Liogenys densata Frey, 1969

Figs. 4; 24.

Liogenys densatus Frey, 1969: 39, 52.

Liogenys densata: Evans 2003: 207 (checklist); Evans & Smith 2009: 176 (checklist); Krajčík 2012: 144 (checklist); Cherman et al. 2016: 764, 766 (systematics); Cherman et al. 2017: 10, 16 (redescription).

Type material. Liogenys densatus female holotype (NHMB): [white typeset] “ ARGENTINE: / La Rioja Prov., / Patquia, / K.J. Hayward. / B. M. 1933-333”, [red typeset] “TYPE”, [white, typeset and handwritten] “ Liogenys / densatus / nov. sp. / Type / det. G. Frey, 1968”. Paratypes (2): One male paratype (NHMB): [white, outlined black, typeset] “Argentina / Pcia. San Juan / Marayes 13.XII.1964 / A. Martinez leg.”, [red handwritten] “ P. Type ”, [white handwritten] “ Liogenys ♂opacicollis / Fairm / [typeset] det. G. Frey 1967 / 68”. One female paratype (USNM): [white handwritten] “ La Rioja / Capital / XI. 958 P. Kohla”, [red, typeset and handwritten] “P. TYPE”, [light red, typeset and handwritten] “Type No / 74008 / USNM”, [white, typeset and handwritten] “ Liogenys / densatus / n. sp. / P.type / det. G.Frey, 1968”, [pink typeset] “Property / USNM”.

Non-type material (12). ARGENTINA. Santiago del Estero: Ciudad de Santiago del Estero, XII.1939, J. Bosq, 1 female (MZUC); Mendoza: Lavalle, Telteca, 16.XII.2005, Marvaldi, Ruiz, Flores, mercury vapor light, 1 male and 1 female (IADIZA); 32º22’59.58’’S 68º03’14.16’’W, 5.II. 2008, 548 m, Ocampo, Ruiz, & San Blas, mercury vapor light, 2 males and 2 females (IADIZA); Reserva de Telteca, 8–10.XII.2002, V.M. Diéguez, 3 females (CMVD), Ñancuñan, [34.0494ºS, 67.9668ºW], XII.1975, S. Roig, 1 male (IADIZA); San Rafael, 2 km Pedro Vargas, 31.I.1979, S. Roig, 1 female (IADIZA).

Diagnosis. Length: 11.9–13.9 mm; width: 6.0– 6.9 mm. Body and elytra purplish brown, elongate, shiny, sides parallel; pronotum slightly darker than elytra; elytra glabrous (Fig. 4A); head and pronotum densely punctate; clypeal emargination deep, rounded and narrow; outer sides of anterior teeth subparallel; clypeal lateral margin strongly convex, with a weak, blunt projection, obtuse angle between this projection and the anterior teeth; antennae with 10 antennomeres; pronotal posterior corners sharp, in obtuse angle (Fig. 4B); hypomere scaly abundantly and with long bristles, mesepisternum, sides of metaventrite, metacoxae and sides of ventrites scaly abundantly; protibial teeth equally spaced; mesotibia cylindrical in cross section, in males longer; two transverse carinae posteriorly, the apical complete (Fig. 4C, E); pygidium flat; subquadrate; pygidial disc with abundant scales throughout except on the apex, with long bristles (Fig. 4D); in males, inner margin of metatibia weakly carinate, protarsi weakly enlarged, mesotarsi not enlarged; basal region of parameres punctate, slightly narrower than both sections of the parameres at the transverse midline, parameral split at 1/3; inner margins strongly concave on inner margin, opened; apex harpoon shaped, angles very sharp, parameres four times longer than apex (Fig. 4F); parameres in lateral view slightly convex, coplanar (Fig. 4G).

Type locality. ARGENTINA, La Rioja, Patquía [30°02’36.8’’S 66°53’02.4’’W].

Geographical distribution. ARGENTINA (Santiago del Estero, La Rioja, San Juan, Mendoza).

Remarks. Liogenys densata is similar to L. opacicollis (Fig. 16) in the body color; the shape of the clypeus and in the head and pronotum densely punctate. This species differs from L. opacicollis (in parenthesis) mainly in the punctures of pronotum finer (cribrose-like); the pronotum and elytra glabrous (with bristles), shinier; in the shape of tibiae; and in the parameres. Liogenys densata also resembles L. obscura Blanchard, 1851 (Fig. 15), differing mainly in the shape of the pygidium, as wide as it is long and covered by scales abundantly (wider than it is long and also setose, but the integument is seen below the bristles). Frey (1969) indicated that the male paratype from San Juan is at MZSP, but we found it at NHMB instead. Frey (1969) mentioned that he received a male specimen under the name of L. opacicollis from The Natural History Museum (London, United Kingdom). The specimen remained at the NHMB and currently bears only one determination label written by Frey, so we suppose he removed the label of The Natural History Museum from the specimen. In the key, Frey (1969) illustrated the parameres of L. densata under the name of L. opacicollis.