Nicrophorus americanus
American burying beetle

American burying beetles, Nicrophorus americanus, at one time may have ranged throughout the United States and Canada. Many populations in Canada, however, are now extinct, and their range is now largely confined to Alaska and the east and west coasts of the United States. They are currently found in only 6 states in United States and are being reintroduced in some areas. ("American Burying Beetle (Nicrophorus americanus) Recovery Plan", 1991; Lomolino and Creighton, 1996; Lomolino, et al., 1995; Ramel, 2008)

Specific habitat preference of American burying beetles is unknown. Like many endangered species, this species seems largely confined to areas with the least human influence. American burying beetles thrive in areas with an abundance of carrion and have been found in grasslands, scrublands and forest edges. (Ramel, 2008; Ratcliffe, 2008)

American burying beetles are the largest carrion-feeding insects in North America, growing up to 35 mm in length. Most carrion beetles of the genus Nicrophorus, including American burying beetles, have shiny black wings with distinctively marked bright orange bands on each wing cover. Unlike other species, however, American burying beetles also have a pronotum, a shield-like area just behind the head. They also have a small orange patch on their face between the eyes. In males this patch is square, while it is triangular in females (Backlund, et al., 2001; Backlund, et al., 2001)

American burying beetles lay their eggs on a carcass of an animal 50 to 200 g in size, and eggs hatch within a few days of being laid. Parents regurgitate food for the larvae until they are able to feed themselves. After larvae feed on the carcass for about a week, parents leave and larvae pupate in the nearby soil. After another month, they emerge as adult beetles. (Backlund, et al., 2001)

Male and female American burying beetles have highly sensitive organs on their antennas that can detect the smell of decaying flesh up to 3.2 km away. They meet at a carcass of of suitable size, generally 50 to 200 g. If a male arrives at a carcass first, he waits for a female. If no female arrives after a period of time, the male sits on top of the carcass in a particular posture and broadcasts pheromones to attract a female. Once a male and female are present at a carcass, they cooperate to move it to suitable substrate and bury it under several inches of soil, chewing through roots as necessary. Once buried, hair or feathers are removed from the carcass, and the two beetles mate. The female creates a chamber above the carcass, in which she lays approximately 30 eggs. (Backlund, et al., 2001; Ramel, 2008; Ratcliffe, 2008)

American burying beetles require a vertebrate carcass of sufficient size in order to successfully breed (between 50 and 200 g). Females breed once a year in June or July and lay their eggs in a chamber above the carcass. If the carcass is too small, it cannot provide sufficient food for all the larvae, and parents may eat some of their young. Larvae pupate and emerge as adults 48 to 68 days after hatching. New adults spend winter in the soil and breed the following summer. (Ramel, 2008; Ratcliffe, 2008)

American burying beetles provide care for their young from the time of birth until adolescence. This type of behavior is typically not observed among invertebrates outside of social bees, wasps, and termites.

Prior to birth, both parents regurgitate partially digested food in the nesting chamber, which accumulates as food for the larvae. They continue to do so until larvae are able to feed directly from the carcass. Parents also regularly maintain the carcass by removing fungi and covering the carrion ball with antibacterial secretions. (Ramel, 2008; Ratcliffe, 2008)

American burying beetles typical live 1 year. Newly emerged adults remain in the soil during the winter season and mate in the summer. Adults die after raising their offspring. (Ratcliffe, 2008)

American burying beetles are very social. They are nocturnal and are usually active when temperatures exceed 15 ˚C. ("American Burying Beetle (Nicrophorus americanus) Recovery Plan", 1991; Backlund, et al., 2001; Kozol, et al., 1988; Lomolino and Creighton, 1996; Lomolino, et al., 1995)

Little information is available regarding the home range of American burying beetles.

Adult American burying beetles can detect dead or decaying flesh up to 3.2 km away using chemical receptors on their antennae. Both males and females are attracted to carcasses, and there is often competition between members of each sex at a carcass until a single pair remains. When necessary, males use pheromones to attract females to a carcass. Males and females cooperatively move and bury a carcass, though how they communicate to do so is unknown. ("American Burying Beetle (Nicrophorus americanus) Recovery Plan", 1991; Lomolino and Creighton, 1996)

American burying beetles are scavengers. Adults hunt for decaying carcasses, which are either used as a source of food or are buried for future use by larvae. (Kozol, et al., 1988; Lomolino and Creighton, 1996; Lomolino, et al., 1995)

There are no known predators of American burying beetles.

As scavengers, American burying beetles play an important role in recycling decaying materials.

American burying beetles have a symbiotic relationship with mites Poecilochirus. A beetle provides mites with access to food and means of dispersal, and the mites clean the beetle of microbes and fly eggs that are carried up from carrions. ("American Burying Beetle (Nicrophorus americanus) Recovery Plan", 1991)

There are no known direct positive effects of American burying beetles on humans.

There are no known adverse effects of American burying beetles on humans.

American burying beetles were listed as an endangered species by U.S. Fish and Wildlife Service in 1989. They are currently considered critically endangered by the IUCN and are likely extirpated from Michigan. Habitat fragmentation and habitat loss are largely held responsible for the decline of this species. Habitat fragmentation and deforestation has reduced populations of species that become carrion in which this species broods. Increased competition with other scavengers has also contributed to the population decline of American burying beetles. ("American Burying Beetle (Nicrophorus americanus) Recovery Plan", 1991; Kozol, et al., 1988; Lomolino and Creighton, 1996; Lomolino, et al., 1995)