Hydrophilus (Hydrophilus) triangularis Say, 1823

Short, A. E. Z. & McIntosh, C. E., 2014, Review of the Giant Water Scavenger Beetle Genus Hydrophilus Geoffroy (Coleoptera: Hydrophilidae) of the United States and Canada, The Coleopterists Bulletin 68 (2), pp. 187-198 : 190-193

Hydrophilus (Hydrophilus) triangularis Say, 1823

( Figs. 2 , 6 , 7 )

Hydrophilus triangularis Say, 1823: 201 .

Stethoxus (s. str.) triangularis (Say) ; Bedel 1891: 313.

Hydrous (Pagipherus) triangularis (Say) ; Kuwert 1893: 89.

Hydrous (s. str.) triangularis (Say) ; Zaitzev 1908: 366.

Stethoxus subsulcatus LeConte, 1854: 221 . Synonymy: LeConte 1855: 367; Knisch 1924: 258.

Hydrous (Pagipherus) triangularis var. subsulcatus (LeConte) ; Kuwert 1893: 89.

Hydrophilus trisitis Motschulsky, 1859: 174 . Synonymy: Gemminger and Harold 1868: 476.

Material Examined. See Appendix 1.

Diagnosis. Size large (35–38 mm). Specimens often distinctly elongated and narrow relative to co-occurring species. Antennal cupule light in color with no to moderate elongation, ca. 1.5–2x as long as wide and not entirely covering first antennal club segment. Protarsal claws of males unequal in both size and shape. Terminal segment of protarsi greatly widened with outer margin forming an obtuse angle ( Fig. 2 ). The abdominal pubescence forms a distinctive “triangular” lateral margin on the glabrous region on each ventrite ( Fig. 6 .).

This species can be easily separated from other North American species by its elongated shape and very distinctive glabrous abdominal region.

Distribution ( Fig. 7 ). CANADA: Alberta, British Columbia, Ontario, Quebec, Saskatchewan; MEXICO: Aguascalientes, Chihuahua, Distrito Federal, Durango, Jalisco, Hidalgo, Michoacán, Morelos, Oaxaca, San Luis Potosí, Tamaulipas; USA: Alabama *, Arizona, Arkansas *, California, Colorado *, Connecticut, Delaware, District of Columbia *, Florida, Georgia, Idaho *, Illinois, Indiana, Iowa *, Kansas *, Kentucky *, Louisiana *, Maryland *, Massachusetts *, Michigan, Mississippi, Missouri *, Montana *, Nebraska, Nevada, New Jersey *, New Mexico *, New York, North Carolina *, North Dakota *, Ohio *, Oklahoma *, Oregon, Pennsylvania, Rhode Island *, South Carolina *, South Dakota *, Tennessee *, Texas, Utah *, Virginia *, Washington, West Virginia *, Wisconsin ( Hansen, 1999).

Remarks. Localities marked with an asterisk (*) indicate new state records. Hydrophilus triangularis is by far the most widespread and commonly encountered member of the genus in North America.

Hydrophilus triangularis

CANADA: Ontario: Port Hope , Dr. Bethane (1) . Québec: (Literature: Smetana 1988). British Colombia: (Literature: Smetana 1988). Alberta: (Literature: Smetana 1988). Saskatchewan: (Literature: Smetana 1988) .

MEXICO: Aguascalientes: Aguascalientes , 3-5. viii.1963, P. J. Spangler (1) . Chihuahua: Ciudad Jimenez , 26.vi.1964, P. J. Spangler (1) . Distrito Federal: “7-8.10” (1); R. Millor (1); Mexico City, Höge (1); Mexico City , O. H. Barrett (1); Mexico City , 28.v.1964, M. W. McFadden (1) . Durango: Lerdo Durango , 12.vi.1918, McKinney & Loftin (2) . Jalisco: 10 mi N. Chapala , 31.vii.1963, P. J. Spangler (1); 15 mi. N. Chapala, 2.viii.1963, P. J. Spangler (4); Guadalajara, 30.vii.1963, P. J. Spangler (1); 25 mi S. Guadalajara, 6.vii.1964, P. J. Spangler (2); Jocotepec, 11.vii.1959, H. E. Evans ( CUIC: 1) . Hidalgo: Ixmiquilpan , 1.vii. 1965, P. J. Spangler (2) . Michoacán: Zitacuaro, 9.viii.1957, David Lauck (1); Near Cuitzeo , 27. vii.1962, J. R. Zimmerman (1) . Morelos: Cuernavaca , xi.1905, Wm. Schaus (1); Cuernavaca, vi (1) . Oaxaca: ix.1894, (2); 4 mi SE El Tule , 6.ix.1964, J. R. Zimmerman (1) . San Luis Potosí: El Salto, 4.vii.1990, J. Danoff-Burg ( SEMC: 1) . Tamaulipas: 25 mi. S. Matamoros , 29.viii.1965, P. J. Spangler (11) . Unknown: San Antonio , 15.27, L. Stevenson ( SEMC: 1) .

USA: Alabama: Mobile, 10.iv.1949, W. Rosenberg (1); Mobile, 17.iii.1950, W. Rosenberg (1); Mobile, viii.1950, W. Rosenberg (1); Mobile, 19.iii.1949, W. Rosenberg (1); Mobile, 1.iii.1948, W. Rosenberg (4); Mobile, 20.v.1949, W. Rosenberg (1); Jasper, 30.vii.1965, L. G. Sanford (1); “Shefield” [treated as Sheffield], 13.iii.1953, B.D. Valentine (1). Arizona: Arivaca, 3 mi W, 15.vi.1968, O. S. Flint (1); Arivaca, 12.vii.1940, L. C. Kuitert (2); Arivaca, 18.ii.1972, “Lenczy” (1); Arivaca, 11.iv. 1970, “Lenczy” (1); Baboquivari Mountains, 24.vii.1941, Burt Hodgden (1); Green Valley, viii.1972, “Lenczy” (3); 5 mi W Portal, SW Research Station, 8.vi.1956, O. L. Cartwright (1); 5 mi W Portal, SW Research Station, 5.vii.1964, (1); “Chiric Mt”, “3.7”, Hubbard & Schwarz (1); Benson, 15.viii.1970, D. Kichman (1); Kansas Settlement, 0.2 mi W Sulphur Springs Comm. Ctr., 21.vii.1991, Lee Guidry (2); Tucson, Hubbard & Schwarz (1); Tucson, Wickham (1); Tucson, (1); Dos Cabezas, 7.vi.1965, O. S. Flint (1); 11 mi SE Willcox, 6.ix.1969, D. Kichman (1); Tucson, F. H. Snow ( SEMC: 2); Tucson, 10.vii.1944, Robert E. Snow ( SEMC: 1); Willcox, 24.vii.1970, D. Richman (1); Tanque Verde Mountains, 12.xi.1986, R. S. Beal (1); Bowie, 7.x.1916, E. G. Holt (2); Gila R. at Duncan, 15.iv.1904, F. M. Chamberlain (2); Phoenix, 10-20.viii.1908 ( CUIC: 2); Cave Creek, “ 9-10-1917 ”, J. V. M. (1); Kirkland, 24-30.vii.1970, J. May (3); Camp Verde, 22.vii.1969, A. & B. Hilton (3); Montezuma Well, 19.vi.1968, Menke & Flint (1); Winslow, “31-7”, Barber & Schwarz (1); Lake Mary, 20.x.1963, Michael Orr (1); Williams, vi.16, H. A. Kaeber (1); Diamond Creek, Grand Canyon, 8-9.v.1967, D. Davis (1); “ ASU Collection, Arizona” (3); Tucson Mt. Park, iv.1969, R. E. Beer ( SEMC: 1); Rt. 170 in Turlingua, 2.viii. 2003, A. E. Z Short (1). Arkansas: Texarkana, 28.viii.1908, E. S. Tucker (1); Hope, Mank Collection ( CUIC: 1); Gould, 2.vi.1954, P. H. Thompson (1); Brinkley, 27.ix.1977, Beyers, May, Young ( SEMC: 2); Devil’ s Den St. Park, 12.vii.1966, R. W. Hodges (1); nr. Imboden, 10.iv. 1925, B. C. Marshall (1); 19.vii.1968, (1); Yarbro, 17.iv.1966, G. Eikwort ( SEMC: 1). California: [without specific locality] (1); Calipatria, 6.vi. 1922, Warwick Benedict ( SEMC: 1); Calipatria, 16.vii.1924, Warwick Benedict ( SEMC: 1); Laguna Beach ( CUIC: 6); Mecca, 11.vii.1923, Warwick Benedict ( SEMC: 1); 4.iv.1924, Warwick Benedict ( SEMC: 1); Palm Springs, 1932, (1); Los Angeles, 22.viii, C. E. Hutchins (1); Needles, Wickham (1); Needles (1); Oceano, 4.viii.1938, R. I. Sailer ( SEMC: 1); Bakersfield, 14.viii.1937, R. E. Beer ( SEMC: 1); Bakersfield, 19.viii.1917, Wheeler (1); Panamit Valley, iv.1891, (1), 48 km NNW Baker, 35 41′N, 116 17′W (148 km?), 5.i.1992, W. E. Steiner & J. M. Swearington; Death Valley, iv.1891, K. (1); Fresno, ix, E. A. Schwarz (4); Fresno, 10.vi.1907 ( CUIC: 5); Ben Lomond, iv.1931, L. Saylor (1); Bass Lake, 25.viii.1922, Warwick Benedict ( SEMC: 1); Travis Air Force Base, 30.ix.1965, Nave & Young (1); Sacramento, 3.v.1921, B. G. Thompson (1); Sacramento, 2.iii. 1921, B. G. Thompson (1); Topaz, “9-4-19”, (1); Colusa, 2.vi.1933, E. C. Zimmerman (1); Willows, 30.viii.1918, A. Wetmore (4); Nr. Seneca, iv.1923, V. S. Barber (1); Pine Creek Valley, 29.vii.2005, G. L. Challet ( SEMC: 1); Coquillett (collector) (1); Mink Park, J. Hoyrang (1); Huntington Beach, 7.vi.1937, R. E. Beer ( SEMC: 1); El Centro, 26.ix. 1962, Peter D. Ashlock ( SEMC: 2). Colorado: Pancha Springs (Treated as Poncha Springs), 14.vii. 1898, E. J. Oslar (1); Buena Vista, 1-6.vii.1896, H. F. Wickham (1); Grand Junction, 29.v.1896, H. K. Plank (1); Denver, Dyar & Caudell (1); Denver, 14.vii.1909, (1); La Porte, 11.vii.1961, J. Toczek (1). Connecticut: Stanford, “ B. T. R. Lab” (treated as Stamford), 1.vii.1929, (1); Stanford, “ B. T. R. Lab” (Treated as Stamford), 19.ix.1929, (1). Delaware: Glasgow, 3.vii.2002, A. E. Z. Short ( SEMC: 1). District of Columbia: (3); 1.x.1917, (3); 17.v.1906, W. L. McAtee (1); 1914, M. T. Van Horn (1); 26.vii.1917, (1); 28.iii.1907, D. H. Clemons (5); 27.iv.1904, D. H. Clemons (1); “22.4”, R. P. Currie (5); 3.vi.1902, S. Shoemaker (1); vi.7.1910, (1); vi.10.1910, (1); vii.16.1910 (1); vii.17.1910, (1); vi.1.1902, (1); 4.iv.1910, F. Knab (3); September, F. Knab (1); 4.4.1905, D. H. Clemons (1); 29.iii.1907, W. L. McAtee (1); 24.4.1905, D. H. Clemons (1); “22.4”, H. S. Barber (10); 1.x.1917, (1); 7.ix.1908, D. H. Clemons (1); 27.iii.1907, D. H. Clemons (1); 14.v.1898, C. E. Burden (1); 10.vii.1906, F. Knab (1); 7.ix.1906, D. H. Clemens (3); Hubbard & Schwarz (2); “vi”, Hubbard & Schwarz (1); 24.iv.1895, R. P. Carrie (1); R. P. Carrie (1); 25.iv.1900, H. S. Barber (1); 22.4, R. P. Curio (2); iv.1908, (1); C. E. Burden (1); 5.ix.1902, C. E. Burden (1); 12.vi.1902, C. E. Burden (2); 14.v.1898, C. E. Burden (1); 8.ix.1902, C. E. Burden (1). Florida: Key West, (1); Ramrod Key, 18.viii. 1967, G. F. Hevel (1); Homestead, 17.xi.1951, R. Mansaeti (1); Archbold Biological Station, 15.viii-21.ix.1978, William Rosenberg (3); Charley Apopka Cr at U. S. 17, 14.xi.1979, D. A. Etnier (2); Tampa, Dyar & Caudell (1); Disney World, 21.vi.1979, A. Freidberg (6); 17 mi. N. Tallahassee, Tall Timbers Res. Station, 12-22. vii.1967, L. Collins (1). Georgia: 25.v.1957, W. Rosenberg (1). Idaho: Twin Falls, 29.vi. 1961, T. R. Coupe (1); Boise, 19.v.1925, (1). Illinois: Browns, 27.vi.1956, D. L. Lauck (3); Moose Lake, Albion, 26.vi.1956, D. L. Lauck (1); Wabash R. 1 mi below mouth of Embarras R., 13.ix.1979, Etnier, Rich, Kubb, Bogardus, Clark (1); Bunker Hill, 7 mi. South, 28.v.1953, D. L. Lauck (2); Vandalia, 13.vi.1956, D. L. Lauck (1); Plainview, 19.iv.1957, David Louck (1); Urbana, (1); Urbana, 8.v.1907, Hart & Hood (1); Urbana, viii.1956, D. L. Lauck (1); Chicago, 21.v.1904, W. M. Mann (2); Lily Lake, 11.vii.1956, D. L. Lauck (2); Lake Forest [black square], 13.viii.1899, J. S. Needham (1); Davis, 15.viii.1956, D. L. Lauck (2); Olni Reservoir [possibly “Olney”], 22.v.1953, D. L. Lauck (1). Indiana: (1); Bloomington, 21.vii. 1956, J. R. Zimmerman (1); Bloomington, 22.vii.1956, J. R. Zimmerman (1); Bloomington, 23.v.1954, B. R. Avery (1); Bloomington, 14.iv.1958, J. J. Chopper (1); Bloomington, 24.v.1954, R.D. Curtis (1); Noblesville, 26.vi.1978, H. Jump (4); Grant Plaza, 18.vii.1972 ( SEMC: 1). Iowa: Keokuk, May, Shaffer (1); Koekuk, 30.iv.1916, E. Stringham (2); Muscatine, 21.iv.1919, F. M. Wadley (1); Iowa City, v.1908 (1); Iowa City, 20.ix.1916, L. Buchanan (1); Iowa City, Wickham (1); Decorah, 8.vii (1); Byrh, v-15, E. J. Bashe (1). Kansas: [without specific locality] (4); Liberal, 3 mi N, 12.viii.1958, J. R. Zimmerman (1); Wellington, J. K. Waggener (1); Wellington, 39582 (1); Pittsburg, 24.iv.1961, G. F. Hevel (1); Isabel, 14.iv.1952, D. R. Bell (1); Wichita, 26.iv.1958, J. R. Zimmerman (1); Wichita, 17.v.1958, J. R. Zimmerman (1); Wichita, 24.x. 1930, E. W. Howe (1); 1916, R. H. Beamer ( SEMC: 14); West shore of Cheney Lake, 16.viii.1993, S. Lingafelter (1); Toronto, Lake Feegan, 21.viii. 1956, P. J. Spangler (3); Calista, 22.vii.1956, P. J. Spangler (1); 26.vii.-2.viii.1917 ( SEMC: 1); F.X. Williams ( SEMC: 2); Lone Star Lake, 7.v.1952, P. J. Spangler (2); Lone Star Lake, 27.iv. 1953, P. J. Spangler (17); Gardner Lake, 2.v.1952, Bell & P. J. Spangler (43); Gardner Lake, 3.v.1952, Bell & P. J. Spangler (8); 1.v.1952, P. J. Spangler (1); 26.iv.1952, Donald B. Woodard (1); 5.v.1951, R. H. Pine (1); 1.x.1951, R. W. Frederickson ( SEMC: 1); “v” ( SEMC: 1); Ft. Hays, vi, Allen (1); F.X. Williams ( SEMC: 9); Sharon Springs; Oak Tree Inn Diner, 23.vii.2004, C. M. B. (2); “Lawrence vicinity”, 15.viii.1986, Robert W. Brooke ( SEMC: 1); “Lawrence vicinity”, 21.vi.1963, ( SEMC: 1); “Lawrence area”, ix.1984, D. Yanega (1); “Lawrence vicinity”, 21.iv.1963, ( SEMC: 12); “Lawrence vicinity”, 5.x.1956, G. W. Byers ( SEMC: 1); Lawrence, 8.xi.1935, M. W. Sanderson ( SEMC: 1); Lawrence, 30.iv.1948, ( SEMC: 1); Lawrence, 17.vi.1933, J. B. Fengold (3); Lawrence, 12.ix.1953, J. Mathawson (1); Lawrence, 5.ix.1951, R. E. Beer ( SEMC: 2); Lawrence, 24.viii.1951, R. E. Beer ( SEMC: 1); Scorpion Hill, Grant Twp., 19.iv. 1952, P. J. Spangler (2); Topeka, 18.v, Popenoe (2); Topeka, 4.v, Popenoe (6); Topeka, 17.vii, Popenoe (1); Topeka, 24.vii, Popenoe (1); Topeka, 1.viii, Popenoe (1); Leavenworth State Park, 14.ix.1952, P. J. Spangler (2); Manhattan, 24.iv.1968, G. F. Hevel (1); Manhattan, xi.1950, (3); Manhattan, 5.v.1965, G. F. Hevel (1); Manhattan, 20.vii.1968, G. F. Hevel (7); Manhattan, 2.vi.1967, G. F. Hevel (1); Manhattan, 7.viii.1967, G. F. Hevel (1); Manhattan, 22.ix.1966, G. F. Hevel (1); Manhattan, Kansas State University Campus, 17.iv.1967, G. F. Hevel (1); F.X. Williams ( SEMC: 1); 12.v., Popenoe (1); 13 SE Greensburg, 11.vii.1992, G. A. Salsbury (1); 4.5 W Coldwater, small pond, 11.viii.1989, G. A. Salsbury (1); 2.viii.1924, C. O. Bare ( SEMC: 2); ( SEMC: 2); 24.viii.1921, Robert Guentert ( SEMC: 3). Kentucky: Crailhope, 15.vii.1943, Carl Cook (4); Sanborn, (1). Louisiana: New Orleans, vi.1940, H. E. Cubert (1); Lafayette, 34. vii. 1973, W. Rosenberg (4); Alexandria, 4.iii.1912, B. R. Coad (1); “Nacogdches”, 28.vi.1905, W. A. Hooker (1). Maryland: [without specific locality] (1); Dickerson, 21.vii.1988, C. L. Staines, Jr. (1); Scientists Cliffs, Nr. Port Republic, 4.ix.1975, O. S. Flint (1); Chesapeake Beach, 7.v.1923, R. A. St. George (1); Royal Oak, 17.vii.1989, (3); Easton, Woodland Pd., 5.vii.1971, Robert Gordon (1); Pickering Creek Audubon Center, 9.5 mi NW Easton, 10.vii.2008, MG Pogue (1); Denton, 11.vii.1989, C. L. Staines (1); “SomrstHts” (Somerset Heights), E. S. G. Titus (1); College Park, ix.1972, J. P. Kurdyla (1); Ruthsburg, 29.vii.1989 (6); Ruthsburg, 25.vii.1988, C. L. Staines (1); Potomac, vii.1970, W. E. Steiner (1); Ford Meade, 15.vi.1968, M. B. Stoetzel (1); Ford Meade, 20.vi.1968, M. B. Stoetzel (1); Baltimore, 27.iv.1940 (1); Baltimore [“Balto”], ix.22.1940, (2); Loch Raven, 3.viii.1979, K. S. Simmons (1); Bowie, “Patwront Ref.”, 7.v.1943, (1). Massachusetts: Amherst, 4.xi.1952, (1); Amherst, 10.x.1952, O. S. Flint (1); Amherst, 21.ix. 1925, E. A. Richmond (2). Michigan: Detroit, 20.vi.1956, D. L. Lauck (1); Detroit, “13.6.74. H ”, Hubbard & Schwarz (1); Detroit, October, Hubbard & Schwarz (1); Sedge Pt. Pool, Doug. Lake, 10.viii.1952, P. J. Spangler (5); Escanaba, 16.7, (1). Mississippi: Gainesville (1); Gainesville, 8.vii.1966, B. Ethridge ( SEMC: 10); 19.viii. 1964, V. H. Owens (1); Greenwood, 15.vi.1972, D. Brzoska ( SEMC: 4); Greenwood, 13.vii.1971, D. Brzoska ( SEMC: 2); Greenwood, 4.vi.1972, D. Brzoska ( SEMC: 4); Greenwood, 19.vii. 1971, D. Brzoska ( SEMC: 1); Greenwood, 14.vi. 1972, D. Brzoska ( SEMC: 1); Greenwood, 12.vi.1972, D. Brzoska ( SEMC: 2); Greenwood, 11.vi.1972, D. Brzoska ( SEMC: 1); Greenwood, 3.vi.1972, D. Brzoska ( SEMC: 1); Greenwood, 29.vi.1971, D. Brzoska ( SEMC: 1); “Scott, Bol. Co.”, 11.vi.1964, V. H. Owens (1); Sireston, 16.vii.1956, Don Stout (3); (Literature: Testa and Lago 1994). Missouri: Steele, vi.19-26.1955, James Perry (9); Steele, 21-23.iv.1953, James Perry (17); Washburn, 5.v. 1930, H. H. Shamel (1); Cassville, Roaring River St. Park, 22.iv.1955, P. J. Spangler (1); Hollister, 12.viii, H. H. Knight (1); Sikeston, “ 4.3.1956 ”, D. W. Stout (9); Newtonia, 19-30.iv.1955, Glenn Cole (13); 1 mi N Winona, Lewis Lake, 14.ix. 1955, P. J. Spangler (1); 2 mi N. Winona, Lewis Lake, 9.iv.1955, P. J. Spangler (1); Joplin, 24.vi. 1970, Dr. Lenczy (1); Cabool, 15.ix.1958, P. J. Spangler (1); Springfield, Phelps Grove Park, 12.iii.1972, P. Gynno (1); Lamar, Public Square, 29.iv.1972, Cook (1); Butler, 17.vii.1971, H. Farris (1); St. Louis, 19.iv.1953, (1); “St. Lewis”, 24.vii. 1894, W. M. Brown ( CUIC: 1); 2 mi. W. Ashland, 13.iv.1955, P. J. Spangler (10); Easely (Treated as Easley), ix.10.1954, P. J. Spangler (1); Colombia, 5 mi S., 19.v.1955, P. J. Spangler (1); University of Missouri, South Farms, 24.iv.1954, (23); Columbia, University S. Farms, 18.vii.1966, F.D. Parker (2); Columbia, University S. Farms, 15.vii.1966, F.D. Parker (1); Columbia, 22.vi.1955, G. W. Thomas (52); Columbia, 14.v.1953, Max Adkins (1); Columbia, 28.vii.1966, F.D. Parker (1); Columbia, 24.viii.1966, F.D. Parker (1); Columbia, 1.v.1953, C. E. Jennims (1); Columbia, 12.v.1953, Rollins Springs (1); Web Groves, Yeddow Park Pond, vii.1923, H. E. R. (1); S. Keston, 16.vi.1956, George Thomas (21); Deer Park, University TV Station, 19.v.1955, P. J. Spangler (1); Columbia, Research Park, 13.vii.1966, F.D. Parker (1); Columbia, Research Park, 19.vii.1966, F.D. Parker (1); Columbia, Research Park, 6.vii.1966, F.D. Parker (1); S Freemont-Springfield, 12.iv.1972, G. T. Smither (1). Montana: Helena, 28.viii.1907 (1). Nebraska: Holdredge Community Hospital, 20. viii.1996, J. E. McGuire ( SEMC: 1); Malcolm, 7.vi.1909, (2); Malcolm, 22.v.1909 (1); 8 mi NE Oshkosh, 12.viii.1955, R. W. Frederickson ( SEMC: 5). Nevada: Fallon, 8.ix.1958, J. R. Alcorn ( SEMC: 2); Fallon, 9.viii.1959, J. R. Alcorn ( SEMC: 1); Fallon, 22.vii.1959, J. R. Alcorn ( SEMC: 1); Austin, 12.viii.1940, L. C. Kuitert ( SEMC: 1). New Jersey: [without specific locality] (1); Riverton, 5.ix.1898, (1); Boonton, (1). New Mexico: [without specific locality] (1); Black River, 1.vii.1956, R. & C. Flint (1); Mecilla (Treated as Mesilla), 28.vi. 1897, A. P. Morse (1); Mesilla Park, 6.vi.1961, J. R. Zimmerman (1); Alamogordo, 13.ix.1905, (1); El Paso Gap, 4.viii.1967, L. P. Anderson (1); 16 km E Roswell, 8.viii.2005, N. L. Rasmussen ( SEMC: 1); 10 mi. E. Roswell, Bottomless Lakes State Park, 22.vi.1964, P. J. Spangler (1); Roswell, vii.1960, “Lenczy” (1); Carrizozo, 23.viii.1923, K. C. Doering ( SEMC: 1); Clovis, 16.v.1969, “Lenczy” (1); ix.1925, C. H. Martin ( SEMC: 1); Albequerque, Wickham (1); Watrous, 5m. S., 16.vii.1965, A. H. Smith (1); Pasamonte, 8 mi E & 2m N., 15.vii.1965, A. H. Smith (6); Maxwell, Lake 13 Pond, 2.x.1975, Alex Mangini (1); Koehler, W. R. Walton (1); Dulce, 24.vi.1965, J. R. Zimmerman, A. H. Smith, R. L. Smith (1); State College, iv.1986, O. A. Hare (1); Capitan White Mountains ( CUIC: 1). New York: [without specific locality] (1); Staten Island, 6.viii. 1919, S. Shoemaker (1); Long Island, “Long Bch”, 23.v.1926 (1); Brooklyn, 25.v.1940, S. Shoemaker (1); Cypress Hills, Brooklyn, 16.v. 1910, S. Shoemaker (1); New York, Empire State Building, 16.vi.1941, E. P. Felt (1); West Point, W. Robinson (1); Allegany State Park, vii.1937, A. R. Shadle (2); Allegany State Park (1); Allegany State Park, 22.viii.1936 (1); Allegany State Park, 1937, A. R. Shadle (1); 12.v.1939 (1); Ithaca, 5.viii. 1979, J. Pakaluk ( SEMC: 1); Ithaca, 13.ix.1935 ( CUIC: 1); Ithaca, 1.ix.1914 ( CUIC: 1); Ithaca, mic. ( CUIC: 3); Buffalo (1); Long Island, “Rock Bch”, 17.vi.1922, S. Shoemaker (1). North Carolina: Balsam, 6.v.1965, W. Rosenberg (1); Balsam, 14.iv.1965, W. Rosenberg (1); Asheville, 8.iv.1955, W. Rosenberg (1); Linville, Kawana Lake (Kawahna Lake), 25.ix.1916, Clark & Robinson (2); Oxford, 9.viii.1950 (1); Charleston, McClellanvlle, Wedge Plantation, 1.iv.1971, J. G. Franclemont ( CUIC: 1). North Dakota: Belfield, 27.viii.1965, Robert Gordon (1); McVille, 27.vii.1937, H. T. Peters ( SEMC: 1); Cavalier, 10 mi W., 26.vi.1966, Robert Gordon (1). Ohio: [without specific locality] ( CUIC: 1); Athens, OU Airport, 20.vi.1950, P. J. Spangler (1); Athens, OU Airport, 17.v.1950, P. J. Spangler (1); Athens, OU Airport, 30.vi.1950, P. J. Spangler (1); Athens Airport, 3.vi.1951, P. J. Spangler (2); Athens Airport, 5.v.1951, P. J. Spangler (1); 7 mi. E. Athens, 2.iv.1950, P. J. Spangler (1); 4 mi E. Athens, Rt. 50, 25.iv.1950, P. J. Spangler (1); Columbus, 10.iv.1917, “ K. L. C.” (2); Columbus, 12.v.1980, S. W. Nichols ( CUIC: 1); 2 mi NE Kent, 2.viii.1967, M. Druckernbrod (1); Jefferson, R. J. & M. B. Sim (1); Ohio, 19.iv.1955, (17); Perkin, 19.iv.1955 (1); 16.v.1955 (2); (Literature: Chapman 1998). Oklahoma: Stillwater, 30.iv.1954, Dean A. Garrett (2); Stillwater, 9.iv.1932, Oren Eastep (1); Stillwater, 1948, L. Hopkins ( CUIC: 2); Stillwater at OK State Univ., 25.iii.2003, N. Rasmussen ( SEMC: 1); Tulsa, 31.viii.1970, “Lenczy” (5); 7.viii.1960, J. F. Reinert (1); 1960, J. F. Reinert (1); Kenton, 28.vii.1933, E. Ivy (1). Oregon: “Enangulans” (locality) (1); “Dilley” (locality) ( CUIC: 1). Pennsylvania: Arendtsville, The Narrows, “17382”, P. J. Spangler (1); Philadelphia, 16.ix.1912 (1); Philadelphia, 23.iv.1897 (1); Philadelphia, “vi-19” (1); Philadelphia, 1.ix. 1905 (1); Philadelphia, 1.v.1913 (1); Philadelphia, 13.v.1916, G. M. Greene (1); Philadelphia, 24.v. 1919, G. M. Greene (1); Philadelphia, 17.v.1919, G. M. Greene (1); Philadelphia, 20.v.1919, G. M. Greene (1); Philadelphia, 1.ix.1905, G. M. Greene (1); Mt. Gretna, “4/5/[19]49”, P. J. Spangler (2); Mt. Gretna, 10.viii.1951, P. J. Spangler (3); “Mem.” Lake St. Park, Indiantown Gap, 6.vi.1965, P. J. Spangler (1); Sunbury (locality) (1); P. J. Spangler (1). Rhode Island: Watch Hill, 28.vii.1905, W. Robinson (1); Watch Hill, 25.vi.1909, W. Robinson (1). South Carolina: [without specific locality] (3); Charleston, 14.viii.1947, O. L. Cartwright (1); Graycourt (Treated as Gray Court), 14.vii.1930, G. F. Simpson (1); Clemson College, 7.v.1931, D. Dunavan (1); Clemson College, Smith’ s pond, 28.ii.1932, D. Dunavan (1). South Dakota: Ardmore, 11.vii.1915, E. G. Holt (2); Cedar Pass, viii-1913, W. H. Over (1); Black Hills National Forest, Sheridan Lake, 11.vii.1962, P. J. Spangler (1); Volga,, Truman (1); ix.12-1913, W. H. Over (1). Tennessee: Friendsville, 1.v.1970, Robert Perry (1); Springhill, 20.vii.1935, (1); Nashville, 20.vii, Osburn (1); Reelfoot Lake at Walnut, leg off Tennessee 22, “ 7/9/1970 ”, Bouchard (6); N. of Athena, Spring Creek, 5.x.1893, B. M. Evermann (1). Texas: [without specific locality] (3) ( CUIC: 1); Davis Mountains, 27.x.1961, J. R. Zimmerman (1); Balmorhea State Park, 7.vii.1963, P. J. Spangler (2); Brownsville ( SEMC: 1); Brownsville, 17.iv. 1967 (1); Brownsville, ix (1); Brownsville, 15.v, McMillan (1); Brownsville, 5.vi.1908, McMillan (2); Brownesville, 19.viii. ( CUIC: 1); Progreso, 1.vii.1938, D. W. Craik ( SEMC: 1); Bentsen State Park, 10-11.viii.1963, P. J. Spangler (1); Raymondville, v-vii.1962 (5); Texas, 20 mi. N. Raymondville, 26.vi.1965, P. J. Spangler (20); Padre Island, vii.1965, Dr. Lenczy (5); Kingsville, C. T. Reed ( CUIC: 4); Corpus Christi, Naval Air Station, 1942 ( CUIC: 3); Hwy 72 1 mi W of 3 Rivers, 31.vii.2003, A. E. Z. Short ( SEMC: 1); Big Bend National Park, Rio Grande Village, 19.iii.1976, W. E. Steiner (1); Uvalde (at Neuces River), 21.iii.2976, W. E. Steiner (1); 6 mi N Uvalde, 12.vii.1964, C.D. Jonhson (1); Galveston, v, F. H. Snow (2); Galveston, May, F. Snow ( CUIC: 2); Galveston, v, F. H. Snow ( SEMC: 2); “New Braunfels”, vii.1902 (1); Big Bend National Park., Boot Springs, 2.viii.1961, JR Zimmerman (1); 12 mi E. Marathon, 30.v.1991, P. & P. Spangler (9); Alpine, 1926, O. C. Poling ( CUIC: 2); 20.viii. 1928, A. M. James ( SEMC: 1); Ft. Davis, 11.v. 1969, A. & M. E. Blanchard (1); Georgetown, 15.vi.1957, David Louck (5); Fort Stockton, 18.vii.1927, L. A. Stephenson ( SEMC: 1); 10 mi. W. Kent, 8.vii.1963, P. J. Spangler (6); El Paso, 29.vii.1909, A. K. Fisher (1); El Paso, 9.viii.1907, H. A. Kaeber (1); El Paso, 26.vii. 1914, J. C. Bradley ( CUIC: 16); Thurber, 26.vii. 1962, J. M. Campbell (2); Ft. Worth, 19.v.1913, A. Wetmore (1); Dallas, 27.iv.1905, F. C. Bishopp (6); Dallas, 27.v.1905, F. C. Bishopp (1); Seymour, 1.viii.1965 (1); Wichita Falls, “10. (?). 1906”, J.D. Mitchell (2); Paducah, 9.vii.1967, A. & M. E. Blanchard (1); Childress, 22 “ J ”?05, A. W. Morrill (1); Amarillo, 2.ix.1962, G. F. Hevel (1); Bellinger, vii.1965, Dr. Lenczy (1); Paps, 16.iv.1904, A. L. Quaintance (1); Highway 72, 1 mi W of 3 Rivers, 31.vii.2003, A. E. Z. Short ( SEMC: 1); Corpus Christi St. Pk., 23.v.1972, R. E. Beer, W. R. Enns, S. E. Thewke ( SEMC: 6); Decatur-Hwy. 287, 18.vi.1975, D. Brzoska (1); 16.vii.1928, R. H. Beamer ( SEMC: 1). Utah: Mill Creek (Treated as Millcreek), “16.6”, Hubbard & Schwarz (1); Salt Lake City, 25.vii.1909, (1); Salt Lake City ( CUIC: 1); Emigration Canyon, pond 2 mi. above mouth of canyon, 5.x.1966, R. W. Baumann (1); Kaysville, 25.vi.1912, E. R. Kalmbach (1); Ogden, “6.7”, Hubbard & Schwarz (1); Mouth of Bear River, 15.viii.1914, A. Wetmore (1); Mouth of Bear River, 5.viii.1916, A. Wetmore (1); Salt Lake, S. W. Garman (6). Virginia: Virginia Beach, 10.iii.1975, A. Campbell (1); Harrison Lake National Fish Hatchery, 16-19.vii.2007, A. V. Evans (2); Radford, 25.iv.1959, H. Floege (1); Radford, 29.iv.1959, M. Pound (1); Petersburg, iv.1905, (1); Savage Neck Dunes, “ NAP ” Custis Pond, 7.x.2003, A. C. Chazal, S. M. Roble (2); Savage Neck Dunes, “ NAP ”, 4.ix.2003, S. Erdle, D. Field (1); Savage Neck Dunes, NAP dune south, 7.06 km WSW Eastville, 15.iv.2004, 9.v. 2004, D. Field, R. Ayers (1); Harrison Lake National Fish Hatchery, 13.vii.2006, A. V. Evans (1); Lynchburg, 20.iv.1966, J. Jennings (1); Roxbury ( CUIC: 1); Richmond, 1.v (1); 13.viii. 1921, W. Robinson (1); 12.viii.1914, W. Robinson (1); Fredricksberg (Treated as Fredericksburg), “8-15-[18]89”, W.D. Richardson (1); E. Falls Church, 26.vii.1917, I. N. Gabrielson (1); 4.1 mi W. Paris, Shenandoah River, 3.viii.1970, G. Noonan, L. Ewin (1); 21.vii.1973, J. Matta (2). Washington: Yakima, C. V. Piper (2). West Virginia: Spurce Knob L. Inlet Marsh, 16–22.v. 1963, Field & Flint (1). Wisconsin: [without specific locality] ( CUIC: 1).

Figures

Figs. 1–2. Hydrophilus species, male protarsi. 1) H. insularis; 2) H. triangularis.

Figs. 3–6. Abdominal ventrites of Hydrophilus species, showing extent of medial glabrous region. 3) H. ovatus; 4) H. ensifer; 5) H. insularis; 6) H. triangularis.

Figs. 7–8. Distribution of Hydrophilus species in the United States and Canada. 7) H. triangularis; 8) H. insularis. Filled points are records examined by us. Open points are literature-only records.