Sibylloconnus sibyllensis (Franz) Jałoszyński, 2020

Jałoszyński, Paweł, 2020, Corrections to the classification of the Neotropical ant-like stone beetles misplaced in Euconnus Thomson (Coleoptera, Staphylinidae, Scydmaeninae). Part 1., Zootaxa 4755 (2), pp. 251-270 : 258-261

Sibylloconnus sibyllensis (Franz) , comb. n.

Euconnus sibyllensis Franz, 1984: 23 .

( Figs 12–22 )

Type material. Holotype: DOMINICAN REPUBLIC (San Cristóbal Prov.): ♂, three historical labels ( Fig. 13 ): “Dominican Republ., Cordillera Central / Colonia Ramphis / 1000 m, 21.1.1974 ” [white, handwritten], “ Euconnus / sibyllensis m. / det. H.Franz ” [white, handwritten and printed], “ Holotypus ” [red, handwritten]; during the present study a new label was added: “ SIBYLLOCONNUS / sibyllensis ( Franz, 1984) / det. P. Jałoszyński, 2020” [white, printed] ( NHMW).

Diagnosis. As for genus.

Redescription. Body of male ( Fig. 12 ) moderately slender and moderately convex, brown, setae and bristles slightly lighter than cuticle; BL 0.83 mm.

Head ( Fig. 15 ) broadest at large, strongly convex eyes, HL 0.13 mm, HW 0.15 mm; frons with pair of lateral impressions ( Fig. 16 ) each situated on round elevated plate, and with V-shaped carina between impressions; additionally subtriangular median tubercle is present between frons and vertex, surrounded laterally and posteriorly by shallow and narrow groove forming a rectangle open anteriorly; tempora slightly shorter than eyes in dorsal view, strongly convergent posteromesad and indistinctly rounded. Vertex and frons with unevenly distributed, small and shallow setiferous punctures; setae moderately long and suberect, sparse, distributed on anteromedian region of frons, along mesal margins of eyes, in front of posterior tubercle, along posterior margin of vertex, on tempora and on genae/postgenae, additionally occipital constriction with group of dense setae at each side of head. Antennae ( Fig. 12 ) slender, AnL 0.40 mm; antennomeres I and II each elongate, III–VI each about as long as broad; VII indistinctly transverse; VIII distinctly transverse and much smaller than VII; IX and X each distinctly transverse; XI distinctly shorter than IX and X combined, about 1.3 × as long as broad.

Pronotum ( Fig. 14 ) broadest near middle; PL 0.20 mm, PW 0.18 mm. Anterior margin weakly rounded; sides in anterior half weakly rounded, more distinctly so at the widest site, in posterior half distinctly concave and just in front of posterior corners slightly divergent posterad; posterior margin shallowly bisinuate; antebasal pits developed as large, diffuse impressions, transverse groove diffuse, slightly convex anteriorly. Punctures on pronotal disc fine, inconspicuous; setae on dorsal region short, sparse, suberect, on sides replaced by long erect bristles.

Elytra ( Fig. 12 ) together oval, broadest near middle; EL 0.50 mm, EW 0.33 mm, EI 1.54; basal impressions short and shallow, humeral calli distinct, elongate and indistinctly carinate, elytral apices rounded together. Punctures and setae similar to those on median region of pronotal disc.

Hind wings long, functional.

Legs long and slender; unmodified.

Aedeagus ( Figs 21–22 ) elongate; AeL 0.10 mm; median lobe in ventral view broadest near base, in lateral view apical region rapidly bent dorsad at a sharp angle; endophallus with long median longitudinal component situated in basal half of median lobe, and with submedian subtriangular structure; parameres shorter than median lobe and slender, but with strongly broadened apices, each with three long and thick apical setae.

Female. Probably unknown (see remarks below).

Distribution. Central-southern Dominican Republic.

Remarks. The type series of Euconnus sibyllensis is composed of the holotype male redescribed above, and a paratype female. According to Franz (1984), both specimens were collected on 30.06. 1974 in Colonia Ramfis. The holotype male bears a label with this locality, but the collecting date is 21.1.1974, and the female was collected in “Cazabita” on 30.06.1974. The locality name Cazabita is mentioned at other species described by Franz (1984) and collected by J. and S. Klapperich, e.g., Microscydmus cazabitanus and Euconnus cazabitae . It may be Casabito (Loma del Casabito mountain and Casabito Mountain Village), a locality in central Dominican Republic, east of Presa de Rincón reservoir, whereas Colonia Ramfis (known also as La Colonia) is in south-central part of the country. The description of E. sibyllensis is predominantly based on the male, and the characters given by Franz (1984) agree with those of the holotype. The female, clearly collected in a different locality and on a different day than the holotype, differs remarkably. It has a narrow, elongate and microphthalmous head, and slightly different shape of the pronotum. Most importantly, the female head, even though with vestigial, barely discernible eyes, is equally wide as that of the male, but longer. This is a strong indication that the female is not conspecific with the male. It may belong in the same genus, as the female maxillary palpomere III is strongly swollen, and the pronotal base bears similar pits and a groove as those in the holotype. Because this species cannot be unambiguously identified, the female specimen was not studied by SEM or in a transparent mount to verify its generic placement.

Figures

FIGURES 12–14. Sibylloconnus sibyllensis (Franz) comb. n., holotype male. Dorsal habitus (12); original set of labels (13); head, prothorax and elytral base in dorsal view (14). Abbreviations: abg, antebasal groove; abp, antebasal pit; bef, basal elytral fovea; slc, sublateral carina.

FIGURES 15–18. Sibylloconnus sibyllensis (Franz) comb. n., holotype male. Head in dorsal view (15); left frontal impression in dorsal view (16); head and prothorax in ventral view (17); prothorax in ventral view (18). Abbreviations: bst, basisternal part of prosternum; gp, gular plate; hr, hypostomal ridge; hyr, hypomeral ridge; mn, mentum; mxp1–4, maxillary palpomere I–IV; nss, notosternal suture; ptp, posterior tentorial pit; smn, submentum.

FIGURES 19–22. Sibylloconnus sibyllensis (Franz) comb. n., holotype male. Pterothorax and abdomen in ventral view (19); mesothorax in ventral view (20); aedeagus in ventral (21) and lateral (22) views. Abbreviations: dlf, dorsolateral fovea; pcr, procoxal rest; msvp, mesoventral intercoxal process; mtvp, metaventral intercoxal process.