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

Authors

    by
  • Bugman

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

    View all posts
  • 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.

    View all posts

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.

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  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.

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  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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