American burying beetle (Nicrophorus americanus)

KingdomAnimalia
PhylumArthropoda
ClassInsecta
OrderColeoptera
FamilySilphidae
GenusNicrophorus (1)
SizeLength: 2.5 - 3.8 cm (2)

Classified as Critically Endangered (CR - A1c) on the IUCN Red List 2002 (1).

The American burying beetle is the largest carrion beetle in North America (2). It has extremely distinctive colouration, being shiny black with bright orange markings; there are four orange bands on the wing cases (known as 'elytra'), but unusually the pronotum and face also have orange markings (2).

Historically found throughout the eastern United States and into southern Canada (2), this burying beetle is today restricted to populations in a handful of central States (3).

The specific habitat requirements of this species are not fully understood and it appears that the availability of carrion may be the limiting factor. In Nebraska, beetles have been observed in grassland prairie, scrubland and forest edges (2).

Burying beetles receive their common name from their specialised mechanism of parental care that involves providing the growing larvae with carrion upon which to feed. At night, beetle pairs will locate a suitable carcass and then cooperate to bury it in the soil, thus protecting their find from competition with other species (2). Once the carcass is beneath the soil, the beetles strip away the fur or feathers and produce a compact ball; the female then lays her eggs in a chamber created above the carcass (2). Unusually for insects, the parents both remain to provide for the larvae after they have hatched, regurgitating food for the growing grubs until they are able to feed for themselves (2). Roughly a week later, the larvae pupate in the soil nearby, having consumed the entire food supply; they will emerge as adults around a month later and overwinter in this stage (2). American burying beetles only live for one season and adults die soon after they have ceased to provide for their young (2).

American burying beetles have been lost from the majority of their former range; populations in the east had largely disappeared by the 1920s, whilst the decline in the American Midwest was well documented in the 1980s (2). One of the major causes of this decline in abundance is the fragmentation of available habitat; leading to changes in the availability of carrion, increased competition, and the isolation of remaining popualtions (2).

The precarious sate of the population of American burying beetles was recognised in 1989 when the species was listed as Endangered on the U.S. Fish & Wildlife Service Endangered Species List (3). A Recovery Plan has been drawn up, and searches for remnant populations are underway (2). In Rhode Island and Oklahoma, the known populations are monitored and their habitats managed, and in Massachusetts a number of beetles, from a captive population at Boston University, have been released (2).

Authenticated (8/5/03) by Brett Ratcliffe, University of Nebraska.
http://www-museum.unl.edu/research/entomology/index.htm

  1. IUCN Red List (April, 2003) www.redlist.org
  2. University of Nebraska State Museum (April, 2003) http://www-museum.unl.edu/research/entomology/index.htm
  3. U.S. Fish & Wildlife Service (April, 2003) http://ecos.fws.gov/species_profile/servlet/gov.doi.species_profile.servlets.SpeciesProfile?spcode=I028