Trogidae Temporal range: | |
---|---|
Trox sabulosus | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Coleoptera |
Suborder: | Polyphaga |
Infraorder: | Scarabaeiformia |
Superfamily: | Scarabaeoidea |
Family: | Trogidae MacLeay, 1819 |
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 to 20 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 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.
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. [3] 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. [4]
The oldest known fossils are from the Early Cretaceous (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 mid-Cretaceous aged Burmese amber. [5]
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. [6] 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. [7] 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. [8]
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. [8]
Species of Trogidae often feed on decomposing carcasses. 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. [9]
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. [10] 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. [8]
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. [11]
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. [12]
The Chinese Academy of Sciences funded a study on the classification of this family of beetles. [13] 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. [14]
The family Trogidae contains the following subfamily and genera: [15]
Forensic entomology is a field of forensic science that uses insects found on corpses to help solve criminal cases. This includes the study of insect types commonly associated with cadavers, their respective life cycles, their ecological presences in a given environment, as well as the changes in insect assemblage with the progression of decomposition. Insect succession patterns are identified based on the time a given species of insect spends in a given developmental stage, and how many generations have been produced since the insects introduction to a given food source. Insect development alongside environmental data such as temperature and vapor density, can be used to estimate the time since death, due to the fact that flying insects are attracted to a body immediately after death, determine any possible movement of the body after death, and the determination of antemortem trauma.. The identification of postmortem interval to aid in death investigations is the primary scope of this scientific field. However, forensic entomology is not limited to homicides, it has also been used in cases of neglect and abuse, in toxicology contexts to detect the presence of drugs, and in dry shelf food contamination incidents. Equally, insect assemblages present on a body, can be used to approximate a given location, as certain insects may be unique to certain areas. Therefore, forensic entomology can be divided into three subfields: urban, stored-product and medico-legal/medico-criminal entomology.
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. Members of Nicrophorinae are sometimes known as burying beetles or sexton beetles. The number of species is relatively small, at 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 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 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 over 1,800 species described.
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.
Troginae is a subfamily of beetles in the family Trogidae which includes extant species and extinct beetle species from the Lower Cretaceous. The subfamily contains the following genera:
Trox is a genus of hide beetle in the subfamily Troginae.
Omorgus suberosus, common name hide beetle, is a beetle of the family Trogidae.
Coprophanaeus is a genus in the family Scarabaeidae. The genus is almost entirely Neotropical, with a single species, C. pluto, ranging into southernmost Texas in the United States. They are medium-sized to large beetles, with the South American C. ensifer and C. lancifer sometimes exceeding 5 cm (2 in) in length, making these two some of the largest dung beetles in the world and the largest in the Americas. They often have a horn on the head, and are typically a bright metallic color, most often blue or green, or black. These diurnal or crepuscular beetles are excellent diggers and good fliers.
Omorginae is a subfamily of beetles in the family Trogidae which includes extant species and extinct beetle species from the Lower Cretaceous. The subfamily contains the following genera:
Glyptotrox boucomonti is a species of hide beetle in the subfamily Troginae.
Glyptotrox brahminus is a species of hide beetle in the subfamily Troginae.
Glyptotrox formosanus is a species of hide beetle in the subfamily Troginae.
Glyptotrox kerleyi is a species of hide beetle in the subfamily Troginae.
Glyptotrox opacotuberculatus is a species of hide beetle in the subfamily Troginae.
Glyptotrox vimmeri is a species of hide beetle in the subfamily Troginae.
Glyptotrox yamayai is a species of hide beetle in the subfamily Troginae.
Glyptotrox tibialis is a species of hide beetle in the subfamily Troginae.
Phoberus cyrtus is a species of hide beetle in the subfamily Troginae discovered by Erwin Haaf in 1953.
Phoberus fumarius is a species of hide beetle in the subfamily Troginae discovered by Erwin Haaf in 1953.