Xenorthrius lugubris 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 : 56-59

Xenorthrius lugubris Gerstmeier & Eberle, 2010 n. sp.

( Figures 36 and 66F )

Specimens examined: Holotype: Laos: Phou Samsoum , Nong Het Dist. , Xieng, Khouang, Laos / 14.V.2008, T. Mizusawa leg. (♂, RGCM).

Paratype: Laos: Tangon , Vientiane , Laos, 9.–10.V.2008, T. Mizusawa leg. (♀, KSCT) .

Measurements: (2 specimens measured) Average total length: 9.5mm, range: 8.8–10.2mm, average elytral length: 6.6mm, average elytral width: 2.6mm, average pronotal length: 1.8mm, average pronotal width: 1.8mm, average head width: 1.8mm.

Head: Dark red-brown, cranium densely vested with short setae, punctation distinct, interstices about one diameter of punctures; posterior part of clypeus red-brown, margins darkened, anterior margin concave centrally, with large punctation and a few long setae laterally, smooth centrally; ventral part yellow to redbrown, smooth, except wrinkles behind the eyes; antennae red-brown, male A4 longer A3, antennomeres gradually decreasing in length from A4 towards A8, A9 to A11 forming a distinct club, A11 globous with sharp tip, male antennae distinctly longer than in female, male A10 and A11 reaching beyond pronotal base when antennae laid back, female antennae as long as pronotum when laid back; gular sutures parallel, gular process broad.

Thorax: Average pronotal length:width ratio 1.0:1; pronotum red-brown, sparsely vested with short yellow setae, pronotal arch with weak punctation, interstices larger than one diameter of punctures, pronotum proper smooth; prosternum yellow, smooth; mesosternum red-brown, margins darkened, vested with yellowish setae; metasternum red-brown, vested with fine setae, punctation weak, interstices among punctation about one diameter of punctures; transverse sulcus on anterior part of mesosternum and mesepisternum indistinct; anterior metasternal process with two strongly sclerotized, ventrally projecting, edges; scutellum round, lighter than surrounding elytra.

Elytra: Average length:width ratio 2.6:1; basal two thirds surrounded red-brown dorsally, one red-brown spot on each elytron in basal half, one broad red-brown postmedian fascia, apical margin of postmedian fascia on each elytron with a deep U-shaped emargination centrally, lateral margins yellow, vested with short decumbent and few longer erect setae, punctation very small and very weak, striae 1 to 4, 9 and 10 mostly obsolete, first punctures visible in striae 5, punctation very consistent in striae 6 to 8, interstices between and within visible striae smaller than one diameter of punctures, punctation never rasp-like, carination absent.

Legs: Yellow, tarsi slightly darker, tarsal pulvilli pale; metatibiae more or less straight, tibiae not carinated.

Abdomen: Ventrites light red-brown, punctation weak and sparse, interstices about two diameter of punctures; male pygidium suboblong, broadest in the middle, apical margin concave; male ventrite 6 with distinct deep U-shaped emargination. Male genitalia ( Fig. 36 ): Lateral margins of tegmen subparallel, parameres rounded apically, ventral sinus deeply V-shaped, dorsal sinus broader U-shaped; phallic plates broad; spicular fork dividing into two branches after one third of length.

Distribution: Laos.

Seasonal occurrence: Collected in May.

Etymology: The specific epithet, lugubris , a Latin adjective meaning mourning, refers to a sad looking face.

Figures

FIGURE 36. Xenorthrius lugubris: (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 66. Habitus photographs: Xenorthrius hoerrmanni n. sp. (A), Xenorthrius incarinipes (B), Xenorthrius lanatus n. sp. (C), Xenorthrius lineatipes (D), Xenorthrius loricus n. sp. (E) and Xenorthrius lugubris n. sp. (F). Scale bars = 4mm.