Dermestidae - WikiHQ

Dermestidae are a family of Coleoptera that are commonly referred to as skin beetles or carpet beetles. Other common names include larder beetles, hide or leather beetles, and khapra beetles. There are over 1,800 species described.

Dermestids have a variety of habits; most genera are scavengers that feed on dry animal or plant material, such as skin or pollen, animal hair, feathers, dead insects and natural fibers. Members of Dermestes are found in animal carcasses, while others may be found in mammal, bird, bee, or wasp nests. Thaumaglossa only lives in the egg cases of mantids, while Trogoderma species are pests of grain.

These beetles are significant in forensic entomology. Some species are associated with decaying carcasses, which may help with criminal investigations. Some species are pests (urban entomology) and can cause extensive damage to natural fibers in homes and places of business.

They are used in taxidermy and by natural history museums to clean animal skeletons. Some dermestid species, commonly called "bow bugs", infest violin cases, feeding on the bow hair.

Description

Adult Dermestidae are generally small beetles (1–12 mm long), rounded to oval in shape, with hairy or scaly elytra that may form distinctive and colourful patterns. Except in genera Dermestes and Trichelodes, there is a single ocellus in the middle of the head. The antennae are clubbed (except in male Thylodrias contractus) and usually fit into a groove on the underside of the thorax, concealing them when the beetle is at rest. Adult females of T. contractus are notable for being larviform, meaning they retain a larval morphology even into adulthood.

Pupae of subfamilies Dermestinae and Attageninae are covered in structures known as gin-traps, as defense against predators. Pupae of Megatominae are protected within the exuviae of the last larval instar. Larvae also move away from light and often hide in any cavity in order to remain undisturbed. Dermestids also attack chocolate, copra, and cocoa beans.

Medical

Dermestid hastisetae (a specific group of detachable setae from the larvae of subfamily Megatominae), both those attached to exuviae and those shed by larvae, cause health problems in humans when inhaled (rhinoconjunctivitis, asthma), ingested in contaminated food (nausea, fever, diarrhea, proctitis, perianal itching) or touched with skin (dermatitis). Similar to the use of flies in forensic entomology, the arrival of D. maculatus to carrion occurs in a predictable succession. Adult D. maculatus beetles generally arrive 5 to 11 days after death. In an attempt to refine this relatively wide range, recent research has repeated arthropod succession studies. These studies are applied to estimate the arrival of various species of Dermestidae after death. Development for dermestids is temperature dependent, and the optimal temperature for D. maculatus is 30 °C. Development data is normalized using Accumulated Degree Days. Dermestids can also be used in cases involving entomotoxicology, where feces and shed larval skins can be analyzed for toxins.

Dermestes maculatus collected from raccoon carcass:

Image:Dermestidae 1.jpg|Lateral view (Dermestes maculatus)

Image:Dermestidae 2.jpg|Head view (D. maculatus)

Image:Dermestidae 7.jpg|Ventral view (D. maculatus)

Image:Dermestidae 6.jpg|Dorsal view (D. maculatus)

</gallery>

Evolution

thumb|Feeding traces from skin beetles on a specimen of the dinosaur [[Nemegtomaia]]

While possible members of the family have been described from the Late Triassic and Early Jurassic based on isolated elytra, the oldest known unambiguous member of the family is Paradermestes from the Middle Jurassic Jiulongshan Formation of China, which appears to belong to the subfamily Dermestinae. Members of the subfamilies Attageninae and Megatominae are known from the Cretaceous, including the living genera Attagenus and Megatoma. The ancestral ecology of the group was likely mycophagy, which is retained in Orphilinae, with the ancestor of most other lineages making the transition to saprophagy.

Dermestidae
Megatominae
Anthrenini
Megatomini
Ctesiini
Dermestinae
Dermestini
Marioutini
Paradermestini
Thorictinae
Thorictini
Thaumaphrastini
Orphilinae
Orphilini
Ranolini
Trinodinae
Cretonodini
Thylodriini
Trichelodini
Trinodini
Trinoparvini
Attageninae
Attagenini
Apphianini
Adelaidiini
Cretodermestini
Eckfeldattagenini
Egidyellini
Trogoparvinae

Genera

Dermestidae contains the following 74 genera: It has two back-curved, spine-like appendages on the posterior end. The larva of the black larder beetle has less strongly curved appendages.

Larder beetles are infrequent household pests. Adults and larvae feed on raw skins and hides. Adult larder beetles are generally 1/3 to 3/8 of an inch long and are dark brown with a broad, pale yellow spotted band across the upper portion of the elytra. There are three black dots arranged in a triangle shape on each wing. The sternum and legs of the larder beetle are covered in fine, yellow setae. Adult larder beetles are typically found outdoors in protected areas during the winter, but during the spring and early summer they enter buildings. Females lay approximately 135 eggs near a food source, and the eggs will hatch in about 12 days. The life cycle of larder beetles lasts around 40 to 50 days.

Hide beetle (leather beetle)

Dermestes maculatus, known as the hide beetle, leather beetle, or skin beetle, feeds on raw skins and hides like the larder beetle. Its life cycle is 60 to 70 days and the female can lay up to 800 eggs. The larvae of the carpet beetle are often referred to as "woolly bears" or "buffalo moths".

Black carpet beetle

The black carpet beetle, Attagenus megatoma, is a widely known stored product pest and one of the most destructive because of its potential damage to household products containing keratin, which is a protein found in animal hair and feathers. They are also able to burrow through various types of food packaging, allowing passage for other insects.

Females can lay up to 90 eggs and they hatch in about 8 to 15 days. Generally, this species only has one generation a year. The average adult size is about 2.8 to 5 mm long and they are oval, dark brown to shiny-black in color, and have brown legs. Females can lay up to 40 eggs and the number of larval instars is seven or eight. The time it takes to become an adult varies from about eight months to a year. In addition, the adults can live around 2 to 6 weeks. This species varies in shape, size, color, and pattern of scales. On average, the adults are 2 to 3 mm in length and have scales that vary from white, brown, yellow, or even gray-yellow.

The khapra beetle is a stored-product pest. Infestations are difficult to control because they crawl into cracks and crevices, remaining for long periods of time.

Pyrethroid insecticides can be used to control carpet beetles. These contain active ingredients such as permethrin, bifenthrin, deltamethrin and tralomethrin.

Image gallery

Image:Larder beetle grub.jpg|The grub of a larder beetle (Dermestes lardarius)

Image:Manduca quinquemaculata dermestidae damage sjh.JPG|Dermestidae damage to a Manduca quinquemaculata in an insect collection

Image:Woolly_bear.jpg|The larva of Anthrenus verbasci beetle

Image:grain_bait_wolly_bear.jpg|The larva of an Anthrenus verbasci beetle, frass, cast skin & a single grain of blue rodent bait damaged by the larva

Image:Sceliphron and pest.jpg|Carpet beetle damaging a Sceliphron destillatorius in an insect collection