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.
Larval Dermestidae range from 5 to 15 mm long and are usually covered in tufts of long, dense hairs (setae). In subfamily Megatominae and the genus Trinodes, some of these setae are hastisetae: barbed setae ending in spear-like heads (hasta being the Latin word for "spear"). Hastisetae serve a defensive role, detaching and entangling predators.
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.
Diet and behaviour
Dermestid larvae are typically found on dry organic items that are hard for other organisms to digest, such as dried foodstuffs, skins, hides, wood and other natural fibers. In forensic studies, the larvae are found on human corpses during the dry and skeletal phases of decomposition, which occurs several days after death.. Forensic Investigations. Larvae also move away from light and often hide in any cavity in order to remain undisturbed. In natural habitats, they can be found on animal carcasses, under bark, and in the webs, nests and burrows of various animals.
Larvae of subfamilies Dermestinae and Attageninae (which lack hastisetae), burrow into feeding substrates, pupate in concealed locations, and show fast escape behaviours when disturbed. Larvae of Megatominae (which have hastisetae), do not burrow, pupate where they have been feeding, and their response to disturbance is to stop moving, arch the body and spread the hastisetae. This difference may be because hastisetae would be a hindrance for burrowing larvae.
Adult dermestids are known to feed on pollen and nectar. Adults of Dermestes are cannibalistic and will eat young larvae and pupae; this means that when kept in captivity, adults should be placed in separate containers from the immature stages.
Economic relevance Urban and stored products
Dermestid beetles are destructive to a number of common items. Natural fibers such as wool, silk, cotton, linen, fur, or feathers are much more prone to attack than synthetic fibers.P.G. Koehler and F.M. Oi (1991). Carpet Beetles. University of Florida IFAS Extension 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).
Forensic
Dermestes maculatus, hide beetles, also have the potential to offer investigators an estimation of the time since death in homicide or questionable cases. 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:
Evolution
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.
Borings in fossil dinosaur bones, such as those found in the Allosaurus specimen "Big Al" from the Late Jurassic, have been attributed to dermestid beetle larvae, and interpreted as evidence for the desiccation of carcasses prior to burial.
Taxonomy According to World Dermestidae catalogue (Jiří Háva, 2023), following taxonomic division is proposed for Dermestidae (at subfamily and tribe levels):
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:
Adelaidella Zhou, Ślipiński & Liu, 2020 Adelaidia Blackburn, 1891 Afrothorictus Andreae, 1967 Amberoderma Háva & Prokop, 2004 Anthrenocerus Arrow, 1915 Anthrenus Geoffroy, 1762 Apphianus Beal, 2005 Apsectus LeConte, 1854 Araphonotos Beal & Kadej, 2008 Attagenus Latreille, 1802 Caccoleptoides Herrmann, Háva & Kadej, 2015 Caccoleptus Sharp, 1902 Chilattagenus Háva, 2021 Claviella Kalík, 1987 †Cretoattagenus Háva, 2020 †Cretodermestes Deng, Ślipiński, Ren & Pang, 2017 †Cretomegatoma Háva, 2021 †Cretonodes Kirejtshuk & Azar, 2009 Cryptorhopalum Guérin-Méneville, 1838 Ctesias Stephens, 1830 Dearthrus LeConte, 1861 Derbyana Lawrence & Ślipiński, 2005 Dermalius Háva, 2001 Dermeanthrenus Háva, 2008 Dermestes Linnaeus, 1758 †Eckfeldattagenus Háva & Wappler, 2014 Egidyella Reitter, 1899 Evorinea Beal, 1961 Globicornis Latreille, 1829 Hemirhopalum Sharp, 1902 Hexanodes Blair, 1941 Hirtomegatoma Pic, 1931 Jiriella Kitano, 2013 Katkaenus Háva, 2006 Labrocerus Sharp, 1885 Liberorphinus Háva & Matsumoto, 2021 Macrothorictus Andreae, 1967 Mariouta Pic, 1898 Megatoma Herbst, 1791 Miocryptorhopalum Pierce, 1960 Myrmeanthrenus Armstrong, 1945 Novelsis Casey, 1900 †Oisenodes Kirejtshuk, Háva & Nel, 2010 Orbeola Mulsant & Rey, 1868 Orphilus Erichson, 1846 Orphinus Motschulsky, 1858 Papuderma Háva, 2021 †Paradermestes Deng, Ślipiński, Ren & Pang, 2017 Paranovelsis Casey, 1900 Paratrogoderma Scott, 1926 Pecticaccoleptus Háva, 2004 Phradonoma Jacquelin du Val, 1859 Ranolus Blair, 1929 Reesa Beal, 1967 Rhopalosilpha Arrow, 1929 Sefrania Pic, 1899 Socotracornis Háva, 2013 Sodaliatoma Háva, 2013 Thaumaglossa Redtenbacher, 1867 Thorictodes Reitter, 1875 Thorictus Germar, 1834 Thylodrias Motschulsky, 1839 Trichelodes Carter, 1935 Trichodryas Lawrence & Ślipiński, 2005 Trinodes Dejean, 1821 Trinoparvus Háva, 2004 Trogoderma Dejean, 1821 Trogoparvus Háva, 2001 †Tuberphradonoma Háva, 2021 Turcicornis Háva, 2000 Valdesetosum Háva, 2015 Volvicornis Háva & Kalík, 2004 Zahradnikia Háva, 2013 Zhantievus Beal, 1992
Selected taxa
Larder beetles
The larva of the larder beetle Dermestes lardarius is longer than the adult and is covered in reddish brown or black setae.Larder Beetle . University of Rhode Island Green Share Factsheets. It has two back-curved, spine-like appendages on the posterior end. The larva of the black larder beetle has less strongly curved appendages. Mature larvae of both species tend to bore into hard substrates such as wood, cork, and plaster to pupate.
Larder beetles are infrequent household pests.Beetle Identification . Pest Solutions Plus. 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.
The black larder or incinerator beetle, Dermestes ater, is completely dark with scattered yellow setae on the body. It is similar to Dermestes maculatus but lacks serrations on its elytra. Its ventral surface is yellow instead of white. This beetle is a pest of fish, mushrooms, and cheese.Genus Dermestes. BugGuide.
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. This species is similar in appearance to the larder beetle, with larvae covered in short and long reddish brown or black setae, but its two spine-like posterior appendages curve forward. Also, in adults, the forewings are dark brown and the sternum is mostly white with some black.Bennett, S. M. (2003). Dermestes maculatus. Its life cycle is 60 to 70 days and the female can lay up to 800 eggs.
The hide and larder beetles both feed on an assortment of animal protein based products and cause serious damage in the areas of silkworm production and museums.
Carpet beetle
Carpet beetle larvae start to feed as soon as they hatch. They are carrot shaped and heavily covered with setae, especially on their posterior end. The number of instars typically ranges from five to 11 and in some cases may reach as high as 20. Larvae of the black carpet beetle Attagenus megatoma may grow up to and be yellow to brown in color. Other types of carpet beetle are regularly long and covered with dark setae. Certain species have distinctive tufts of setae extending from their posterior end. These beetles are attracted to soiled fabrics and crevices where dead insects may serve as a food source.Lyon, William F. Carpet Beetle. Ohio State University Extension Fact Sheet. The larvae of the carpet beetle are often referred to as "woolly bears" or "buffalo moths".
Black carpet beetle