Dermestid beetles, with their ability to quickly skeletonize carcasses, seem almost too good to be true for tasks like cleaning bones or preserving museum specimens. But could these insects also pose any risk to humans under the right conditions?
If you’re short on time, here’s a quick answer: dermestid beetles are generally not harmful to living humans, but their larvae could potentially cause minor skin irritation through close contact.
In this nearly 3000 word guide, we’ll cover everything you need to know about the risks and benefits of dermestid beetles when it comes to humans. We’ll discuss how their biology and behavior shapes their limited interactions with people, look at whether their sharp mouthparts or shed skins could cause issues, and more.
Dermestid Beetle Biology and Behavior
What Are Dermestid Beetles?
Dermestid beetles belong to the family Dermestidae, a group of approximately 500 species of scavenging beetles. They are common insects that can be found worldwide. Some of the most well-known dermestid species include the black larder beetle (Dermestes ater), hide beetle (Dermestes maculatus), and varied carpet beetle (Anthrenus verbasci).
Adult dermestid beetles are oval-shaped, reaching between 1.5 to 8 mm in length. They have clubbed antennae with 11 segments. Dermestids can be identified by their hairy appearance with bands of brown, black, white, and yellow scales on the elytra (hardened forewings).
The larvae are hairy, brown or black in color, and resemble small caterpillars.
While the adult beetles feed on pollen, nectar, and fungi, the larvae are scavengers that feed on dry animal matter like skin, hair, feathers, horn, and hooves. Some species are pantry pests known to infest stored meats, cheeses, grains, and museum insect collections.
The varied carpet beetle is a common fabric pest.
Dermestid Habitats and Food Sources
Dermestid beetles inhabit a wide range of habitats both outdoors and indoors. Outdoors, the beetles live in nests of birds, bees, wasps, and mammals where they feed on shed hair, feathers, skin, and carcasses. They are also found in animal burrows and dens.
Indoors, dermestids infest pantries, warehouses, museums, and homes feeding on stored food products, natural fibers, and insect collections.
The food sources sought by dermestids depend on the species. Hide beetles feed on dried meats, cheeses, and preserved specimens in museums. Larder beetles consume dried meats, cheeses, grains, cereals, flour, and fruit.
Varied carpet beetles feed on wool, silk, leather, fur, dried meat, feathers, dead insects, and natural fibers.
Reproduction and Life Cycle
The female dermestid beetle lays hundreds of eggs either individually or in small batches in food sources. The eggs hatch in 4-10 days into larvae. The larvae undergo 6-11 instars over 35-90 days feeding voraciously to build up fat stores for the pupal stage.
They then seek isolated locations like wood crevices or folds in fabric and construct a pupal chamber from saliva, shed larval skins, and substrate debris. After 5-30 days, the adult beetles emerge to mate and restart the lifecycle.
The entire lifecycle takes 2-4 months depending on species, food availability, and environmental conditions. Dermestids can produce multiple generations per year. Ideal conditions for dermestids include temperatures between 70-95°F and dry environments with moisture levels below 65%.
Unchecked dermestid populations in homes or pantries can cause extensive damage to fabrics, foods, and museum specimens.
Do Dermestid Beetles Bite Humans?
Dermestid Mouthparts and Feeding
Dermestid beetles have chewing mouthparts specialized for eating skin, hair, feathers, and skeletal remains. Their jaws are not adapted for aggressive biting or defensive attacks (dermestids cannot bite through human skin or living tissue).
Instead, their jaws are best equipped for scraping, tearing, and consuming dead tissue.
Dermestids feed on dried animal hides, taxidermy specimens, natural history collections, and carrion found in nature. They are unable to attack and consume living animals or humans. In fact, dermestids tend to avoid living/moving creatures given their easy and ample access to non-living food sources.
Lack of Interest in Living Humans
Dermestid beetles evolved to feed on animal carcasses and byproducts like shed fur/feathers – they did not evolve to attack creatures larger than themselves or consume living tissue. As such, they lack any biological drive or instinct to bite, infest, or harm living humans.
Additionally, their physical characteristics (small size, lack of wings, slow movement) make them incapable of pursuing, attacking, overcoming, or extracting blood from humans, even hypothetically. Simply put: humans, whether dead or alive, do not register as suitable food or hosts in dermestids’ biological wiring.
Accidental Contacts are Rare
That said, dermestids may occasionally come into incidental contact with living humans – for example, an exploratory walk across exposed skin – but this would only occur in captive scenarios involving direct handling of beetle colonies (dermestids avoid humans in natural settings).
Even then, the beetle would not bite or break the skin – though sensitive individuals could potentially mistake its touch or footsteps for a “bite”. Proper handling techniques avoid most direct contact.
Dermestid Larvae and Human Skin
Sharp Mandibles of Larvae
Dermestid beetle larvae have sharp, scissors-like mandibles that they use to feed on dried animal material. These mandibles are strong enough to bite through bone, skin, and cartilage. While dermestid larvae pose little threat to living animals, their powerful jaws can give a painful nip if handled carelessly.
Most dermestid breeders recommend wearing gloves when handling larvae colonies to avoid accidental bites. The bites are not medically significant but can be quite painful due to the sharp mandibles piercing the skin. There is also a risk of infection if the bite area is not properly cleaned.
Shed Skins Can Cause Minor Irritation
As dermestid larvae grow, they shed their exoskeletons several times before reaching the pupal stage. These cast-off larval skins contain urticating hairs that can cause skin irritation in sensitive individuals if directly handled.
The irritation is similar to fiberglass splinters and results in a localized rash or bumps on the skin. For most people, the irritation is minor and subsides quickly once exposure to the hairs stops. However, those with highly sensitive skin may require topical creams to ease discomfort.
Wearing gloves when handling larval colonies prevents skin contact with irritating hairs. Proper cleanup and disposal of old skins, frass, and other debris also reduces exposure risk.
Precautions When Handling Colonies
Here are some tips for safely handling dermestid beetle larvae:
- Wear gloves to avoid bites and skin irritation.
- Wash hands thoroughly after handling larvae or cleaning colonies.
- Avoid touching your face, eyes, or mouth while handling larvae.
- Clean and disinfect any bite sites immediately.
- Keep larvae securely contained and avoid free-roaming colonies.
- Properly dispose of old larval skins, frass, and debris.
- Work in a well-ventilated area to avoid inhaling irritating hairs.
While dermestid larvae are not inherently dangerous, simple precautions can prevent potential health issues from bites, allergic reactions, or accidental ingestion. Careful handling and hygiene practices ensure safety for both the larvae handler and the beetles.
Using Dermestids Safely for Skeletonization
Proper Colony Setups and Handling
When setting up a dermestid beetle colony for skeletonization projects, proper housing and handling techniques are crucial for both human and insect safety (BonesAndBugs.com). Colonies should be kept in well-ventilated plastic or glass enclosures with a wire mesh lid to prevent escapes.
Beetles prefer temperatures between 70-90°F and some form of humidity control like a moist sponge. Direct skin contact should always be avoided when handling dermestids given the possibility of bites or allergic reactions.
Routine colony maintenance involves removing frass (beetle excrement), adding new egg laying medium, and replacing food sources (dead animals) to sustain an active dermestid population. Protective clothing like gloves and particle masks are recommended when servicing colonies.
Overall, proper care promotes skeletonization efficiency while reducing risks to both beetles and their human caretakers.
Avoiding Accidental Releases
Preventing dermestid escapes is a multifaceted process focused on enclosure security and transport containment. Colony housing should have tightly-fitted lids with fine mesh barriers. When moving colonies to clean cages or change locations, beetles can be temporarily kept in sealed plastic containers.
These efforts reduce the possibility of loose dermestids slipping into homes or natural environments.
In the unlikely event of an accidental laboratory release, prompt beetle recapture efforts are advised. Open food sources like raw meat or fish can act as bait to attract hungry escapees. Sticky traps are also effective capture tools.Swift action is prudent since loose dermestids could damage furnishings, spread bacteria, or disturb local arthropod populations if an infestation arises.
Monitoring for Escapes
Routine inspection for potential escape points or sightings of loose beetles enables proactive containment. Some signs of a containment breach include:
- Holes in enclosure mesh or barriers
- Closure failures in doors/lids allowing gaps
- Presence of beetles outside colonies
- Sudden drops in colony beetle numbers
Monitoring escape indicators and conducting perimeter checks for stray dermestids allows for timely incident intervention. Undetected escapes risk household infestations or outdoor establishment requiring extensive control efforts. Stopping an issue before exponential spread is key.
| Benefits | Risks |
| Efficient, clean skeletonization | Bites, allergies, or skin irritation |
| Educational opportunities | Structure infestations |
| Prevent specimen damage | Disruptions to local species |
The Benefits Outweigh the Limited Risks
Dermestid beetles provide significant benefits that far outweigh the minimal risks they may pose to humans. Here are some of the key reasons why dermestid beetles are widely used despite concerns about safety:
They’re an Eco-Friendly Alternative for Skeletonizing
Dermestid beetles are a green way to clean skeletons. The alternative is using harsh chemicals like ammonia and bleach – dangerous substances that pollute the environment. Dermestid beetles biologically break down flesh, leaving bones pristine.
This natural method prevents chemical runoff and is better for the planet.
They Help Solve Crimes and Identify Remains
Forensic investigations depend on dermestid colonies. The beetles delicately remove flesh from skeletons and small remains, revealing evidence to identify bodies, determine cause of death, or provide clues that help solve murders and mysteries.
Without this natural cleaning method, many cases would go unresolved.
They’re a Vital Resource for Taxidermists
Taxidermists rely on dermestid beetles to remove the flesh from hides and prepare them for mounting. Dermestids work better than other techniques which can damage the fur or feathers. The beetles leave the skin intact with minimal effort from the taxidermist.
This helps preserve animals for educational displays in a cost-effective, efficient manner.
They Pose Little Risk with Proper Handling
Dermestid beetles do not bite, sting, or transmit diseases. The main risks come from inhaling hairs or feces. However, most beetle activity occurs in enclosed spaces with ventilation systems. As long as proper precautions are taken, such as wearing gloves and masks, the risks are negligible.
The benefits dermestids provide clearly outweigh these limited hazards.
They’re Easy to Contain and Control
Dermestid beetles only eat dead, dried tissue so they’re simple to manage. Keeping them in secured containers with screened lids prevents escape. Their population remains proportional to the food supply, so they won’t overrun a space. If needed, freezing or chemical treatment can kill an infestation.
But for those using dermestids responsibly, this is rarely necessary.
Conclusion
As we’ve explored throughout this guide, dermestid beetles and their larvae pose little real threat to humans. While their mandibles and shed skins mean they require safe handling, their preference for dried carcasses over living flesh greatly limits any hazard.
So if you need an efficient way to strip skulls or preserve delicate skeletons, a dermestid colony can still be an incredibly useful tool when set up and monitored properly. Just be sure to take basic precautions, and you can safely reap the benefits these remarkable insects provide.
