Liogenys rectangula 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 : 43-45

Liogenys rectangula Frey, 1969

Figs. 19 ; 25

Liogenys rectangulus Frey, 1969: 47 , 59–60; Krajčík 2012: 145 (checklist); Cherman et al. 2017: 5 (generic history);

Liogenys rectangula: Cherman et al. 2017: 13 , 20, 75 (illustration; natural history, taxonomy); Cherman et al. 2019: 36 (taxonomy).

Type material. Liogenys rectangulus male holotype ( USNM): [white handwritten] “Formosa / P [Puerto] Pilcomayo / Argent. 1950”, [red typeset] “ PARATYPE ”, [white, typeset and handwritten] “ Liogenys rectangu / lus n. sp / det. G. Frey, 1968”, [white, typeset in red] “Smithson., / Cartwr.”, [white handwritten] “ +1”, genitalia mounted. Paratypes (3): One male ( NHMB): [white typeset] “San José Chiq. / X.26. Lind. [Lindner] / D. Chaco-Exped. [Deutchen Chaco-Expedition]”, [red typeset] “TYPUS”, [white, typeset and handwritten] “ Liogenys rectangu / lus n sp / Type / det. G. Frey, 1968”, genitalia mounted. One female ( NHMB): [white handwritten] “ Salta, Argent. / Dep. Rivadavia”, [red typeset] “ PARATYPE ”, [white typeset] “ ♀ ”, [white, typeset and handwritten] “ Liogenys rectangu- / lus n sp / det. G. Frey, 1968”, [white, typeset in red] “Smithson., / Cartwright”, [white typeset] “Museum Frey / Tutzing”. One male ( MZSP): [white typeset] “ Argentina / Formosa / Ciudad XII.1949 / A. Martinez leg.”, [red typeset] “ PARATYPE ”, [white, typeset and handwritten] “ Liogenys / rectangu- / lus n sp / det. G. Frey, 1968”, genitalia mounted .

Non-type material (8). BOLIVIA. Santa Cruz, San José de Chiquitos [17°50’04.6’’S, 60°45’01.7’’W], X.26, Lindner , 1 male ( NHMB) . ARGENTINA. Formosa: Ingeniero Juárez, 24º05’27’’S 61º56’49’’W, 13.XII.2008, Ocampo, San Blas , & Campón , mercury vapor & ultraviolet light, 4 males and 3 females ( IADIZA) .

Diagnosis. Length: 9.0– 10.2 mm; width: 4.2–4.7 mm. Body and pronotum reddish brown, elongate, sides almost parallel; elytra testaceous, glabrous, opaque, somewhat pruinose ( Fig. 19A ); clypeal emargination very shallow, rounded and wide, in males as wide as the distance between eyes; outer sides of anterior teeth following the clypeal lateral margin; clypeal lateral margin straight or concave; antennae with 10 antennomeres; pronotal posterior corners sharp, in obtuse angle ( Fig. 19B ); mesotibia quadrate in cross section; two transverse carinae posteriorly, the apical incomplete or weakly complete; pygidium flat; subtrapezoidal; pygidial disc with short, thick, erect bristles throughout ( Fig. 19D ); in males, inner margin of metatibia strongly carinate straight towards apex; tarsi abundantly with bristles dorsally, protarsomere II as long as it is wide; parameres widened medially and abruptly narrowed sub-basally; parameral split slightly beyond the midline; apex spatulate ( Fig. 19E ); parameres in lateral view straight, not coplanar ( Fig. 19F ).

Type locality. ARGENTINA, Formosa, Puerto Pilcomayo .

Geographical distribution. BOLIVIA (Santa Cruz); ARGENTINA (Salta, Formosa).

Remarks. Liogenys rectangula resembles L. moseri Frey, 1969 ( Cherman et al. 2017, 2019a) in the body size and color, in the shape and vestiture of pygidium, and in the protarsi abundantly with bristles. Liogenys rectangula differs from L. moseri (in parenthesis) mainly in the clypeus laterally straight, without tooth-like projection (convex, with a sharp tooth-like projection) and in the elytra in general pruinose (shiny or slightly semiopaque in some specimens). Frey (1969) described L. rectangula from a series collected in Pilcomayo, Formosa, Argentina; the holotype was deposited at the USNM and the paratypes (Frey did not state the number) at NHMB. At the USNM the specimen deposited by Frey bears a paratype label instead. At the NHMB, specimens with type label found are from other localities but the one stated by Frey (1969): one specimen is from “San José Chiquitos” ( Bolivia) and other is from “ Salta, Dep. Rivadavia” ( Argentina), with holotype and paratype labels, respectively. As they are not from the type locality stated by the author, they are not considered types. There is another paratype specimen deposited at the MZSP, which is from Formosa Ciudad ( Argentina). As the author did not state the ocurrences from Chiquitos ( Bolivia) and Salta ( Argentina) in the original description, we consider them as new L. rectangula state and country records, respectively.

Figures

FIGURE 19. Liogenys rectangula Frey, 1969 male holotype views: A) dorsal, B) head and pronotum, C) lateral, D) pygidium, and parameres in views: E) dorsal and F) lateral.

FIGURE 25. 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).