Liogenys truncata Cherman, 2021

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 : 48-50

Liogenys truncata Cherman , new species

Figs. 21 ; 27 .

http://zoobank.org/ D09F18D9-F0DA-429B-A7DF-C70B253EAC08

Type material. Holotype labeled ( CMNC): [white typeset] “ ARGENTINA, Prov. Salta / 3 km W Cabra Corral Dam / 30.I.1982 / H & A Howden”, [red, typeset and handwritten] “ LIOGENYS TRUNCATA / HOLOTYPE / Cherman M. A.”, genitalia mounted . Paratypes (3), one male and two females ( CNCI): “ ARGENTINA / Stgo. del Estero / Choya [strikethrough] XII-1958 ”, [yellow, typeset and handwritten] “ LIOGENYS TRUNCATA / PARATYPE / Cherman M. A.” .

Holotype deposited at CMNC. Paratypes deposited at CNCI.

Diagnosis. Body elongate; yellowish brown, pronotum and elytra unicolored, elytra uniformly with bristles ( Fig. 21A ); clypeal emargination very wide and shallow, almost truncate ( Fig. 21B ); procoxal and mesotibial surface smooth, metatibial surface coarsely punctate; apical inner margin of metatibia with sparse, long bristles ( Fig. 21C ); pygidium with bristles and as wide as it is long ( Fig. 21D ); in males protarsomeres I to IV weakly enlarge; parameres narrowed subapically; apex flap shaped, outer margin angulate inferiorly, angle in a plane below the apex ( Fig. 21E ).

Holotype. Male. Length: 7.7 mm; width: 3.5 mm. Yellowish brown, head and margins of pronotum darker. Head: distance between eyes almost three times the width of one eye; frons with bristles; anterior margin of clypeus apparently truncate; clypeal emargination very shallow, almost straight, as wide as the distance between eyes; lateral margin of clypeus straight, slightly convex near the canthus; distal maxillary palpomere, maximum width less than twice the apical width; fovea shallow, extending up to the transverse midline; antenna with 10 antennomeres, club equal in color and longer than the funicle. Thorax: anterior margin of pronotum slightly produced medially; pronotum anteriorly narrowed forming a depressed ring; pronotal disc glabrous, punctures coarse and very sparse; posterior corners subangulate, angle obtuse; hypomere with long bristles, mesepisternum and sides of metaventrite with thick and fine bristles; distance between mesocoxae and metacoxae slightly longer than the metacoxa; scutellum ogival, finely punctate throughout. Elytra: shiny, uniformly with bristles, bristles longer at the margins of the elytra, unicolored with the pronotum; elytral suture unicolored with the elytron and not elevated; all elytral ridges weakly defined. Legs: procoxa with bristles, smooth; three protibial teeth, the apical the longest; the three teeth equally spaced; mesofemural surface almost glabrous, setae on margins; mesotibia cylindrical in cross section, surface smooth; two transverse carinae, the apical carina incomplete; metacoxa with sparse, thick bristles; basal apophysis of metacoxa produced; metatibia carinate along the inner margin towards the apex, apical inner surface sparsely setose, bristles long; metatibial surface coarsely punctate; two metatibial transverse carinae present posteriorly; metatibial apical spurs of different lengths; the larger equal in length to the diameter of the tibial apex; protarsomeres I to IV enlarged; metatarsomere I slightly shorter than metatarsomere II; claw bifid, symmetrical, superior tooth of a claw longer and equal in width to the inferior, distance between teeth shorter than the inferior tooth. Abdomen: ventrites and propygidium with bristles; pygidium slightly convex, subquadrate, as wide as it is long; pygidial width not exceeding distance between spiracles of propygidium; pygidial disc with bristles throughout; pygidial apex quadrate. Parameres: basal region slightly wider than both sections of the parameres at the transverse midline, parameral split at 2/3; inner margins convergent at the apex, narrowed subapically; apex flap shaped, outer margin angulate inferiorly, angle in a plane below the apex; parameres in lateral view slightly convex, coplanar ( Fig. 21F ).

Variation. Male paratype: length: 8.2 mm; width: 4.2 mm. Equal to the holotype except in the pronotal punctures finer and sparser and pygidial apex rounder. Female paratypes: length: 7.8–8.0 mm; width: 3.6–3.9 mm. Equal to the holotype except in the abdomen with bristles less abundant and more sparse.

Etymology. Adjective in the nominative singular. From Latin truncâtus, perfect passive participle of truncô (“maim, reduce to a trunk”), meaning that a structure is ending abruptly as if cut across at the base or tip. This term is referring to the clypeus truncate in Liogenys truncata .

Type locality. ARGENTINA, Salta, 3 km W Cabra Corral [25°16’37.6’’S 65°23’20.4’’W] .

Geographical distribution. ARGENTINA (Salta, Santiago del Estero) .

Remarks. Liogenys truncata resembles L. rufoflava Moser, 1918 in the body color and the bristle pattern of pronotum, elytra, and pygidium. Liogenys truncata differs from L. rufoflava (in parenthesis) mainly in the body size smaller, the clypeus almost truncate, not forming noticeable anterior teeth (two distinct teeth and a wide emargination between them), lateral margin of clypeus straight (convex, with a rounded projection); the pronotal punctures denser at the disc; the elytra entirely shiny (pruinose at the margins); the pygidium as long as it is wide (longer than it is wide); and in males the protarsi and mesotarsi slightly enlarged (distinctly enlarged); and the parameres longer, with apex spatulate (lanceolate).

Figures

FIGURE 21. Liogenys truncata Cherman, new species, male holotype views: A) dorsal, B) head and pronotum, C) lateral, D) pygidium, and parameres in views: E) dorsal, and F) lateral.

FIGURE 27. Geographical distribution of the Liogenys new species. Shaped points: new species; colors: Neotropical provinces (Morrone 2014) and Monte province from the South American Transition Zone (Roig-Juñent et al. 2018).