenebrionidae family within the Coleoptera order of insects. These beetles are typically small-to-medium-sized and dark in color. Their elytra (hardened wing covers) can be smooth or textured with ridges or bumps, depending on the species. Adult darkling beetles can measure up to 1.5 inches (3.8cm) in length 1.

Habitat

Darkling beetles are found in various habitats worldwide, including the shrub-steppe regions of the Columbia Basin 2 and throughout North America 3. They are nocturnal insects, which means they are active at night and prefer staying in dark, sheltered environments during the day.

Diet

The diet of darkling beetles consists mainly of dead materials. They are scavengers feeding on rotting wood, fungi, and various other decomposing materials. In some cases, darkling beetles might also consume stored foods, clothing, or rugs 4. It is essential to note that darkling beetles don’t bite humans or animals, primarily focusing on decaying matter as their food source.

Biting and Behavior

Mandibles and Biting

Darkling beetles are primarily scavengers and have biting and chewing mouthparts adapted for that purpose 1. Their jaws, called mandibles, are designed for breaking down dead materials and plant matter, rather than biting humans 2. However, instances of biting are reportedly rare and generally considered harmless to humans.

Touch and Human Interaction

  • Mostly harmless to humans
  • Nocturnal scavengers
  • Important decomposers

Darkling beetles pose little threat to humans when touched or handled. They are nocturnal and scavengers, mostly active at night searching for dead materials to consume 3. As decomposers in the ecosystem, darkling beetles play a crucial role in breaking down plant and insect matter 4. If you were to accidentally touch a darkling beetle, it would likely try to avoid you rather than bite.

Feature Darkling Beetle Notorious Biting Insects
Bite frequency Rare Common
Bite severity Harmless Painful or dangerous
Main Function Scavengers Predators or blood-feeders

In comparison to notorious biting insects such as mosquitoes or wasps, darkling beetles are significantly more docile and less likely to bite when interacting with humans.

Life Cycle and Biology

Eggs

Darkling beetles, belonging to the family Tenebrionidae, begin their life cycle as eggs. Female beetles lay small, white-to-yellow eggs on or near suitable food sources. The eggs are oval in shape and hatch into larvae after about 7 to 10 days.

Larvae

The larvae stage is a key phase in the life cycle of darkling beetles. They usually appear as small, worm-like creatures that are often dark in color. These nocturnal scavengers feed on dead material such as clothing, rotting wood, or fungi.

  • Larval Features:
    • Nocturnal scavengers
    • Worm-like appearance
    • Dark in color

Pupae

After undergoing several molts, the larva will then enter the pupation stage. During this stage, the beetle remains in an inactive state but is undergoing a transformation inside its protective case. This phase is crucial for the development of adult features.

Adults

The adult darkling beetles emerge from the pupal case as fully mature insects. They are completely black in color and can range in size, with some species reaching up to 1.5 inches (3.8 cm) in length. Adult beetles have leathery or hard wings, usually not used for flying.

Comparison Table: Life Cycle Stages

Stage Characteristics Duration
Eggs Oval shape, white-to-yellow, laid by females 7 to 10 days
Larvae Worm-like, dark, nocturnal scavengers Varies by species
Pupae Inactive stage, transformation Varies by species
Adults Black in color, hard or leathery wings Varies by species

The life cycle and biology of darkling beetles contribute greatly to their ability to survive and adapt to various environments. Their various stages in development allow them to function as an important part of the ecosystem as both decomposers and occasional prey for other organisms.

Importance in Nature and Culture

Role as Scavengers

Darkling beetles play an important role as scavengers in various ecosystems. They feed on:

  • Dead materials like clothing and rugs
  • Rotting wood
  • Fungi

Their scavenging activities help break down organic matter, contributing to the recycling of nutrients in the environment.

Food Source for Wildlife

Darkling beetles serve as a valuable food source for many animals, including:

  • Birds
  • Small mammals (e.g. rodents)

Their presence in the ecosystem supports a healthy balance within the food chain, providing sustenance for their predators.

Use in Pet Industry

Darkling beetles and their larvae (mealworms) are popular as a food source in the pet industry, especially for:

  • Pet reptiles
  • Lizards

Pet stores often sell these insects as food for captive reptiles, contributing to the care and nutrition of various pet species.

Management and Control

Pest Control Strategies

Darkling beetles can be successfully managed using various control methods. The key is to utilize a combination of strategies to obtain optimum results.

  • Prevention: Proper sanitation can drastically reduce darkling beetle populations. For example, avoid leaving pet food and water out overnight, and remove clutter such as stacks of newspapers or cardboard. Adequately sealing off their entry points is also helpful (source).

  • Trapping: In cases where darkling beetles have invaded homes, sticky traps can be used to capture them. Place them near the infested areas.

  • Insecticides: Using chemical treatment should be done only when necessary. Choose an appropriate insecticide and follow the directions carefully.

Natural Predators

A variety of natural predators can help control these beetles in the ecosystem. These include:

  • Birds: Numerous bird species feed on darkling beetles as a part of their diet. Encouraging birds to your yard by providing bird feeders, nesting areas, and water supply can help.

  • Rodents: Some rodents, such as mice and rats, can also benefit from darkling beetle consumption. However, remember that rodents have their own set of issues, and encouraging them should be approached cautiously.

In conclusion, effective darkling beetle management and control is possible by employing preventative measures, utilizing natural predators, and applying insecticides only when necessary.

Footnotes

  1. PNNL: Science & Engineering – Shrub-Steppe Series: What about Darkling … 2

  2. Darkling Beetles (Tenebrionids) – Missouri Department of Conservation 2

  3. Darkling Beetle (Family Tenebrionidae) – Field Station 2

  4. Darkling Beetles – U.S. National Park Service 2

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 – Darkling Beetle from Kuwait are “Confissas”: Adesmia cancellata

 

Desert something
Bugman:
This was found just outside our hooch in Kuwait. A friend in the states guessed darkling beetle. Any idea? I have seen no insects in Baghdad larger than a mosquito. Anything interesting I should keep an eye out for? Or good places to look? Thanks,
CTT1 Micah Coleman and CTR1 Fred Smith (He actually spotted the beetle)
Camp Slayer, Baghdad

Hi Micah,
We are in agreement with your friend who identified this as a Darkling Beetle. Darkling Beetles are in the family Tenebrionidae. Our two most common submissions from the Gulf are Mole Crickets and Camel Spiders.

Letter 2 – Darkling Beetle from South Africa is White-Legged Tok-Tokkie

 

Subject: What is this bug???
Location: South Africa, Grassland biome
December 2, 2012 11:08 am
We came across this bug while hiking, its black with white legs, it looks like it has 8 legs but it could be 6 and 2 antennae. It was found in a rock, summer time, cloudy weather, on a hill… hopefully this helps, I’m not sure what bug it is. Thanks so much,
Abigail

White-Legged Tok-Tokkie

Hi Abigail,
We believe this is a Darkling Beetle in the family Tenebrionidae, but we have not been able to verify that speculation with any matching images online including at the Beetles of Africa catalog page nor at Beetles in the Bush.

Thanks.. I can’t seem to find any images of the Darkling bug I found.. are there any sites or even books I can search ????

White-Legged Tok-Tokkie

Update:  December 3, 3012
Thanks to a comment posted by Cesar Crash of Brazil, we now know that this is a Darkling Beetle known as the White-Legged Tok-Tokkie,
Dichtha incantatoris.  That has to be one of the best common names we have heard in a long time and it was found in Beetles in the Bush which links to this photograph by Eckart Stolle.

Letter 3 – Darkling Beetle from India, we believe

 

Subject: What Beetle
Location: Noida, U.P. India
December 11, 2016 12:22 pm
Dear Daniel,
Kindly assist in identifying this matt Charcoal coloured Beetle.
thanks
Signature: Aditi

Darkling Beetle, we believe
Darkling Beetle, we believe

Dear Aditi,
We believe this is a Darkling Beetle in the family Tenebrionidae, and it looks similar to this individual posted to FlickR and to the Dusty Brown Beetle posted to Plantwise.  Because we will be away from the office during the holidays, we are postdating this submission to go live toward the end of the month.

Letter 4 – Darkling Beetle from Singapore

 

Beetle With Humpy Back
Location: Singapore
March 4, 2012 5:27 pm
Hi again, but what is this curious looking beetle with strange bumps at its back. We sometimes see this during our outdoor trekking in one forest trail here. Thanks.
Signature: Antonio

Darkling Beetle

Our automated response
Thank you for submitting your identification request.
Please understand that we have a very small staff that does this as a labor of love. We cannot answer all submissions (not by a long shot). But we’ll do the best we can!

Hi,
Thanks. I understand. But can you possibly reply back if ever the bug is identified and is posted in your site, at least I would be notified. Thanks again. 🙂

Hi Antonio,
We do not recognize your Beetle, but we have posted the photo.  Leave a comment on the posting and you should be notified in the future if we receive a comment that identifies your fascinating creature.  It somewhat resembles a Leaf Beetle in the family Chrysomelidae, but we don’t believe that is correct.  Eric Eaton once wrote that if we are unsure of the family, a good bet to check is the Darkling Beetle family Tenebrionidae.  We are linking to both the BugGuide Leaf Beetle page and the BugGuide Darkling Beetle page even though Bugguide is a North American insect site.

Update:  November 2, 2015
We just received a comment from Dominik Hofer identifying this as
Phymatosum rufonotatum.  In addition to the FlickR link, it is also pictured on Beetles@SG Blog.

Letter 5 – Darkling Beetle from Egypt

 

Subject: Egyptian beetle
Location: Egypt, Wadi Degla
February 23, 2013 10:12 am
Hi Bug guy,
I live in Cairo, Egypt. When I walk in the desert there is one diurnal beetle I see a lot. Yesterday I saw 20 of them, three together at one place. They are noticeably long-legged, with grooved elytra. Can you tell me what family or genus this beetle is in? Thanks, Greg
Signature: Greg

Darkling Beetle
Darkling Beetle

Hi Greg,
This is a Darkling Beetle in the family Tenebrionidae.  It reminds us of the Desert Stink Beetles or Acrobat Beetles in the genus
Eleodes that are found in North America, and though we do not believe your beetle is in the same genus, you can see the more specific taxonomy provided on BugGuide.  Your beetle looks similar to this Egyptian Darkling pictured on Getty Images and this Israeli Darkling on Media Focus.

Darkling Beetle
Darkling Beetle

Thanks!  I had figured it was a teneb.  If you find out anything else about it I’m interested.  Thanks again, Greg

 

Letter 6 – Darkling Beetle from Israel

 

Unknown bug / beetle
Location: Israel
April 18, 2011 3:03 am
Hi,
I’d be happy if you could identify this bug. I photographed it in the bike trail near Kibbutz Be’eri (in Israel) a few days ago.
Thanks,
Signature: Oren B.

Darkling Beetle

Dear Oren,
We are nearly certain that this is some species of Darkling Beetle in the family Tenebrionidae.  In our haste to post a few letters and rush off to work, we haven’t the time to try to find a species identification, however, we did find a photo of a similar looking beetle on Shutterstock Images.

Hi Daniel,
Thank you for the identification. I did some more digging and it seems this beetle may be the Adesmia dilatata. What do you think?
Oren

Hi Oren,
While it looks similar, the textured pattern on the elytra of your specimen seems different.

Letter 7 – Darkling Beetle from South Africa

 

Subject:  Beetle, what family?
Geographic location of the bug:  Worcester, Western Cape, South Africa
Date: 05/13/2019
Time: 04:28 PM EDT
Your letter to the bugman:  About 10mm long. Moves along very fast, wants to burrow into soil as soon as it can. Very adept at turning back on its feet once overturned.
How you want your letter signed:  Marthinus

Darlking Beetle

Dear Marthinus,
We believe this is a Darkling Beetle in the family Tenebrionidae.  We are not certain of the species.

Letter 8 – Darkling Beetle from Mauritania

 

Subject: Mystery beetle
Location: Chinguetti, Mauritania
January 21, 2016 11:04 am
I wrote 11/19/2015 and at that time only had a photo of the beetle on its back. It appears early in the morning when it’s still cool. It is 4cm long. In winter It appears all day long.
The manuscript librarian said there is another species in the evening that looks like this one but with grey spots on its back. It only appears at night. It walks on the walls and makes holes to sleep inside.
Neither bug eats manuscripts but we are curious as to what it is? Please help.
Thanks,
Signature: Michaelle Biddle

Darkling Beetle
Darkling Beetle

Dear Michaelle,
Our hunch is that this is a Darkling Beetle in the family Tenebrionidae, but we do not have time to research a more specific identity this evening.  Your beetle does remind us of the Stink Beetles in the genus
Eleodes that we have in the Los Angeles area and desert climates in the Southwest U.S.

Darkling Beetle
Darkling Beetle

Dear Daniel –
Thanks for the information.  I notice the picture is already up on your pages.
Best,
Michaelle

Letter 9 – Darkling Beetle from India

 

Unknown Bug(mebbe beetle?)
April 23, 2010
Hi Daniel. I taken a pic of a bug while Himaliyan Trek during June 2007. I tried to find the bug info on internet but failed and so I had requested BUG ID to Eric Eaton at AllExperts.com and he suggested that it might be a “Leaf Beetle” but he wasn’t sure. So he referred me to you that you or your readers might be able to properly identify it.
Mayank Raichura
Parvati Valley, Himachal Pradesh, India

Darkling Beetle

Dear Mayank,
WE agree with Eric Eaton that this looks very much like a Leaf Beetle.  We will post it on our website and we hope our readership will help to identify it.

Update:  4 September 2016
We just received a comment from Boris and he provided links indicating this is a Darkling Beetle, NOT a Leaf Beetle.

Letter 10 – Darkling Beetle from Mexico

 

Leafhopper and beetle identification
Location: Huejutla de Reyes, Hidalgo, México
June 30, 2011 11:55 am
Der Bugman,
Help me with the identification of the leafhopper and the beetle as I have not managed to find anything like it in the network. Regards
Signature: Axel

Darkling Beetle

Hi Axel,
We do not recognize your beetle, and our first attempt to identify it did not produce any significant leads.  though the coloration reminds us of a Ground Beetle in the family Carabidae, the form, legs and antennae remind us more of a Darkling Beetle in the family Tenebrionidae.  We will check with Eric Eaton to get his opinion.

Eric Eaton provides information
Right you are, Daniel.  This is indeed a darkling beetle in the family Tenebrionidae.  I just have no idea which one!  That family is extremely diverse.  Well, our own North American Tarpela micans looks very similar to that Mexican specimen…I do wonder if they don’t mimic the big, stinky ground beetles like the caterpillar hunters….
Eric

Letter 11 – Darkling Beetle from Namibia

 

Subject: Namibian Beetle
Location: Namibia, Africa
November 1, 2016 7:16 am
Hello! I found this insect crawling on a petrified sand dune in Spitzkoppe, Namibia last April. I am having a very hard time identifying it. Thank you for your help!
Signature: Josh

Darkling Beetle, we believe
Darkling Beetle, we believe

Dear Josh,
We suspect that this is a Darkling Beetle in the family Tenebrionidae, but though we have located several black and white striped African species online, nothing quite matches your lovely individual.  We couldn’t even locate a match on the Beetles of Africa site.  Perhaps one of our readers will have better luck.

Identification:  Cesar Crash provided us with this link to Margy Green Photo Design of Trachynotus sp. (Tenebrionidae) that sure looks similar.  This genus is not well represented on the internet and we did find a removed Ebay posting of a specimen for sale that was listed as “extremely rare.”

Hi Daniel,
Thank you so much for your response.  I’m glad to have some further clarification as to its identity.
Thanks again!
Josh

Authors

  • Daniel Marlos

    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.

  • 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.

32 thoughts on “Do Darkling Beetles Bite? Debunking Myths and Facts”

  1. I was looking through some Singapore beetle photos, and while I didn’t see any matches, I did see some Fungus Beetles that had some funky formations on their elytra and they also had similar swellings on the shiny upper legs. Just my 2 cents (Canadian).

    Reply
  2. Further searching led me to the Strohecker collection of Handsome Fungus Beetles: http://www.ent.uga.edu/mchugh/Strohecker%20Files/Strohecker%20Genera%20Pages/Amphisternus.htm. I didn’t find any exact matches, but I think Antonio’s beetle must at least be a cousin to one of these guys, or one of the other similar genera. Aside from the distribution of the bumps, the main differences I see are the striations on the elytra, and the fact that Antonio’s seems a little narrower through the abdomen.

    Reply
  3. Your images looks simmilar, Bugophile. The helitrum striation are present in the A. verrucosus. There is another genus, the cacodaemon, but the most of them or much more “spiny”.
    http://www.forestryimages.org/search/action.cfm?q=cacodaemon
    ForestryImages.com has an impressive collection of 1001 images of fungus beetles http://www.forestryimages.org/search/action.cfm?q=fungus%20beetle, many of them have the same protuberance in the helytrum. Spathomeles also call me the attention http://www.forestryimages.org/search/action.cfm?q=Spathomeles.

    Reply
  4. Hey found a beetle in my house just like that… was big, like length of short pack of cigaretts big… so slightly bigger than a mouse… cat was chasing it… is it really a darkling beetle? We live in Central eastern Illinois… know any more about it?

    Reply
  5. I found these guys in my boots a couple of times – harmless. The Kuwaiti locals called them “confissas.” They made tracks in the sand about 3cm apart over long distances. They most closely resemble Egyptian Darkling Beetles.

    Reply
  6. I was also trying to find out what they were and was calling them “All-Terrain-Beetles,” until I did! They are the Pinstriped Ground Weevil. They do look like ATVs when they move so fast and over sand, rocks, etc, like it’s nothing. Their legs are long, holding them up off the ground about an inch (unless they haven’t survived the birds long enough to grow up!)

    Reply
  7. I can see, even if blurry, that tarsal formula is 5-5-4.

    This beetle belongs in Tenebrionidae: Alleculinae – and is unusually colourful for the group. Species ID will be no problem, unless one has a book that contains this species.

    Reply
  8. I can see, even if blurry, that tarsal formula is 5-5-4.

    This beetle belongs in Tenebrionidae: Alleculinae – and is unusually colourful for the group. Species ID will be no problem, unless one has a book that contains this species.

    Reply
  9. A pity! Tenebrionidae, and most beetle families, never covered!
    Remains the accidental google hit – or a well-sorted museum collection to scroll through.

    Reply
  10. A pity! Tenebrionidae, and most beetle families, never covered!
    Remains the accidental google hit – or a well-sorted museum collection to scroll through.

    Reply
  11. Daniel, a reader, Marquinhos, gave me a book called Besouros e Seu Mundo (Beetles and their World), written and illustrated by the brazilian coleopterist Celso Lima Godinho Jr. It has 1.400 illustrations of beetles from all over the world. I searched there Trachynotus. Searching in Google I found this single source: http://www.margygreen.com/keyword/Trachynotus%20sp./ The white in the elythra is not striking like this one, but certainly a match.

    Reply

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