Pseudoechthistatus glabripennis, Bi, Wen-Xuan & Lin, Mei-Ying, 2016

Bi, Wen-Xuan & Lin, Mei-Ying, 2016, A revision of the genus Pseudoechthistatus Pic (Coleoptera, Cerambycidae, Lamiinae, Lamiini), ZooKeys 604, pp. 49-85 : 75-77

Taxon classification Animalia Coleoptera Cerambycidae

Pseudoechthistatus glabripennis sp. n. Figures 7, 8, 23, 33, 40, 48, 51, 62, Map 1

Type material.

Holotype: male, "CHINA. Yunnan / Menglun, 55 km / 650 m 2012.IV.25 / leg. Chao Wu" (IZAS, IOZ(E) 1905354). Paratypes (8 males, 9 females): China: 1 female, "Yunnan, Pingbian, Daweishan / peak, 2013.VIII.15 / leg. Chun-Xiang Liu & Kai-Qin Li", "2094 m light trap / 22°54'23.1"N, / 103°41'48.5"E (IZAS, IOZ(E) 1905351); 1 male, "CHINA. Yunnan, Pingbian / Daweishan / 2100 m 2010.V.20 / leg. Wen-Hsin Lin" (CCCC); 1 male, ditto except "2093 m 2012.IX.27 / leg. Xiao-Dong Yang" (CCCC); 1 female, ditto except "2090 m 2011.VI.11" (CCCC); 1 female, ditto except “2011-VI-11” (CJM); 1 male, 2 females, ditto except "2129 m 2016.IV.20" (CCCC); 1 female, ditto except "2013.V.13 / leg. Chao Li light trap" (CLC); 1 male, 2 females, "Yunnan Honghezhou Pingbian / Daweishan 2015.V.21 / leg. Tian-Long He", " 22.551172°N / 103.415424°E / 1989 m observe" (CHTL); 2 males, 1 female, "Yunnansheng, Honghezhou, Pingbianxian / Daweishan Ziranbaohuqu / 2015.V.18 / Tian-Long He leg." (CGQH); Vietnam: 1 male, "VIETNAM: Cao Bang Prov. / Phia-Oac Mtn. road, 1800 m / 22°36.914'N, 105°51.798'E / 2 May 2012 - sweeping / S. W. Lingafelter"(NMNH); 1 male, ditto except "on road (day) / Eduard Jendek, coll."(NMNH).

Description.

Male. (Fig. 7). Body length 22.0-25.6 mm, humeral width 6.7-7.4 mm. Body brownish black; head, pronotum covered with tawny and brown pubescence, ventral surface with tawny pubescence and forming two discontinuous longitudinal bands on each side of abdomen. Head with a pair of tawny vittae on each side of occiput and reaching apical margin of vertex. Antennal scape, pedicel and basal one-fourth of 3rd antennomeres moderately covered with light yellowish pubescence, remainder covered with fine brown pubescence. Pronotum with two longitudinal tawny bands on each side of disk and other two longitudinal postmedian bands on lateral margins, the discal bands about four-fifths as long as pronotal length. Scutellum densely clothed with tawny pubescence, except a narrow median glabrous line. Elytron with dark purple sheen, with tawny pubescence narrowly forming the subbasal annular marking and some small spots scattered mainly near suture, with yellowish pubescence forming the middle band and the preapical stripe, remainder with very fine pubescence; the middle band moderately oblique, complete, regularly shaped, nearly reaching suture; the preapical stripe narrow, slightly longer than one-fourth of elytral length. Legs (Fig. 33) clothed with sparse brown and dense light yellowish pubescence of which the lighter one forming small spots sparsely scattered.

Body elongate, fusiform. Head (Fig. 23) with frons sparsely and finely punctured; lower eye lobe 1.3 times as long as width, 0.6 times as long as gena. Antennae ca. 1.7-1.8 times as long as body length, surpassing elytral apex by six antennomeres; 3rd antennomere ca. 1.8 times as long as scape, ca. 1.3 times as long as 4th antennomere; coarsely punctured on scape to 3rd antennomere; scape to 3rd antennomere fringed beneath. Pronotum 1.2 times as long as basal width, lateral spine short, slightly thickened at base with acute apex; metasternum ca. 1.5 times as long as mesosternal length. Elytra 1.6 times as wide as pronotal base, 2.1 times as long as humeral width; distinctly widest across humeri, then strongly convergent toward subacute apices; disk smooth, very finely punctured, moderately granulated near humerus; subbasal tubercle strongly developed and raised, ca. 1.4-1.6 times as wide as scutellar width. Hindwings (Fig. 48) developed, ca. 1.5 times as long as elytral length. Legs long and slender, metafemora almost exceeding elytral apices.

Male genitalia (Figs 51, 62). Tergite VIII (Fig. 51a) slightly longer than width, slightly emarginated apically and straight sided. Tegmen (Fig. 51 b–c) with lateral lobe widest at base, gently narrowed toward apical half then straightly toward rounded apex. Median lobe (Fig. 51 d–e) with apex roundly acuminate in antero-dorsal view. Endophallus (n = 4, Fig. 62) slightly longer than triple length of median lobe, the length of MT ca. 2.1 times as long as the length of BPH, the length of CT+PB slightly shorter than the length of BPH; MPH moderately curved at apical one-fourth, PB cylindrical at basal half, basal swelling (bs) of CT well developed; APH strongly constrictive, ca. one half as wide as the maximum width of PB at base, with apical bulb (ab) slightly sclerotized ventrally, subcylindrical in lateral view; small spicules densely distributed on apical bulb, apical margin and dorsal surface of PB.

Female (Fig. 8). Body length 24.0-25.1 mm, humeral width 7.3-7.4 mm. Almost identical to male in general appearance. Antennae ca. 1.2 times as long as body length, apical 3 antennomeres surpassing elytral apex; scape to 6th antennomere fringed beneath; pronotum subequal in length and basal width; elytra subparallel-sided in basal half; elytron longer than males in proportion to body length; legs comparatively short, metatibia exceeding elytral apices at basal two-third.

Remarks.

This new species is easily distinguishable from congeners by combination of the following characters: elytral disk smooth, very finely punctured and pubescent, with dark purple sheen; middle band of elytron moderately oblique, complete; elytra distinctly widest across humeri (at least in males). Endophallus with the overall shape unique, especially by basal swelling (bs) of CT distinctly tuberculate laterally; APH strongly constrictive and subcylindrical in lateral view.

Etymology.

The new species is named from a combination of the Latin stem, ‘glabri’and ‘pennis’referring to the smooth surface of elytra.

Distribution

(Map 1). China: Yunnan; Vietnam: Cao Bằng.

Biological notes

No biological information has been so far available for Pseudoechthistatus . This overview is based on notes from several collectors and the observation of the first author as well as the label data from the specimens. Most species appear to occur in broadleaf deciduous or mixed coniferous and broadleaf forests (Fig. 69) at high elevations between 1800-3000 m, with the exception of an individual of Pseudoechthistatus glabripennis collected at 650 m, the lowest elevation known for this genus.

Adults were mostly observed on dead leaves and branches: Pseudoechthistatus granulatus were feeding on dead leaves or bark of Pterocarya sp. ( Juglandaceae ) and Acer spp. ( Aceraceae ); the population of Pseudoechthistatus chiangshunani from Manwanzhen, Lincang City were crawling on the trunk of dead Juglans regia ( Juglandaceae ) or feeding on dead leaves of Alnus cremastogyne ( Betulaceae ); some specimens of Pseudoechthistatus sinicus and Pseudoechthistatus obliquefasciatus were collected by beating dead branches of Cyclobalanopsis spp. and Quercus spp. ( Fagaceae ), while the population of Pseudoechthistatus sinicus in Xiaobaicaoling, Santaixiang, Dayao County, were feeding on living leaves of Acer sp. Some adults of Pseudoechthistatus pufujiae were reared from larvae collected under bark of a fallen tree of Pterocarya (Figs 75-77) in Yaojiaping, some larvae of Pseudoechthistatus granulatus were found in the same tree species in Gongshan but failed to emerge. One adult of Pseudoechthistatus chiangshunani was found in its pupal cell in a partly rotten wood of Alnus cremastogyne ( Betulaceae ). Two possible larvae of Pseudoechthistatus granulatus and Pseudoechthistatus sinicus , which were collected under bark of conifers but died due to the high temperature at lower elevation, were preserved properly for a further study.

Most species are nocturnal, and remain hidden in or around their host plants during daytime (Figs 71-72). Most specimens were collected by observing, beating, sweeping vegetation or by using light traps. Some individuals of Pseudoechthistatus sinicus were observed crawling on ground in the daytime. One female of Pseudoechthistatus pufujiae laying eggs on a fallen log was observed at noon (Fig. 74).

Besides the species with reduced hindwings which are apparently flightless, Pseudoechthistatus pufujiae (Fig. 73) with normal hindwings was observed flying only short distances when disturbed in the lab or in the field. A series of Pseudoechthistatus glabripennis attracted to a light trap indicates strong flying ability of that species.

Up to now, only Pseudoechthistatus glabripennis and Pseudoechthistatus holzschuhi , both with normally developed hindwings, are known to be sympatric in Fenshuiling, southeast Yunnan (Map 1). Those species with reduced hindwings appear to be allopatric. The Gongshan population of Pseudoechthistatus granulatus appears to be close to the northern population of Pseudoechthistatus obliquefasciatus , which is actually separated by the Nushan Mountains. Pseudoechthistatus obliquefasciatus is not known to be sympatric with Pseudoechthistatus sinicus , but the type locality of Pseudoechthistatus obliquefasciatus cannot be precisely localized (see the remarks of Pseudoechthistatus obliquefasciatus ).

Pseudoechthistatus sinicus and hunting spiders (possibly Lycosidae ) were active on ground vegetation simultaneously at night (observed in Weibaoshan and Xiaobaicaoling). In consideration of the elytral subbasal tubercles of Pseudoechthistatus that resemble the posterior median eyes of the spiders, we suppose this resemblance may represent a case of Batesian mimicry, but more evidence is required before any conclusion can be reached.