Scolytoplatypus geminus Gebhardt & Beaver, 2021

Gebhardt, Heiko, Beaver, Roger A. & Allgaier, Christoph, 2021, Three new species of Scolytoplatypus Schaufuss from China, and notes on the movement and functions of the prosternal processes (Coleoptera: Curculionidae: Scolytinae), Zootaxa 5082 (5), pp. 485-493 : 489-490

Scolytoplatypus geminus Gebhardt & Beaver sp. nov.

Fig. 1G–M , 2B

Type material. Holotype: male: CHINA, Yunnan, Lijiang , 27.1433N, 100.2266E, 3221 m, 18.v.2018, G02, LJ(X)3200-4FI, L.Z. Meng ( CAS, 1m) . Paratypes: as previous except: 27.1435N, 100.2261E, 3244m, 28.vi.2018, LJ(X)3200-3FI ( RAB, 1m); as previous except: 27.1663N, 100.2350E, 3551 m, 28.v.2018 , LJ(X)3600-5FI ( CAS, 2m; RAB, 3m); as previous except: 27.1657N, 100.2354E, 3545 m, 3.vi.2018 , LJ(X)3600-3FI ( NHMUK, 3m; NHW, 3m; HGT, 3m) .

Diagnosis. The species is distinguished from most Asian species of Scolytoplatypus by the lack of a tooth on the upper side of the profemur, and the absence of spines or teeth at the summit of the elytral declivity. It is most closely similar to S. blandfordi Gebhardt , which it resembles in its elongate body with elytra about 1.7‒2.0 times as long as pronotum, elytral declivity beginning in apical third of elytra, and prosternum raised in a triangle with apex anterior. However, it is distinguished from S. blandfordi by characters of the male frons and anterior processes of the prosternum. In S. geminus , lower half of frons shining, slightly gibbous towards sides at level of antennal insertions; marginal fringe of setae on upper half of the frons short, with tips of setae rarely reaching midline, and not overlapping; underlying hairlike setae forming the vestiture below the marginal fringes more numerous, more closely placed, longer and finer. In S. blandfordi , lower half of frons matt, not gibbous towards sides; marginal fringe of setae on upper part of the frons much longer, setae meeting in midline and slightly overlapping; setae forming underlying vestiture less closely placed, shorter and slightly coarser. In S. geminus , anterior end of raised prosternal triangle ends in a sharply pointed projecting tip; anterior processes of prosternum directed anteriorly, diverging at an angle of about 60 o ( Fig. 2B ). In S. blandfordi , anterior tip of raised prosternal triangle rounded or truncate; anterior processes directed laterally, diverging at an angle of about 160 o ( Fig. 2E ).

Description:

Male: 2.9‒3.3 mm long, about 2.1 times as long as wide, yellowish-brown to brown, anterior half of pronotum, elytral suture, margins and declivity usually darker.

Frons. Concave, lower half shining, the whole surface minutely reticulate, a triangular area above the epistoma glabrous and unpunctured, slightly gibbous on each side at the level of the antennal insertions, the surface above the triangle finely, moderately densely punctured, bearing grey-white, fine, hairlike setae directed towards the midline, the setae erect at margins of frons, becoming appressed towards centre, but with upwardly curved tips near midline; margin from top of eye to near the vertex with longer, incurved, pale yellowish fine hair-like setae, their tips not reaching the middle of the frons.

Antennal club. 1.8 times longer than wide, nearly oval, widest near the middle, the surface covered with pale, appressed hairs, apex with a few, long, dark setae, anterior margin with a row of, widely separated, long, strong, dark setae.

Pronotum. 1.2 times wider than long, anterior margin with a median emargination, pronotum widest just before the middle, constricted posteriorly, posterior angles moderately pointed, posterior margin slightly produced in the middle, surface minutely reticulate, finely, distantly punctured, the punctures usually separated by 3‒5 times their diameter, towards the posterior margin more densely punctured, surface on the anterior two-thirds with semi-erect hairlike setae directed posteriorly, setae on posterior portion more appressed, shorter, those near mid-line directed laterally, anteroventral angles with an orbicular fovea extending to anterior and ventral margins.

Prosternum. Triangularly raised in the middle, apex of triangle anterior and sharply pointed, punctures with setae directed posteriorly, anterior to apex of triangle with two curved falcate processes, with sharply pointed tips, diverging at an angle of about 60 o, between them a very small, rounded process with numerous setae.

Procoxae. Flattened anteriorly, slightly swollen posteriorly, with coarse, yellow setae, longer and denser at the anterior tip and the posterior margin, the longest hairs a little longer than the length of the procoxa, not forming a distinct brush.

Elytra. 1.3‒1.4 times longer than wide, about two times longer than pronotum, wider than pronotum, scutellum sunken, from dorsal view sides nearly straight, weakly diverging, on posterior fourth strongly converging to the rounded apex, from lateral view the convex declivity beginning about three-fourths from base, elytral base carinate, disc shining, striae and interstriae indistinct, with irregular, fine, punctures, bearing short, yellowish, erect hairlike setae; towards declivity, setae longer, and punctures more densely placed and larger; on summit of declivity punctures closely spaced, declivity dull with distinct and moderately close punctures, setae on upper part long, erect, towards the apex shorter and appressed, declivity with feebly impressed striae, interstriae densely rugulose-granulate on upper part, on lower part interstriae 1, 3 and 5 with a row of larger granules, apical margin carinate, with small, acutely pointed spines laterally on interstriae 9.

Female: Not known. Probably very similar to that of S. blandfordi .

Distribution. China (Yunnan). A montane species found only above 3000 m.

Etymology. The name refers to the similarity to Scolytoplatypus blandfordi Gebhardt , from the Latin geminus = twin.

Host plants. Unknown.

Figures

FIGURE 1. Habitus and details of Scolytoplatypus spp. nov.: S. costatus male (2.2‒2.3 mm), habitus dorsal (A), habitus lateral (C), frons anterior (D); S. costatus female (2.3‒2.4 mm), habitus dorsal (B), habitus lateral (E), frons anterior (F); S. geminus male (2.9‒3.3 mm), habitus dorsal (G), pronotum (H), habitus lateral (I), frons anterior (J), pronotum anteroventral with f = fovea (K), declivity (L), prosternum (M); S. peniculatus male (4.7‒4.8 mm), habitus dorsal (N), habitus lateral (P), frons anterior (Q); S. peniculatus female (4.9‒5.3 mm), habitus dorsal (O), habitus lateral (R), frons anterior (S). The bars represent 0.5 mm.

FIGURE 2. Male prosternum of Scolytoplatypus costatus, S. geminus and S. peniculatus in comparison to their close relatives: S. costatus (A), S. geminus (B), S. peniculatus (C), S. zahradniki (D), S. blandfordi (E), S. pubescens (F). The bars represent 0.5 mm.