Liogenys acutidens Moser, 1919

Cherman, Mariana Alejandra, Mise, Kleber Makoto, Moron †, Miguel Angel, Vaz-de-Mello, Fernando Z. & Almeida, Lucia Massutti de, 2017, A taxonomic revision of Liogenys occurring in Brazil with an interactive key and remarks on New World Diplotaxini (Coleoptera, Melolonthidae), ZooKeys 699, pp. 1-120 : 11-12

Liogenys acutidens Moser, 1919 Figs 56, 93

Liogenys acutidens Moser, 1919: 14 (orig. desc.); Blackwelder 1944: 228 (check.); Frey 1969: 47 (key); Evans 2003: 207 (check.); Evans and Smith 2005: 171 (check.); Evans and Smith 2009: 175 (check.)

Type material.

Liogenys acutidens male holotype (ZMHB): [white printed] “Brasília / [handwritten] Cuyaba", [white handwritten] " Liogenys / acutidens /Mos./Typen", [light red printed] “Typus”, " Liogenys / acutidens /Mos", [red printed] "HOLOTYPUS/ Liogenys / acutidens Moser, 1919/ labelled by MNHUB 2011". Genitalia mounted.

Non-type material.

BRAZIL. MT: Cuiabá, without date and collector, 1 ex. (ZMHB); MG: Unaí (Faz. Bolívia), 22-24/X/1964, Exp. Dep. Zool. col., 1 ex. (MZSP).

Diagnosis.

Body yellowish brown; elongate; elytra testaceous, lighter in color than pronotum; clypeal emargination wide and rounded; outer sides of anterior teeth parallel; lateral margin convex and slightly produced; distance between clypeal lateral projection and anterior tooth equal to basal width of anterior tooth, distance between clypeal lateral projection and anterior margin of eye shorter than one eye, obtuse angle between outer side of anterior teeth and clypeal lateral projection; mesotibia quadrate in cross section; pygidium convex, bristled throughout, reticulated punctures; in males, inner margins of parameres convergent; subapical projections on outer margins; parameres strongly narrowed between subapical projections and apex; apex spatula-like, sharp edges, curved outwards, not reaching the level of the parameres outer margin (Fig. 56F).

Redescription.

Length: 8.0-9.0 mm; width 3.7-4.2 mm. Yellowish to testaceous. Head: distance between eyes nearly twice the width of one eye; frons equal in length to clypeus; clypeus bristled anteriorly, emargination shallow, wide and rounded; outer sides of anterior teeth parallel; outer margin of anterior teeth shorter than the eye; lateral margin convex and slightly produced; distance between clypeal lateral projection and anterior tooth equal to the basal width of anterior tooth, distance between clypeal lateral projection and anterior margin of eye shorter than one eye, obtuse angle between outer side of anterior teeth and clypeal lateral projection; canthus not exceeding the outer margin of the eye; distal maxillary palpomere, maximum width less than twice width of apex; fovea deep, extending up to the transverse midline of the palpomere; labium transversely carinated, as wide as it is long; antenna 10-articulated, lamellae lighter in color than flagellum, and equal in length. Thorax: anterior margin of pronotum straight; maximum length of pronotum exceeding the length of tarsomeres I, II and III together; disc glabrous, punctures sparse and fine; pronotal posterior corners sub-angled, obtuse; proepisternum with short bristles; mesepisternum scaly, as are the sides of metasternum, also with few long bristles on the anterior margin; distance between meso- and metacoxae up to twice the metacoxa length; scutellum triangular, smooth or basally punctured at the sides. Elytra: shiny, glabrous, uniform yellowish to testaceous, barely lighter in color than the pronotum; elytra more than three times longer than the pronotum; elytral suture slightly darker than elytron and not elevated; all four elytral ridges barely noticeable. Legs: procoxa, sparse scales on infra-carinal surface, punctures visible at 12 × magnification; three protibial teeth, middle and apical equal in size, distance between basal and middle teeth slightly longer than between middle and apical; protibial inner apical spur present; mesofemural disc setose, mesotibia quadrate in cross section, disc finely sculptured, two mesotibial transverse carinae, the apical one incomplete; basal apophysis of metacoxa produced beyond the outer margin of trochanter; inner margin of metatibia carinated towards apex, apical inner surface setose; metatibial disc finely sculptured; a metatibial transverse carina present posteriorly and posterior discontinuous longitudinal carina; basal metatarsomere and tarsomere II equal in size, protarsomere II short and wide; pro- and mesotarsomeres I to IV enlarged, protarsomeres slightly wider than the mesotarsomeres, less than twice as wide as the metatarsi; claw bifid, symmetrical, superior tooth narrower than the inferior and equal in length; distance between teeth shorter than the inferior tooth. Abdomen: ventrites bristled and on sides also scaly; propygidium visible, bristled and scaly; pygidium convex, sub-trapezoidal, wide; pygidial width not exceeding distance between spiracles of propygidium; pygidial disc bristled throughout, reticulated punctures; pygidial apex sub-quadrate. Parameres: width of basal region equal to the parameres together at its maximum width; parameral split at 2/3; inner margins of parameres convergent; outer margins with subapical projections; strongly narrowed between subapical projections and apex; apex spatula-like, edges sharp, curved outwards, not reaching the level of the parameral outer margin (Fig. 56F). In lateral view parameres concave; apex slightly curved downwards (Fig. 56G).

Type-locality.

BRAZIL, Cuiabá, Mato Grosso.

Geographical distribution.

BRAZIL (MT, MG).

Remarks.

Liogenys acutidens resembles L. bidenticeps (Fig. 58) in size and color, however, L. acutidens elytra are somewhat lighter in color; the clypeus is bristled anteriorly; the clypeal teeth are sharper and slightly longer-, the lateral margin of clypeus is slightly projected; the meso- and metatibia are quadrate in cross section with discs both finely sculptured; the mesotibial apical carina is incomplete; the pygidium is convex with reticulated punctures on disc alike L. santaecrucis (Fig. 71) and protarsomeres wider. Female of L. acutidens remains unknown.