Liogenys xanthocera Harold 1869
Creators: name: Cherman, Mariana A.
name: Basílio, Daniel S.
name: Mise, Kleber M.
name: Frisch, Johannes
name: Smith, Andrew B. T.
name: Almeida, Lúcia M.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Melolonthidae
Liogenys
Liogenys xanthocera

description: Liogenys xanthocera Harold, 1869
Figs. 10, 13F, 14
Liogenys pallidicornis Blanchard, 1851: 168; Lacordaire 1855: 269 (generic redescription); Frey 1969: 42 (key).
Liogenys xanthocerus Harold 1869a: 123 (new replacement name for L. pallidicornis); Harold 1869b: 1140 (checklist, synonymy); Kolbe 1907: 5 (checklist); Bruch 1911: 200 (checklist); Dalla Torre 1913: 318 (checklist); Frey 1969: 42 (key; junior synonym of L. pallidicornis [sic]); Krajčík 2012: 145 (checklist); Cherman et al. 2017: 4 (generic history).
Liogenys xanthoceris [sic]: Frey 1969: 57 (synonym of L. pallidicornis [sic]).
Liogenys xanthocera: Blackwelder 1944: 227 (checklist); Evans 2003: 215 (checklist); Evans & Smith 2009: 183 (checklist).
Type material. Male lectotype of Liogenys pallidicornis here designated (MNHN): [white handwritten] “6051 / 34”, [light green, typeset and handwritten] “Patagonie / d’Orbigny / MUSÉUM PARIS ”, [green handwritten] “ L. pallidicornis. / Cat. Mus. / Baie de San Blas (Patagonie) / M. D’Orbigny”, [white typeset] “Southern Neotropical Scarabs / database # AS 2615155 / Liogenys xanthocera / Harold 1869 ♂ / DET:A.B.T.SMITH 2008”, [red, outlined, typeset and handwritten] “ LIOGENYS / PALLIDICORNIS / BLANCHARD, 1851 / LECTOTYPE / Des. Cherman M. A.”. Male paralectotype (MNHN) bearing the labels: [white handwritten] “6051 / 34”, [white handwritten] “1052”, [light green typeset and handwritten] “Patagonie / d’Orbigny / MUSÉUM PARIS ”, [white typeset] “Southern Neotropical Scarabs / database # AS 2615156 / Liogenys xanthocera / Harold 1869 ♂ / DET: A.B.T.SMITH 2008”, [red, outlined, typeset and handwritten] “ LIOGENYS / PALLIDICORNIS / ♂ / BLANCHARD, 1851 / PARALECTOTYPE / Des. Cherman M. A.”
Non-type material (14). ARGENTINA. Patagonia: without locality, date, and collector, 1 female (ZMHB); Buenos Aires: Puán, Felipe Solá, XII.1944, A. Martínez, 2 males (CMNC); Puán, Felipe Solá, II.1946, A. Martínez, 4 males (CMNC); Puán, Felipe Solá, A. Martínez, XII.1951, 3 males (MZSP); Puán, Felipe Solá, XI.1959, A. Martínez, 1 male (MZSP); Puán, Felipe Solá, XII.1960, A. Martínez, 2 males (MZSP); Estancia Barraú, 30 km SW Villa Iris, XI.1946, A. Martínez, 1 male (CMNC).
Diagnosis. Body elongate; body, head, and pronotum in general dark purple; elytra glabrous, shiny yellow, sides subparallel (Fig. 10A); clypeal emargination deep, narrow and rounded; clypeal lateral margin convex and produced, obtuse angle between outer side of anterior teeth and clypeal lateral projection (Fig. 10C); antenna with 10 antennomeres, yellow, club nearly twice as long as the funicle; posterior corners subangulate, obtuse; mesotibia cylindrical in cross section (Fig. 10D); pygidium slightly convex; wide, subtrapezoidal; pygidial disc glabrous or with unconspicous bristles throughout (Fig. 10E); males with inner margin of metatibia not carinate; transverse carina weakly defined; protarsomere II elongate; parameres narrowed at the midline; splitted after the midline; inner margins straight; apex spatulate (Fig. 10F).
Redescription. Length: 7.3–7.6 mm; width: 3.8–3.9 mm. Dark purple in body, head, and pronotum, elytra dull yellow. Head. distance between eyes more than three times the width of one eye; clypeal emargination deep, narrow, and rounded; outer sides of anterior teeth parallel; clypeal lateral margin convex and produced, forming a rounded projection; distance between clypeal lateral projection and anterior tooth longer than the basal width of anterior tooth, distance between clypeal lateral projection and anterior margin of eye longer than one eye; obtuse angle between outer side of anterior teeth and clypeal lateral projection; antenna with 10 antennomeres, club nearly twice as long as and lighter in color than funicle. Thorax: anterior margin of pronotum straight; pronotal disc with punctures coarse, shallow and sparse; posterior corners subangulate, obtuse; hypomere, mesepisternum, sides of metaventrite, and metacoxae with sparse, long bristles; distance between mesocoxae and metacoxae less than twice the metacoxa width; scutellum ogival to rounded, punctate throughout. Elytra: shiny, glabrous; elytral suture and elytron unicolored, elevated; two inner pair of elytral ridges more defined than the other two ridges. Legs: procoxa with bristles; protibia with three teeth, middle and apical teeth equal in size, all three teeth equally spaced; mesotibia cylindrical in cross section, mesotibia dorsally smooth with two transverse carinae, the apical carina complete; inner margin of male metatibia not carinate; surface finely sculptured; metatibia with one transverse carina present posteriorly and weakly defined dorsally; metatibial apical spurs of equal lengths, equal to the diameter of the tibial apex; metatarsomere I shorter than metatarsomere II; in males protarsomeres and mesotarsomeres I–IV enlarged, protarsomere II long; protarsomeres and mesotarsomeres equally enlarged; claw bifid, symmetrical, superior tooth of claw almost three times longer and narrower than the inferior tooth; distance between teeth longer than the length of inferior tooth. Abdomen: ventrites with sparse bristles; propygidium glabrous; pygidium slightly convex; subtrapezoidal; pygidial width not exceeding distance between spiracles of propygidium; pygidial disc with inconspicuous bristles, finely and very sparsely punctate; pygidial apex subquadrate. Parameres: basal region wider than both sections of the parameres at its maximum width, parameres narrowed at the midline; parameral split after the midline; inner margins straight; apex spatulate, angulate; parameres straight or slightly convex in lateral view (Fig. 10G).
Type locality. ARGENTINA. Baie de San-Blas (Patagonie) [Buenos Aires, Bahia de San Blas, 40°33’8’’S 62°14’4’’W].
Geographical distribution. ARGENTINA (Buenos Aires).
Remarks. Liogenys xanthocera is easily recognized among the other Liogenys by its characteristic dark body, pronotum, and scutellum contrasting with the elytra dull yellow; and by the club nearly twice the length of the funicle. The teeth of the galea are reduced (Fig. 13F), as in L. sinuaticeps Moser (Cherman et al. 2016, 2017). The specimen from 30 km SW Villa Iris, Puán, Buenos Aires [38°21’15.8’’S 63°20’37.4’’W] shows variations in the body color, entirely dull yellow, the lateral margin of clypeus more produced, and the parameres strongly convex. As we have only this specimen with these single features, we presume that those differences are only intraspecific variations, needing further material to determine if it is a different species.
The lectotype (Fig. 10B) was collected Bahía San Blas, Buenos Aires, Argentina during the period from 14 January–18 February 1829 by A.D. d’Orbigny. The region around the nearby village of “Patagones” (now known as Viedma, Río Negro) was collectively called Patagonia (Patagonie) at the time (see Smith 2017). The “1052” code number on the paralectotype corresponds with an entry in the original field notes of d’Orbigny (available from the MNHN library). D’Orbigny made these observations (text transcribed and translated): “we found this species in great numbers in January and February. They emerged from the earth every day, in numbers. We never saw them during the day, when they were hiding underground”.
Blanchard (1851) described two species in Liogenys with the epithet “ pallidicornis ”, the first one in page 167 and the other in the next page. Harold (1869) corrected this homonym by replacing the name of the second one described, as L. xanthocera. The first one described, Liogenys pallidicornis Blanchard, 1851 is a valid name (Cherman et al. 2017).
description: Published as part of Cherman, Mariana A., Basílio, Daniel S., Mise, Kleber M., Frisch, Johannes, Smith, Andrew B. T. & Almeida, Lúcia M., 2020, Liogenys Guérin-Méneville, 1831 (Coleoptera: Scarabaeidae: Melolonthinae) from the southern South American Transition Zone and boundaries: taxonomic overview with four new species, pp. 46-84 in Zootaxa 4896 (1) on pages 74-82, DOI: 10.11646/zootaxa.4896.1.2, http://zenodo.org/record/4359172