Syncosmetus medusa Lopes-Andrade et Grebennikov

Lopes-Andrade, Cristiano & Grebennikov, Vasily V., 2015, First record and five new species of Xylographellini (Coleoptera: Ciidae) from China, with online DNA barcode library of the family, Zootaxa 4006 (3), pp. 463-480 : 470-471

Syncosmetus medusa Lopes-Andrade et Grebennikov , sp. nov.

Figs. 15–21 , 35 , 37

Diagnosis. Prothorax with sides explanate and visible for most of their lengths from above; edge of lateral carina minutely crenulated. Pronotum with longitudinal midline in low relief, mostly glabrous and unpunctate, surface microreticulate; anterior portion with surface between punctures somewhat in high relief; border along the posterior edge unpunctate, glabrous. Aedeagus with basal portion of tegmen homogeneously sclerotized, and apical portion with somewhat a spoon-like shape ( Fig. 19 ).

Description, holotype male ( Figs. 15–21 ). GenBank accession: HQ987127 . Fully pigmented adult. Measurements in mm: TL 1.53, PL 0.63, PW 0.83, EL 0.90, EW 0.98, GD 0.78. Ratios: PL/PW 0.76, EL/EW 0.92, EL/PL 1.44, GD/EW 0.79, TL/EW 1.56. Body rounded, extremely convex, mostly dark brown; venter slightly lighter than dorsum, with antennal funicle and palpi yellowish brown; dorsal vestiture of minute setae, conspicuously shorter than a puncture-width; ventral vestiture of slender decumbent setae, as long as a puncturewidth or less. Head with coarse punctures, separated from each other by about a puncture-width; surface between punctures microreticulate; vertex with a median knob. Antennae bearing ten antennomeres with the following lengths (in mm, left antenna measured): 0.09, 0.04, 0.03, 0.02, 0.02, 0.02, 0.02, 0.03, 0.04, 0.08 (FL 0.11 mm, CL 0.15 mm, CL/FL 1.36). Eyes coarsely facetted and with about 25 ommatidia; GW 0.11 mm. Pronotum with coarse punctures, irregular and separated from each other by about a puncture-width; in the anterior portion, the surface in between punctures is somewhat microstriated and tumid, forming lines in high relief; in the posterior portion, the surface is microreticulate and usually not tumid; longitudinal midline in low relief, mostly unpunctate, glabrous and smooth, forming a sulcus broadest and most conspicuous at disc, with surface microreticulate; anterior edge broadly rounded; anterior angles slightly projected forward; sides broad, explanate, weakly crenulate, with microreticulate and unpunctate surfaces, their posterior portion visible from above; posterior edge broadly rounded, the surface bordering it unpunctate, glabrous and somewhat granulate. Scutellum very small, almost indiscernible, confused with the beginning of the median keel of elytra; BW 0.02 mm. Elytra tightly locked but not fused, with punctures deep and coarse, separated from each other by at least a puncture-width and with smooth surface in between them; pseudoepipleura unpunctate and glabrous, their surface smooth and dull; each elytron with first longitudinal keel extending to about the middle of elytral edge; first two keels diverging close to elytral base ( Fig. 16 , arrow); second and third keels not united at their apices. Prosternum in front of coxae biconcave, extremely tumid at middle and bearing a longitudinal carina; lateral concavities deep, with posterior margin carinate; punctation shallower at concavities than at disc and prosternal process, with surface in between punctures microreticulate. Hypomera with shallow coarse punctures, the surface in between them microreticulate. Protibia not expanded, three times as long as broad; inner facet with a conspicuous tuft of long bristles at the apical half; apical angle broadly rounded, its edge bearing a row of spines; outer edge apparently devoid of spines (a few spines visible at higher magnification). Meso- and metatibia not expanded, four times as long as broad; outer edge apparently devoid of spines; outer apical angle rounded, not produced; apical edge with a row of spines. Metaventrite without discrimen; punctures very coarse and separated from each other by a puncture-width or less; surface in between punctures microreticulate. Abdominal ventrites with very coarse punctures, concentrated at the anterior portion of each ventrite and separated by approximately a puncture-width; surface in between punctures and elsewhere microreticulate; length of the ventrites (in mm, from base to apex at the longitudinal midline) as follows: 0.22, 0.04, 0.04, 0.04, 0.13; first ventrite bearing a small circular, foveate sex mark, located anterad of center and with a transverse diameter of 0.02 mm. Male abdominal terminalia in the holotype ( Fig. 18–21 ) with sternite VIII ( Fig. 18 ) subtrapezoidal; posterior edge narrow, curved inward; posterior angles bearing a few long setae. Tegmen ( Fig. 19 ) with basal edge mostly straight, with a short subtriangular extension at middle; lateral edges subparallel at basal two-thirds; apex enlarged and broadly rounded, most sclerotized laterally and bearing a broad concavity, making the tegmen similar to a spoon. Basal piece ( Fig. 20 ) subquadrate, the sides slightly convergent to the anterior portion. Penis ( Fig. 21 ) very elongate; lateral struts linked at base; lateral edges subparallel; apex membranous.

Females. Similar to male, but devoid of abdominal sex patch. Female abdominal terminalia with conspicuous gonostyli; gonocoxites transversely divided into two parts; paraprocts shorter than gonocoxites together; opening of proctiger close to basal gonocoxites.

Variation. No male other than the holotype is known. Females, measurements in mm (n = 2): TL 1.68–1.80 (1.74 ± 0.09), PL 0.70–0.75 (0.73 ± 0.04), PW 0.83–0.88(0.85 ± 0.04), EL 0.93–1.00 (0.96 ± 0.05), EW 1.08–1.13 (1.10 ± 0.04), GD 0.85–0.90 (0.88 ± 0.04). Ratios: PL/PW 0.80–0.91 (0.85 ± 0.08), EL/EW 0.86–0.89 (0.87 ± 0.02), EL/PL 1.32–1.33 (1.33 ± 0.01), GD/EW 0.79–0.80 (0.80 ± 0.01), TL/EW 1.56–1.60 (1.58 ± 0.03).

Type series. Holotype: male (dissected, IZCAS) “P.R. China, Sichuan, Emeishan, N29º33’36.3” E103º20’38.0” 22.vi.2010, 1947m sifting39, V. Grebennikov \ CNCCOLVG00000915 \ Syncosmetus medusa Lopes-Andrade & Grebennikov HOLOTYPUS [handwritten, red paper]”. Paratypes: 1 female ( CNCI) “P.R. China, Sichuan, Emeishan, N29º33’09.9” E103º20.39.1” 16.vi.2010, 2266m, sifting34, V. Grebennikov \ CNCCOLVG00000916”; 1 female ( LAPC) “P.R. China, Sichuan, Emeishan, N29º32’48.4” E103º20’06.3” 17.vi.2010, 2342m, sifting36, V. Grebennikov \ CNCCOLVG00000917”. All paratypes additionally labelled \ Syncosmetus medusa Lopes-Andrade & Grebennikov PARATYPUS [yellow paper]\.

Etymology. The species epithet is a Latinized Greek mythical name of the youngest of the three Gorgon sisters, beheaded by the hero Perseus ; noun in apposition.

Comments. The species closely resembles Sync. euryale sp. nov., which is known from Gaoligong Shan.

Figures

FIGURE 35. Known distribution of Xylographellini beetles in the Palaearctic Region outside of Japan.

FIGURE 37. Lower part of the Maximum Likelihood inference phylogram, upper part of which is depicted on Fig. 36. HT: holotype.

FIGURES 15 – 21. Syncosmetus medusa sp. nov., male holotype from Emei Shan (Figs. 15 – 17): (15) dorsal view; (16) lateral view, with arrow showing first two elytral keels diverging close to elytral base; (17) ventral view. Pregenital segment and aedeagus of a paratype from the type locality (Figs. 18 – 21): (18) sternite VIII; (19) tegmen; (20) basal piece (= phallobase); (21) penis. The apices of sclerites of male abdominal terminalia are oriented to the left. Scale bars: 0.5 mm (Figs. 15 – 17); 0.1 mm (Figs. 18 – 21).