Dryopidae is a family of beetles, commonly named long-toed water beetles, in the superfamily Byrrhoidea. It was described by Gustaf Johan Billberg in 1820.[1][2]

Parnida species
Scientific classification e
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Suborder: Polyphaga
Infraorder: Elateriformia
Superfamily: Byrrhoidea
Family: Dryopidae
Billberg, 1820


Long-toed water beetles are named for their extended claws. Adults have dense hairs, which allow the beetles to breathe while underwater. The flight muscles of the females weaken as they age.[3]

When the pupae complete the imago stage of their life cycle, they move towards running water, and may be attracted to lights.[3]

Despite being referred to as aquatic insects, the beetles are unable to swim,[2] clinging to detritus that float. All long-toed water beetles feed on plants that are in the water, but the larvae also prey on small animals and most of them are terrestrial. Stygoparnus is the only genus in the family in which both the larvae and adults are aquatic.[2][3][4]

Genera of the family closely resemble riffle beetles, but the antennae are different from the long-toed water beetles, looking similar to clubs.[5]


Members of this family are found on every continent, except Antarctica and Australia, being more common in the tropics.[6] In 2005, a possible fossilized specimen of Dryopidae was found in the Crato Formation by entomologists David Grimaldi and Michael S. Engel.[4]

Beetles that have water as a habitat, including long-toed water beetles, can help show the quality of fresh water.[7]


Essay questions about the long-toed water beetles were placed in a teacher's manual about insects, written by entomologist Matthew Cooke and published in 1884.[8]



  1. ^ "Dryopidae Billberg, 1820". Integrated Taxonomic Information System. Retrieved July 21, 2013.
  2. ^ a b c Tory Peterson, Roger (1998). The Beetles of North America. Houghton Mifflin Harcourt. p. 163. ISBN 9780395910894. Retrieved July 21, 2013.
  3. ^ a b c V. Evans, Arthur; N. Hogue, James (2006). Field Guide to Beetles of California. University of California Press. pp. 137–138. ISBN 9780520246553. Retrieved July 21, 2013.
  4. ^ a b M. Martill, David; Bechly, Günter; F. Loveridge, Robert (2007). The Crato Fossil Beds of Brazil. Cambridge University Press. p. 345. ISBN 9781139467766. Retrieved July 21, 2013.
  5. ^ Watson-Ferguson, Kami; Han, Cindy; McGarvey, Jason; Miller, Leah (2006). A Guide to Aquatic Insects and Crustaceans. Stackpole Books. p. 30. ISBN 9780811732451. Retrieved July 21, 2013.
  6. ^ H. Arnett, Ross; C. Thomas, Michael; E. Skelley, Paul; Howard, Frank (2010). American Beetles, Volume II. CRC Press. p. 122. ISBN 9781420041231. Retrieved July 21, 2013.
  7. ^ R. Spellman, Frank (2008). Handbook of Water and Wastewater Treatment Plant Operations, Second Edition. CRC Press. p. 496. ISBN 9781420075311. Retrieved July 21, 2013.
  8. ^ Cooke, Matthew (1884). Teachers' Manual, Or, the Best Method of Teaching the Natural History of Injurious and Beneficial Insects. H.S. Crocker. p. 52. Retrieved July 21, 2013. long-toed water beetles.
  9. ^ "Bulletin de la Société entomologique de France - Google Livros". Retrieved 2015-01-08.