Alloraphes opticus, Jałoszyński, 2020

Jałoszyński, Paweł, 2020, Four new species and new records of the Neotropical genus Alloraphes Franz (Coleoptera: Staphylinidae: Scydmaeninae), Zootaxa 4810 (2), pp. 335-343 : 336-337

Alloraphes opticus sp. n.

( Figs 1–2 , 9–12 )

Type material. Holotype: FRENCH GUIANA (commune Montsinéry-Tonnegrande): ♂, two labels: “GUY- ANE FRANÇAISE / Montsinery IV-81 / forêt secondaire / TAVAKILIAN (lum.)” [white, printed]; “ Alloraphes / opticus m. / P. JAŁOSZYŃSKI, 2020 / HOLOTYPUS ” [red, printed] ( MHNG).

Diagnosis. Male: frons delimited from vertex by diffuse transverse impression; eyes conspicuously large, in dorsal view width of eye comparable to width of frons; pronotum with arcuate antebasal transverse groove with indistinct median pit; elytra unmodified; aedeagus in ventral view with strongly asymmetrical apex of median lobe; parameral apices in ventral view pointed, in lateral view broadly rounded, parameres massive, each with large subapical broadening, all three parameral setae subapical and thickened.

Description. Body of male ( Fig. 1 ) moderately convex, light brown, covered with yellowish vestiture; BL 0.85 mm.

Head ( Fig. 2 ) broadest at conspicuously large, strongly convex and coarsely faceted eyes, HL 0.15 mm, HW 0.20 mm; vertex distinctly convex at middle and flattened at sides, delimited from frons by short transverse and diffuse impression, median area of frons in front of eyes flattened; supraantennal tubercles feebly elevated. Punctures and setae on frons and vertex virtually absent. Antennae slender, AnL 0.38 mm; antennomeres I and II each about 1.7 × as long as broad, III–X each slightly transverse, XI much shorter than IX and X combined, about 1.5 × as long as broad, with rounded apex.

Pronotum broadest near anterior third; PL 0.23 mm, PW 0.23 mm. Anterior margin and lateral margins in anterior fourth strongly rounded; sides slightly narrowing posterad and sinuate; posterior margin arcuate; antebasal transverse groove distinct and arcuate, with indistinct median pit, distinctly deepened at each end. Punctures on pronotal disc inconspicuous, fine and sparse; setae moderately dense, short and nearly recumbent, lateral bristles short and poorly visible.

Elytra together oval, distinctly flattened and unmodified, broadest between middle and anterior third; EL 0.48 mm, EW 0.38 mm, EI 1.27; subhumeral lines diffuse and about as long as 0.2 EL; elytral apices separately rounded. Punctures on elytra only slightly more distinct than those on pronotum but still inconspicuous; setae short, sparse and recumbent. Hind wings well developed.

Legs long and slender, unmodified.

Aedeagus ( Figs 9–12 ) slender and lightly sclerotized; AeL 0.20 mm; in ventral view apical region of median lobe strongly asymmetrical, with deep oblique emargination; apical projections simple, the longest forming slender and strongly curved hook visible in lateral view; parameres in lateral view broad, strongly broadened in subapical region, each with three subapical and thickened setae.

Female. Unknown.

Distribution. Northern French Guiana ( Fig. 25 ).

Etymology. The name opticus refers to the conspicuously large eyes.

Remarks. This species is externally similar to A. cayennensis sp. n. described below, also their aedeagi share similar shapes of the median lobes, apical structures and arrangement of parameral setae. However, in A. opticus eyes are so large that the frons between them is almost as wide as width of eye in dorsal view, whereas in A. cay- ennensis the frons between eyes is over twice as broad as width of eye in dorsal view. Moreover, in males of A. opticus elytral apices are unmodified, whereas those in A. cayennensis bear distinct dimples. Despite similarities in the median lobe, the parameres differ considerably. In lateral view, those in A. opticus are massive and strongly broadened in subapical region and then narrowed again, whereas in A. cayennensis the parameres are slender and the subapical broadening is indistinct. Alloraphes peckorum Jałoszyński, 2013 ( Bolivia) has a similar structure of the aedeagus, but males of this species have strongly modified elytra, each with a deep and asymmetrical subapical lateral impression filled with and surrounded by setae different than those on elytral disc; A. opticus has unmodified elytra.

Alloraphes opticus , and describe below A. cayennensis , are the first species of this genus known to occur in French Guiana.

Figures

FIGURE 25. Distribution of nominal Alloraphes species.

FIGURES 1–8. Dorsal habitus (1, 3, 5, 7) and head in dorsal view (2, 4, 6, 8). Alloraphes opticus sp. n. (1–2), A. cayennensis sp. n. (3–4), A. iyonolanus sp. n. (5–6), and A. ecuadoranus sp. n. (7–8).

FIGURES 9–16. Aedeagus in ventral (9, 11, 13, 15) and lateral (10, 12, 14, 16) views. Alloraphes opticus sp. n. (9–12), and A. cayennensis sp. n. (13–16).