Rhinusa brisouti Caldara

Rhinusa brisouti (Faust, 1891)

Fig 2

Gymnetron brisouti Faust, 1891: 409. Reitter 1907: 41.

Rhinusa brisouti (Faust). Caldara 2001: 185. Caldara et al. 2010: 52. Alonso-Zarazaga et al. 2017: 203.

Type locality. Eastern Siberia (Russia).

Type series. This species was described from a single male, which we examined at SMTD, from Eastern Siberia without more detailed indication and with the following labels “[golden square card] / ♂ Sibiria, Eversmann / Bri- souti Faust / Brisout vid. / Coll. J. Faust Ankauf 1900 / TYPE [red card] / Staatl. Museum für Tierkunde Dresden / solutum / HOLOTYPE Gymnetron brisouti Faust det. R. Caldara 2019 [red card] / Rhinusa brisouti (Faust) Caldara det. 2013”.

Redescription. Male. Body: oval, stout (Fig. 2). Rostrum: reddish, short (Rl/Pl 0.62); in lateral view strongly curved, very stout in basal third, further slightly narrowed to apex (as in R. linariae, Fig. 10); in dorsal view with subparallel sides, with weakly visible antennal scrobes, striate-punctate in basal two thirds, further smoother and shining, in basal third with sparse recumbent short (l/w 2–3) whitish scales. Head: between eyes as wide as rostrum at base, without fovea. Eyes almost flat. Antennae: dark brown, inserted at middle of rostrum; scape 2.5× longer than wide, funicle distinctly longer than scape, with segment 1 twice longer than wide, slightly stouter than and about as long as segment 2, which is 2.5× longer than wide, segments 3–5 gradually more transverse; club short, oval, with segment 1 pubescent similarly to others. Pronotum: black, with dense and regular punctures, intervals between punctures narrow, smooth and shining, well visible between rather dense recumbent moderately long (l/w 4–8) setiform greyish brown scales; distinctly transverse (Pw/Pl 1.47), moderately constricted at apex, with distinctly rounded sides, widest at middle, almost flat. Elytra: reddish, short (El/Ew 1.12), suboval, 1.33× as wide as pronotum, with basal margin transverse until interstria 5, further moderately beveled anteriorly, with moderately rounded sides, widest between basal and middle thirds, weakly convex on disc; interstriae poorly visible between dense recumbent elliptical to sublanceolate greyish brown scales, 0.50–0.75× as long as width of interstria (l/w 4–7) and arranged in 3–4 irregular rows; striae well visible, half as wide as interstriae, with a row of scales distinctly narrower than those on interstriae. Legs: reddish, stout, with sparse recumbent to suberect whitish scales distinctly shorter than width of tibia; femora subclavate, without tooth; tibiae stout, distinctly sinuous at middle, protibiae with outer margin distinctly carinate; unci brown, thin, all of same size; tarsi with tarsomere 1 1.7× longer than wide, tarsomere 2 1.2× longer than wide, tarsomere 3 bilobed and distinctly wider than tarsomere 2, onychium as long as tarsomeres 1–3 taken together; claws brown, equal in length. Venter: metasternum black, with sparse subrecumbent long setiform whitish scales. Mesepimera, mes- and metepisterna with sparse long setiform whitish scales. Abdomen black except sternites 4 and 5 reddish, with dense and regular punctures, slightly visible between dense recumbent to subrecumbent setiform greyish brown scales; length ventrites 1+2/3+4 2.20. Penis: as in R. linariae (Fig. 27).

Female. Rostrum slightly longer (Rl/Pl 0.67) (as in R. linariae, Fig. 11), in dorsal view smooth and shining from antennal insertion to apex, antennae inserted between basal and middle thirds of rostrum. Spiculum ventrale and spermatheca as in R. linariae (Figs 33 and 39).

Variability. Length 2.6–3.0 mm. Sometimes elytral integument reddish brown and dorsal vestiture whitish with sericeous reflection. The body of the penis varies a little in length (l/w 5–6) and curvature in lateral view.

Remarks and comparative notes. This species differs from R. linariae by the integument of elytra and legs being reddish instead of black. In addition, the elytra are shorter, subquadrate, the pronotum is distinctly transverse and the protibiae have the outer margin distinctly carinate and distinctly directed outward apically. At first sight this species can be confused with R. soluta belonging to the R. neta group, with which it shares the habitus, characterized by subquadrate elytra and reddish colour of the integument. However, R. brisouti differs from R. soluta by the clear characters distinguishing the R. linariae group from the R. neta group (shape of the rostrum, lack of femoral tooth, shape of the aedeagus) and also by the carinate outer margin of the protibiae.

Biological notes. No data are available.

Distribution. Southern part of Eastern Siberia and Russian Far East, Mongolia.

Non-type material examined. Russia: Tuva Republic, Turan, Uyuk River, 11.VI.1980, leg. Korotyaev (1, ZISP); near mouth of Uyuk River, 3–5.VI.1995, leg. Marusik (1, ZISP); Zabaikal’skiy Territory (formerly Chita Province), Lake Bolshoi Chindant, 4.VII.1965, leg. Mordkovich (1, ISEA); Daurskii Nature Reserve, between lakes Zun-Torei and Barun-Torei, 26–29.V.1999, leg. Rudykh (1, RCCM). Mongolia: Central Aimak, Chentej, Tereldsh, Turtle Valley, 9–11.VI.1979, leg. Göllner (1, ZMHB). Bajan-Hongor, 17.VI.1976, leg. Popov, Ponomarenko & Pritykina (1, ZISP).