Dermestid beetles facts for kids
Quick facts for kids Dermestid Beetles |
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| Varied Carpet Beetle (Anthrenus verbasci) | |
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Bostrichiformia
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Bostrichoidea
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Dermestidae
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Dermestidae are a family of beetles. They are also called skin beetles, larder beetles, hide beetles, leather beetles, carpet beetles, and khapra beetles. There are about 500 to 700 different species of Dermestid beetles. They can grow to be 1 to 12 millimeters long. Adult beetles have round or oval bodies. These bodies are covered in tiny scales or hairs (called setae). They can fit into small, deep spaces.
Most Dermestid beetles are scavengers. This means they eat dry animal or plant material. Their food includes animal skin, hair, feathers, and dead insects. Some Dermestids live in dead animals and feed on them. Others live in the nests of mammals, birds, bees, or wasps. One type, Thaumaglossa, only lives in the eggs of mantids. Many Trogoderma species are pests because they eat grain.
Because these beetles are often found on dead animals, scientists study them in forensic entomology. This field helps with criminal investigations by using insects. Some species are pests in homes and businesses. They can damage natural fibers like wool or silk. However, museums use some Dermestid species to clean animal skeletons. Some Dermestid species, known as bow bugs, even eat the bow hair of a violin.
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Dermestid Beetles and Your Home
Damage to Items and Food
Dermestid beetles can cause a lot of damage to common household items. Natural fibers like wool, silk, cotton, linen, fur, or feathers are easily attacked. Synthetic (man-made) fibers are usually safer. Dermestids also eat chocolate, copra (dried coconut meat), and cocoa beans. Most of the damage is done by the beetle's larval stage (the young, worm-like form). Adult beetles usually feed on flowers and shrubs.
How They Help Solve Mysteries
Scientists study Dermestid beetles in forensic entomology. This helps them understand how long a body has been in a certain place. For example, Dermestes maculatus beetles were found on a dead raccoon. By studying the beetles' life stages, scientists can estimate how long the raccoon had been dead.
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Side view of a Dermestes maculatus beetle
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Head view of a D. maculatus beetle
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Bottom view of a D. maculatus beetle
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Top view of a D. maculatus beetle
Dermestid Beetle Life Cycle
Like all beetles, Dermestid beetles go through a complete metamorphosis. This means they have four main life stages: egg, larva, pupa, and adult. Unlike some other insects, Dermestid larvae never have visible wing pads.
Dermestid larvae are covered in many tiny hairs (setae). This makes them look "fluffy." The larvae are usually dark brown to black. They also have two spine-like parts at the end of their abdomen. Most beetle larvae have chewing mouthparts and a hard head. They also have three pairs of legs on their thorax. This helps tell them apart from fly maggots.
The size of the larva depends on the species. They are usually less than 1/2 inch long. You can often find Dermestid larvae on dry organic materials. These materials are hard for other creatures to eat. Examples include dried food, skins, hides, wood, and natural fibers. In forensic studies, larvae are found on bodies during the dry and skeletal stages of decomposition. This happens several days after death. Larvae also like to hide from light in any small space.
Larder Beetles
The larva of the larder beetle (Dermestes lardarius) is longer than the adult. It is covered in reddish-brown or black hairs. It has two spine-like parts at its back end that curve backward. The larva of the black larder beetle has less curved spines. When they are ready to turn into pupae, mature larvae often bore into hard things. This can include wood, cork, or plaster.
Larder beetles are sometimes found as pests in homes. Both adults and larvae eat raw skins and hides. Adult larder beetles are usually 1/3 to 3/8 of an inch long. They are dark brown with a wide, pale yellow band across the top of their wing covers (called elytra). There are three black dots in a triangle shape on each wing. The underside (sternum) and legs of the larder beetle are covered in fine, yellow hairs.
Adult larder beetles usually spend winter outdoors in protected spots. In spring and early summer, they come into buildings. Females lay about 135 eggs near a food source. The eggs hatch in about 12 days. The whole life cycle of larder beetles takes around 40 to 50 days.
The black larder beetle, Dermestes ater, is completely dark. It has scattered yellow hairs on its body. It looks similar to Dermestes maculatus but its wing covers are not jagged. Its underside is yellow instead of white. This beetle is a pest of fish, mushrooms, and cheese.
Hide Beetles (Leather Beetles)
Dermestes maculatus, also known as the hide beetle, leather beetle, or skin beetle, eats raw skins and hides. It is similar to the larder beetle. It has short and long reddish-brown or black hairs. However, its two spine-like parts at the back curve forward. Also, its front wings are dark brown, and its underside is mostly white with some black. Its life cycle is 60 to 70 days. A female can lay up to 800 eggs.
Both hide and larder beetles eat many animal protein products. They cause serious damage in places that produce silkworms and in museums.
Carpet Beetles
Carpet beetle larvae start eating as soon as they hatch. They are shaped like carrots and are very hairy. The number of times they shed their skin (called instars) can be from 5 to 11, and sometimes up to 20. Larvae of the black carpet beetle, Attagenus megatoma, can grow up to 1/2 inch (12 mm) long. They are yellow to brown. Other types of carpet beetles are usually 1/4 to 1 inch (6 to 25 mm) long. They are covered with dark hairs. Some species have special tufts of hair at their back end. These beetles are drawn to dirty fabrics and cracks where dead insects might be food. Carpet beetle larvae are often called "woolly bears" or "buffalo moths."
Black Carpet Beetles
The black carpet beetle, Attagenus megatoma, is a common pest in stored products. It is one of the most damaging because it can harm household items with keratin. Keratin is a protein found in animal hair and feathers. These beetles can also chew through food packaging. This lets other insects get inside.
Females can lay up to 90 eggs. The eggs hatch in about 8 to 15 days. Usually, this species has only one generation per year. It takes six months to a year for them to become adults. An adult black carpet beetle can then live for another two months. Adult beetles are about 2.8 to 5 mm long. They are oval, dark brown to shiny-black, and have brown legs.
Varied Carpet Beetles
The varied carpet beetle, Anthrenus verbasci, attacks typical household items. Carpet beetles are often found with carpets, wool, furs, and any processed animal or plant food. They also eat dead insects, spiders, and even nectar and pollen. They are found across the United States and Canada. Females can lay up to 40 eggs. The larvae go through 7 to 8 stages of growth. It takes about eight months to a year for them to become adults. Adults can live for about 2 to 6 weeks.
This species comes in different shapes, sizes, colors, and scale patterns. On average, adults are 2 to 3 mm long. Their scales can be white, brown, yellow, or gray-yellow. The tiny, sharp hairs of the larvae can cause allergic reactions in humans. This can include skin rashes or blisters if you touch them.
Khapra Beetles
When they hatch, khapra beetle larvae are about 1.6 to 1.8 mm long. They are mostly covered with thick hairs. Khapra beetle, Trogoderma granarium, larvae have special body hairs, including simple hairs and barbed hairs. Larvae are yellow-white, but their head and body hairs are brown. As they grow, their color changes to golden or reddish-brown. Their abdomen becomes shorter. Mature larvae can reach a maximum length of 6 mm long and 1.5 mm wide.
The khapra beetle is a pest of stored products. It is hard to control infestations because they crawl into cracks and stay there for a long time. They often infest grains and cause serious losses to stored foods. Adult beetles are covered with hairs. They are about 1.5 to 3 mm long and 1 to 2 mm wide. Male khapra beetles are brown to black with reddish-brown marks on their wing covers. Females are a bit larger and lighter in color. Their short antennae have 11 segments. The last 3 to 5 segments form a club. This club fits into a groove on the side of their pronotum (the top part of their thorax).
Controlling Dermestid Beetles
Hide and Larder Beetle Control
Modern ways of processing and storing meat have helped reduce hide beetle problems. Keeping your home clean is very important to prevent these beetles. Dead insects in homes attract these beetles because they are a main food source. Food should be sealed tightly or stored in a refrigerator. This stops beetles from getting to it. Freezing food for a week or heating meat for a long time can kill insects in infested foods. This also stops them from spreading.
Household fibers like wool and silk can easily be damaged by moths and beetles. Special cleaning, including moth-proofing, should be done often. Insecticides should be used only in small spots. Apply them to cracks and hidden places where beetles might be hiding. Products with Pyrethrins are approved for use against hide beetles. Insecticides used for carpet beetles also work against hide and larder beetles.
Carpet Beetle Control
Regularly cleaning up spilled food or lint will remove places where carpet beetles can breed. Items that can be damaged, like food, woolens, and furs, should be stored in containers that insects cannot get into. If you think you have an infestation, you must remove and destroy the source of the problem. This helps stop them from spreading further. These beetles can be killed with extreme heat or by putting items in a freezer.
Pyrethroid insecticides can be used to control carpet beetles. These insecticides contain active ingredients like permethrin, bifenthrin, deltamethrin, and tralomethrin.
Diatomaceous earth is also a good way to control them.
Images for kids
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The grub of a larder beetle (Dermestes lardarius)
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Dermestidae damage to a Manduca quinquemaculata in an insect collection
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The larva of Anthrenus verbasci beetle
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The larva of an Anthrenus verbasci beetle, frass, cast skin & a single grain of blue rodent bait damaged by the larva
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Carpet beetle damaging a Sceliphron destillatorius in an insect collection
See also
In Spanish: Derméstidos para niños
