Synonyms and other taxonomic changes
incl. Georissidea=Georyssidae, Helophoridae, Hydrochidae, Spercheidae, Sphaeridiidae
Numbers
Arnett, p. 399, lists 284 species for North America
(1).
Worldwide, 168 genera and 2803 species (
Australian Faunal Directory).
Family Hydrophilidae Latreille, 1802
Subfamily Helophorinae Leach, 1815*
Genus
Helophorus Fabricius, 1775
Subfamily Epimetopinae Zaitzev, 1908*
Genus Epimetopus Lacordaire, 1854
Subfamily Georissinae Laporte, 1840*
Genus Georissus Laporte, 1840
Subfamily Hydrochinae Thomson, 1859*
Genus
Hydrochus Leach, 1817
Subfamily Hydrophilinae Latreille, 1802
Tribe Sperchopsini Hansen, 1991
Genus Ametor Semenow, 1900
Genus Sperchopsis LeConte, 1862
Tribe Berosini Mulsant, 1844
Genus Hemiosus Sharp, 1882
Genus
Berosus Leach, 1817
Genus
Derallus Sharp, 1882
Tribe Chaetarthriini Bedel, 1881
Genus Chaetarthria Stephens, 1833
Tribe Anacaenini Hansen, 1991
Genus
Anacaena Thomson, 1859
Genus
Crenitis Bedel, 1881
Genus
Paracymus Thomson, 1867
Tribe Laccobiini Bertrand, 1954
Genus
Laccobius Erichson, 1837
Tribe Hydrophilini Latreille, 1802
Genus
Cymbiodyta Bedel, 1881
Genus
Enochrus Thomson, 1859
Genus
Helobata Bergroth, 1888
Genus Helochares Mulsant, 1844
Genus
Helocombus Horn, 1890
Genus
Hydrobiomorpha Blackburn, 1888
Genus
Hydrobius Leach, 1815
Genus
Hydrochara Berthold, 1827
Genus
Hydrophilus Geoffroy, 1762
Genus
Tropisternus Solier, 1834
Subfamily Sphaeridiinae
Tribe Coelostomatini Heyden, 1891
Genus
Phaenonotum Sharp, 1882
Genus
Dactylosternum Wollaston, 1854
Tribe Omicrini Smetana, 1975
Genus Omicrus Sharp, 1879
Tribe Megasternini Mulsant, 1844
Genus Agna Smetana, 1978
Genus
Cercyon Leach, 1817
Genus
Cryptopleurum Mulsant, 1844
Genus Cycrillum Knisch, 1921
Genus Deltostethus Sharp, 1882
Genus Megasternum Mulsant, 1844
Genus Oosternum Sharp, 1882
Genus Paraoosternum Scott, 1913
Genus Pelosoma Mulsant, 1844
Genus Tectosternum Balfour-Browne, 1958
Tribe Sphaeridiini Latreille, 1802
Genus
Sphaeridium Fabricius, 1775
*Subfamilies treated sometimes as families
Identification
Small to large beetles, most are aquatic. The aquatic groups superficially resemble Dysticidae, the Predaceous Diving Beetles. (Note differences in antennae--see print references.) Some genera have prominent keel on underside.
Water Scavenger beetles come up for air head first, while Predaceous Diving Beetles (Dysticidae), come up for air tail first. Hind legs move alternately in Hydrophilidae, together, like oars, in Dysticidae.
Habitat
Most genera aquatic. One subfamily lives in dung and moist soil.
Food
Some adults are scavengers and feed on dead plant and animal material, others are predatory. Larvae often predatory. Somme terrestrial species feed on dung or other decaying matter and associated maggots.
Print References
American Beetles, Vol. 1, Chapter 13
(2)
Ciegler, Water Beetles of South Carolina, pp. 90-135
(3)
Dillon, pp. 158-173, plates XVI, XVII
(4)
White, pp. 104-108, illustrates several genera.
(5)
Castner, pp. 113-114, has representative photos, comparing with other aquatics on other plates.
(6)
Brimley, pp. 133-134, lists Helophorus, Hydrochus, Berosus, Hydrophilus, Dibolocelus, Hydrochara, Tropisternus, Hydrobius, and several more genera for North Carolins.
(8)
