Dermestid Beetle

Wayne and Gladys Valley Children's Zoo


In the Zoo
9-14 mm
9-14 mm
1-2 pounds
7 years

Geographic Range

North America

Scientific Information

Scientific Name:
Dermestes marmoratus

Lifestyle and Lifespan

Activity Time Frame:
Sexual Dimorphism:
60 days gestation, 8 month incubation Lifespan in the Wild: 70+ years
Lifespan in the Wild:
2-3 years
Lifespan in Captivity:
2-3 years


Not Evaluated


Of the 500 species of dermestid beetles worldwide, 123 live in North America. They are sometimes called museum beetles, bow bugs, or carpet beetles, depending on where they are found and what they eat.

Species Specifics

This is the largest dermestid in California with a length of 9 to 14 mm. An adult has a slightly flattened elongated oval carapace. It is black with gray scales forming spots and a broad band across the base of the wing covers. The underside is mostly whitish. Larvae are elongated and reddish brown with a pale stripe down the back. They are covered with long reddish brown hairs.

Physical Characteristics

The hair of the larvae break off readily and cause irritation of tender skin (e.g. in a bird’s mouth), thus acting as a defense mechanism. Coleoptera means sheathed wing. Beetles have their forewings strengthened and hardened with a special material called chitin as protective covers for the operative under pair.



Low to middle elevations in North America.


Habitats: Found mostly in the Eastern United States, Box Turtles occur as far north as Michigan and Maine, South to Florida, and as far West as Texas and Kansas. Found rarely above 1,000 feet in elevation, preferring low land habitats where water collects. Commonly associated with deciduous forests having high leaf litter and moisture these turtles are often located near rivers, streams, ponds, lakes and other bodies of fresh water, however, they are not good swimmers.


Dermestid beetles feed on decaying flesh but have expanded their diet to include human-made items. Beetles of the Dermestidae family feed on a great many things such as cereal products, grains, rugs and carpets, various stored foods, upholstery, fur coats, etc. and thus most are considered destructive pests. Some dermestids are harmful in museums since they may feed on mounted birds or mammals and specimens of plants and insects, while other dermestids are employed by museums to clean skeletons for exhibits.

Ecological Web

Dermestid beetles show up on carcasses when they start to dry-out. They break down and decompose decaying flesh which helps keep ecosystems clean and healthy. They will also eat fresh carcasses in captivity but in the wild they are pushed out by more aggressive maggots who need more moist food.

Activity and Behavior

Activity Pattern

Like most reptiles, activity is temperature dependent, preferring conditions that are moist, humid, and warm. Ideal temperature is 80-95°F and they are more active during rainy periods and immediately after it has rained. During drought, turtles may spend time in burrows and in excessive heat turtles will seek out shallow pools of water to soak in. In fall months turtles are observed basking in the sunlight for energy. In Northern climates turtles will enter hibernation in late October. In places like Florida, turtles are active year around.


The gecko will lick its eye to clean it from dust and other particles.

Social Behavior

Solitary. Although monitors are not social, neither are they territorial. Bipedal ritual combat has been observed in the trees during the breeding season. Since their tails are so important, they defend their tails, rather than use them as whips. Black Tree Monitors in the wild are reported to be nervous and high-strung; they will flee if threatened, and if handled carelessly, will scratch, bite and then defecate on the offender.

Reproductive Behavior

Adult female insects emerge from the pupa with a full complement of eggs retained in the ovaries. Sperm introduced by the male is stored and released as the eggs pass out through the ovipositor. This beetle’s eggs are usually deposited in carrion.


Beetles lay eggs which produce larvae quite different in form from the adult. When full-size, such larvae undergo a further change of form to become a pupa which is inert and does not feed. The pupa undergoes metamorphosis and emerges as the adult. Adult female insects emerge from the pupa with a full complement of eggs retained in the ovaries. Sperm introduced by the male is stored and released as the eggs pass out through the ovipositor. This beetle’s eggs are usually deposited in carrion.



Three-Toed Box Turtles are not considered endangered at the national level in the United States, Canada or Mexico, although several U.S. states, including Michigan, New Hampshire, Massachusetts and Connecticut, list T. carolina as a species of special concern. It is considered endangered in Maine. IUCN: VulnerableCITES: Appendix II


It is thought dermestid beetles were introduced into California by hide traders in the early days.

Current Threats

Introduced Non-Native, Domestic, and Invasive Species

Our Role

Oakland Zoo exhibits dermestid beetles in the Bug House and educates the public about their role in ecosystems. At Halloween time, we have a special exhibit at our event, Boo at the Zoo, where you can see many different carcasses being eaten by dermestid beetles.

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How You Can Help

Please be aware of the pets you choose to buy. Never get a pet that has been taken from the wild and never return a pet to the wild. Be aware of pesticide applications so as to not poison native animals that benefit your ecosystem. Finally, be conscious of your trash and waste so as to not attract unwanted animals such as ravens.

Fascinating Facts

The name "dermestid" comes from the Greek word for "skin," a perfect name considering their favorite food.

Dermestid beetles are used to clean bones for zoo and museum displays, as well as in forensic investigations. Chemicals can also be used to clean bones but they can sometimes cause damage to marks or wounds on the bones.

Beetles typify the success of insects. This order contains not only the most numerous species (over 330,000 worldwide) of the insects, but also of the animal kingdom.


VanClay, Mary. "Bow Bugs, Dermestids." Johnson String Instrument.