Morphostenophanes planus Zhou

Zhou, De-Yao, 2020, A revision of the genus Morphostenophanes Pic, 1925 (Coleoptera, Tenebrionidae, Stenochiinae, Cnodalonini), Zootaxa 4769 (1), pp. 1-81 : 69-71

Morphostenophanes planus Zhou , new species ḎṮẎȐAEƤ

( Figs. 45 A–D; 47D, I, N, S; 48D, H, S–U; 49C, G, J)

Type materials. CHINA: Yunnan: ♂ (Holotype, SNUC) , Diqing Prefecture , Weixi County, 27°6’18.32”N, 99°3’30.64”E, 3500 m, 2018.iii, native collector. Paratypes (8♂♂, 3♀♀) : CHINA: Yunnan: 1♀ ( SNUC) , 2 ♂♂, 1♀ ( MHBU) , 4 ♂♂, 1♀ ( CZDY, a male was preserved in 99.7% ethanol at –18 °C) , Diqing Prefecture , Weixi County, 27°6’18.32”N, 99°3’30.64”E, 3500 m, 2018.iii, native collector; 2 ♂♂ ( CZDY) , Weixi County, near Paidi , 2019. iv, native collector .

Diagnosis. Small, elongate and flattened species, with bronzy metallic luster. Pronotum coarsely punctate. Elytra with irregularly scattered short strial punctures, intervals moderately convex. Mesotibiae curved in apical third. Sternites III and IV depressed in posterior middle, with central portions of impressions convex.

Description. Male ( Fig. 45A, C ). Bronzy, antennae and mouthparts dark brown; tarsi green; major portions of femora and claws reddish brown. Body elongate, length 15.5–17.4 mm, width 5.0–6.0 mm, moderately convex dorsad, noticeably constricted between pronotum and elytra.

Head ( Fig. 47D, I ) somewhat semicircular, densely and coarsely punctate, with outer margin faintly notched between genae and clypeus; clypeus transversely hexagonal, slightly convex in middle, gently bent downwards in front, with apex slightly rounded, emarginate in middle, frontoclypeal suture finely depressed, widely U-shaped; genae gently raised, depressed before eyes, gently and roundly produced anterolaterally; frons rather broad, distinctly sloping forwards; eyes transversely reniform, moderately convex laterally; inner ocular sulci faint in front, sharp and deep along inner margins and becoming shallower and broader posteriorly; tempora moderately convex, coarsely punctate. OI = 57.3–59.0. Antennae ( Fig. 48D ) slender, reaching basal sixth of elytra, with antennomeres weakly thickened to apices; relative lengths of antennomeres: 0.49: 0.26: 0.71: 0.66: 0.65: 0.68: 0.77: 0.68: 0.66: 0.65: 0.80. Mentum ( Fig. 47I ) quadrate, lateral margins rounded; medial surface wrinkled and coarsely punctate, with several large pores bearing long setae, gradually rising anteriorly, depressed in posterior half of both sides.

Pronotum ( Fig. 47N ) barrel-shaped, PW/PL = 1.12, finely microsculptured, widest in middle or slightly after basal third, anterior margin nearly straight, anterior marginal border faintly presented, obscured or completely interrupted in middle; lateral margins weakly rounded, occasionally broadened in posterior third, lateral marginal borders thin; posterior margin emarginate, posterior marginal border marked; anterior angles rounded, slightly produced anteriorly; posterior angles obtuse; disc weakly convex, coarsely punctate. Scutellum widely triangular, smooth, sparsely scattered with small punctures.

Elytra ovate, rather elongate, widest near middle, EL/EW = 2–2.05; slightly more convex than pronotum, highest near basal third; disc with irregularly scattered short strial punctures; intervals moderately convex, with sharply marked scattered punctures.

Prosternum ( Fig. 47S ) rugulose, finely and sparsely punctate; prosternal process declivous, truncate at apex; hypomeron strongly rugulose, sparsely and finely punctate. Metasternum weakly wrinkled and finely punctate, metaventral anterior process transversely wrinkled. Abdomen ( Fig. 48H ) depressed, surface somewhat wrinkled, coarsely punctate; sternites III and IV depressed in posterior middle, with central portions weakly convex.

Legs slender. Protibiae ( Fig. 48S ) curved in near apical third, apical half of inner margins pubescent; mesotibiae ( Fig. 48T ) strongly curved in apical third, apical half of inner margins pubescent; metatibiae ( Fig. 48U ) nearly straight, outer margins widely emarginate in middle, more than half of apical part of inner margins pubescent, outer margins weakly depressed before apices.

Aedeagus ( Fig. 49C ) elongate, curved in lateral view, with a pair of large pits on apical flank of basal piece; parameres slender, gently curved towards dorsally in basal half, dorsum weakly ridged along midline, 0.23 as long as total length, with broadly widened and flabellate apex, bearing apical marginal carina. Apical lobes of sternite VIII ( Fig. 49G ) with rounded interior margins.

Female ( Fig. 45B, D ) slightly larger than male, length 16.6–18.6 mm. Distance between eyes longer, OI = 60–61.3; more constricted between pronotum and elytra; lateral margin of pronotum evenly and weakly rounded, PW/PL = 1.12; elytra more convex and widened, EL/EW = 1.86–1.98; abdomen straight in lateral view, without depressed area on sternites III and IV. Ovipositor ( Fig. 49J ) shortened, apex beveled.

Variability. The holotype has pronotum widest behind basal third, lateral margins distinctly widened at the widest point (as shown in Fig. 45A ), such character states are indistinct or missing in other males (as shown in Fig. 47N ). Considering that the holotype bears the largest body size, these features indicate that the holotype was a well-developed individual.

Comparative notes. This new species resembles Morphostenophanes crassus , M. jendeki jendeki and M. jendeki similis . They share small body and similar elytral sculpture. M. planus can be distinguished from these congeners by flattened body with bronzy luster, more coarsely punctate pronotum, more elongate elytra, and more rounded produced apical lobe of male sternite VIII.

Distribution. ( Map 1 ) CHINA: Yunnan.

Etymology. The new species is named from the Latin epithet ‘planus’ referring to its flattened body.

Figures

Map 1. Distribution of the Morphostenophanes species. A. Enlargement of Central and Western Yunnan Province.

FIGURE 45. Habitus of Morphostenophanes planus Zhou new species. Male (A, C), and female (B, D); in dorsal (A, B), and lateral view (C, D). Scale bars = 3 mm.

FIGURE 47. External characters of Morphostenophanes species in the jendeki-group: M. crassus Zhou new species (A, F, K, P), M. jendeki jendeki Masumoto (B, G, L, Q), M. minor Zhou new species (C, H, M, R), M. planus Zhou new species (D, I, N, S), M. tanikadoi Masumoto (E, J, O, T). Male heads in dorsal (A–E) and ventral view (F–J); male prothoraces in dorsal (K–O) and ventral view (P–T). Scale bars = 1 mm.

FIGURE 48. External characters of Morphostenophanes species in the jendeki-group: M. crassus Zhou new species (A, J–L), M. jendeki jendeki Masumoto (B, M–O, F), M. minor Zhou new species (C, P–R, G), M. planus Zhou new species (D, S–U, H), M. tanikadoi Masumoto (E, V–X, I). Male antennae in dorsal view (A–E); abdomens (F–I); protibiae in dorsal view (J, M, P, S, V), mesotibiae in ventral view (K, N, Q, T, W), and metatibiae in dorsal view (L, O, R, U, X). Scale bars = 1 mm.

FIGURE 49. Anatomic structures of Morphostenophanes species in the jendeki-group: M. crassus Zhou new species (A, E), M. minor Zhou new species (B, F, I), M. planus Zhou new species (C, G, J), M. tanikadoi Masumoto (D, H). Aedeagi (A–D), male sternites VIII (E–H), and female reproductive organs (I, J); in dorsal view (d), lateral view (l), and enlargements of parameres apices (p). Scale bars of A–H= 1 mm; I, J = 2 mm.