Phaeoxantha (Phaeoxantha) nocturna crassipunctata ssp. nov.

(Figs 42–66)

Type locality. Paraguay: Paso Horqueta (department of Concepción).

Type material. Holotype ♂ in JWCW (long term loan of ZSM), labelled: “ Paraguay / 27.-30. 10 / Dep. Concepcion 1991 / Paso Horqueta, leg / Ulf Drechsel” [green, printed]. // “ Megacephala (Phaeoxantha) / limata Perty, 1830 ” / det J. Wiesner 1992 ” [printed]. Allotype. ♀ in (JWCW, long term loan of ZSM) with same labels as holotype. Paratypes. 14 ♂♂, 5 ♀♀ in JWCW (long term loan of ZSM), 4 ♂♂, 5 ♀♀ in CCJM, 1 ♂, 1 ♀ in MNHN (ex JWCW) with same labels as holotype. 4 ♂♂, 2 ♀♀ in JWCW (long term loan of ZSM), 4 ♂♂, 3 ♀♀ in CCJM (ex JWCW), 1 ♂, 1 ♀ in BMNH: “ Paraguay / Dep. Concepcion, Paso / Horqueta 27.-30.X.1991, / leg. U. Drechsel” [green, printed] // “ Megacephala (Phaeo / xantha limata / Perty 1830 / det. Wiesner 1996” [printed]. 1 ♂, 3 ♀♀ in CDCL: “ Paraguay / Concepcion Prov. / Paso Horqueta / Coll. Dheurle” [printed] // “27-II-99 / Ugarte Pena leg” [printed]. 1 ♂ in CDCL, 1 ♀ in CCJM: “ Paraguay. Dep. / Concepcion, Garay- / Cue, S 22°41’ W 52° 22’ / leg. Drechsel, 12-14-II-2010 ” [printed] // “ Phaeoxantha / laminata / Perty, 1830 ” [printed]. 1 ♂ in CDCL: “ Paraguay, 17-02-92 / Dpto San Pedro, Nueva / Germania, Paso Carmona / Dheurle coll.” [printed]. 3 ♂♂, 2 ♀♀ in SDEI: “Puero Beroni / Alto Paraná / Paraguay ” [printed] // “Coll. W. Horn / DEI Eberswalde” [printed] // “ Phaeoxantha / nocturna (Dejean, 1831) / R. Naviaux dét. 2009” [printed] // “ SDEI Müncheberg / Col-18809” [green, printed]. 1 ♂, 1 ♀ in JWCW (long term loan of ZSM): “ Brazil, Rio Cuiaba / beach San Antonio, / 15°52´19´´, 56°05´36´´W / leg. Zerm 17.IX.1998 ”. 1 ♂ in JWCW (long term loan of ZSM): “ Brazil, Casares Mz. / Praia de Carne / 16°05´43´´, 57°43´19´´ W / leg. Zerm, 22.IX.1998 ”. 1 ♀ in NMPC: “ Paraguay, II.1992 / San Carlos / Nueva Germania / Paso Carmona” [handwritten] // “ex Col. Petr Votruba / National Museum / Prague, Czech Republic ” [printed] // “ Megacephala / (Ph.) limata / det. Votruba 2001” [handwritten]. 1 ♀ in CCJM: “ Paraguay / dep. Concepcion / San Carlos, S22°19´; W57°10´/ 28-30.X.2002, leg. U. Drechsel”.

Other material examined. 1 ♂ in NMPC: “ Paraguay / Jesús y T r, Šedý [lgt].

1 ♂, 1 ♀ in JWCW: “ Brazil /AM, km 19 / AM-010 highway / Manaus-Itacoatiara, / lane Borm Sossego / VIII. 1999, M. Zerm coll.” [somewhat intermediate between nominotypical subspecies].

Differential diagnosis. Distinguished from the nominotypical subspecies by its generally larger and darker dorsal body coloration and particularly by its much coarsely punctate and distinctly setose elytral surface, as well as by much darker, black areas, particularly the posteromedian black area is notably large, usually almost reaching outer elytral margins (Figs 42–47, 57–58, 60). Also pronotal surface and outer margins (Figs 55–56) are covered with notably longer, hairlike setae (likewise along elytral margins, particularly in females). The length of the setae is rather variable and similar elytral setosity (yet shorter) occurs, though rarely, in some specimens of P. (P.) n. nocturna from the Manaus area, where also specimens with intermediate size of punctation occur (see Remarks below).

Phaeoxantha (P.) epipleuralis is morphologically very close to P. (P.) n. nocturna, yet it is more similar to P. (P.) n. crassipunctata due to its coarse elytral punctation, distinguished from both by the elytral shape. Although the female elytra in P. (P.) epipleuralis are sometimes subparallel or only indistinctly dilated posteriad (Fig. 97), both males and females of P. (P.) n. nocturna and P. (P.) n. crassipunctata have their elytra at least slightly attenuated posteriad. The aedeagi of these three taxa are practically of the same shape (within usual variability). For other differences see under P. (P.) epipleuralis below.

Description. Body (Fig. 42) small, of rather variable size independent of sex (but some females larger than males and the AT), 9.40–10.1 (HT 10.0, AT 9.50) mm long, 3.40–4.60 (HT 3.70, AT 4.05) mm wide.

Head (Fig. 48) 3.00– 3.05 mm wide including large eyes, slightly wider than pronotum, but notably narrower than body and appearing notably short (as the temples are emerged into anterior pronotal lobe), ochre-brownish, usually with cinnamon-brown tinge, or reddish-brown darkened (concolorous with pronotum and elytra).

Frons partly merging with clypeus in middle and entirely confluent with vertex, ochre to cinnamon-brown, glabrous but usually with few scattered punctures and microtubercles.

Vertex concolorous with frons, supraantennal plates rather indistinct, with small posterior edge; juxtaorbital areas often blackened with one long, whitish (easily abraded) juxtaorbital sensory seta (on either side); surface on anteromedian area usually sparsely punctate (punctures passing from frons), but also median or entire vertex surface covered with scattered, barely visible microsetae which may be more distinct and longer on posterolateral areas.

Clypeus ochre to cinnamon-brownish with brownish areas and darkened lateral margins, glabrous and almost smooth, with fine wrinkles or few micropunctures and long whitish or mahogany-coloured sensory seta (on each side).

Genae ochre-brownish or brown and partly blackened, with distinct, sharp ventral edge, glabrous and smooth.

Labrum (Figs 51–54) as in nominotypical subspecies short and transverse, 0.60–0.70 mm long, 1.80–2.05 mm wide, 4-setose, ochraceous and uniformly shaped in both sexes, outer margins arcuate, anterior margin with fourth small teeth, which are mostly subacute and usually blackened.

Mandibles (Figs 48–50) with three teeth (and basal molar), terminal teeth long and acute, normally shaped but sexually dimorphic: subsymmetrical in male (Figs 48–49), asymmetrical in female (Fig, 50), ochraceous with brownish-darkened teeth with blackened apices.

Palpi (Fig. 48). Both maxillary and labial palpi ivory-yellow to ochre-testaceous (shaped and coloured as in nominotypical subspecies), markedly elongate (as in other species of the genus), terminal palpomeres of maxillary palpi moderately spatulate-dilated, while those of labial palpi more elongate.

Antennae (Figs 42, 48) with all antennomeres ivory-yellow to ochre-yellow as in nominotypical subspecies yet sometimes somewhat darker; scape usually pale brownish darkened, with one or two long, apical sensory setae and sparsely scattered and barely visible microsetae on its surface.

Thorax. Pronotum (Figs 55–56) generally shaped as in the nominotypical subspecies, 2.20–2.60 mm long, 2.60–3.30 mm wide, but its surface more distinctly and usually more densely punctate-setose and with much longer setae, particularly notable along outer margins; female pronotum often darker, reddish-brown (like elytra of some females); lateral and ventral thoracic sterna as in the nominotypical subspecies but sometimes in females darker or blackened: proepisterna smooth and glabrous; metepisterna (particularly in some females) sometimes minutely punctate-setose; mesepisterna smooth and glabrous, in females lacking coupling sulcus in form of any pit; prosternum, mesosternum and metasternum often blackened (particularly in some females) with few scattered punctures with microsetae in females.

Elytra (Figs 43–47, 57–58, 60) of a similar shape as in the nominotypical subspecies, but generally rather stouter, length 5.90–7.00 mm, lateral margins almost subparallel, widest above middle, moderately gradually attenuated towards arcuate anteapical angle and obliquely towards blunt or subacute apex; epipleura finely serrate; elytral surface moderately convex, with indistinctly brownish or black-brown anterior area along median sutures, in females usually wider and blackened, connected along the sutures with much larger and darker, black-brown or black posterior area which almost reaches outer elytral margins.

Legs (Fig. 42) as in nominotypical subspecies but sometimes darker, particularly in some females; femora, tibiae and tarsi ochre-yellow or ochre-testaceous, except for notably darkened last three (distinctly dilated) male protarsomeres; femora with rows of rather dense mediocre long setae, which are denser on tibiae, with notably long but pale thorns at tibial apices.

Abdomen. Ventrites ochre-cinnamon, in some females black-brown, their surface covered with sparse or rather dense minute setae.

Aedeagus (Figs 61–64) shaped as in nominotypical subspecies, 2.80–3.00 mm long, 0.55–0.60 mm wide, with similar pattern of sclerites within internal sac (Figs 65–66).

Distribution and ecology. The type locality Paso Horqueta lies about 150 km (by air) northwards from San Carlos which is the locality of one female paratype (CCJM) situated on the border of the Brazilian state of Mato Grosso do Sul (predominantly with “Bioma Cerrado” biotopes), while the locality of another female (CCJM) from Estancia Garay Cué is situated between these two places (all in the Paraguayan department of Concepción). Two paratypes from the Cuiabá River, as well as the male paratype from Casares Mz., Praia de carne on the Rio Paraguay (closer to Bolivia, but also not far from Paraguay), come from the Brazilian state of Mato Grosso. The locality Puerto Bertoni of the five historical specimens (paratypes in SDEI), is situated near Puerto Iguazú in the border between the Brazilian state of Paraná and Argentinean province of Misiones, a very long distance from the type locality.

Despite the long distances, however, all these known localities lie in parts of the Rio de La Plata Basin (Fig. 326), formed by the streams and tributaries of the Paraguay and Paraná Rivers, forming the La Plata River, a very long distance from the localities of the nominotypical subspecies in the Amazon Basin (Fig. 325).

Remarks. The subspecies or alternatively species status of P. (P.) n. crassipunctata is not clear, because, as mentioned above, the adaptation of some populations to different environmental changes may tend, under evolutionary forces, to form an allopatric speciation. The diagnostic characters of the examined specimens of P. (P.) n. crassipunctata from the geographically separated Rio de La Plata Basin are rather constant, differing also from some intermediate specimens from the area of the Amazon Basin near Manaus. Two specimens (JWCW) from the area between Manaus and Itacoatiara (if the labels were not confused) are barely recognizable from some less distinctly punctate specimens of P. (P.) n. crassipunctata.

Notwithstanding, the lectotype and paralectotypes (MNHN) of Megacephala nocturna (Figs 13–14, 27–28), as well as most other, both historical and recently caught specimens, are immediately distinguished from P. (P.) n. crassipunctata due to their notably smoother elytral surface.