Pterorthochaetes yunnanensis Ballerio, 2014

Jiang, Ri-Xin, Ballerio, Alberto, Liu, Hao-Yi & Wang, Shuo, 2021, Description of the male of Pterorthochaetes yunnanensis Ballerio, 2014 (Coleoptera Scarabaeoidea: Hybosoridae: Ceratocanthinae), Zootaxa 4950 (1), pp. 196-200 : 196-198

publication ID	https://doi.org/ 10.11646/zootaxa.4950.1.12
DOI	https://doi.org/10.5281/zenodo.4643352
persistent identifier	https://treatment.plazi.org/id/126F87CF-E840-FFDE-FEF5-FC53FE441AC9
treatment provided by	Plazi
scientific name	Pterorthochaetes yunnanensis Ballerio, 2014
status

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Pterorthochaetes yunnanensis Ballerio, 2014 View in CoL (云南毛ńƙDz)

( Figs 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 )

Pterorthochaetes yunnanensis Ballerio, 2014: 277 View in CoL (type locality: “ China: Yunnan, Xishuangbanna (NJVhffi), ca. 15 km w Menglun (勐仑), 5.11.1999, ca. 700–800 m a.s.l., leg. Jäch, et al.”, deposited in the Naturhistorisches Museum Wien, Vienna, Austria).

Material examined (4 specimens): 3 ♂♂, 1 ♀, labeled: “ China: Yunnan Prov., Dehong Autonomous Prefecture (德 Ė傣tāüta治州›, Yingjiang County (A江县), Taiping Town ( R 平Þ), Mangyun Village (K允ffl›, H: 930 m, 10.VIII.2020, in rottenwood, local people leg.” (2 ♂♂ and 1 ♀ in MYNU, 1 ♂ in ABCB).

Description of male. Body ( Fig. 1 View FIGURE 1 ) dark-brown to black, large sized, surface shiny, and covered with dense large punctures and short erect clavate setae.

Head ( Fig. 1A View FIGURE 1 ), wider than long, subpentagonal, clypeus triangular, apex blunt, anterior margin serrate. Interocular distance about 9 times of the maximum width of dorsal ocular area. Genae obviously protruding outwards, dorsal ocular area large. Punctures of head strongly impressed and horseshoe-shaped on frons and clypeal disc, becoming irregular transverse lines near clypeal apex, all punctures on disc bearing an erect simple short seta. Antennae short, with nine antennomeres: scape securiform, pedicel about as long as wide and rounded; flagellomeres I about as long as wide, near trapezoidal, II-IV similar, strongly transverse, antennal club (flagellomeres V–VII) covered with dense short yellow hair.

Pronotum ( Fig. 1A View FIGURE 1 ) transverse, widest at middle. Anterior angles rounded, lateral margins curved, fringed with a row of short simple setae spaced out by an interval about their length. Margins of pronotum with thin but distinct groove. Disc of pronotum covered with dense ocellate punctures, larger ocellate punctures present also at discal sides then becoming larger horseshoe-shaped punctures, with opening directed outwards, punctures at sides bigger than on disc, each punctures with a pore in the middle and bearing a clavate erect short seta. Interpunctural distance shorter than (or rarely equal to) punctural diameter.

Scutellum ( Figs 1A, D View FIGURE 1 ), slightly wider than long, lateral sides proximally subparallel and distinctly notched by apical portion of mesepisternum, base and sides smooth, apex elongate and acute and sides slightly curved inwards. Dorsal surface covered with dense horseshoe-shaped punctures with opening directed backwards, each with a pore in the middle and bearing a clavate erect short seta. Punctures on scutellum are larger at base and smaller at apex.

Elytra ( Figs 1A, D View FIGURE 1 ) suboval in shape, strongly convex, longer than wide, surface, apart from base, which is covered by some transverse irregular short lines, covered with dense small horseshoe-shaped punctures, with opening directed backwards or outwards, each one with a pore in the middle bearing a clavate erect short seta, a few simple fine punctures mixed to horseshoe-shaped punctures. Interpunctural distance of horseshoe-shaped punctures equal to or shorter than punctural diameter.

Legs. Outer margin of protibiae ( Figs 2A–B View FIGURE 2 ) with an irregular number of weak outer teeth and apex with two stronger outer teeth, apical spur abruptly hooked at apex. Mesofemora ( Fig. 2E View FIGURE 2 ) obviously expanded near middle, mesotibiae ( Fig. 2C View FIGURE 2 ) slightly expanded basally, with a short inner apical spur bent inward at a right angle. Metatibiae ( Fig. 2D View FIGURE 2 ) subtriangular, strongly expanded apically, apex with two short spurs, the inner one longer and tortile.

Male genitalia. Aedeagus ( Figs 3A–E View FIGURE 3 ), asymmetrical and tortile, basal piece about 2.5 times the length of parameres. Parameres as in Figs. 3A–E View FIGURE 3 . Internal sac with a distinctive weak sclerotized plate irregularly S-shaped occupying about half the length of the sac and with a transverse thick short sclerification in the middle ( Fig. 3F View FIGURE 3 ). Genital segment ( Fig. 3G View FIGURE 3 ) asymmetrical and curved with branches apically fused and with short manubrium.

Measurements of male: BL: 5.65–5.95 mm; HL: 0.95–1.00 mm, HW: 1.75–1.85 mm; PL: 1.70–1.80 mm, PW: 2.80–2.95 mm; EL: 3.00– 3.15 mm, EW: 2.70–2.75 mm.

Supplementary description of female (based on the specimen from Mangyun village). Generally similar to male, apical spur of protibiae ( Figs 2F–G View FIGURE 2 ) thinner and straighter; apical spur of mesotibiae ( Fig. 2H View FIGURE 2 ) straight. Outer apical spur of metatibiae ( Fig. 2I View FIGURE 2 ) straight and sharp. Spermatheca ( Fig. 3I View FIGURE 3 ) C-shaped, both extremities flattened in lateral view.

Measurements of female: BL: 5.75 mm; HL: 1.00 mm, HW: 1.80 mm; PL: 1.75 mm, PW: 2.85 mm; EL: 3.00 mm, EW: 2.65 mm.

Distribution. China: Yunnan Province: Dai Autonomous Prefecture of Xishuangbanna (type locality), Dehong Autonomous Prefecture (new record).

Habitat and biology. The adults of P. yunnanensis can be collected from rotten wood. The locality of new specimens in this study is in the tropical rainforest climate and characterized by the presence of a moist broadleaf evergreen primary forest ( Zeng, 2018). They were also found associated with adults and larvae of Passalidae species inside rotten wood, this latter observation confirms what has already been reported for the genus Pterorthochaetes in Malaysia ( Kon et al. 2010, 2014).

Discussion. The discovery of more specimens of P. yunnanensis allows us to better define the species. The distinguishing characters listed by Ballerio (2014) are confirmed and can be better defined. The species is characterized by: a) the presence of small impressed ocellate punctures on pronotal disc, present also at discal sides, although larger, then becoming horseshoe-shaped and distinctly larger at pronotal sides; b) pronotal interpunctural distance smaller than punctural diameter, c) pronotal lateral margins fringed with a row of long simple setae, spaced out by an interval about their length or longer, d) elytral punctation made of dense medium sized impressed horseshoe-shaped punctures with opening directed backwards, spaced out by an interval subequal to (or shorter than) their diameter, mixed with simple impressed punctures irregularly distributed, e) shape of bursal sclerites, f) shape of endophallites. Pterorthochaetes insularis is confirmed as the species closest to it and the differences listed by Ballerio (2014) are also confirmed apart from the periscutellar punctation, which is basically the same with some transverse irregular lines. The endophallites are different from the ones present in P. insularis , a species which lacks the weak sclerotized plate irregularly S-shaped occupying about half the length of the sac.