Other Common Names
Long-toed Water Beetles
(1), but this name now refers to the
DryopidaeSynonyms and other taxonomic changes
Psephenidae
Lacordaire, 1854 (
ITIS)
Explanation of Names
Water penny: larvae are flat and circular, and live in water
Psephenidae is from genus
Psephenus Haldeman, that from Greek
psepheno dark, obscure and/or
psepho meaning "a small stone" or darkness
(2).
Numbers
16 species in 6 genera in North America
(3)Identification
Adults are medium-sized rather flattened beetles, usually dark:
The aquatic larvae are found more easily than adults, perhaps. They have a distinctive flattened form and cling to rocks:
Range
in North America, most species occur in the west
also found in several regions of the world; greatest diversity in the Orient
Habitat
Larvae are aquatic and cling to the underside of rocks in fast-flowing streams.
Adults crawl over rocks and vegetation along streams.
Food
Larvae graze on algae. Adults are short-lived and perhaps(?) feed little.
Print References
Arnett, American Beetles, Vol. 2, Chapter 48
(4)
Borror, entries for
psepheno,
psepho (2)
Dillon and Dillon, p. 365, plate 18--adult of
Psephenus herricki (1)Internet References
Hammond, G. 2009. "Psephenidae" (On-line), Animal Diversity Web. Accessed November 30, 2009 at
http://animaldiversity.ummz.umich.edu/site/accounts/information/Psephenidae.html
live larva image and distinguishing characteristics of larva (North Carolina State University)
live larva images showing upper and lower surfaces (Danielle Love, Western Washington Univ.)
