Phaeoxantha (Phaeoxantha) nocturna nocturna (Dejean, 1831)

(Figs 13–41).

Megacephala nocturna Dejean, 1831: 263 .

Phaeoxantha nocturna: Chaudoir 1850: 7 (as “ nocturna Klug ” and as a synonym of P. limata). Megacephala limata sensu auctorum (partim, see “Remarks” below).

Phaeoxantha limata sensu auctorum (partim, see “Remarks” below).

Megacephala (Phaeoxantha) nocturna: Wiesner 1992: 45.

Phaeoxantha nocturna: Naviaux 2008: 514 (513, figs 1–5).

Phaeoxantha nocturna: Wiesner 2020: 31.

Unavailable names. Megacephala menetriesi: Dejean 1837: 2, in litt.

Megacephala brevicollis: Chaudoir 1865: 42, in litt.

Type locality. Brazil, environs of Pará.

Type material. Lectotype (designated here) ♂ in MHNH, labelled by small, square, plane green label (usually attached to type specimens by Dejean) and: “Muséum Paris / Coll. Chaudoir 1874” [greenish, printed, the date means when the specimens accessioned by MNHN] . Paralectotype. 1 ♂ in MHNH with same labels . Other five specimens with same labels in MNHN are obviously syntypes, thus becoming paralectotypes .

Other material examined. Historical specimens. 1 ♂ in ZSM [wrongly labelled as a holotype of in fact never described Megacephala limata Perty, 1830], labelled: “Amazon / F. / Perty” [large square tarnished label with thin green border, handwritten] // “ Holotypus / Megacephala / limata / Perty / 1830 / Staatssamml. München” [red, printed] // “ Phaeoxantha / nocturna (Dejean, 1831) / R. Naviaux test. 2009 / Phaeoxantha ” [printed] // “SNSB-Zoolo-gische / Staatssammlung München / digital imaging / ZSM-COL–00114” [printed]. 1 ♂ in BMNH: “5302” // “Amazon / Bates” // “Fry Coll. / 1905–100” // NHMUK015009549”. Other data. 1 ♂ in CDCL: “Dr Hahnel/ Amazonas / (Staudinger)” // “ex coll. Bokor” // “ Megacephala / limata Perty’’. 2 ♂♂, 1 ♀ in CDCL: “Teffe / Amazon”. 3 ♂♂, 1 ♀ in CDCL: “Amazone” [green, handwritten] // “629/34” [small rounded, handwritten]. 1 ♂ in CDCL: “Amazone” [green, handwritten] // “629/34” [small, rounded, handwritten] // “ Tetracha laminata ” [handwritten]. 2 ♂♂, 1 ♀ in CDCL: “Brazilia, Amazonia, 120 km /N. of Manaus. Boa Vista road / Prai forest, sept. 20-30.89 / M. Hrabovsky lgt”. 2 ♀♀ in CDCL: “ Brazil, Amazonas / L. bank of Rio Negro / 8 km N. of Manaus/on beach, Oct. 6-89 / M. Hrabovsky col.” // “Meg.( Phaeoxantha) / limata Perty, 1837 / Werner det. 1996.”. 2 ♂♂, 2 ♀♀ in CCJM: “ Brazil, Amazonas / L. bank of Rio Negro / 8 km N. of Manaus/on white sand beach / 4.X.1989 M. Hrabovsky”. 2 ♂♂, 4 ♀♀ in CCJM, 2 ♂♂, 2 ♀♀ in CJVB: “Brasilia – Amazonia / Manaus – Rio Negro / 20.IX-14.X.1989 / M + P. Hrabovský leg”. 2 ♂♂, 4 ♀♀ in CCJM, 2 ♂♂, 4 ♀♀ in CJWB: “ Brazil – Amazonas, Manaus / Parque das Laranjarias / sandy at night 14.X.1993 / M. Hrabovský lgt.”. 1 ♂ in CJVB: “ Brazil, Amazonas / Parintins rd. to airport / white sand at night / 10.IX.1996, M. Hrabovsky lgt.”. 1 ♀ in CDCL: “ Brazil, Casares Mt / Praia de Carne / 16°05’43” S. 57°43’10’’W / leg Zerm, 22-IX- 998” // Phaeoxantha / limata/ Perty, 1830 / det J. Wiesner, 1998”. 1 ♀ in CDCL: “ Brazil, Rio Cuiaba / beach San Antonio / 15°52’19’’S. 56°05’36W / leg. Zerm. 17-IX-1998 ” // “ Phaeoxantha / limata / Perty, 1830 / det J.Wiesner, 1998”. 1 ♂ in CDCL “Ponta du Arare / Rio Negro, Bras.” // “Ca 50 km oberhalb / Manaus auf Sand -/ banken” // “21-11-62/ leg. Irmler” // “ Megacephala (Phaeoxantha) / limata Perty, 1830 / det J. Probst”. 2 ♂♂, 2 ♀♀ in MHCP, 2 ♂♂, 1 ♀ in CCJM, 1 ♂, 1 ♀ in COSJ: “ Brasil / R. Preto da I Eva / 20.-25.XI.1994 / Hrdý M. lgt.”. 4 ♂♂, 1 ♀ in COSJ: “ Brasil /Amazone prov. / Rio Jalapu / I.1995, Gada lgt.”.

Differential diagnosis. Phaeoxantha (Phaeoxantha) nocturna nocturna is one of the four smallest species of the nominotypical subgenus with adults measuring 9.00–10.5 (LT 9.30) mm. It is immediately distinguished from similarly small (9–10 mm long) P. (P.) laminata by its almost subparallel, slightly posteriad attenuated elytra (Figs 13–14, 18, 27–32, 34)) (more notably so in males), in contrast to the ovoid, sexually dimorphic elytra with tuberculate surface in P. (P.) laminata (Figs 98–100, 103–106, 111–114, 123–125); the coloration varies from conspicuously pale, yellow-ochre with ochre to pale brownish, or brownish-darkened, or blackish elytral areas; elytral surface often appearing partly translucent, almost smooth, finely and mostly sparsely punctate, rarely with larger punctures,, appearing almost glabrous as covered with scattered or more dense but very short setae (Figs 27–31, 34); epipleura finely serrate; pronotal surface smooth and almost glabrous, or with sparse microsetae (in contrast to conspicuously more coarsely punctate and densely setose elytra and notably setose pronotum in P. (P.) n. crassipunctata ssp. nov.). Rather similar P. (P.) epipleuralis can be distinguished by its subparallel-side elytra with outer margins widest below the middle or slightly dilated posteriad, and by elytral punctures on anterior elytral half surrounded by shallow, fovea-like greyish circle (Figs 86, 95–97).

P. (P.) tremolerasi (Figs 127–141) is clearly distinguished by its larger body with notably stout elytra (in contrast to posteriad-attenuated elytra in P. (P.) n. nocturna and P. (P.) n. crassipunctata). Moreover, elytral surface in P. (P.) tremolerasi is distinctly and rather densely punctate in their anterior half (Figs 130, 139–141) and outer elytral margins lack any serrulation (which is present in other species of the nominotypical subgenus). P. (P.) cruciata and P. (P.). bifasciata immediately differ in their much larger size.

Remarks. Naviaux (2008) supposed that no type specimen of Megacephala nocturna Dejean, 1831 was preserved. However, seven specimens, obviously syntypes of this taxon, were found in MNHN recently, two males presented here, one of them designated as a lectotype (Fig. 13), the other as a paralectotype (Fig. 14), the remaining five syntypes in MNHN becoming paralectotypes. Because Dejean and Chaudoir did not label type specimens with locality or type labels, Rivalier, who arranged the boxes of the General Collection of MNHN in 1970, failed to recognize the specimens as syntypes of M. nocturna . He shifted the specimens into the newly arranged box and placed them under the label “ limata Perty ”. Fortunately, most of Dejean’s types are recognizable by a specific shape of pins, and particularly by a small, square plain green label (Figs 15, 17) attached to the specimens (see also Moravec 2010: 18, 2018, 2020). All these latent syntypes were subsequently (after the Dejean-Chaudoir collection was accessioned as part of the MNHN collection) labelled by curators with large greenish printed labels “Muséum Paris / Coll. Chaudoir 1874”; fortunately, due to these labels, Rivalier arranged them alongside in the first line of the series in the MNHN box.

For a rather detailed description of this species see Dejean (1831) and more specified redescription by Naviaux (2008). Nevertheless, the male ZSM specimen (Fig 32), wrongly labelled as a “ holotype of Megacephala limata ” was inappropriately considered by Naviaux (2008) as a juvenile adult. It cannot be true also due to the well-developed aedeagus (obvious in Fig. 32 near right protarsus) and elytral black areas of the male, because juvenile adults (also examined) are entirely pale-translucent, with only indicated ochre-brownish darkened posterior area, and their aedeagi are translucent and deformed due to their more or less distinctly collapsed membrane.