Xenorthrius furcalis Gerstmeier & Eberle, 2010

Gerstmeier, Roland & Eberle, Jonas, 2010, Revision of the Indo-Australian checkered beetle genus Xenorthrius Gorham, 1892 (Coleoptera: Cleridae, Clerinae) 2584, Zootaxa 2584 (1), pp. 1-121 : 43

Xenorthrius furcalis Gerstmeier & Eberle, 2010 n. sp.

( Figures 10A , 28 and 65D )

Specimens examined: Holotype: Taiwan: Nanshanchi , Nantou Hsien, Taiwan, 14. Apr. 1985, Y. Kusakabe leg. (♂, RGCM).

Paratypes: Taiwan: [ Mt. Kuantao ], Nantou Hsien, Taiwan, 24. Apr. 1984, Y. Kusakabe leg. ( KSCT). Nanshanchi, Formosa, 26.VI.1971, Y. Maeda; Xenorthrius sp. (1ex., 1ex. 27.6.1971, EUMJ) .

Measurements: (4 specimens measured) Average total length: 14.0mm, range: 13.2–14.7mm, average elytral length: 9.6mm, average elytral width: 3.4mm, average pronotal length: 3.0mm, average pronotal width: 2.5mm, average head width: 2.5mm.

Head: Red-brown, cranium vested with shorter setae, punctation distinct, interstices not exceeding one diameter of punctures; posterior part of clypeus red-brown, anterior margin concave, with large punctation and a few long setae laterally, smooth centrally; ventral wrinkled, smooth centrally; antennae red-brown, A4 longer than A3, antennomeres gradually decreasing in length from A4 towards A8, A9 to A11 forming an indistinct club, male A11 reaching slightly beyond pronotal base when laid back; gular sutures diverging apically, gular process broad.

Thorax: Average pronotal length:width ratio 1.2:1; pronotum red-brown, vested with short yellowish setae, pronotal arch with distinct punctation, interstices about one diameter of punctures, pronotum proper with denser punctation; prosternum red-brown, smooth, mesosternum red-brown; metasternum red-brown, punctation fine, interstices about three diameters of punctures; two strongly sclerotized edges projecting ventrally on anterior metasternal process; scutellum oval, colored like elytra.

Elytra: Average length:width ratio 2.9:1; suture apically strongly dehiscent, apical curve concave, uniformly red-brown, slightly lighter dorsally and near lateral margins, subcutaneous structures only slightly visible, vested with short decumbent and few longer erect setae, punctation relatively small, striae 1 and 2 obsolete behind basal quarter of elytra, striae 3 to 5 becoming constantly longer until striae 5 is entirely present, striae 6 and 7 as long as striae 5, striae 8 slightly shorter, striae 9 and 10 with weak punctation, interstices between striae about two diameters of punctures, interstices within striae about one diameter of punctures; punctation not rasp-like, carination absent.

Legs: Yellow, tarsal pulvilli pale; metatibiae slightly bent centrally, anterior and posterior face of each tibia carinate, carination red-brown, distinct, especially on metatibia.

Abdomen: Ventrites red-brown, interstices about two diameters of punctures; male pygidium suboblong, apical margin concave; female ventrite 5 with distinctive double-emargination ( Fig. 10A ); male ventrite 6 with distinct U-shaped emargination. Male genitalia ( Fig. 28 ): Tegmen apically narrower, sinus deeply Vshaped; phallic plates broad; spicular fork dividing into two branches after quarter of length.

Distribution: Taiwan.

Seasonal occurrence: Collected from April to June.

Etymology: The specific epithet, furca, a Latin noun meaning fork, refers to the characteristic emargination of the female ventrite 5.

Figures

FIGURE 10. Female ventrite 5: (A) X. furcalis and (B) Xenorthrius robustus or X. prolongatus.

FIGURE 28. Xenorthrius furcalis: (A) Tegmen in ventral view, (B) phallus in ventral view, (C) tip of aedeagus in lateral view, (D) spicular fork, (E) male pygidium, (F) male ventrite 6 and distribution map.

FIGURE 65. Habitus photographs: Xenorthrius dorsalis (A), Xenorthrius elongatus (B), Xenorthrius ephippiatus (C), Xenorthrius furcalis n. sp. (D), Xenorthrius geniculatus (E) and Xenorthrius guerlachi (F). Scale bars = 4mm.