Tarchius yunnanensis Omar et Zhang

Omar, Youssef Mohamed, Han, Kyungduk & Zhang, Runzhi, 2006, Description of a new species, Tarchius yunnanensis (Coleoptera: Curculionidae: Cossoninae), from China, Zootaxa 1270, pp. 35-43 : 37-39

Tarchius yunnanensis Omar et Zhang , new species

( Fig. 11 )

Holotype. China. Yunnan: Female [Mengla [21.4N, 101.5E], Xishuangbanna, Yunnan Province; 620–650m, 9­VI­1959; collected by Pu Fuji ( IOZ)]. Paratypes. 7 female specimens, same data as the holotype.

Diagnosis: Antennal scape twice as long as wide; first segment of antennal funicle a little longer than wide; antennal club longer than greatest width; pronotum with sparse, fine punctures, space between punctures wider than the diameter of puncture; anterior margin of pronotum slightly narrower than base; pronotum widest at middle; elytra very short, length 1.26 width; elytral intervals flat.

Description. Holotype, female. Size ( Fig. 1 ): BL: 2.92 mm; EL: 1.80 mm; EWB: 0.92 mm; EWW: 1.48 mm; EH: 0.84 mm; PNL: 0.84 mm; PNW: 1.12 mm; RL: 0.41 mm; RWA: 0.38 mm; RWB: 0.34 mm; AL: 0.56 mm; ASL: 0.15 mm; AFL: 0.22 mm; ACL: 0.19 mm; ACW: 0.13 mm. Habitus: stocky, convex. Colour: derm black, glossy; tibia glossy with some reddish­brown colour; tarsi and antennae yellowish. Head: opaque, oval, with fine punctures sparsely; rostrum stout, slightly convex, with fine punctures sparsely, with small fovea at base; epistoma obscure ( Fig 2 ); antennal scrobe lateral, curved downward before eye, well­defined, deep, the point of antennal insertion located on anterior two third of rostrum; antenna glossy, brownish, long, stout; antennal club with tawny pubescences; antennal scape short; antennal funicle with a clear seven segments, first one stout, others sub­equal; antennal club with 4 antennomeres, antennomeres 1, 2 and 3 with setae sub­erected toward apex, antennomeres 1 as long as the length of 2 + 3 ( Fig. 4 ); eyes oval, black, flat, with coarse convex facets, clearly separated from head, widely interocular. Prothorax: pronotum globular, both sides strongly inflated, anterior margin slightly constricted and rounded, basal margin with weakly bisinuate constricted area forming a frame, with fine circular punctures sparsely, distances between punctures broader than diameter of a puncture; Legs: femur glossy, robust, inflated, inside slightly tumid, outside slightly pressed; tibia with strongly arcuated uncus and small mucro on the other side, apex reddish­brown, both sides of tibia straight and parallel ( Fig. 5 ); tarsus with 5 tarsomeres, yellowish, with 4–6 setae at apex, seta 1 to 3 from inside approximately equal in length, tarsomere 5 a little shorter than 1 + 4, long; tarsal claw simple, long curved, bifurcate. Scutellum: present, clearly visible, triangular in shape, convex; Elytra: strongly convex, surface smooth and shiny; lateral margin strongly sinuate upward near the middle (up the hind leg); striae formed by strong circular punctures, distance between each other broader than puncture diameter, striae 4 and 5 fused together and does not reach apex, as well striae 3 and 6 the same as the preceding, striae 9 fused with 10 at the middle part of each elytron ( Figs 8 & 9 ); intervals flat, smooth, impunctate; humeri strong, subquadrate, each humerus formed between anterior part of the striae 7 and 8; Ve n te r: prosternum narrow, procoxae contiguous; mesosternum broader than prosternum, with a mesosternal process pointing downwards below level of metasternum at the centralposterior margin; mesocoxae separated; metasternum with a weak central longitudinal groove, posterior margin bi­sinuate; metacoxae separated widely ( Fig. 6 ); ventrite I (sternite III) much broader than ventrite II, ventrite II a little broader than III+IV; ventrite III and IV narrow, glossy; ventrite V glossy, posterior margin sub­rounded, a little broader than II; suture between ventrite I and II ambiguous; sutures between ventrite II and III, III and IV, IV and V carved, forming a transverse groove at each suture ( Fig. 7). Female genital organs: Fig. 10 .

pronotum width.

Etymology. The specific name is based on the name of the type locality Yunnan Province in China.

Distribution. Known from the type locality only.

Remarks. In this genus, three species ( T. pinguis , T. impressifrons and T. anthrax ) are recorded from Indonesia (Sumatra and Java) and the new species described here is a new record of the genus for continental Asia. Members of the genus Tarchius are mainly found in mountain areas of the Oriental Region (based on the collection localities). It is very difficult to distinguish males and females. The three specimens dissected in this study are all females. It is thus possible that this new species could be parthenogenetic like some other weevils (e.g. Pseudocneorhinus spp.) distributed in southern part of Japan ( Hayashi and Morimoto, 1994; Han et al., 2000). However, we do not have biological data to support this hypothesis at the present.

Figures

FIGURE 1. Tarchius yunnanensis sp. nov. Dorsal view: BL, body length; EL, elytral length; EWB, elytral width of base; EWW, elytral width of the widest part; PNL, pronotum length; PNW,

FIGURE 6. Ventral view of meso­ and metasterna of Tarchius yunnanensis sp. nov. A: mesepisternum; B: mesepimeron; C: metepisternum; D: metepimeron.

FIGURE 10. Female genital organs of Tarchius yunnanensis sp. nov. A: ovary; B: ovipositor and spermatheca; C: 8 th sternite.

FIGURE 11. Tarchius yunnanensis sp. nov. A: dorsal view; B: lateral view; C: ventral view.

FIGURES 2 – 5. Tarchius yunnanensis sp. nov. 2: dorsal view of head and rostrum (RL: rostrum length; RWA: rostrum width of apex; RWB: rostrum width of base); 3: lateral view of head and prothorax; 4: antennae; 5: hind tibia.

FIGURES 8 – 9. Elytra of Tarchius yunnanensis sp. nov. 8: lateral view; 9: posterior view.