Phaeoxantha (Phaeoxantha) tremolerasi (W. Horn, 1909)

(Figs 127–141)

Megacephala (Phaeoxantha) tremolerasi W. Horn, 1909a: 32 .

Phaeoxantha tremolerasi: Horn 1923: 212.

Megacephala (Phaeoxantha) tremolerasi: Wiesner 1992: 45.

Phaeoxantha tremolerasi: Cassola & Pearson 2001: 11.

Phaeoxantha tremolerasi: Wiesner 2020: 31.

Type locality. Uruguay: Salto .

Type material. Syntypes. 1 ♂, 1 ♀ in SDEI, labelled: “ Salto (Urug.) / Tremoleras” [ochre-tarnished, handwritten] // “Type! / Dr. W. Horn ” [ochre-tarnished, printed] // “ Syntypus ” [dark red, printed] // “ Coll W. Horn / DEI, Eberswalde ” [printed] // “ SDEI Coleoptera / # 302354” [printed] .

Note. According to Horn (1909a), there are other two female syntypes (not observed by us), one from the type locality (SDEI), the other (MSNG) from Argentinean province of Entre Rios .

Other material examined. 3 ♂♂, 1 ♀ in CDCL: “ Argentina / Entre Rios / Enero, 1994 / coll. Dheurle ” // “ Ugarte Pena leg” . 1 ♀ in CDCL: “ Argentine / Entre Rios, Liebig / IV-89 / Coll. Dheurle ” . 1 ♂, 1 ♀ in CCJM: “ Argentinien / Colon, E. Rios / coll. 24.II.1976 / Kirschenhofer ” . 1 ♀ in CCJM: “ Argentinien / Entre Rios / Prov. Liebig /. XI.1976 ” . 1 ♂ in CCJM: “ Colon / Entre Rios / XII.1981 ” . 5 ♂♂, 5 ♀♀ in MKPC: “ Uruguay, Rio Negro dept. SW / of Fray Benots, Rio Uruguay / S 33°11.368´, W58°21.336´, 10m / 20.I.2017 D. Brzoska, H.S Chong / hand collected at night. Wet sandbank” . 2 ♂♂, 1 ♂ in MKPC with same locality except for: S 33°11.313´, W58°21.143´ . 1 ♂, 1 ♀ in MKPC: “ Argentina ” .

Differential diagnosis. Phaeoxantha (P.) tremolerasi is easily recognizable within species of the nominotypical subgenus by its stout, medium-sized body, 11.3–12.5 mm long, 5.10–5.90 mm wide. Elytra (Figs 130, 139–141) notably stout, outer margins only moderately convex, generally widest in middle, lacking any serrulation; elytral surface shiny cinnamon-brownish, rather densely punctate throughout except for anteapical-apical area, often with a row of few foveae on elytral disc along sutures, variably lacking black areas, or when they are present, they are either distinct and almost reaching outer elytral margins, or usually only diffusing on posterior elytral half or only indicated.

Distribution. Apart from the type locality in Uruguay, P. (P.) tremolerasi is also distributed in other parts of the Rio de la Plata basin. Most of examined specimens come from the Uruguayan province of Rio Negro and Argentinean province of Entre RÍos (see also Horn 1909a, Bruch 1911). Wiesner & Bandinelli (2014) listed and illustrated this species also from the area of Iguazú in the Argentinean province of Misiones.According to the labels, adults are nocturnal and inhabit sandy banks of rivers.