Hairy Rove Beetle

Appearance

Larvae of the hairy rove beetle range from 20–25 millimetres long and are cylindrical and stout. The adult is a shiny black color and approximately 12–18 mm long. They are easily characterized by their elytra, which cover the first few abdominal segments. They have large eyes, and their mandibles close across each other in the front of the head and can inflict a painful stab if harassed or handled carelessly. Golden setae are located on posterior angles of the head and slightly on the anterior angle of the pronotum. These setae can be found on the last few abdominal segments and on elytra. The hairy rove beetle has needle-like jaws that close across in front of head and large, prominent eyes. The antennae are thick, beaded, and composed of 11 segments.

The development of eggs is around 4 days, larvae 14 days, and pupae 16 days. The eggs are milky white colored, 2 to 3 mm long and hatch in about 3 days . The larval stage lasts around 14 days. The pupae, which is around 11 mm wide lasts 16 days. The estimation of the total duration of ''Creophilus maxillosus'' lasts 37 days.

Naming

Creophilus maxillosus Linnaeus, 1758

Two subspecies are named:
C. m. villosus ( pale setae on the forebody)
C. m. maxillosus ( dark setae on the forebody)

Distribution

C. m. villosus is native and widespread in North America, northern Central America, the West Indies, Chile, Argentina, and Peru. C. m. maxillosus is native to the Palaearctic and is known from scattered records from Ontario, Quebec, and Massachusetts.

Behavior

Larvae of the hairy rove beetle range from 20–25 millimeters long and are cylindrical and stout. The adult is a shiny black color and approximately 12–18 mm long. They are easily characterized by their elytra, which cover the first few abdominal segments. They have large eyes, and their mandibles close across each other in the front of the head and can inflict a painful stab if harassed or handled carelessly. Golden setae are located on posterior angles of the head and slightly on the anterior angle of the pronotum. These setae can be found on the last few abdominal segments and on elytra. The hairy rove beetle has needle-like jaws that close across in front of the head and large, prominent eyes. The antennae are thick, beaded, and composed of 11 segments.

Habitat

Generally, C. maxillosus are found throughout the eastern U.S. in the fall and spring, but can also be found in the summer. They are usually in wooded habitats such as forest leaf litter, decaying plant material, and under dead tree bark. They can also be found in carrion, dung, under stones or rocks, and in fresh water areas in washed-up brown algae.

Like most rove beetles, Creophilus maxillosus can be found in a variety of habitat types, including leaf litter, under tree bark, on decaying fruit and vegetation, under stones, and especially on carrion. They generally prefer moist environments and are often encountered near ponds, lakes, moist soil, and along coastal plains

Reproduction

The development of eggs is around 4 days, larvae 14 days, and pupae 16 days. The eggs are milky white-colored, 2 to 3 mm long and hatch in about 3 days. The larval stage lasts around 14 days. The pupae, which is around 11 mm wide lasts 16 days. From egg to adult takes about 30 to 37 days.

When well-fed, an adult female hairy rove beetle can lay up to eight eggs per day and up to 500 during her lifetime. Even with a 30% mortality rate from egg to adult, the progeny from one female could number nearly 422,000 females in only three generations. The life cycle from egg to adult lasts approximately 37 days, with three to four of the days in the egg stage, 14 days in larval development, and 16 days in the pupal stage.

Food

This particular species is predacious in both the larvae and adult stages of life. The larvae and adults have long, curved mandibles which are used for chewing. They feed on carcasses, as well as on maggots that tend to be on dead animals.

Defense

C. maxillosus has abdominal defensive glands used to secrete a mixture of substances that act as an irritant to predators. These glands are located beneath the abdominal tergites. When threatened or disturbed, the beetle revolves its abdomen and touches the abdominal tip to the offender to wipe the glands. Ants are a common offender and have portrayed that this defense takes place. The ants are shown to be repelled by the four major components of secretion. Dihydroneptalactone is the main principle ingredient of chemical defense. Hairy rove beetles use this survival defense mechanism to repel ants during carrion competition and to ward off larger predators, as well as humans. In addition to its chemical defense, the hairy rove beetle can curl into a defensive posture, as well as inflict a painful bite with its powerful mandibles if threatened.

Adults will form their bodies into a tight ball and roll off carrion into leaf litter when disturbed. For defense against other arthropods, C. maxillosus has an eversible Y-shaped gland at the apex of the abdomen that produces iridodiols and other repellant compounds. Other species of Staphylinina also have this gland and produce similar secretions dominated by iridodial.

Uses

Creophilus maxillosus beetles, along with other carrion-feeding rove beetles, are valuable tools in forensics. Knowledge of the hairy rove beetle’s life cycle allows forensic entomologists to determine ecological succession, and subsequently, the post-mortem interval (PMI) of a cadaver. Some researchers have questioned the accuracy of these methods because succession on a corpse can be highly variable depending on the geospatial location, environmental conditions (i.e. temperature and humidity), and type of dead organism in question. During warm summer months, adult hairy rove beetles can inhabit a corpse as early as two days after death, with incubation time lasting five days. The presence of larvae, in conjunction with adult absence, indicates a much later PMI.