Beaver beetle

The beaver beetle (Platypsyllus castoris) is an ectoparasitic beetle that is only found on its host species, beavers,^[2][3] and the sole member of the genus Platypsyllus. It is flattened and eyeless,^[4] resembling a flea or tick. It used to be placed in a separate family called Leptinidae, but is now placed in the family Leiodidae, in the subfamily Platypsyllinae.^[1]

Platypsyllus castoris
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Coleoptera
Suborder:	Polyphaga
Infraorder:	Staphyliniformia
Superfamily:	Staphylinoidea
Family:	Leiodidae
Subfamily:	Platypsyllinae
Genus:	Platypsyllus Ritsema, 1869
Species:	P. castoris
Binomial name
Platypsyllus castoris Ritsema, 1869[1]
Synonyms
Platypsyllus castorinus Westwood, 1869

Description

The beaver beetle has various modifications to suit its ectoparasitic mode of life. It resembles a flea or a louse in appearance and the family Platypsyllidae was originally placed in the flea order Siphonaptera,^[5][6] and one taxonomist treated it as a unique example of a new order of insects.^[7] It has no wings and no eyes, and its antennal clubs have the antennomeres numbered 3 to 11 shortened, compacted globularly, and partly enclosed in a scoop-shaped antennomere. The larvae are also ectoparasitic on beavers and have hooks on the three thoracic segments which enable it to cling to its host.^[1]

Distribution

The beetle exists only in the northern hemisphere (holarctic) and is restricted to areas in which beavers are found, North America and northern Europe and Asia.^[1]

Behaviour

Besides the North American beaver (Castor canadensis) and the Eurasian beaver (Castor fiber), the only other host on which this beetle has been found is the North American river otter (Lontra canadensis), and this was only on one occasion. It is hypothesized that the otter may have picked up the parasite when it entered a beaver lodge or perhaps killed a young beaver, a thing that otters are believed to do on occasion. Both adult beetles and larvae feed on epidermal tissue, and also perhaps on skin secretions and liquids oozing from wounds. It is possible that the larvae may also act as scavengers in the beaver lodge.^[1]

References

1. Peck, S. B. (March–June 2006). "Distribution and biology of the ectoparasitic beaver beetle Platypsyllus castoris Ritsema in North America (Coleoptera: Leiodidae: Platypsyllinae)". Insecta Mundi. 20 (1–2): 85. ISSN 0749-6737. Archived from the original on 16 March 2013. Retrieved 8 April 2013. ...and Platypsyllus Ritsema 1869 with one apparently Holarctic species, ectoparasitic on the two species of Castor.
2. Cardé, Vincent H.; Resh, Ring T., eds. (2009). Encyclopedia of Insects (2nd ed.). Amsterdam: Elsevier/Academic Press. p. 197. ISBN 9780080920900. Platypsyllus castoris beetles of the family Leiodidae are specialists on beavers,...
3. Whitaker, John O. (1996). National Audubon Society Field Guide to Mammals (Revised ed.). New York: Knopf. p. 568. ISBN 0-679-44631-1. Beavers are hosts to a unique parasite that lives on the exterior of their bodies—a highly specialized beetle that parasitizes only beavers.
4. Goater, Timothy M.; Goater, Cameron P.; Esch, Gerald W. (2013). Parasitism: The Diversity and Ecology of Animal Parasites (2nd ed.). Cambridge University Press. p. 325. ISBN 9780521190282. All genera [of Coleoptera, which includes Platypsyllus,] are wingless and are eyeless or have reduced eyes, and are markedly dorsoventrally flattened.
5. Ritsema, C. (1869). "No title". Petites Nouvelles Entomologiques. 1: 23.
6. Ritsema, C. (1869). "No title". Petites Nouvelles Entomologiques. 1: 38.
7. Westwood, J.O. (1869). "Notice of a new order of hexapod insects". Entomologist's Monthly Magazine. 6: 118–119.

• Behrendt, Marc (July–August 2003). "Beaver Beetles" (PDF). Buckeye Trapper. Retrieved 8 April 2013.

External links

• Beaver Beetles by David Moskowitz