Trogidae

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Trogidae
Temporal range: Aptian–Recent
Trox.sabulosus.Reitter.jpg
Trox sabulosus
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Suborder: Polyphaga
Infraorder: Scarabaeiformia
Superfamily: Scarabaeoidea
Family: Trogidae
MacLeay, 1819
Genera

Omorgus
Phoberus
Polynoncus
Trox
Cretomorgus
Paratrox
Kresnikus

Contents

Diversity
c. 300 species

Trogidae, sometimes called hide beetles, is a family of beetles with a distinctive warty or bumpy appearance. Found worldwide, the family includes about 300 species contained in four or five genera. [1]

Trogids range in length from 2.5 to 20.0 mm. Their shape is oblong to oval, with a generally flat abdomen. Their color ranges from brown to gray or black, and they often encrust their bodies with soil. They resemble scarab beetles with heavy limbs and spurs.

They are scavengers and are among the last species to visit and feed on carrion. They are most often found on the dry remains of dead animals. Both adults and larvae eat feathers, fur, and skin. Some species are found in bird and mammal nests. Details of the life histories of many species are poorly known, since many are specialized to particular types of nests. They are often overlooked by predators and collectors due to their behaviors of covering their bodies with soil and becoming motionless when disturbed.

This group may also be considered Troginae, a subfamily of the Scarabaeidae. The common name "skin beetle" is sometimes used in reference to these beetles, but more often refers to species of the Dermestidae.

Origins

Hide beetles are found worldwide. More species of Trogidae are found in dry environments instead of moist environments, typically temperate plains areas. Each genus is more diverse in different regions of the world. Trox is found in the Holarctic/Ethiopian area, Omorgus within the southern continents, and Polynoncus is found in South America. [2]

Controversy exists over whether Trogidae is a family of its own or a subfamily of Scarabaeidae. [2] One major reason for the dispute between classifications is the possible evolution of the ommatidium in the eyes[ citation needed ]. Different environmental pressures and predators may have led to the adaptation of ommatidium structures within this family. For example, the more advanced and numerous the ommatidium, the more present the larger the ability of the insect to escape and elude predators. The Trogidae may have evolved in Australia. [3]

The oldest known fossils are from the Aptian Zaza Formation of Russia and the Shar-Tolgoy and Dzun-Bain Formations of Mongolia, assignable to the extant genus Trox as well as the extinct genera Cretomorgus and Paratrox . Other known fossils include Kresnikus beynoni found in Cenomanian aged Burmese amber. [4]

Anatomy

Trogidae are characterized by their distinct soil-encrusted, warty, or bumpy appearance. They are usually brown, gray, or black in color and are covered with short, dense setae. Their body shape is oblong to oval with a flat abdomen and their length varies from 2 to 20 mm. The antenna of hide beetles are usually short and clubbed. [5] The hardened elytra of Trogidae, which are generally covered with small knobs giving the beetle their rough appearance, meet along the midline of the body and cover the entire abdomen and well-developed wings. Their heads are bent down and covered by the pronotum. [6] They also have heavy limbs and spurs resembling those of scarab beetles. Trogidae larvae are a creamy yellow/white in color, except at their caudal end which darkens as it accumulates feces. Their heads are dark and heavily sclerotized. The abdominal segments of hide beetles have at least one or more transverse rows of setae. [7]

Diet and habitat

Predators rarely attack species of Trogidae. They avoid detection and predation due to their soil covering and motionless behavior. Birds prey upon hide beetles that have invaded the bird nests. [7]

Species of Trogidae often feed on decomposing carcasses. [8] In one lab experiment done in 1998 by the Department of Zoology at the University of Melbourne, the hide beetles ate all tissues on a sheep carcass and left the bones.[ citation needed ] Along with carrion, hide beetles are found within the pellet of many animal species, on other decaying dry matter, and around birds’ and mammals’ nests and feathers, as well as aging bones.

Mating habits and life cycle

Little is known about the specifics of the Trogid life cycle. Female Trogids of several species produce chirping noises in order to attract males to their burrows for mating. [9] After impregnation of the female by the male, the female lays the eggs and the larvae hatch after an unknown amount of time. During decomposition of a carcass, the beetles leave their nests to feed on the carrion. As the last succession of insects to appear on the carcass, both larvae and adults can be found feeding on the dry remains. At the site of the carcass, an impregnated female digs small, vertical columns underneath the carcass to lay her eggs, allowing the larvae to locate food after hatching. Trogidae usually have three to five instars. [7]

Forensic importance

The use of Trogidae in forensic entomology is unknown at this time. Though they typically arrive last in the order of succession, they can be the first in succession on burned and charred bodies. After the burned skin is eaten away by the trogids, the corpse (with now-exposed, "fresher" surfaces) allows for viable colonization by other forensically important insects that help determine accurate post mortem interval estimates. [10]

Various species of Trogidae have been used by museums to clean up skeletons by eating any remaining dried material left on the skeletons, leaving them clean for display. This method of bone-stripping has been used by some museums for many years, as it is the most effective method. [11]

Research

The Chinese Academy of Sciences funded a study on the classification of this family of beetles. [12] The forensic importance of African Trogidae and other carrion-associated beetles is being studied at the University of Pretoria. This project is investigating how the presence of beetles on carrion affects the infestation of other arthropods in carrion in Africa. [13]

Related Research Articles

Beetle Order of insects

Beetles are a group of insects that form the order Coleoptera, in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 species, is the largest of all orders, constituting almost 40% of described insects and 25% of all known animal life-forms; new species are discovered frequently. The largest of all families, the Curculionidae (weevils), with some 83,000 member species, belongs to this order. Found in almost every habitat except the sea and the polar regions, they interact with their ecosystems in several ways: beetles often feed on plants and fungi, break down animal and plant debris, and eat other invertebrates. Some species are serious agricultural pests, such as the Colorado potato beetle, while others such as Coccinellidae eat aphids, scale insects, thrips, and other plant-sucking insects that damage crops.

Forensic entomology

Forensic entomology is the scientific study of the invasion of the succession pattern of arthropods with their developmental stages of different species found on the decomposed cadavers during legal investigations. It is the application and study of insect and other arthropod biology to criminal matters. It also involves the application of the study of arthropods, including insects, arachnids, centipedes, millipedes, and crustaceans to criminal or legal cases. It is primarily associated with death investigations; however, it may also be used to detect drugs and poisons, determine the location of an incident, and find the presence and time of the infliction of wounds. Forensic entomology can be divided into three subfields: urban, stored-product and medico-legal/medico-criminal entomology.

Silphidae Family of beetles

Silphidae is a family of beetles that are known commonly as large carrion beetles, carrion beetles or burying beetles. There are two subfamilies: Silphinae and Nicrophorinae. Nicrophorines are sometimes known as sexton beetles. The number of species is relatively small and around two hundred. They are more diverse in the temperate region although a few tropical endemics are known. Both subfamilies feed on decaying organic matter such as dead animals. The subfamilies differ in which uses parental care and which types of carcasses they prefer. Silphidae are considered to be of importance to forensic entomologists because when they are found on a decaying body they are used to help estimate a post-mortem interval.

Histeridae Family of beetles

Histeridae is a family of beetles commonly known as clown beetles or Hister beetles. This very diverse group of beetles contains 3,900 species found worldwide. They can be easily identified by their shortened elytra that leaves two of the seven tergites exposed, and their geniculate (elbowed) antennae with clubbed ends. These predatory feeders are most active at night and will fake death if they feel threatened. This family of beetles will occupy almost any kind of niche throughout the world. Hister beetles have proved useful during forensic investigations to help in time of death estimation. Also, certain species are used in the control of livestock pests that infest dung and to control houseflies. Because they are predacious and will even eat other Hister beetles, they must be isolated when collected.

Dermestidae Family of beetles

Dermestidae are a family of Coleoptera that are commonly referred to as skin beetles. Other common names include larder beetle, hide or leather beetles, carpet beetles, and khapra beetles. There are approximately 500 to 700 species worldwide. They can range in size from 1 to 12 mm. Key characteristics for adults are round oval shaped bodies covered in scales or setae. The usually clubbed antennae fit into deep grooves. The hind femora also fit into recesses of the coxa. Larvae are scarabaeiform and also have setae.

Varied carpet beetle Species of beetle

The varied carpet beetle is a 3 mm-long beetle belonging to the family Dermestidae. They are a common species, often considered a pest of domestic houses and, particularly, natural history museums, where the larvae may damage natural fibers and can damage carpets, furniture, clothing, and insect collections. A. verbasci was also the first insect to be shown to have an annual behavioral rhythm and to date remains a classic example of circannual cycles in animals.

Cleridae Checkered beetles

Cleridae are a family of beetles of the superfamily Cleroidea. They are commonly known as checkered beetles. The family Cleridae has a worldwide distribution, and a variety of habitats and feeding preferences.

<i>Omorgus suberosus</i> Species of beetle

Omorgus suberosus, common name Hide Beetle, is a beetle of the family Trogidae.

<i>Dermestes maculatus</i> Species of beetle

Dermestes maculatus is a species of beetle with a worldwide distribution, being present on all continents except Antarctica. In Europe, it is present in all countries.

Forensic entomological decomposition is how insects decompose and what that means for timing and information in criminal investigations. Medicolegal entomology is a branch of forensic entomology that applies the study of insects to criminal investigations, and is commonly used in death investigations for estimating the post-mortem interval (PMI). One method of obtaining this estimate uses the time and pattern of arthropod colonization. This method will provide an estimation of the period of insect activity, which may or may not correlate exactly with the time of death. While insect successional data may not provide as accurate an estimate during the early stages of decomposition as developmental data, it is applicable for later decompositional stages and can be accurate for periods up to a few years.

In forensic entomology, entomotoxicology is the analysis of toxins in arthropods that feed on carrion. Using arthropods in a corpse or at a crime scene, investigators can determine whether toxins were present in a body at the time of death. This technique is a major advance in forensics; previously, such determinations were impossible in the case of severely decomposed bodies devoid of intoxicated tissue and bodily fluids. Ongoing research into the effects of toxins on arthropod development has also allowed better estimations of postmortem intervals.

<i>Nicrophorus tomentosus</i> Species of beetle

Nicrophorus tomentosus is a species of burying beetle that was described by Friedrich Weber in 1801. The beetle belongs to the family Silphidae which are carrion beetles. The beetles have sensitive antennae that contain olfactory organs. Thus, the beetle can locate dead animals (carcass), and then as the name suggests, can bury them. However, unlike other burying beetles, N. tomentosus does not feed these brood carcasses. They instead eliminate the soil under the carcass, so the carcass will sink underneath. Recognition of these beetles can be distinguished by its black color with orange markings on the wing covers (elytra).

<i>Nicrophorus orbicollis</i> Species of beetle

Nicrophorus orbicollis is a nearctic burying beetle first described by Thomas Say in 1825. It is a member of the genus Nicrophorus or sexton beetles, comprising the most common beetles in the family Silphidae. This species is a decomposer feeding on carcasses of small dead animals. N. orbicollis can be used for scientific research both medically and forensically.

Trox scaber Species of beetle

Trox scaber is a beetle of the Family Trogidae. The 5 to 8 mm long insect is found worldwide, including in Europe, and lives in bird nests

<i>Creophilus maxillosus</i> Species of beetle

Creophilus maxillosus, the hairy rove beetle, is a species of rove beetle

<i>Oiceoptoma noveboracense</i> Species of beetle

Oiceoptoma noveboracense is a member of the family Silphidae, or carrion beetles, which feed on decaying organic matter such as dead animals. Its common name is the margined carrion beetle, from the orange-red margins on the pronotum, which are helpful when identifying this species. The larva is typically light brown to red and also has vertical ridges on its thorax like the adult. This diurnal beetle can be found mainly in the spring into the fall, and it has a strong preference towards a deciduous forest habitat. The primary forensic importance of this beetle is its ability to use the succession of insect fauna to provide confirmation of postmortem intervals.

Carrion insects are those insects associated with decomposing remains. The processes of decomposition begin within a few minutes of death. Decomposing remains offer a temporary, changing site of concentrated resources which are exploited by a wide range of organisms, of which arthropods are often the first to arrive and the predominant exploitive group. However, not all arthropods found on or near decomposing remains will have an active role in the decay process.

<i>Alphitobius diaperinus</i> Species of beetle

Alphitobius diaperinus is a species of beetle in the family Tenebrionidae, the darkling beetles. It is known commonly as the lesser mealworm and the litter beetle. It has a cosmopolitan distribution, occurring nearly worldwide. It is known widely as a pest insect of stored food grain products such as flour, and of poultry-rearing facilities. It is a vector of many kinds of animal pathogens.

Trox hispidus Species of beetle

Trox hispidus is a beetle of the Family Trogidae.

<i>Necrobia violacea</i> Species of beetle

Necrobia violacea is a species of beetle in family Cleridae. It is found in the Palearctic

References

  1. Jameson, Mary Liz (2002): "Trogidae", in Ross H. Arnett, Jr. and Michael C. Thomas, American Beetles (CRC Press, 2002), vol. 2
  2. 1 2 Deloya, C. (2005): Omorgus rodriguezae especie nueva de México y clave para separar las especies del género para centro y norteamérica (Coleoptera: Trogidae) Archived 28 September 2007 at the Wayback Machine . Folia Entomol. Mex 44: 121-129. PDF
  3. LAWRENCE, J. F. and E. B. BRITTON. 1991. Coleoptera. The Insects of Australia, 2nd edition, Volume 1, pp. 543-683. Melbourne University Press, Carlton.
  4. Tihelka, Erik; Huang, Diying; Cai, Chenyang (15 July 2019). "A new subfamily of hide beetles from the Cretaceous of northern Myanmar (Coleoptera: Scarabaeoidea: Trogidae)". Historical Biology: 1–8. doi:10.1080/08912963.2019.1641705. ISSN   0891-2963.
  5. Watson, L. and Dallwitz, M. J.. 2003 onwards. British Insects: the Families of Coleoptera: Trogidae Version: 9 April 2007. http://delta-intkey.com
  6. Carcass Beetles CSIRO Entomology
  7. 1 2 3 Jameson, Mary Liz. Guide to New World Scarab Beetles - Trogidae UNL State Museum - Division of Entomology
  8. Murawski, Darlyne (2013). Ultimate Bug-opedia. Washington, DC: National Geographic Society. p. 153. ISBN   9781426313776.
  9. Alexander, Richard D., Thomas E. Moore, and Robert E. Woodruff. "The evolutionary differentiation of stridulatory signals in beetles (Insecta: Coleoptera)." (1963).
  10. Trogidae [ permanent dead link ] Australian Biological Resources Study, Department of the Environment and Heritage
  11. Reid, Craig. Bones Stripped Bare. Australian Geographic; Jan-March2005 Issue 77, p15, 1/4p
  12. GuoDong, Ren and Hou Lin. Advance in taxonomic research of the Trogidae. Entomological Knowledge, 2003 (Vol. 40) (No. 6) 505-508
  13. Williams, K.A. and M.H. Villet. A history of South African research relevant to Forensic Entomology. South African Journal of Science 102, January/February 2006. p4.