Chydaeus shunichii Ito, 2006

Kataev, Boris M., Liang, Hongbin & Kavanaugh, David H., 2012, Contribution to knowledge of the genus Chydaeus in Xizang Autonomous Region [Tibet] and Yunnan Province, China (Coleoptera, Carabidae, Harpalini), ZooKeys 171, pp. 39-92 : 40-44

Chydaeus shunichii Ito, 2006 Figs 1-9 56 64-65

Material examined.

A total of 15 specimens (6 males and 9 females, including 2 males and 5 females in CAS, 3 males and 4 females in IOZ, and 1 male in ZIN) were examined from the following localities: China, Yunnan Province. Lushui County: 1 male, Gaoligongshan, Nujiang Pref., Pianma Yakou, 3200 m, 25°54.4'N, 98°41.0'E, 11.X.1998, Stop 98-113A, D.H. Kavanaugh, C.E. Griswold, C. Ferraris & C.-L. Long leg. (IOZ); 3 females, Pianma, Fengxue Yakou, roadside, 25.97244°N, 98.68376°E, 3150 m, 11.V.2005, H.B. Liang leg. (CAS, IOZ); 3 males, 4 females, Luzhang, Fengxue Yakou, roadside, 25.97347°N, 98.68780°E, 3130 m, 17.V.2005, D. Kavanaugh & D.Z. Dong leg. (CAS, IOZ, ZIN); 1 female, same data, but 25.97360°N, 98.68905°E, 3120 m, 17.V.2005, H.B. Liang leg. (IOZ); 1 female, same data, but Y.H. San leg. (IOZ); 1 male, Luzhang, Fengxue Yakou, road, 25.97410°N, 98.67716°E, 3120 m, 18.V.2005, D. Kavanaugh & D.Z. Dong leg. (CAS); 1 male, Luzhang, Yaojiaping, roadside, 25.97526°N, 98.71000°E, 2513 m, 19.V.2005, H.B. Liang leg. (IOZ).

Re-description

(based on the specimens from Lushui County, Yunnan). Size: Body length 6.9-8.0 mm, width 3.5-3.9 mm.

Color: Body black, slightly shiny on dorsum, labrum and bases of mandibles paler, reddish brown in some specimens. Antennae brown, with antennomere 1 more or less infuscated. Palpi yellowish brown. Legs dark brown to black, with tibiae basally and tarsi brown.

Microsculpture: Head with dorsal microsculpture visible throughout, comprised of very fine, more or less isodiametric meshes. Pronotum with microsculpture clearly visible throughout, comprised of distinct isodiametric meshes. Elytra with microsculpture developed throughout, comprised of distinct, slightly transverse meshes.

Head: Comparatively large (HWmax/PWmax = 0.69-0.72 and HWmin/PWmax = 0.59-0.61), impunctate, with small and moderately convex eyes; tempora flat, sloped to neck. Clypeus slightly concave and with slightly convex bead along anterior margin. Frontal suture distinct, slightly impressed. Frontal foveae small, faintly deepened; clypeo-ocular prolongations absent. Supraorbital setae situated slightly behind hind margins of eyes.. Antennae short, not extended to pronotal basal margin, with antennomeres 5 to 7 each 1.4-1.6 times as long as wide. Labrum deeply emarginate apically. Left mandible truncate at apex. Ligular sclerite more or less parallel-sided, with apex straight and apical angles slightly extended laterad.

Pronotum ( Fig. 1 ): Markedly transverse (PWmax/PL = 1.55-1.63), narrowed basad (PWmax/PWmin =1.22-1.30) and widest in anterior third. Sides distinctly rounded in anterior two-thirds and very slightly rounded, almost rectilinearly convergent basad in posterior third, with one lateral seta on each side in apical third. Apical margin arcuately emarginate, bordered only laterally. Basal margin nearly straight, slightly oblique at basal angles, distinctly bordered throughout, slightly wider than apical margin and slightly shorter than elytral base between humeral angles. Apical angles slightly less than 90°, produced anteriad and narrowly rounded at apices. Basal angles obtuse, sharp at apices, each with a small, obtuse denticle extended laterad. Pronotal disc moderately convex, slightly depressed basally, slightly sloped to sides and more abruptly sloped to apical angles. Lateral depressions present as narrow furrows behind apical angles, slightly widened behind lateral setigerous pore, and either extended basad to pronotal base or fused in basal quarter with large latero-basal depressions. Basal foveae distinct within latero-basal depressions, comparatively small, somewhat flat or slightly deepened. Areas between basal foveae and between basal foveae and lateral depressions slightly convex in most specimens. Pronotal surface coarsely and irregularly punctate along base and in lateral depressions, finer and sparser punctation present also along apical margin.

Elytra: Oval, markedly rounded at sides, wide (EL/EW= 1.20-1.29, EL/PL = 2.58-2.69, EW/PWmax = 1.32-1.37), widest approximately at middle, not fused along suture. Humeri widely rounded at apices, each with indistinct denticle hardly visible from behind; sides just behind humeral angles markedly rounded. Subapical sinuations present, shallow. Sutural angles not separated from each other, less than 90°, with apices blunt in both sexes. Basal borders faintly sinuate, joined with lateral margin at a markedly obtuse angle. Striae smooth, impunctate, faintly impressed along entire length. Parascutellar striae present, short, basal setigerous pores present; in some specimens, distal part of parascutellar stria connected with first (sutural) stria. Intervals faintly convex along entire length, impunctate, only slightly narrowed toward apices. Umbilicate setal series widely interrupted at middle, with anterior group comprised of 7 or 8 setigerous pores and posterior group comprised of 8 or 9 such pores.

Hindwings: Reduced to small scales.

Venter: Prosternum with scattered and short setae apically. Prosternal medial process not projected posteriad. Proepisterna smooth, impunctate. Metepisterna ( Fig. 3 ) distinctly narrowed posteriad, approximately as wide as long. Sternum VII (anal) in both sexes with two pairs of setae along apical margin and widely rounded at apex. Tergum VII (anal) of female rounded at apex.

Legs: Metacoxae ( Fig. 2 ) with additional postero-medial setigerous pore and, in most specimens, with additional medial setigerous pore at least on one side. Metafemora with two setae along posterior margin. Protibiae with one ventroapical spine, the outer margin in both sexes with three or four uniform preapical spines. Tarsi glabrous dorsally, at most with a few setae on enlarged male protarsomeres; tarsomere 5 with three pairs of lateroventral setae. Metatarsi in both sexes notably shorter than minimum linear distance across neck constriction just behind eyes; tarsomere 1 longer than tarsomere 2 and shorter than tarsomeres 2+3. In males, protarsi moderately enlarged, with tarsomere 1 about as long as wide, tarsomeres 2 to 4 distinctly wider than long and tarsomeres 1 to 4 with adhesive vestiture ventrally (only apically on tarsomere 1); mesotarsi comparatively slightly enlarged, with tarsomere 1 slightly longer than wide, tarsomere 2 approximately as long as wide, tarsomere 3 slightly wider than long, tarsomere 4 much smaller than tarsomeres 2 and 3 and deeply concave apically; mesotarsomeres 2 and 3 with adhesive vestiture ventrally.

Female genitalia ( Figs 4-5 ): Apical stylomere comparatively slightly curved.

Aedeagus ( Figs 6-9 ): Median lobe markedly widened medially (dorsal aspect), markedly bent ventrad behind basal bulb and with terminal lamella slightly curved dorsad (lateral aspect), its ventral margin nearly straight medially. Terminal lamella ( Fig. 6 ) flat, triangular in dorsal aspect, slightly wider than long, narrowly rounded at apex and without any apical capitulum. Apical orifice in dorsal position, prolonged to basal bulb. Internal sac with several spiny patches.

Distribution.

Fig. 56 . This species is known only from the Gaoligong Shan in Lushui and Tengchong counties, western Yunnan Province, China, at elevations of 2500-3200 m.

Habitat.

Specimens were collected in roadside and road cut open areas, hidden under stones and other debris during daylight hours and active on the soil surface at night ( Figs 64-65 ).

Remarks.

Chydaeus shunichii was originally described on the basis of one male from "Dakei, alt. 2430-2440 m, Mts. Gaoligongshan, Tengchong Xian, Yunnan" ( Ito 2006). The specimens from Lushui County share with the holotype most of the characters listed by Ito in the original description, but they differ slightly in the male genitalia. The apical part of the median lobe is less markedly curved dorsad than that illustrated by Ito (2006) and with a more acute, unbordered apex. The ventral side of the median lobe is nearly straight medially in lateral aspect, and the internal sac possesses the very characteristic spiny armature, without "a peg-shaped sclerite" mentioned by Ito (2006) for the holotype. In addition, there are also differences in several characters of external morphology. In the specimens from Lushui County, the head is smooth ("sparsely and coarsely punctate and transverse rugosities on frons" in the holotype), the pronotal dorsal microsculpture consists of the isodiametric meshes ("consisting of transverse meshes" in the holotype), the elytra have seven to eight setigerous pores in anterior group of the umbilicate setal series (five in the holotype), and only mesotarsomeres 2 and 3 in males have adhesive vestiture ventrally ("mid tarsi of male bearing spongy adhesive hairs on ventral surface of 2nd to 4th segments" in the holotype). One of us [HBL] was able to examine the holotype of Chydaeus shunichii at Ito’s home (Kawanishi City, Japan) and found that at least the aedeagus of the holotype was described and illustrated inaccurately by Ito (2006) because it is identical to that of the specimens from Lushui County as described above. The extent to which specimens of Chydaeus shunichii from Lushui County actually differ morphologically from those from Tengchong County requires further study based on additional material from Tengchong.

Chydaeus shunichii members are similar in habitus and male genitalia to those of Chydaeus kasaharai Ito, 2002, which was described from Dashennongjia Mountain in the eastern part of the Daba Shan (western Hubei Province). However, in members of the latter species, the head and elytra are punctate at least laterally, the basal borders of the elytra are markedly sinuate laterally and form with lateral margin of elytra a sharp, nearly rectangular angle, the elytral striae are distinctly crenulate, the tarsi are pubescent dorsally, and the median lobe of the aedeagus is narrower, with much longer terminal lamella and with only one narrow, curved spiny patch in the internal sac apically. These two species ( Chydaeus shunichii and Chydaeus kasaharai ) are distinct from other known species of Chydaeus in their morphology and, in our opinion, form a natural species group named here the kasaharai group. The main distinctive characters of members of this group are: the wide body, the elytra with comparatively short parascutellar stria and with basal parascutellar setigerous pore present, the umbilicate setal series of elytra usually with a more or less wide gap medially, rarely continuous, the metepisterna slightly wider than long or approximately as wide as long, and the metacoxae with a posterolateral setigerous pore and (in most specimens) additional medial setigerous pores. Members of the kasaharai group are very similar in these characters to those of the irvinei group (sensu Kataev and Schmidt 2002, 2006), but the latter are distinguished from members of the kasaharai group in having elytra without a parascutellar setigerous pore and without a parascutellar striole (the latter present as only a rudiment in a few specimens).

Figures

Figures 1 - 9. Chydaeus shunichii Ito (Pianma Yakou). 1 Pronotum 2 Left metacoxa (m. p. = medial setigerous pore, p. - m. p. = postero-medial setigerous pore) 3 Left metepisternum. 4 Right hemisternite and stylus, ventral view 5 Stylus, lateral view 6 Terminal lamella of median lobe, dorsal view 7 Median lobe, left lateral view 8 Median lobe, dorsal view 9 Middle portion of median lobe, right lateral view. Scale lines: A = 1.0 mm (Fig. 1), B = 0.5 mm (Fig. 6), C = 1.0 mm (Figs 2 - 5, 7 - 9).

Figures 56 - 57. Toporelief map of southeastern Asia, illustrating localities for Chydaeus species 56 Chydaeus shunichii Ito = red dots, Chydaeus fugongensis sp. n. = pink diamond, Chydaeus gutangensis sp. n. = yellow square, and Chydaeus hanmiensis sp. n. = light blue triangle 57 Chydaeus baoshanensis sp. n. = dark blue square, Chydaeus asetosus sp. n. = yellow triangles, and Chydaeus obtusicollis Schauberger = red dots. Only new records reported here are shown. Scale bar = 300 km (in 100 km increments).

Figures 64 - 65. Digital photographs of habitats for Chydaeus species 64 Yaojiaping, Lushui County, Yunnan Province, China, ca. 2500 m; locality for Chydaeus satoi Ito and Chydaeus shunichii Ito 65 Fengxue Yakou, Lushui County, Yunnan Province, China, ca. 3150 m; locality for Chydaeus bedeli difficilis Kataev & Schmidt and Chydaeus shunichii Ito.