Morphostenophanes atavus ( Kaszab, 1960 )

Zhou, De-Yao, 2020, A revision of the genus Morphostenophanes Pic, 1925 (Coleoptera, Tenebrionidae, Stenochiinae, Cnodalonini), Zootaxa 4769 (1), pp. 1-81 : 42-44

Morphostenophanes atavus ( Kaszab, 1960) ÑẎȐAEƤ

( Figs. 25 A–G; 31A, E, K, P; 32A, G–I; 33A, G)

Promorphostenophanes atavus Kaszab, 1960: 278 (type locality: Yunnan), fig. 9; Ando & Ren 2006: 90; Löbl et al. 2008: 347; Gao & Ren 2009: 311.

Morphostenophanes atavus ( Kaszab, 1960) : Masumoto & Bečvář 2008: 209, fig. 4; Gao & Ren 2009: 311 , figs. 16–22, 43 [misidentification of Morphostenophanes brevigaster ].

Type material examined. Holotype of Promorphostenophanes atavus labelled: ‘ Yunnan Tientshun [handwritten in pink label] // Holotypus 1960 Promorphostenophanes atavus Kaszab [handwritten on a pink label with red border]’ (female, HMHM, Fig. 25 C–G). Examined through five photographs taken by Tamás Németh ( HNHM) and sent by Ottó Merkl .

Additional material examined (1♂). CHINA: Yunnan : 1♂ ( MYNU), east slope of Mount Gaoligong , 25°17’48.33”N, 98°45’52.98”E, 2402 m, 2014.iv.11, at night, Xuan-Kong Jiang & Tian Lu .

Diagnosis. Body large and elongate, black. Antennae short, reaching basal 2/7 of elytra; Pronotum widest in anterior fourth; elytra striate, with aspect ratio exceeding 1.8 in male, and 1.7 in female; apical spurs of mesotibiae exposed and visible in ventral view; metafemora reaching anterior half of sternite VII; metatibiae nearly straight; apical lobes of sternite VIII narrowly hooked in lateral view.

Description of male. Male ( Fig. 25A, B ). Color black, antennae, all tibiae, mouthparts, and claws reddish brown, shagreened. Body elongate, length 23.7 mm, width 8.4 mm, strongly convex, noticeably constricted between pronotum and elytra.

Head ( Fig. 31A, F ) transversely quadrate, sparsely and finely punctate, with outer margin distinctly notched between genae and clypeus; clypeus transversely hexagonal, slightly convex in middle, gently bent downwards in front, anterior margin nearly straight, weakly emarginate; frontoclypeal suture finely depressed, widely U-shaped, weakly protruding backwards in middle; genae strongly raised, depressed before eyes, strongly and roundly produced anterolaterally; frons broad, anterior part gradually sloping forwards, flattened in middle; eyes transversely reniform, strongly convex laterally; inner ocular sulci finely depressed, moderately grooved along inner margins, becoming broader posteriorly; tempora moderately convex, more coarsely punctate than frons. OI = 46.4. Antennae ( Fig. 32A ) slender, reaching basal 2/7 of elytra, with antennomeres weakly thickened to apices; relative lengths of antennomeres: 0.71: 0.34: 1.19: 1.14: 1.29: 1.31: 1.29: 1.16: 1.14: 1.04: 1.19. Mentum ( Fig. 31F ) inversely trapezoidal, lateral margins weakly rounded; medial surface finely punctate, with several large pores bearing long setae, gradually rising from base to apex, depressed along both sides.

Pronotum ( Fig. 31K ) inversely trapezoidal, PW/PL = 1.10, widest in anterior fourth, anterior margin nearly straight, anterior marginal border fine, interrupted in middle; lateral margins weakly rounded, lateral marginal borders thin, visible in dorsal view slightly before anterior half; posterior margin weakly rounded, emarginate in middle, posterior marginal border marked; anterior angles rounded; posterior angles obtuse; disc strongly convex, shagreened, finely and sparsely punctate, with a pair of vague impressions on middle. Scutellum widely triangular, glossy, finely punctate.

Elytra elongate oval, widest near middle, EL/EW = 1.84; strongly convex, highest in basal 2/5; with 9 continuous furrowed striae; 9 th stria branching before apex, 1 st and 9 th, 2 nd and 7 th, 3 rd and 6 th, and 4 th and 5 th, converging at ends, 2 nd and 3 rd, and 5 th and 6 th converging at anterior ends; intervals strongly convex, shagreened, sparsely and finely punctate.

Prosternum ( Fig. 31P ) shagreened, finely and sparsely punctate; prosternal process declivous, truncate at apex; hypomeron weakly rugulose, shagreened. Metasternum glossy, metaventral anterior process weakly wrinkled. Abdomen depressed, somewhat rough and finely punctate, sternites III and IV sulcate on both sides, sternite V depressed laterally.

Legs slender. Protibiae ( Fig. 32G ) weakly curved, apical 3/5 of inner margins pubescent; mesotibiae ( Fig. 32H ) weakly curved near apical third, apical 3/5 of inner margins pubescent, ventral apical tuft interrupted, mesotibial spur uncovered (marked in Fig. 32H ); metatibiae ( Fig. 32I ) straight, apical 3/5 of inner margins pubescent, outer margins depressed before apices.

Aedeagus ( Fig. 33A ) elongate, curved in lateral view; parameres slender, 0.22 as long as total length, with ovoid apex. Sternite VIII ( Fig. 33G ) with apical lobes narrowly hooked in lateral view.

Comparative notes. Morphostenophanes atavus most resembles M. brevigaster . They share similar appearance and indistinguishable aedeagi. However, M. atavus can be easily distinguished from M. brevigaster by its shorter antennae which reaches 2/7 of elytra, compared to those of M. brevigaster reaching third of elytra; each antennomere less sharply dilated towards apex; pronotum widest in apical fourth, compared to that of M. brevigaster widest near the middle; elytra more elongate, highest posterior to the midpoint, compared to those of M. brevigaster highest anterior to the midpoint; elytral striae less depressed than those of the latter; all legs shorter, metafemora reaching anterior half of sternite VII, compared to those M. brevigaster reaching apex of sternite VII; protibiae in male evenly curved, compared to that of M. brevigaster curved at apical third; mesotibiae with apical spur exposed and visible in ventral view, compared to those of M. brevigaster covered by tuft and obscured; metatibiae slightly more straight; apical lobes of male sternite VIII narrowly hooked, compared to those of M. brevigaster broadly hooked.

Comments. Morphostenophanes atavus was described from a single female from ‘Yunnan’ without detailed location (‘ohne nähere Angabe des Fundortes’ in original description). The male was then illustrated by Masumoto & Bečvář (2008), identified as M. atavus , however, no description or locality was given. Later, Gao & Ren (2009) provided detiled locality for this species, as well as a photograph of the female.

In the present study, the author examined the holotype of M. atavus through photos. Specimens with similar appearances from three localities were studied, with one male from the eastern slope of Gaoligong Mountains, and two series containing both males and females from Yingjiang County and an adjacent area and Lincang City. According to the original description, the elytral aspect ratio of the M. atavus holotype female is 1.7, which is different from those from around Yingjiang County with an average ratio of 1.59 (n = 10) and maximum of 1.65. Moreover, the elytral striae of the M. atavus holotype are distinctly less depressed than those of the latter. The elytral aspect ratio of those from Lincang ranges from 1.7 to over 1.9, which matches that of the M. atavus holotype, but they are distinctly different by the latter having much more convex pronotum and elytra. The elytral aspect ratio of the male from the western slope of Gaoligong Mountains is 1.84, which is comprable to the M. atavus female. Moreover, this male has antennomeres less thickened anteriorly, elytral intervals less convex, and ventral apical tuft is interrupted, which are identical with those of the female holotype. Therefore, this male from the Gaoligong Mountains is identified as M. atavus . The female holotype possesses bulges at each side of the base of the pronotum, which are indistinct in the male. This is probably due to interspecific variation. Specimens from Yingjiang County and Lincang City are identified as belonging to M. brevigaster and M. lincangensis .

On the label of M. atavus holotype, the author found ‘Tientshun’ after the locality ‘Yunnan’, which refers to ‘Tengchong’, a city reaching the western slope of the Gaoligong Mountains. Such detailed locality was not mentioned in the original publication. The type locality associated with data of here examined male suggest a potential distribution of M. atavus along the southern Gaoligong Mountains, spreading over both slopes of mountains.

The male specimen in Masumoto & Bečvář’s photograph (2008, Fig. 4 ) was in dorsal view, so the author measured its elytral aspect ratio, the result is 1.86. Moreover, its pronotum is constricted before the base, and its protibiae are only slightly curved, based on the revised diagnostic characters, it is undoubtedly a true M. atavus . Based on the known distribution, the female specimen mentioned by Gao & Ren (2009) from Yingjiang county is considered a misidentified of M. brevigaster .

Distribution. ( Map 1 ) CHINA: Yunnan.

Figures

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

FIGURE 4. Habitus of Morphostenophanes aenescens Pic. Male from Xishan District, Qujin City (A, C) and female from Mianmian Mountain (B, D); in dorsal (A, B) and lateral view (C, D). Scale bars = 5 mm.

FIGURE 25. Habitus of Morphostenophanes atavus (Kaszab). Male in dorsal (A) and lateral view (B). Holotype female in dorsal (C), ventral (E) and lateral view (G), with an enlargement of ventral apical portion of left mesotibiae (D), and labels (F). Scale bars of A, B = 5 mm; C–G not to scale.

FIGURE 31. External characters and anatomic structure of Morphostenophanes species in the atavus-group: M. atavus (Kaszab) (A, E, K, P), M. bannaensis Zhou new species (B, G, L, Q), M. birmanicus (Kaszab) (C, H, M, R), M. brevigaster Zhou new species (D, I, N, S), M. lincangensis Zhou new species (E, J, O, T, Y), and M. vietnamicus (Kaszab) (U–X, Z). Male heads in dorsal (A–E, U) and ventral view (F–J, W); male prothoraces in dorsal (K–O, V) and ventral view (P–T, X); female reproductive organs (Y); and male mesotibiae in dorsal view (Z). Scale bars of A–X = 1 mm; Y = 2 mm.

FIGURE 32. External characters of Morphostenophanes species in the atavus-group: M. atavus (Kaszab) (A, G–I), M. bannaensis Zhou new species (B, J–L), M. birmanicus (Kaszab) (C, M–O), M. brevigaster Zhou new species (D, P–R), M. lincangensis Zhou new species (E, S–U), and M. vietnamicus (Kaszab) (F, V–X). Male antennae in dorsal view (A–F). Male protibiae in dorsal view (G, J, M, P, S, V), mesotibiae in ventral view (H, K, N, Q, T, W) and metatibiae in dorsal view (I, L, O, R, U, S). Scale bars = 2 mm.

FIGURE 33. Anatomic structures of Morphostenophanes species in the atavus-group: M. atavus (Kaszab) (A, G), M. bannaensis Zhou new species (B, H), M. birmanicus (Kaszab) (C, I), M. brevigaster Zhou new species (D, J), M. lincangensis Zhou new species (E, K), and M. vietnamicus (Kaszab) (F, L). Aedeagi (A–F) and male sternites VIII (G–L); in dorsal view (d), lateral view (l), and enlargements of parameres apices (p). Scale bars = 1 mm; all parameres apices not to scale.