Stephostethus yuanfengensis, Rücker & Chan, 2021

Ho, Yu-Hsiang, Rücker, Wolfgang H. & Chan, Mei-Ling, 2021, On the genus Stephostethus LeConte, 1878 (Coleoptera: Latridiidae: Latridiinae) from Taiwan, with descriptions of two new species, European Journal of Taxonomy 735 (735), pp. 1-14 : 5-8

Stephostethus yuanfengensis sp. nov.

urn:lsid:zoobank.org:act:4DE4DC6D-203D-4AEF-8978-CE3E204EE6BF

Figs 4-6 , 10, 12

Diagnosis

This species is closely related to Stephostethus setosus Rücker, 2004 from China, but can be distinguished by the following characters: (1) hairs on elytra are shorter than those of S. setosus , (2) pronotum is more slender than that of S. setosus , and (3) structure of genital segments of male is different from that of S. setosus . In S. setosus , the apical end of the genital segments is sharper than in S. yuanfengensis sp. nov.

Etymology

The specific epithet, yuanfengensis , is named after the type locality, Yuanfeng, in central Taiwan.

Material examined

Holotype

TAIWAN • ♂; Nantou, Yuanfeng ; 8 Sep.–4 Oct. 2005; C.S. Lin and W.T. Yang leg.; Malaise trap; NMNS ENT 7393-180 .

Paratypes

TAIWAN • 1 ♂; Miaoli, Taian ; 19 Dec. 1989; K.W. Huang leg.; sweeping; NMNS ENT 1113-203 • 1 ♂; Taichung City, Heping, Qika ; 4 Apr. 2010; W.B. Yeh leg.; sweeping; NCHU • 1 ♂; Taichung City, Heping, Qika ; 24.387279° N, 121.284885° E; 5 Apr. 2009; W.B. Yeh leg.; sweeping Miscanthus ; WRCN • 1 ♂; Taichung City, Shei-Pa National Park ; 24.383298° N, 121.286318° E; 2 Apr. 2010; W.B. Yeh leg.; sweeping shrub; WRCN • 1 ♂; Nantou, Lienhuachih, Watersher n° 3; 1 Aug.–7 Sep. 2005; C.S. Lin and W.T. Yang leg.; Malaise trap; NMNS ENT 6773-89 • 1 ♂; Nantou, Jenai , Piluchi ; 4 Dec. 1991; Y.C. Shiau leg.; sweeping net; NMNS • 1 ♂; Hualien Hsien, Tayuling ; 2560 m a.s.l.; 9–16 Jun. 1980; K.S. Lin and B.H. Chen leg.; TARI • 1 ♂; Nantou Hsien, Meifeng ; 2150 m a.s.l.; 22 May 1982; L.Y. Chou leg.; TARI • 1 ♂; Nantou Hsien, Meifeng ; 2230 m a.s.l.; 10 May 1979; K.C. Chou leg.; TARI • 1 ♂; Nantou, Meifeng ; 5 Jul.–2 Aug. 2005; C.S. Lin and W.T. Yang leg.; Malaise trap; NMNS ENT 7488-934 • 1 ♂; Nantou, Yunhaipaohsienso ; 4 May 1992; W.T. Yang leg.; sweeping net; NMNS ENT 1447-1046 • 2 ♂♂; Nantou, Yuanfeng ; 7 Mar.–13 Apr. 2006; C.S. Lin and W.T. Yang leg.; Malaise trap; NMNS ENT 7421-36 , 7421-64 • 1 ♀; same collection data as for preceding; 5 Mar.–16 Apr. 2003; NMNS ENT 6603-19 • 1 ♂; same collection data as for preceding; 5 Mar.–7 Jun. 2005; NMNS ENT 7388-345 • 1 ♂; same collection data as for preceding; 8 Mar.–12 Apr. 2005; NMNS ENT 7388-22 • 1 ♂; same collection data as for preceding; 13 Apr.–9 May 2008; NMNS ENT 7421-594 • 1 ♂; same collection data as for preceding; 6 Apr.–11 May 2004; NMNS ENT 6660-180 • 3 ♂♂; same collection data as for preceding; 9 Apr.–19 May 1998; NMNS ENT 3113-127 , 3113-161 , 3113-188 • 1 ♀; same collection data as for preceding; 17 Apr.–7 May 2003; NMNS ENT 6603-192 • 1 ♀, 2 ♂♂; same collection data as for preceding; 9 May–6 Jun. 2006; NMNS ENT 7421-1098 (♀), 7421-1094 (♂), 7421-1106 (♂) • 6 ♂♂; same collection data as for preceding; 6 Jun.–25 Jul. 2006; NMNS ENT 7423-1993 , 7423-1897 , 7423-1826 , 7423-1923 , 7423-1825 , 7423-2018 • 2 ♂♂; same collection data as for preceding; 25 Jul.–22 Aug. 2006; NMNS ENT 7423-3062 , 7423-3119 • 1 ♂; same collection data as for preceding; 2 Aug.–8 Sep. 2005; NMNS ENT 7392-1104 • 5 ♂♂; same collection data as for preceding; 8 Sep.–4 Oct. 2005; NMNS ENT 7393-65 , 7393-153 , 7393-157 , 7393-159 , 7393-199 • 2 ♂♂; same collection data as for preceding; 7 Oct.–4 Nov. 2003; NMNS ENT 6658-27 , 6658-38 • 1 ♂; Nantou Hsien, Tsuifeng ; 2300 m a.s.l.; 8 Nov. 1981; S.C. Lin and W.S. Tang leg.; TARI • 1 ♀, 1 ♂; Nantou, Hsini , Patungkuan ; 13–15 Jun. 1989; K.W. Huang; sweeping; NMNS ENT 460-463 (♂), 460- 466 (♀) • 1 ♂; Chiayi Hsien, Alishan ; 2400 m a.s.l.; 5–9 Aug. 1981; L.Y. Chou and S.C. Lin leg.; TARI • 1 ♂; Chiayi County, Alishan , Shishan race ; 8 Mar. 2020; Y.H. Ho and P.Y. Shih leg.; PCHO • 1 ♂; Chiayi, Yu-shan West peak ; 15 May 1991; C.C. Chiang leg.; sweeping and sucking; NMNS ENT 1127- 46 • 4 ♂♂; Kaoshiang [Kaohsiung, mistyped] (TM12), Tengchih ; 22–30 Dec. 2008; C.-T. Yao leg.; TARI • 1 ♂; Kaoshiang [Kaohsiung, mistyped] (MM2), Shihshan logging trail ; 18–25 Feb. 2009; C.- T. Yao leg.; TARI • 1 ♂; Kaohsiung City, Taoyuan , Shishan logging trail ; 8 Feb. 2020; C.T. Hsu leg.; beating; PCHO • 1 ♂; Pintung, Kuaiku Coffage ; 21 May 1991; C.C. Chiang leg.; sweeping and sucking; NMNS ENT 1125-10 • 2 ♂♂; Taitung, Peinan , Panchiu Station ; 16 Dec. 2004 – 17 Feb. 2005; C.S. Lin and W.T. Yang leg.; Malaise trap; NMNS ENT 5871-102 , 5871-104 .

Description

LENGTH. 1.83–2.02 mm.

WIDTH. 0.86–0.91 mm.

COLOUR. General body colour light brown, with head and pronotum dark brown.

HEAD. Slightly longer than wide, width to length ratio 1.00: 1.20, strongly punctate, clypeus narrower than head, with some short setae. Eyes strongly developed, with more than 20 facets; temple narrower than eye, about half length of eye, hind angle with or without a sharp tooth. Antennae 11-segmented, 3 rd segment slightly longer than 4 th segment, 5 th to 8 th segment same in length, apical three segments clubbed.

PRONOTUM. Slightly longer than wide, width to length ratio 1.00: 1.05, widest at anterior margin, narrowest at anterior third. Sides carinate; front angle strongly protruded and bluntly rounded, posterior one-third with a pair of round depressions. Surface irregularly and densely punctate, with a pair of carinae on disc. Sometimes covered with wax on lateral and ventral sides.

ELYTRA. Broadly oval, width to length ratio 1.00: 1.40, broadest at middle, apex round. Depression on posterior third indistinct. With eight punctate striae, 1 st striae complete, 2 nd striae connected with 7 th striae at posterior end of elytra, 3 rd striae connected with 6 th striae, 4 th striae connected with 5 th striae, 8 th striae incomplete. 5 th interstriae not carinate, 7 th interstriae weakly carinate, only extended to anterior one-fifth, slightly protruded. Scutellum broadly pentagonal.

METASTERNUM. Strongly convex, with fovea situated under mid coxa on each side and surrounded by radial striae. Sometimes covered with wax on meso- and metasternum.

LEGS. Long and slender, covered with short setae on femora and tibiae. Male with one distinct tooth on each anterior end of protibia, mid tibia and hind tibia; anterior end of protibia expanded and curved, mid tibia and hind tibia straight. Female without any teeth on tibia.

MALE GENITALIA. Aedeagus weakly chitinized, long and slender, sides parallel, weakly curved at middle, and straight at apex in lateral view. Genital segments long and slender, broadest at base, middle area less chitinized, apical end spear-shaped ( Fig. 5 ).

Distribution

Central to southern Taiwan ( Fig. 12 ). This species can be found in areas from low to high elevation (300–3518 m a.s.l.).

Remarks

From our records, S. yuanfengensis sp. nov. can be caught in Malaise traps in large numbers (ca 100 individuals at a time) at the type locality. Some of the specimens were collected by beating dry dead branches and damp leaves in an artificial red oak forest (~ 2300 m a.s.l.) ( Fig. 10 ).

Figures

Figs 4–6. Stephostethus yuanfengensis sp. nov., holotype (NMNS ENT 1113-203) 4. Habitus, dorsal view. 5. Male genital segments, dorsal view. 6. Male tibiae, A = protibia, B = midtibia, C = hindtibia. Scale bars: 4 = 0.5 mm; 5–6 = 0.1 mm.

Figs 10–12. Habitat and distribution map of Stephostethus LeConte, 1878 in Taiwan. 10. Habitat of S. yuanfengensis sp. nov. 11. Habitat of S. chinensis (Reitter, 1877) (photo courtesy of F.S. Hu). 12. Distribution map of species of Stephostethus in Taiwan: S. taiwanus sp. nov. (open circle), S. yuanfengensis sp. nov. (open square), S. chinensis (open star).