Liogenys diodon Burmeister, 1855

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 : 27-29

Liogenys diodon Burmeister, 1855 Figs 62, 89

Liogenys diodon Burmeister, 1855: 15 (orig. desc.); Blackwelder 1944: 228 (check.); Frey 1969: 47 (key); Evans 2003: 208 (check.); Evans and Smith 2005: 178 (check.); Evans and Smith 2009: 177 (check.)

Liogenys caviceps Frey, 1964: 692 (orig. desc.); Frey 1969: 44 (syn.).

Type material.

Liogenys diodon female holotype (MLUH): [green handwritten] " diodon Br./Bras. Mlly", [white handwritten] " Liogenys / diodon Brm/ Type F/[printed] det. G. Frey 1967/68", [white printed] "Prof. Hüsing/Halle”. Genitalia mounted.

Liogenys caviceps male holotype (NHMB): [white printed] "Mossoro/R.G.N. Bras. /X.1951", [red printed] "TYPE [handwritten] M", [white handwritten] "Type M/ [printed] Liogenys [handwritten] diodon Burm [printed] det. G. Frey 1968". Genitalia mounted. Paratypes (4): L. caviceps female paratype (NMHB): [white printed] "Mossoro/R.G.N. Bras./X.1951", [white printed] “f”, [white printed] " Liogenys [handwritten] diodon /F/Burm [printed] det. G. Frey 1968". L. caviceps female paratype (AMNH): [white printed] "Mossoro/R.G.N. Bras./X.1951", [white printed] “f”, [white printed] "CUM TYPO/COMPARATUM", [white printed] " Liogenys [handwritten] diodon /F/Burm [printed] det. G. Frey 1968", [white handwritten] "Plectris [wrong genus] caviceps Frey/= " diodon Burm." In NHMB another two female paratypes remain not studied.

Non-type material.

BRAZIL: PI: Piracuruca. Parque Nacional Sete cidades, Poço da bananeira, 4°5'56"S, 41°40'34"W, 11/II/2013,158 m, D. M. Takiya and APM Santos cols., "Pennsylvania trap", 1 ex. (CEMT); CE: without date and collector, 1 ex. (MNRJ); RN: Jardim de Angicos, I/1952, A. Alvarenga col. 2 ex. (DZUP); Mossoró, X/1951, without collector, 2 ex. (NHMB); 1 ex. (AMNH); PE: Buique. Parque Nacional Catimbau, 8°37'S, 37°9'W, 25/I/2005, M. Schessl col. 2 ex. (CEMT); SE: Caninde do São Francisco, Fazenda Poço verde, 4/III/2000, L. Iannuzzi col. 1 ex.; (CEMT); Fazenda Miramar, 8/III/2001, L. Iannuzzi, 1 ex. (CEMT); GO: Cabeceiras, 24-27/X/1964, Exp.Dep. Zool. col. (MZSP).

Diagnosis.

Body reddish brown; elongate, sides almost parallel in males; elytra brownish, pronotum slightly darker; clypeal emargination deep, rounded and narrow; outer sides of anterior teeth concave, follow the lateral margin of clypeus; meso- and metatibia quadrate or sub-quadrate in cross section, metafemur with thick and erect bristles on posterior margin; pygidial width exceeding distance between spiracles of propygidium; bristles only at apex. In males, apex of pygidium more rounded; parameres; more than five times the length of their apex; apex harpoon-like with lateral angle projecting straight downward (Fig. 62F).

Redescription.

Length: 8.8-9.5 mm; width: 4.7-5.5 mm. Reddish brown. Head: distance between eyes nearly twice the width of one eye; frons shorter than clypeus; clypeal emargination narrow, deep and rounded; outer sides of anterior teeth follow the lateral margin of clypeus; lateral margin concave; canthus not exceeding the outer margin of the eye; distal maxillary palpomere, maximum width almost equal to the apex; fovea shallow, extending to or past the transverse midline of the palpomere; labium transversely carinated, as wide as it is long; antenna 10-articulated, lamellae lighter in color than flagellum, in males lamellae and flagellum equal in length. Thorax: anterior margin of pronotum slightly produced medially, flanged throughout; maximum length of pronotum exceeding the length of tarsomeres I, II and III together; disc glabrous, punctures sparse; pronotal posterior corners rounded (Fig. 62D); proepisternum with long bristles; mesepisternum scaly; sides of metasternum scaly and bristled; distance between meso- and metacoxae up to twice longer than the metacoxa; scutellum ogival, scarsly punctured. Elytra: shiny, glabrous, uniform reddish brown; elytra more than three times longer than the pronotum; elytral suture slightly darker than elytron and distinctly elevated; two pairs of inner ridges more noticeable than the two outer pairs. Legs: procoxa scaly on infra-carinal and outer surface; punctures visible at 12 × magnification; three protibial teeth, the apical the longest, in males the three teeth equally spaced, slightly different in females; protibial inner apical spur present; anterior margin of mesofemur with a row of long bristles; mesotibia quadrate or sub-quadrate in cross section, disc finely sculptured, two mesotibial transverse carinae, in males the apical one incomplete; basal apophysis of metacoxa produced beyond the outer margin of trochanter; metafemur with thick and erect bristles on posterior margin; metatibia with posterior discontinuous longitudinal carina; metatibial apical spurs of different lengths, the longest one exceeding the diameter of the tibial apex; inner margin of male metatibia carinated towards apex; apical inner surface setose; disc finely sculptured; two metatibial transverse carinae present posteriorly; basal metatarsomere smaller than the tarsomere II and as wide as; in males protarsomere II short and wide; pro- and mesotarsomeres I to IV enlarged and more than twice as wide as metatarsi; claw bifid, symmetrical, superior tooth longer and narrower than the inferior; distance between teeth shorter than the inferior tooth. Abdomen: band of scales visible at the lowest magnification beneath the outer margin of elytra; ventrites bristled on disc and sides; propygidium slightly visible, bristled and scaly; pygidium convex, sub-trapezoidal, wide; pygidial width exceeding distance between spiracles of propygidium; pygidial disc scarsly bristled on apex; pygidial apex sub-rounded in males. Parameres: width of basal region equal to the parameres together at its transverse midline, parameral split at 2/3; total length of parameres more than five times the length of their apex; inner margins straight; apex harpoon-like with lateral angle projecting straight downward (Fig. 62F). In lateral view slightly convex (Fig. 62G).

Type-locality.

Liogenys diodon : BRAZIL ( “Norte”) [Northern Brazil]; Liogenys caviceps (syn.): BRAZIL. Mossoro, R.G.N [Rio Grande do Norte state].

Geographical distribution.

BRAZIL (PI, CE, RN, PE, SE, GO).

Remarks.

Liogenys diodon resembles L. bilobata (Fig. 59), they share the deeply emarginate clypeus with lateral margin concave; clypeal teeth longer in males; protarsi wider than mesotarsi; pygidial width exceeding distance between spiracles of propygidium and thick and erect bristles on posterior margin of metafemur, this latter feature also seen in L. sinuaticeps (Fig. 33). Liogenys diodon differs from L. bilobata in the smaller size; clypeal lateral margin being less concave; canthus not exceeding the outer margin of the eye; pronotal posterior corners rounded; metatibia with outer longitudinal carina barely defined or absent, disc finely sculptured; metatarsomere I shorter than tarsomere II; disc of ventrites bristled instead of scaly; pygidium convex, almost glabrous with sub-rounded apex and male metafemur not medially produced on posterior margin. Liogenys caviceps types (NMHB) bear a label written by Frey (1964) with the name Liogenys diodon instead of L. caviceps . We suppose they are in fact the primary types as the type-locality written in the labels is exactly the same mentioned in the original description. We believe that when Frey (1969) synonymized those species, he must have swapped the original labels with the species name, leaving in the types of L. caviceps only the name of its senior synonym.