Liogenys rugosicollis Frey, 1969

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 : 45-47

Liogenys rugosicollis Frey, 1969

Figs. 20 ; 24 .

Liogenys rugosicollis Frey, 1969: 51 , 63; Evans 2003: 214 (checklist); Evans & Smith 2009: 182 (checklist); Krajčík 2012: 145 (checklist); Cherman et al. 2017: 5 (generic history).

Type material. Liogenys rugosicollis male holotype labeled ( USNM): [white handwritten] “ Formosa / P. P. Icomajo [Puerto Pilcomayo] / Argentinien ”, [red typeset] “TYPE”, [white, typeset and handwritten] “ Liogenys / rugosi- / collis n sp / Type / det. G Frey, 1968”, [pink handwritten] “Cartwright / Smithson”, [red, typeset and handwritten] “Type Nº / 74009 / USNM”, genitalia mounted. Paratypes (1) ( NHMB): [white handwritten] “ Formosa / P.P. Icomayo [Puerto Pilcomayo] / XII.950—Daguerre”, [orange, round, empty label], [pink typeset] “Property / USNM”, [red typeset] “ PARATYPE ”, [white, typeset and handwritten] “ Liogenys / rugosi / collis / n sp. / det. G. Frey, 1968”, genitalia mounted .

Non-type material (2). ARGENTINA. Salta: Chaco Occidental , 100 km NE Los Colorados [20 km NE Cafayate], I.1993, M. McLaqughlin & B. Bestelmeyer, 1 female ( UNSM) ; Santiago del Estero: Ciudad de Santiago del Estero, XII.1939, J. Bosq, 1 female ( MZUC) .

Diagnosis. Length: 11.0–12.0 mm; width: 5.5–6.1 mm. Body and elytra purplish brown, elongate; pronotum sometimes darker than elytra, disc roughly punctate, punctures dense ( Fig. 20A ); frons somewhat swollen and depressed medially, especially in females; clypeal emargination deep, rounded and narrow, slightly wider in males; outer sides of anterior teeth parallel; clypeal lateral margin with a sharp tooth-like projection, stronger in females, forming an acute angle between this projection and the anterior teeth, angle narrower in females; antennae with 10 antennomeres; pronotal posterior corners sharp, in obtuse angle ( Fig. 20B ); hypomere, mesepisternum, sides of metaventrite, metacoxae and ventrites beneath the elytra scaly abundantly ( Fig. 20C ); mesotibia cylindrical in cross section; in males mesotibial and metatibial inner margin strongly concave; in females only on mesotibial inner margin; two transverse carinae present posteriorly, the apical one complete; pygidium flat; subtrapezoidal, apex subrounded; propygidium and pygidial disc densely scaly throughout, except on apex, with long, erect bristles ( Fig. 20D ); in males, metatibial inner margin strongly concave, carinate on apical portion; protarsomere II elongate, mesotarsi weakly enlarged; parameres strongly concave on inner margin and convergent apically; parameral split at 2/3; apex harpoon-shaped, parameres five times longer than the apex ( Fig. 20E ); parameres in lateral view convex, not coplanar ( Fig. 20F ).

Type locality. ARGENTINA, Formosa, Puerto Pilcomayo .

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

Remarks. Liogenys rugosicollis resembles L. densata ( Fig. 4 ) in the body shape, size, and color and in the white-scaled vestiture covering the propygidium and most of the pygidium; and in males, the metatibial inner margin concave, although stronger in L. rugosicollis . It differs from L. densata (in parenthesis) in the lateral margin of clypeus with a sharp tooth-like projection, and acute angle between this projection and the anterior teeth (blunt projection, obtuse angle or angle absent); pronotal disc rugose, very coarsely punctate (finely punctate); mesotibiae and metatibiae shorter; pygidium narrower; in males the metatibial inner margin strongly concave (slightly concave); the inner margin of metatibia carinate only apically (weakly carinate along the entire margin); and mesotarsi slightly more enlarged. The parameres look quite alike except in their curvature in lateral view; the basal region slightly longer and the apex slightly shorter. Frey (1969) mentioned that there is only one primary type of Liogenys rugosicollis , reportedly deposited at the USNM, but we found this paratype at the NHMB.

Figures

FIGURE 4. Liogenys densata Frey, 1969 male views: A) dorsal, B) head and pronotum, C) lateral, D) pygidium, E) metatibia, and parameres in views: F) dorsal, and G) lateral.

FIGURE 20. Liogenys rugosicollis Frey, 1969 male views: A) dorsal, B) head and pronotum, C) lateral, D) pygidium, and parameres in views: E) dorsal, and F) lateral.

FIGURE 24. 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).