Ligyrus (Ligyrodes) relictus
Creators: name: López-García, Margarita M.
name: Deloya, Cuauhtémoc
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Scarabaeidae
Ligyrus
Ligyrus relictus

description: Ligyrus (Ligyrodes) relictus (Say, 1825)
(Figs. 2E, 4C, 5C, 6C, 8C, F, 11D, 14C, 15G, 17F, 25D; 33)
Scarabaeus relictus Say, 1825: 194. Original combination. Type lost. Type locality: Pennsylvania.
Ligyrodes clypealis Casey, 1915: 181. Synonym. Male lectotype (USNM) “N.J. // Horn. // CASEY / bequest / 1925 // TYPE USNM / 48602 // clypealis / Csy” here designated. Male paralectotype (USNM) “N.J. // Horn. // CASEY / bequest / 1925 // PARATYPE USNM / 48602 // clypealis / Csy”.
Ligyrodes parviceps Casey, 1915: 181. Synonym. Male lectotype (USNM) “Ia // CASEY / bequest / 1925 // TYPE USNM / 48604 // parviceps / Csy” here designated.
Ligyrodes quadripennis Casey, 1915: 182. Synonym. Male lectotype (USNM) “Canadian / Aferi / Tx // CASEY / bequest / 1925 // TYPE USNM / 48601 // quadripennis / Csy” here designated. Female paralectotype (USNM) “Ia // CASEY / bequest / 1925 // PARATYPE USNM / 48601 // quadripennis / Csy”. Female paralectotype (USNM) “ N. Ill // CASEY / bequest / 1925 // PARATYPE USNM / 48601 // quadripennis / Csy”.
Ligyrodes relictus vernicicollis Casey, 1915: 183. Synonym. Female holotype (USNM) “Ia // CASEY / bequest / 1925 // TYPE USNM / 48603 // vernicicollis / Csy”
Ligyrodes dawsoni Casey, 1924: 334. Synonym. Male holotype (USNM) “ So. Sioux City, Nebraska // L.T. Williams / July 8. 1912 //CASEY / bequest/1925 // TYPE USNM / 48600 // dawsoni / Csy”.
Description. Habitus as in Fig. 25D. Length 16.7–22.2 mm; humeral width 8.0– 11.48 mm. Color dark reddish brown to black. Head: Frons slightly concave between eyes and before frontal tubercles; surface deeply rugopunctate, with large and sparse punctures, nearly smooth on vertex with only sparse, small punctures. Frontoclypeal region with 2 tumescences separated by 1/2 a tumescence width. Ocular canthus rounded and wide, with 3–4 ventral setae. Clypeal surface rugopunctate, striae denser than those on frons. Clypeus subtriangular to trapezoidal, base 2.0–2.5 times as wide as apex. Clypeal teeth transverse to widely triangular, separated by 1.5 times a tooth diameter. Mandible with 2 apical and 1 lateral, truncate tooth, tooth 1 shorter and narrower than tooth 2 (Fig. 5C). Interocular distance 3 times an eye width. Antennal club long. Pronotum: Surface with small, sparse punctures. Apex without tubercle or fovea (Fig. 25D). Elytra: First interval punctate, punctures similar to the other intervals. Inner surface of apex with small transverse tubercles forming about 70 parallel lines. Abdomen: Apex of tergite IV with a diagonal line of 12 transverse parallel short carinae. Pygidial surface with large, evenly sparse punctures. Strongly (male) to slightly (female) convex in lateral view. Legs: Protibia tridentate, with an additional basal denticle; teeth equidistant (Fig. 11D). Protarsus of male with inner claw wide, apex with a spine-like projection (Fig. 10E). Metatibia not narrowed before apex, sides nearly parallel. Apex of metatibia crenulate, with 6–9 spinules. Male genitalia: Spiculum gastrale wide, apex truncate (Fig. 14C). Parameres short; strongly contracted at middle; ventral margin with an apical acute, tooth long on each side (Figs. 15G, 17F).
Diagnosis. Ligyrus relictus is differentiated from the other species in the genus by the protibia with basal denticle and without a denticle between the basal and second tooth (Fig. 11D) (with a denticle in L. sallaei); pygidium with dense rugosity; clypeus trapezoidal; and parameres short, with the ventral tooth acute and placed at middle (Figs. 15G, 17F).
Taxonomic remarks. The species was originally described in the genus Scarabaeus by Say (1825). Although it has stridulatory area on the inner face of the elytra as the other species included by Burmeister (1847) in Ligyrus, for unknown reasons he placed it in Heteronychus and later LeConte (1856) combined it in Ligyrus.
Distribution. Central and eastern United States to southeastern Canada (Cartwright 1959; Endrödi 1969; Ratcliffe & Cave 2017).
Locality records (Fig. 33). 432 examined specimens from CEIOC, FSCA, IEXA, MZUSP, UNSM, USNM. Localities from Canada and United States of America counties are listed from Ratcliffe & Cave (2017). CANADA (518). Manitoba (79): Aweme; Souris; Winnipeg. New Brunswick (32): Fredericton; Kouchibouguac National Park; Saint Andrews, Huntsman Marine Science Centre; Saint John. New Scotia (139): Antigonish; Cape Breton; Halifax; Iverness; Kentville; Pictou; Victoria. Ontario (142): Arnprior; Aylmer; Britannia Heights; Canfield (4 km S); Carp; Chaffey’s Lock; Chalk River; Constance Bay; Cumberland Village; Dunks Bay; Dunnville; Dunrobin; Goderich, Maitland River and Highway 21; Grand Bend; Kerr Lake; Latta; London; Mallorytown; Marmora; Merivale, Midland; Muskoka; Normandale; Ottawa; Richmond (6 mi. W); Rondeau Provincial Park; Rostrevor; Sauble Falls, road along Bruce County forest; Severn Bridge; Sharbot Lake; Wolf Lake, Nipissing. Prince Edward Island (7): Charlottetown; Cornwall; Meadowbank. Quebec (119): Aylmer; Aylmer, Queen’s Park; Beamish Hill; Bécancour; Choisy; Eardley; Farrelton; Fort Coulonge; Hull; Île Perrot; Lac Cloutier; Lac Heney, Chermin Sharp; Lanoraie; Lévis; Limbour; Lucerne; Montreal; Norway Bay; Parc Paul-Sauve; Parc Paul-Sauvé, Deux-Montagnes; Perkins; Pont-Rouge; Rigaud; Riviera, Touraine; Sainte-Foy; Terrebonne; Thurso; Touraine; Vaudreuil; Ville Laval, Duvernay. UNITED STATES OF AMERICA (2,400). Alabama (1): Mobile. Arkansas (23): Hempstead, Washington. Colorado (28): Boulder; Denver; Jefferson; Larimer; Logan; Weld; Yuma. Connecticut (19): Fairfield; Litchfield; Middlesex; New Haven; New London; Tolland. Delaware (10): New Castle. District of Columbia (25): Washington. Illinois (168): Champaign; Cook; Douglas; Jasper; Kankakee; Lake; Macon; Marshall; Mason; McLean; Peoria; Pike; Rock Island; Saline; Vermilion. Indiana (60): Brown; Elkhart; Kosciusko; La Porte; LaGrange; Lake; Porter; Steuben; Sillivan; Tippecanoe; Vigo. Iowa (91): Appanoose; Boone; Bremer; Buchanan; Carroll; Cerro Gordo; Cherokee; Davis; Decatur; Deleware; Des Moines; Dickinson; Fremont; Henry; Jefferson; Johnson; Keokuk; Linn; Louisa; Lucas; Marion; Monona; Monroe; Muscatine; Page; Plymouth; Polk; Pottawattamie; Scott; Shelby; Story; Wapello; Winneshiek. Kansas (182): Atchison; Barber; Clark; Crawford; Dickinson; Doniphan; Douglas; Harvey; Kingman; Kiowa; Labette; Neosho; Pottawatomie; Reno; Riley; Sedgwick; Shawnee; Sherman; Stafford; Sumner; Wabaunsee. Louisiana (1): Grant. Maine (27): Aroostook; Cumberland; Hancock; Kennebec; Lincoln; Penobscot; Somerset. Maryland (31): Anne Arundel; Calvert; Cecil; Dorchester; Prince George’s; Queen Anne’s; St. Mary’s; Talbot. Massachusetts (73): Barnstable; Dukes; Middlesex; Nantucket; Norfolk; Suffolk. Michigan (191): Arenac; Barry; Bay; Berrien; Branch; Calhoun; Cheboygan; Huron; Ingham; Iosco; Kalamazoo; Kent; Lake; Lenawee; Livingston; Macomb; Midland; Monroe; Oakland; Oceana; Ottawa; Shiawassee; St. Joseph; Van Buren; Washtenaw; Wayne. Minnesota (13): Clay; Hennepin; Olmsted; Otter Trail; Ramsey. Missouri (182): Adair; Atchison; Bates; Boone; Buchanan; Caldwell; Callaway; Cedar; Cooper; Howard; Jackson; Pike; McDonald; Monroe; Osage; Randolph; St. Louis; Vernon. Montana (54): Carter; Custer; Powder River; Richland; Roosevelt; Rosebud; Treasure; Yellowstone. Nebraska (275): Antelope; Blaine; Boone; Box Butte; Boyd; Brown; Buffalo; Cass; Cherry; Custer; Dakota; Dixon; Douglas; Dundy; Franklin; Gage; Garfield; Grant; Greeley; Hall; Hamilton; Harlan; Holt; Jefferson; Keith; Kimball; Lancaster; Lincoln; McPherson; Merrick; Nemaha; Otoe; Red Willow; Sarpy; Saunders; Scotts Bluff; Thomas; Valley; Wayne; Wheeler. New Hampshire (17): Rockingham; Strafford. New Jersey (42): Atlantic; Bergen; Cape May; Gloucester; Middlesex; Monmouth; Morris; Ocean; Salem; Union. New York (63): Clinton; Essex; Nassau; Onandaga; Orange; Queens; Richmond; St. Lawrence; Suffolk; Westchester. North Dakota (372): Adams; Barnes; Burleigh; Cass; Grand Forks; Morton; Ransom; Richland; Slope; Stutsman; Wells; Williams. Ohio (13): Athens; Auglaize; Champaign; Defiance; Erie; Fairfield; Stark. Oklahoma (62): Caddo; Canadian; Cleveland; Kay; Latimer; Lincoln; Logan; McClain; Osage; Ottawa; Payne; Seminole; Texas; Tulsa; Wagoner; Woods. Pennsylvania (79): Allegheny; Armstrong; Beaver; Centre; Clearfield; Crawford; Dauphin; Fayette; Forest; Lycoming; Monroe; Montgomery; Northampton; Philadephia; Venango; Westmoreland; York. Rhode Island (11): Kent; Providence; Washington. South Dakota (144): Bennett; Bon Homme; Brookings; Brown; Brule; Buffalo; Clay; Cluster; Gregory; Haakon; Hughes; Hyde; Jones; Kingsbury; Marshall; Oglala; Pennington; Tripp; Yankton; Texas (14): Bexar; Cameron; Hardin; Hemphill; Hidalgo; Kleberg; McLennan; Travis; Wheeler. Vermont (44): Addison; Chittenden; Grand Isle; Windham. Virginia (15): Arlington; Caroline; Chesapeake; Chesterfield; King George; Northampton. West Virginia (5): Mason; Preston. Wisconsin (58): Clark; Columbia; Dane; Grant; Jackson; Jefferson; Kenosha; Marinette; Milwaukee; Monroe; Polk; Racine; Richland; Sauk; Walworth; Waukesha; Winnebago; Wood. Wyoming (5): Campbell; Platte.
Natural history. The larvae can be found under piles of straw and decaying hay or horse or cattle dung (Hayes 1925; Ritcher 1966). The eggs are laid between April and May, and adults emerge in August, so winter is passed as an adult under soil; it is a beneficial species that contributes to the decomposition of organic material (Hayes 1929).
description: Published as part of López-García, Margarita M. & Deloya, Cuauhtémoc, 2022, Cladistic analysis reveals polyphyly of Tomarus (Coleoptera: Scarabaeidae: Dynastinae): new classification and taxonomic revision, pp. 1-119 in Zootaxa 5211 (1) on pages 31-32, DOI: 10.11646/zootaxa.5211.1.1, http://zenodo.org/record/7345007