Pericalus (s. str.) acutidens , Shi, Hongliang & Liang, Hongbin, 2018
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|Pericalus (s. str.) acutidens|
Pericalus (s. str.) acutidens sp. n. Figs 7, 8, 17, 21, 37, 45, 56, 59
Pericalus formosanus (in part); Fedorenko 2017: 311.
Holotype (IZAS): male, body length = 10.4 mm, board mounted, genitalia dissected and deposited in micro vial pinned under specimen, "Yunnan, Longchuan county, Mangdong, 1770 m, 2016.X.2, night, Yang Xiaodong leg., 16Y, CCCC" [in Chinese]; "HOLOTYPE ♂ Pericalus acutidens sp. n., des. SHI & LIANG 2018" [red label] (Fig. 17). Paratypes (36 ex.): Yunnan: 1 male, 2 females (CCCC), same data as holotype. 2 males, 1 female (CCCC), same data as holotype, but date 2016.IX.28. 4 males, 1 female (IZAS), same data as holotype, but date 2016.IX.30. 1 male, 3 females (CCCC), same data as holotype, but date 2016.VI.3. 1 female (CCCC), same data as holotype, but date 2016.IX.27, beating on vegetation. 1 female (IZAS), "Yunnan, Gongshan county, Dulongjiang, Maku, 1540m, 2015.VII.23, Yang Xiaodong leg". 1 female (IZAS), "Yunnan Prov., Longyang, Mangkuan, Baihualing, on shrub, 25.30985, 98.79485, 1440 m, 2007.10.10 day, David Kavanaugh coll". 1 female (IZAS), "Yingjiang county, Xima, Huihe power station, 1514 m, board leaf forest, 2013.IX.20, Yang Xiaodong leg". 1 female (IZAS), "Yunnan, Nabang, 2013.IX.7 Zhu Xiaoyu leg". 2 males (IZAS), "Yunnan, Ruili, Bangda village, 1432 m, 2014.IX.14, light trap, Yang Xiaodong leg". 3 males, 1 female (CCCC), "Yunnan, Ruili, Bangda village, 1432m, 2014.IX.16, night, Yang Xiaodong leg". 1 female (IZAS), "Yunnan, Ruili, Bangda Mt., 2014.IX.14, light trap, Cai Yinan leg". 1 female (IZAS), "Yunnan, Ruili, Bangda Mt., 1450m, 2015.VIII.30, mixed forest, night, Lu Yanquan leg". Xizang: 1 male (IZAS), "Xizang, Medog county, 850-900 m, 1987.II.19, Lin Zai leg". Myanmar: 4 males, 1 female (IZAS), "Myanmar, Kachin state, Putao distr., way btw. Upper Shankhaung to Wasandum; rain forest; 1075 m, N27.4765, E97.2060, 2016.XII.11, SHI H.L. lgt., in dead log; CAS-SEABRI exp. 2016". 1 male (IZAS), "Myanmar, Kachin state, Putao distr., 5 km NW. of Upper Shankhaung; rain forest; 666 m, N27.4415, E97.2584, 2016.XII.21, SHI H.L. lgt., in dead log; CAS-SEABRI exp. 2016". 1 male (IZAS), "Myanmar, Kachin state, Putao distr., way btw. Ziradum and camp I; rain forest; in dead log; 27.5679, 97.1062 1022 m - 27.5991, 96.9948 1593 m, 2016.XII.14, SHI H.L. lgt. CAS-SEABRI exp. 2016".
Medium size in the subgenus, body length 9.2-12.0 mm; dorsal surface black, elytra usually with faint cyan hue; anterior patch round in form, usually slightly transverse and zigzag, three to five intervals wide; posterior patch separate, composed of three small spots, normally on intervals 2-3, 4-5, and 7 respectively. Pronotum lateral margins sinuate before posterior angles, posterior angles nearly rectangular. Elytra plain; apical truncation distinctly curved; outer apical angles acuminate, forming sharp tooth (Fig. 21); sutural angles blunt; third interval with three setigerous pores. Median lobe of aedeagus with apical orifice small, opened to the left side; apical lamella narrow and long, length near two times the basal width.
The new species is very similar and close to P. ornatus , but can be distinguished by male genital characters: (1) in P. acutidens , the apical orifice of aedeagus is much smaller and opened exactly to the left side of median lobe; larger and opened to the left-dorsal side in P. ornatus ; (2) in lateral view, median lobe of aedeagus a little narrower and less bent in the new species than in P. ornatus ; (3) the apical lamella is a little narrower and longer in P. acutidens ; (4) in ventral view, apical lamella of P. acutidens is almost straightly pointed to apex; in P. ornatus , the apical lamella is slightly bent to the right.
Externally, these two species are different in: elytral outer apical angles generally acuminate, projected outwards, forming short tooth in P. acutidens (Fig. 21); not or less pointed, acute, obtuse, or rarely rounded in P. ornatus (Figs 22-26). P. acutidens is also different from P. o. ornatus in elytral anterior patch usually a little transverse (versus usually nearly round), and from P. o. formosanus in elytral third interval with three setigerous pores (versus usually two pores). Generally, the difference on elytral outer apical angles well distinguishes these two species for specimens from China. But in S. Vietnam, both species have the outer apical angles acuminate or acute (Figs 1-4, 6-7 in Fedorenko, 2017). Thus the differentiation of them through external characters can be difficult sometimes. For specimens from China, it is easier to diagnose P. acutidens n. sp. from P. ornatus by their allopatric distributions (Fig. 59), but they are sympatric in at least S. Vietnam.
The new species is sympatric with P. obtusipennis and P. amplus in SW. Yunnan, and they all have similar elytral patterns. From the latter two, P. acutidens can be easily distinguished by the acuminate elytral apical outer angles and the elytral posterior patches which do not have a separate small spot on the sixth interval.
Body length 9.2-12.0 mm. Coloration. Dorsal surface black, elytra with faint cyan metallic hue, with yellowish patches; mouthparts, antennomeres 2-11 reddish brown; legs blackish, tarsus reddish brown; ventral side black. Elytral anterior patch round in form, generally a little transverse and zigzag, in the fourth to sixth intervals, sometimes also in parts of the third and seventh. Elytral posterior patch divided into three small spots, usually in intervals 2-3, 4-5, and 7 respectively; occasionally the first one only on the third interval, the second one only on the fifth interval or on the fourth, fifth, and sixth intervals. Microsculpture faint and nearly isodiametric on vertex and pronotal disc, strong and linear on elytral intervals. Head densely wrinkled; three or four wrinkles on each side extending from clypeus to frons; seven to ten fine wrinkles along each side of inner margin of eye, reaching level of posterior margins of eyes; wrinkles very weak on vertex, occiput almost smooth. Eyes strongly prominent; temporae gradually constricted after eyes. Pronotum strongly transverse, PW/PL = 1.52-1.61, subequal to the width of head with eyes (PW/HW = 0.96-1.02); posterior margin subequal to the width of anterior margin; lateral margins rounded in the middle, distinctly sinuate before posterior angles; posterior angles nearly rectangular, apex sharp, not projecting laterally; lateral expansions wide and rugose; disc a little convex, with fine wrinkles, with a pair of shallow pits on each side; sub-anterior impression barely visible, median line fine, not reaching anterior nor posterior margin; basal fovea shallow, extending medially merged with the shallow sub-posterior impression, extended posteriorly forming very shallow short oblique grooves. Elytra ovate, weakly convex; EW/EL = 0.65-0.73; much wider than pronotum, EW/PW = 1.50-1.65; apical truncation distinctly curved; outer apical angles generally acuminate, or rarely acute; sutural angles blunt; striae moderately incised, without punctures; third interval with three setigerous pores, the first one at approximately basal eighth, the second one at approximately middle, the third one close to apex; the first one adjacent to the third stria, the other two close to the second stria; intervals slightly convex, the eighth interval tumid apically, the eighth and ninth interval with sparse fine setae aside of umbilical series; lateral expansions narrowly extended, a little widened near basal third. Male genitalia (Fig. 37). Median lobe of aedeagus slender and bent, weakly sinuate in ventral and dorsal view; in lateral view, ventral margin evenly curved in the middle; apical orifice small, opened to the left; apical lamella narrow and long, sides parallel in ventral view, in lateral view gradually narrowed to apex, length near two times the basal width, apex rounded; endophallus simple, with very fine scales all through length, without spines. Right paramere with apex extended and expanded, round in form. Female genitalia. Internal reproductive system (Fig. 56): spermatheca pedunculate, inserted on the base of common oviduct; spermathecal body fusiform, longer than the pedicel, distinctly bent; spermathecal gland inserted on the joint of spermathecal pedicel, apex not dilated (probably spermathecal gland apex missing), close to the length of spermatheca. Gonocoxite 2 of ovipositor (Fig. 45) scimitar-shaped, abruptly bent to the outer side at apical third; length approximately six times basal width; outer margin with three or four dorsolateral ensiform setae, the basal one finer than the other ones; inner margin with one doromedial ensiform seta near apex.
A relatively widely distributed species, known from several localities west to Salween River: Myanmar: Putao, Shan States; China: Xizang ( Mêdog), Yunnan (Nujiang, Dehong, Baoshan Prefectures), S. Vietnam ( Fedorenko 2017); probably also in north India, Thailand, and Cambodia (Fig. 59).
The name acutidens comes from Latin, referring to the generally acuminate elytral outer apical angles of the new species.
According to the collecting data, this new species prefers tropical forests with the elevational range between 1000m and 1500m. Adults were collected on/in dead tree trunks, or attracted by light at night.
This new species was recorded by Fedorenko (2017) as P. formosanus in south Vietnam. Based on the figures of male genitalia in Fedorenko (2017), we determined that his Vietnam P. formosanus is not the true P. formosanus of Dupuis, but is exactly identical to our new species.
From the examined materials in the present study, the new species is strictly allopatric with P. ornatus in China. The natural boundary in China between them seems to be the Salween River (Fig. 59). But we didn’t examine any material form regions between the Salween River and Mekong River. These two species are sympatric in south Vietnam, and the new species is rarer than P. ornatus (Fedorenko, 2017).
Pericalus ornatus was previously recorded from North India (Assam, Sikkim, Garo Hills), Myanmar (North Shan States, Karin Chebà), Thailand, Laos, and Cambodia. We doubt some of these records are actually P. acutidens sp. n. The record from North Shan States ( Andrewes 1923) is very close to Ruili (Yunnan) where P. acutidens sp. n. was recorded and P. ornatus does not occur. Thus this record should be confirmed to P. acutidens sp. n. According to the confirmed records (solid spots in Fig. 59) we inferred that these two species could be sympatric in S. Laos, S. Myanmar, Thailand, and Cambodia, and P. ornatus may not occur in N. India and N. Myanmar. The records from north India ( Andrewes 1923) may refer to P. acutidens sp. n. or some other unknown species (empty red circles in Fig. 59).
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