Chydaeus luxiensis, Kataev, Boris M., Wrase, David W. & Schmidt, Joachim, 2014

Kataev, Boris M., Wrase, David W. & Schmidt, Joachim, 2014, New species of the genus Chydaeus from China, Nepal, Myanmar, and Thailand, with remarks on species previously described (Coleoptera: Carabidae: Harpalini), Zootaxa 3765 (1), pp. 1-28 : 24-25

Chydaeus luxiensis sp. n.

( Figs 52 , 66–70 )

Type material. Holotype: ♂, “ CHINA (Yunnan) Dehong Dai Aut. Pref ., mount. range 31 km E Luxi, 2280 m 24°29'31"N / 98°52'58"E (grassland/pasture, under stones/shrubs, in moss/litter) 3.VI.2007 D.W.Wrase [19]”, “ Chydaeus spec. 3 Wrase det. 2012”, “Coll. Wrase BERLIN ” (cWR).

Paratype: ♀, same data as holotype (cWR).

Description. Dorsal habitus: Fig. 52 .

Morphological characters as described for C. wuliangensis sp. n. except as follows:

Body smaller: in holotype, length 8.4 mm, width 3.7 mm; in paratype 8.7 and 3.9 mm, respectively. Coloration black, with palpi, antennae, knees and tarsi brown. Microsculpture on head in both sexes recognized in area under eyes; microsculpture on pronotum in male strongly obliterate, meshes almost indistinct; in female microsculpture distinct almost throughout except medial parts at apical and basal margins, consisting of more or less isodiametric meshes; elytral microsculpture in male as in C. wuliangensis sp. n., in female distinct throughout, consisting of isodiametric, almost granulate meshes on two lateral intervals throughout and on intervals 2–6 in basal half and of slightly finer, comparatively large transverse meshes on remaining surface. Head covered with micropunctures mostly in and around frontal foveae. Clypeo-frontal suture slightly shallower than in C. wuliangensis sp. n. Antennae slightly longer, in male reaching pronotal edge, with antennomeres 5 to 7 each about 1.8–2.0 times as long as wide, in female antennae slightly shorter than in male, with antennomeres 5 to 7 each about 1.5–1.6 times as long as wide. Pronotum less markedly narrowed basad than in C. wuliangensis sp. n., with basal margin slightly longer than apical margin; denticle at apices of basal angles almost indistinct. Basal foveae relatively shallow. Elytra with slightly shallower subapical sinuations; striae impressed along entire length and intervals slightly convex up to apices. Metepisterna: Fig. 66 .

Female genitalia ( Fig. 67–68 ). Apical stylomere moderately wide in lateral aspect, moderately curved in ventral aspect.

Aedeagus. Median lobe ( Fig. 69 ) bent ventrad just behind basal bulb and at about a quarter from apex, with almost straight middle portion, convex in lateral aspect along dorsal side throughout and on ventral side at middle; terminal lamella comparatively long, triangular in dorsal aspect; apical capitulum small, almost transverse, protruding ventrad and dorsad, with its dorsal flange noticeably larger than ventral one. Apical orifice as in C. wuliangensis sp. n., slightly shifted to the right and prolonged to basal bulb. Internal sac with two elongate spiny patches basally and one oblique medial spiny patch on the left side.

Proportions: HWmax/PWmax = 0.72–0.74; HWmin/PWmax = 0.61–0.62; HWmax/HWmin = 1.18–1.19; PWmax/PL = 1.45–1.55; EL/EW = 1.35 in male and 1.33 in female; EL/PL = 2.38 in male and 2.63 in female; EW/ PWmax = 1.21 in male and 1.28 in female; PWmax/PWmin = 1.27–1.29.

Etymology. The specific name refers to Luxi, a city in Yunnan, China, in which surroundings the type series was collected.

Comparative remarks. Chydaeus luxiensis sp. n. is very similar in habitus and external structural features to the six species from Yunnan ( Fig. 70 ): C. satoi , C. wuliangensis sp. n., C. baoshanensis , C. asetosus , C. convexus , and C. malaisei (the latter occurs also in the adjacent part of Burma). All these species are very similar to each other in appearance and seem to constitute a natural subgroup within the semenowi species group, with the following main distinctive features: shape of pronotum with rounded sides and with distinct obtuse basal angles; hind wings absent; metepisterna short; elytral microsculpture in males more or less effaced on disc, in females comprised of isodiametric, nearly granulate meshes in basal half and on two or three lateral intervals apically and of slightly transverse meshes on inner intervals in apical half. Chydaeus luxiensis sp. n. is smallest among the mentioned species (8.4–8.7 mm versus 8.8–10.8 mm) and has a very peculiar male genitalia with the terminal lamella of the median lobe rather strongly bent ventrad, much stronger than in the other species. The male of C. luxiensis sp. n. is similar to those of C. asetosus , C. wuliangensis sp. n. and C. baoshanensis in sternum VII with rounded apex and differs in the same character from males of C. convexus , C. malaisei and C. satoi , which have the apex of sternum VII truncate. In addition, the male of C. luxiensis sp. n. differs from those of C. asetosus and C. baoshanensis as well as of C. convexus , C. malaisei and C. satoi in less strongly enlarged mesotarsi; further, males and females of C. asetosus are distinguished from those of the new species in having the pronotum more markedly narrowed basad and lacking lateral setigerous pores. The male and female of Chydaeus luxiensis sp. n. differs from those of C. wuliangensis sp. n. in having the elytra with striae impressed along the entire length and the pronotum with the basal margin slightly longer than the apical margin and with almost indistinct denticles at apices of the basal angles; other differences between C. luxiensis sp. n. and C. wuliangensis sp. n. are listed in the description of the former species. In the structure of the median lobe of the aedeagus, C. luxiensis sp. n. is most similar to C. convexus , differing from the latter, apart from the already mentioned less strongly curved terminal lamella, in the presence of an additional oblique medial spiny patch in the internal sac (very rarely a small oval spiny patch present in C. convexus ).

Distribution. Known only from the type locality, a mountain range 31 km E of Luxi, western Yunnan, China ( Fig. 70 ).

Figures

FIGURE 70. Map of Yunnan Province (China), illustrating localities for the Chydaeus convexus species subgroup.

FIGURES 49 – 52. Chydaeus, dorsal habitus (holotypes). 49, C. ganeshensis sp. n.; 50, C. chuliensis sp. n.; 51, C. wuliangensis sp. n.; 52, C. luxiensis sp. n. Scales = 2.0 mm.

FIGURES 64–69. Chydaeus. 64–65, C. wuliangensis sp. n. (holotype); 66–69, C. luxiensis sp. n. (66, 69, holotype; 67–68, paratype). 64, 66, left metepisternum; 65, 69, median lobe of aedeagus; 67, laterotergite IX and stylus; 68, stylus. 64, 66–67, ventral aspect; 65, 68–69, lateral aspect. Scale = 1.0 mm.