Stereoborus chinensis Omar and Zhang, 2007

Cantil, L. F., Sánchez Conicet, M. V., Dinghi, P. A. & Genise Conicet, J. F., 2007, Fig. 2 in Food Relocation Behavior, Nests, and Brood Balls of Canthon quinquemaculatus Laporte de Castelnau (Coleoptera: Scarabaeidae: Scarabaeinae), The Coleopterists Bulletin 24 (2), pp. 200-207 : 202-206

Stereoborus chinensis Omar and Zhang , new species

( Figs. 1–16 )

Holotype. China. Xizang: Male [Chayu [28.38 N, 97.29E] Tiyu, Chayu, Xizang Autonomous Region, 25.VII.1973; Coll. Unknown (Institute of Zoology, the Chinese Academy of Sciences, Beijing)].

Paratypes. 4 male, 10 female specimens, same data as the holotype .

Diagnosis. Rostrum wider than long; head and disc of pronotum with dense, fine punctures; pronotum: with a black collar anteriorly, more narrow anteriorly than posteriorly, with a deep, circular, unevenly distributed punctures; elytra fuscous, glossy, with a greenish-blue tint; tibia normal, nearly straight, widening slightly distally.

Description. Male. BL: 5.75–6.09 mm; EL: 3.25–3.36 mm; EWB: 1.75– 2.10 mm; EWW: 1.75–2.10 mm; PL: 1.56–1.69 mm; PW: 1.56–1.60 mm; RL: 0.37–0.38 mm; RWA: 0.87–0.90 mm; RWB: 0.83–0.89 mm; AL: 1.23–1.41 mm; ASL: 0.30–0.34 mm; AFL: 0.34–0.38 mm; ACL: 0.34–0.35 mm; ACW: 0.25– 0.26 mm. Habitus ( Figs. 1 and 2 ) oblong, linear. Color: ranges from castaneous to dark castaneous, with a dark reddish-brown tint, glossy. Rostrum stout, short, wider than length, shagreened, sparsely, shallowly fine punctate; with a single tubercle in middle at base of rostrum; frons with two shiny tubercles, confluent together to form longitudinal elevation ( Figs. 5 and 6 ). Scrobe well-defined, deep, upper anterior margin in line with middle of eye, then slanting to run underneath eye at posterior margin, point of antennal insertion at middle of rostrum. Antenna brownish-red with pilose club; scape: short; funicle: with 7 articles, first article stout, width equal to length; second article longer than wide, articles 6 and 7 wider than long with sub-erect setae, other articles sub-equal; club: longer than wide, oval, composed of 3 articles; articles 2 and 3 setigerous, setae sub-erect towards apex. Head shallow constriction behind eye, shagreened, oval, frons and anterior 2/3 matte with minute circular punctures, punctures separated by 1–3X puncture diameter, posterior 1/3 with more sparse, fine punctures, their density decreasing towards vertex. Eyes oval, black, prominent, with coarse, convex facets; clearly separated from head. Pronotum with a black collar anteriorly, more narrow anteriorly than posteriorly, deep, circular, unevenly distributed punctures, punctures separated by 2–4X puncture diameter, posterior margin bi-sinuate.

Scutellum glossy, subcircular, positioned slightly below level of elytra. Elytra shiny, with greenish-blue tint, convex, smooth, lateral margin crenulate, striae with shallow, circular punctures, punctures separated by approximately 1–2.5X puncture diameter, striae 3 and 7 fused at beginning of declivity, as are striae 4 and 6; intervals smooth, fine and sparsely punctate, sub-equal, slightly convex.

Humeri slightly umbonate, forming an angle slightly greater than 90 degrees.

Venter pro-sternum with coxal cavity closed, pro-coxae separated by approximately 0.5X diameter of coxa, a slight depression in front of procoxae anteriorly; meso-sternum transverse, meso-coxae separated by approximately 0.75X diameter of coxa, coxal cavity open; meta-sternum with posterior margin bisinuate, a longitudinal sulcus medially, coxal cavity open, coxae separated by approximately 0.5X diameter of coxa; with minute, circular punctures bearing pale, yellowish appressed setae. Ventrite I transverse, II slightly shorter than I, I and II separated with a clear suture, III and IV narrow, V transverse, sparsely punctate. Leg with femur glossy, shiny, robust, laterally flattened, with sparse, minute punctures; tibia nearly straight, widening slightly distally; protibia enlarged, widening much more distally and laterally flattened; with large and arcuate uncus at outer margin, small mucro at inner margin, with minute, sparse, circular punctures, bearing small, pale, yellowish setae; tarsus brownish-red, with 5 tarsomeres, each with a ventral white tuft of setae at apex, tarsomere 1 approximately equal in length to 2 and 3 combined, 2 and 3 short, sub-equal, 5 slightly longer than 1, curved, glossy, glabrous; pre-tarsal claw simple, long, free.

Male genitalia. Aedoeagus lateral view, dorsal view and speculum gastrale, illustrated in ( Figs. 9–11 ).

Female measurements. BL: 5.44–7.19 mm; EL: 3.06–3.67 mm; EWB: 1.50– 1.95 mm; EWW: 1.65–2.03 mm; PL: 1.50–1.88 mm; PW: 1.53–2.03 mm; RL: 0.34–0.50 mm; RWA: 0.78–1.08 mm; RWB: 0.74–1.03 mm; AL: 1.26–1.63 mm; ASL: 0.30–0.45 mm; AFL: 0.32–0.50 mm; ACL: 0.34–0.38 mm; ACW: 0.30– 0.32 mm. Female genitalia. Hemisternites; spermatheca and 8th sternite, illustrated in ( Figs. 14–16 ). Female inner structure. metendosternite, ventral view, and proventriculis illustrated in ( Figs. 12 and 13 ).

Sexual dimorphism. Male with two tubercles on frons and rostrum ( Figs. 1, 2 , 5 and 6 ); shiny; head and rostrum with fine, sparse punctures. In females frons with a shallow fovea ( Figs. 3, 4 , 7 and 8 ); the head of female also has a greenishblue tint.

Etymology. The specific name is derived from China, the country in which this species was collected.

Host Plant. Pinus yunnanensis Franchet.

Distribution. Xizang Autonomous Region, China.

Discussion. The genus Stereoborus previously contained nine species; those can be distinguished by the above key from each other as well as from S. chinesis . Besides the previous key, also, Voss’s key ( Voss 1951) is a good tool for distinguishing the four New Guinean species, S. robustus , S. affinis , S. punctirostris and S. inductus , from the new species, S. chinesis . The other three, S. laporteae , S. interstitialis and S. brevirostris , from Australia are be distinguished from the new species by their length, which ranges between 4.50– 5.00 mm and the new one between 5.44–7.19 mm; as well as their scape either as long as funicle, equal or little longer than funicle and club combined where the scape of the new one is shorter than funicle ( Lea 1896 and 1915). The Indonesian species, S. monticola , has tibia wide, cuneiform, and with interior margin dentate and concave ( Voss 1957) where S. chinensis has a normal tibia. The Samoan species, S. binodifrons , is distinguished by its stria 10 with a carina below it and its mesepimeron impressed on its posterior half and with a trace of shallow punctures along the anterior edge of the impression ( Marshall 1921) which those characters are absent in the new species.

Figures

Figs. 1–2. S. chinensis: male. 1, lateral view; 2, dorsal view.

Figs. 3–4. S. chinensis: female. 3, lateral view; 4, dorsal view.

Figs. 5–8. S. chinensis head and rostrum. 5) male, dorso-anterior view; 6) male, lateral view. 7) female, dorso-anterior view; 8) female, lateral view.

Figs. 9–11. S. chinensis: male genitalia. 9) aedeagus, lateral view; 10) aedeagus, dorsal view; 11) spiculum gastrale.

Figs. 12–16. S. chinensis: metendosternite, proventriculis and female genitalia. 12) metendosternite, ventral view; 13) proventriculis; 14) hemisternites; 15) spermatheca; 16) 8th sternite.