Liogenys opacicollis Fairmaire, 1892

Cherman, Mariana Alejandra, Basílio, Daniel Silva, Mise, Kleber Makoto, Frisch, Johannes & Almeida, Lúcia Massutti De, 2021, Liogenys Guérin-Méneville, 1831 (Coleoptera: Scarabaeidae: Melolonthinae Diplotaxini) from the Chacoan Province and its boundaries: taxonomic overview with four new species, Zootaxa 4938 (1), pp. 1-59 : 36-39

Liogenys opacicollis Fairmaire, 1892

Figs. 16 ; 23 .

Liogenys opacicollis Fairmaire, 1892: 243 ; Dalla Torre 1913: 318 (checklist); Moser 1921: 140 ( L. densicollis original description); Blackwelder 1944: 227 (checklist); Frey 1969: 39, 53 (key, systematics); Krajčík 2012: 145 (checklist); Evans 2003: 212 (checklist); Evans & Smith 2009: 180 (checklist).

Liogenys densicollis Moser, 1921: 140 ; Blackwelder 1944: 227 (checklist); Frey 1969: 38–39 (key); Krajčík 2012: 144 (checklist); Evans 2003: 208 (checklist); Evans & smith 2009: 176 (checklist). New synonym.

Type material. Liogenys opacicollis female lectotype here designated ( MNHN): [white typeset] “MUSÉUM PARIS / 1906 / Coll. Léon FAIRMAIRE”, [white handwritten] “ Liogenys / opacicollis / Fairm / Rioja / Planta ”, [red, outlined black, handwritten] “ LIOGENYS / OPACICOLLIS / FAIRMAIRE ♀ / [typeset] LECTOTYPE / des. M. A. Cherman ” .

Liogenys densicollis male lectotype here desigated ( ZMHB): [white, outlined black, typeset] “ Argentinien / Santiago del Estero ”, [white handwritten] “ Liogenys / densicollis / Mos / Typen ♂”, [light red typeset] “Typus”, [white typeset] “ Liogenys / densicollis / Mos.”, [red typeset] “ SYNTYPUS / Liogenys / denticulata Moser, 1918 [misspelled] / labelled by MNHUB 2012”, [white, outlined red, typeset] “ LECTOTYPE / Liogenys densicollis / Moser, 1921 / Cherman M. A. 2013”, genitalia mounted. Paralectotypes (10) ( ZMHB): one male with the labels [white typeset] “ Argentinien / Santiago del Estero ”, [white handwritten] “ Liogenys / densicollis / Mos / Typen ♂”, [light red typeset] “Typus”, [white typeset] “ Liogenys / densicollis / Mos.”, [red typeset] “ SYNTYPUS / Liogenys / densicollis Moser, 1921 / labelled by MNHUB 2012”, [white, outlined red, typeset] “ PARALECTOTYPE / Liogenys densicollis / Moser, 1921 / Cherman M. A.” Nine female specimens with the same labels, but instead of: [white handwritten] “ Liogenys / densicollis / Mos / Typen ♂”, the label is: [white handwritten] “ Liogenys / densicollis / Mos / Typen ♀ ”.

Non-type material (81). BOLIVIA. Santa Cruz: Caballero, ~ 9 km SW Comarapa, XII.2008, 1694 m, 17º58.926’S 64º34.365’W, W.D. Edmonds & T. Vidaurre, thorn forest, human feces, 2 males ( CEMT); Samaipata. Bolivia Andina, 25.XI.1959, Zischka, 1 female ( NHMB). ARGENTINA. Salta: Las Tablillas, without date, G.L. Harrington, 1 female ( CASC); Viñaco, 15 km S El Carril, 12.II.1982, H. & A. Howden, 2 females ( CMNC); 1 km N Cafayate, 26º03’52’’S 65º56’19’’W; 24.XI.2006, F. Ocampo, E. Ruiz, G. San Blas, & G. Salazar, ultraviolet & mercury vapor light trap, 8 males and 2 females ( IADIZA); El Naranjo, Rosario de la Frontera, I.1944, Duret-Martínez, 1 male ( CMNC); Departamento Anta. Las Lajitas, XII.1982, A. Martínez, 1 male ( CMNC); Olleros [Chañar Muyo], II.1958, Daguerre, 2 males and 2 females ( USNM); Rivadavia, XII.1950, Daguerre, 3 females ( USNM); [without month].1905, Steinbach, 1 male ( ZMHB); Formosa: without locality and date, Mallo, 1 female ( MLPA); Pilcomayo, XII.1950, Daguerre, 2 males and 2 females ( USNM); Chaco: Gancedo, 8.XII.1939, Biraben & Bezzi, 1 female ( MLPA); Santiago del Estero: Río Salado, without date, E.R. Wagner, 2 females ( CMNC); La Palisa del Bracho, 25 km NNW d’Icaño, Laguna Mamaita, [without month].1904, E.R. Wagner, 1 male ( CASC); banks of Río Salado, D’Icaño environs, Mistol Paso, [without month].1909, E.R. Wagner, 3 females ( CASC); El Pinto, XI.1960, without collector, 1 male and 2 females ( NHMB), 1 female ( CNCI); Catamarca: without locality, C. Bruch, 1.II.1907, 1 male ( MLPA); without locality, C. Bruch, 4.II.1910, 1 female ( MLPA); without locality, date, and collector, 1 male and 1 female ( MLPA); Andalgala km 1508 [5 km W, along Ruta Nacional 9, 1000 m, in Larrea cuneifolia bushes (Zigophyllaceae) ( Schultz 1981)], 12.XI.1973, J.C. Schultz, 2 males ( CASC); La Rioja: Sañogasta (Camping), 7.XII.2013, Arriagada & Castillo, light trap, 2 males and 1 female ( CMVD); 6 km E Chepes, without date and collector, 1 female ( CMNC); Santa Fé: Carcarañá, without date and collector, 1 male ( USNM); Córdoba: without locality and date, Davis, 1 male; without locality, date, and collector, 1 female ( AMNH); Mediolanza, 24.XII.2004, E. Ruiz, 1 male ( IADIZA); San Vicente, without date, Frenzel, 2 males and 1 female ( ZMHB); Potrero de Garay, II.1948, A. Martínez, 2 males ( CMNC); Diquecito, without date, Frenzel, 1 female ( NHMB); San Luis: Quines, 24.XI.1995, S. Roig & G. Flores, 1 male ( IADIZA); El Molle, 7.II.2017, 33º02’22.8’’S 66º30’47.6’’W, 622 m, light, G. Arriagada, 1 male and 1 female ( CEMT); Sa Jerónimo, I.1979, Williner, 2 females ( CMNC); Mendoza: without locality and date, C. Bruch, 1 female ( MLPA); Buenos Aires: Felipe Solá. Puán, 17.II.1944, A. Martínez, 2 males ( CMNC); Neuquén: San Martín de los Andes, II.1956, A. Martínez, 1 male ( MZSP); Río Negro: Gral. Conesa, I.1931, without collector, 1 male ( CMNC); Coronel Gómez, XI.1945, J. Grosso, 1 male ( CMNC); Departament Gral Roca, Catriel, 4.I.2005, F.C. Ocampo, 2 females ( CMNC); San Antonio Oeste, I.1976, M. Zunino, 1 male ( CMNC); Valcheta, XII.1992, at lights, without collector, 4 males, 1 female ( CMNC).

Diagnosis. Dark purplish brown. Head and pronotum densely punctate, cribrose-like surface; elytra uniformly with bristles, vertex scaly; clypeal emargination forming a semicircle, clypeal lateral margins convex; pronotal posterior corners in obtuse angle ( Fig. 16 A–B); in males inner margin of male metatibia carinate towards the apex, subapically slightly concave ( Fig. 16F ); apical inner margin with tooth-like projection contiguous to the smaller spur ( Fig. 16H ); metatibial transverse carina complete; mesotarsomere I ventrally produced, proximal margin sometimes prickled ( Fig. 16 G–H); abdominal ventrites, propygidium, and pygidium setose, with bristles and scales throughout; pygidial apex subquadrate to rounded ( Fig. 16J ); parameres with apex spatulate shaped in a single plane, rounded, or spiked laterally, apical length from 1/3 to 1/4 the length of the parameres after the basal split ( Fig. 16K ).

Redescription. Length: 9.8–12.1 mm; width: 4.4–6.0 mm. Dark purplish brown. Head. Densely punctate, cribrose-like surface; vertex scaly; distance between eyes twice the width of one eye in males, three times in females; vertex scaly, sometimes with bristles on frontoclypeal surface and inner margins of eye; clypeal emargination deep, wide and rounded, forming a semicircle; outer sides of anterior teeth follow the lateral margin of clypeus, clypeal lateral margin convex; distal maxillary palpomere, maximum width more than twice the apical width; fovea deep, extending past the transverse midline of the palpomere; antenna with 10 antennomeres, club lighter in color and longer than funicle. Thorax: anterior margin of pronotum slightly produced medially; sides of pronotum with sparse, long bristles, pronotal disc coarsely punctate, punctures dense, disposed tightly; pronotal posterior corners in obtuse angle; hypomere with long bristles and scaly; mesepisternum, sides of metaventrite and metacoxae scaly abundantly, scales dense; distance between mesocoxae and metacoxae less than twice longer than the metacoxa; scutellum rounded, coarsely punctate throughout. Elytra: shiny, erect bristles disposed uniformly; elytral suture and elytron unicolored, weakly elevated; all four elytral ridges weakly defined. Legs: procoxa scaly and punctate; three protibial teeth, middle and apical equal in size, distance between basal and middle teeth equal to or slightly longer than between middle and apical; mesofemural surface setose; mesotibia subquadrate to cylindrical in cross section, mesotibial surface coarsely sculptured; apical mesotibial transverse carina strong and complete, the basal one weakly defined or absent; metafemur setose throughout; inner margin of male metatibia carinate towards the apex, slightly concave subapically ( Fig. 16F ); apex with tooth-like projection below the smaller spur ( Fig. 16I ); metatibial transverse carina complete in males and females; surface coarsely sculptured; metatibial apical spurs of different lengths, the larger as long as the diameter of the tibial apex; metatarsomere I shorter than metatarsomere II and wider; in males protarsomeres I to IV enlarged; protarsomere II elongate, piriform; mesotarsomeres not enlarged; mesotarsomere I in males ventrally produced, proximal margin sometimes prickled ( Fig. 16 G–H); claw bifid, symmetrical, superior tooth of a claw longer and slightly narrower than the inferior; distance between teeth equal to the length of the inferior tooth. Abdomen: band of abundant thick scales disposed tightly beneath the outer margin of elytra; disc of ventrites setose, with bristles and scales throughout in males, sides scaly and with bristles at the midline in females, as well as the propygidium; pygidium flat or slightly convex; subquadrate; pygidial width not exceeding distance between spiracles of propygidium; pygidial disc setose, erect bristles throughout and scales mainly from the base up to the midline; pygidial apex subquadrate to rounded. Parameres: basal region equal in width to both sections of the parameres at its maximum width, parameral split at 2/3; inner margins straight or sometimes convex; apex spatulate-like in a single plane, rounded or angulate laterally, apical length from 1/3 to 1/4 times the length of the parameres after the basal split; parameres in lateral view straight, not coplanar ( Fig. 16L ).

Type locality. Liogenys opacicollis : ARGENTINA, La Rioja ; L. densicollis : ARGENTINA, Santiago del Estero .

Geographical distribution. BOLIVIA (Santa Cruz); ARGENTINA (Salta, Formosa, Santiago del Estero , Chaco, Catamarca, La Rioja, Santa Fé, Córdoba, San Luis, Mendoza, Buenos Aires, Neuquén, Río Negro).

Remarks. Frey (1969) mentioned that L. opacicollis and L. densicollis could be the same species; but did not propose the synonymy because he could not find the type of L. opacicollis . After examining the type material of both species we determined that the male lectotype of L. densicollis ( Fig. 16B, D ) matches with the female lectotype of L. opacicollis ( Fig. 16A, C ), and this is identical to the female paralectotype of L. densicollis . Here, we propose the synonymy of both names.

There is a population from Catamarca ( Argentina) that has some noteable differences from the type specimens, as the clypeal teeth more rounded, pronotal punctures finer and in males the apex of parameres shorter and more angulate. We conclude that these are intraspecific variations, although we recommend further studies on our concept of this species. The specimens from Catamarca were collected on “Jarilla”, Larrea cuneifolia Cavanilles, 1800 (Zygophyllaceae) , an evergreen xerophytic shrub common in western South America ( Mercado et al. 2018).

The confirmed association of L. opacicollis with xerophytic vegetation, typical from Arid Chaco and Monte ecoregions, is shared with L. cribricollis , with the latter more associated with Schinus shrubs.

Figures

FIGURE 16. Liogenys opacicollis Fairmaire, 1892 female lectotype views: A) dorsal, C) labels; L. densicollis Moser, 1921 male lectotype views: B) dorsal, D) labels, E) lateral, F) mesotibia and metatibia, white arrow indicates shape of metatibial margin, G) mesotarsomere I, arrow indicates modified inner margin and H) its variation, I) apex of metatibia, white arrow indicates projection below the spurs, J) pygidium, and parameres in views: K) dorsal and L) lateral.

FIGURE 23. Geographical distribution of four known Liogenys species occurring in the Chacoan province and its boundaries. Shaped points: previously known species; colors: Neotropical provinces (Morrone 2014) and Monte province from the South American Transition Zone (Roig-Juñent et al. 2018).