A new subgenus and two new species of the troglobitic genus Dongodytes Deuve from Guangxi , China ( Coleoptera , Carabidae )

In the present paper, a new subgenus and two new species of the cave-dwelling genus Dongodytes Deuve, 1993 are described and illustrated: Dongodytes (Dongodytodes) deharvengi, subgen. and sp. nov. and Dongodytes baxian, sp. nov. from Du’an Xian, North


INTRODUCTION
Since Sinaphaenops mirabilissimus Uéno & Wang, the fi rst blind trechine was described in mainland China (Uéno and Wang 1991), many new genera and species have been discovered in southern Provinces or Regions such as Guizhou, Guangxi, Yunnan, Hunan, Sichuan and Chongqing, making China one of the richest countries in cave-dwelling trechine beetles on both generic and specifi c aspects (Tian 2008).Furthermore, all Chinese genera and species of cave-dwelling beetles are endemic, most of them occurring in a very narrow area, generally known only from the type locality, i.e. one or a few caves (Latella and Chen 2008).Because China holds the largest karstic areas in the world it is supposed that more and more new taxa of cave-dwelling trechines will be discovered in near future even they are always so rare.
It is too early to discuss the phylogenetic relationships of cave-dwelling trechines in China because of poor knowledge on the cave fauna of the country.For instance, the peculiar genus Dongodytes Deuve, 1993 is one of the most cave adapted trechine genera in the world (Ueno 1998).It is composed of three species so far, viz.D. fowleri Deuve, 1993, D. grandis Uéno, 1998 andD. giraffa Ueno, 2005.But the relationship of this genus within Trechinae has not been well determined.It was regarded either close to Sinaphaenops Uéno & Wang (Deuve, 1993), or allied to European trechine Aphaenops series (Vigna Taglianti 1997;Uéno 1998); for the latter hypothesis, there would be a big challenge to explain how to link between both lineages from the zoogeographical point of view.
Our recent discovery might provide a very important evidence for this interesting topic.Sponsored by a World Bank project which managed by the Biodiversity Offi ce, Guangxi Forestry Bureau, Nanning, Dr. Louis Deharveng (the Paris Museum of Natural History, MNHN), and the author, with assistance of Dr. Anne Bedos (MNHN) and Dr. Li Youbang (Guangxi Forestry Bureau, Nanning), made a twenty-day collecting exploration on cave fauna in several selected karstic areas of Guangxi Zhuang Minority Autonomic Region in April, 2010.Among the large collected material, we found two new species of Dongodytes, one of them represents a new subgenus which evidently different from the nominate subgenus.

MATERIALS AND METHOD
All specimens used in the study were collected in Du'an Yao Minority Autonomic Xian, Hechi City, Guangxi.All specimens are deposited in the insect collection of South China Agricultural University (SCAU), except two paratypes of Dongodytes (Dongodytodes) deharvengi sp.nov. in MNHN, Paris.Abbreviations of measurement used in the text are the same as in Tian (2009)., Type species: Dongodytes (Dongodytodes) deharvengi, sp.nov.

Dongodytodes
Diagnosis.Dongodytodes, subgen.nov. is similar to Dongodytes (s.str.)concerning the evidently swollen prothorax, the very elongate elytra without humeral angles, the unmodifi ed protarsi of male, the bisetose labial palpomere 2 and the chaetotaxal pattern of elytra.However, the following peculiar features of Dongodytodes make it fall into another lineage rather than Dongodytes (s.str.):(1) head more stout and broadly convex posteriorly, widest at the level of the end of frontal furrows, and neck very short in Dongodytodes, versus long and narrowly gradually convergent posteriorly, widest at the level of anterior supraorbital pores, neck much longer in Dongodytes (s.str.);frontal furrows shorter, straight and subparallel-sided before divergence in Dongodytodes, versus longer, evidently sinuate and not parallel-sided before divergence in Dongodytes (s.str.); head with two pairs of supraorbital pores, posterior pores far from anterior ones and closer to neck in Dongodytodes, versus both anterior and posterior pores (the latter sometimes not well marked, and irregularly located, or wanted) closer to each other than the posterior one to the neck in Dongodytes (s.str.);(2) antennae stouter and much shorter, hardly extending to beyond apices of elytra in Dongodytodes, versus much longer, elongate, and evidently extending over elytral apices in Dongodytes (s.str.);(3) clypeus sexsetose in Dongodytodes, versus quadrisetose in Dongodytes (s.str.);(4) surface of body densely covered with long and erected hairs or pubescence, and more or less punctate on elytra in Dongodytodes, versus with only a few sparse setae on head or sometimes on pronotum, and glabrous and impunctate on elytra in Dongodytes (s.str.);(5) the elytral chaetotaxal pattern of Dongodytodes is quite similar to that of Dongodytes (s.str.), but stria 3 with only one setiferous pore at about 3/5 from base in Dongodytodes, versus two or three in Dongodytes (s.str.);(6) elytral striae more or less evident throughout in Dongodytodes, but rather faint in Dongodytes (s.str.);(7) abdominal ventrite VII of male with only one pair preapical setae in Dongodytodes, versus two pairs in Dongodytes (s.str.);ventrites IV-VI each with only one pair of paramedian setae in Dongodytodes, versus two pairs in Dongodytes (s.str.);(8) body of Dongodytodes smaller than that of the members of Dongodytes (s.str.); and (9) Dongodytodes with much slender, and longer male aedeagus than that of Dongodytes (s.str.)considering its smaller body size.
Etymology.The name of the new subgenus refers to its similarity to Dongodytes (s.str.).
Diagnosis.Small sized, blind, dark reddish brown beetle, surface covered with dense and short bristly setae, head and pronotum smooth, elytra evidently rugose and punctate; antennae not exceeding over the elytral apices; head evidently expanded posteriorly, posterior supraorbital pores close to neck; protarsomere 1 not modifi ed in male; aedeagus small and slender, evenly arcuate throughout, parameres elongate, each with four long setae at apex.

Description
Length (including mandible): 6.2-6.4 mm.Habitus as in Fig. 1.Whole body covered with dense and bristly setae, dark reddish brown.Surface moderately shiny, smooth on head and pronotum, more or less rugose and punctate on elytra.Microsculptural meshes fi ne transversal lines on head and pronotum, and strongly transversal polygons on elytra.
Head (Fig. 2) elongate and narrow, HL/HW=2.6-2.8;widest at about the level of end of frontal furrows, gently expanded from the level of posterior pores to frontal furrows, then suddenly and strongly constricted to neck; neck constriction evident, base of neck distinctly convex, ring-shaped; dorsal surface convex, frons and supraorbital area gently convex; frontal furrows comparatively short, well marked, subparallel-sided before the evidently divergence, ended a little behind the anterior supraorbital pores; the two pairs of supraorbital pores far from each other, posterior ones much closer to neck than to the anterior ones; mandibles moderately slender; labrum sexsetose, slightly bisinuate at frontal margin, with median margin nearly straight; clypeus sexsetose; mentum and submentum well separated by labial suture; mentum moderately concave, with the median tooth simple; ligula quite narrow, with two setae at apex; labial palpomere 2 bisetose at inner side; antennae rather long and slender, but not extending over elytral apices; antennomere 1 short and stout, slightly longer than antennomere 2; antennomeres 3, 4 and 5 subequal in length, each 2.3 times as long as antennomere 2.
Ventral surface wholly pubescent, denser in median portion of ventrites; apical margin of apical abdominal ventrite complete, with a pair of anal setae in male but two in female; ventrites IV-VI each with one pair of paramedian setae in both sexes.
Legs quite slender, but more or less shorter than those of Dongodytes (s.str.);tarsomere 1 long, pro-and metatarsomere 1 as long as pro-and metatarsomeres 2-4 combined, respectively, mesotarsomere 1 longer than tarsomeres 2-4 combined; protarsi not modifi ed in male, though both male and female with protarsomere 1 slightly stouter than others.
Male aedeagus (Figs.4-5) with the median lobe small and slender, evenly arcuate throughout; inner sac armed with a long and rather thin sclerotized copulatory piece, which is about 1/3 as long as the median lobe, base orifi ce quite narrow; in dorsal aspect, apex broad and symmetric, nearly parallel-sided; parameres elongate, the right one as long as the left, each with four long apical setae.
Sexual dimorphism.No sexual dimorphism; male and female similar, the protarsi not modifi ed in male, but abdominal ventrite VII with only one pair of setae in male, while two pairs in female.
Remarks.Dongodytes (Dongodytodes) deharvengi, sp.nov. is more or less similar to members of Dongodytes (s.str.).But it is very easy to separate this new species from all Dongodytes (s.str.)species by its smaller and pubescent body, stouter head, shorter antennae, sexsetose clypeus, punctuate elytra and slender aedeagus.
Etymology.This new species is named in honor of Dr. Louis Deharveng (MNHN, Paris), a well known specialist of Collembola and cave biodiversity.
Distribution.Guangxi (northern Du'an Xian).Known only from the type locality cave which is still anonymous.It is a ruined coal mine (Fig. 6-8).The entrance is about 200 m from the main road (National Road G050) on the west side.First part of the passage is an horizontal mine, straight for about 30 m, then gradually going down for about 50 m, where it joins a natural cave passage.The natural passage continues towards the left (not explored); towards the right and upwards, it is a large and steep gallery for about 50 m; then, after a relatively narrower path, it goes down for about 50 m to a large room about 40 m wide.All the beetles were collected on the steep, wet and muddy slopes of this room and on formations.At the bottom of the room, the passage decreases in size and continues horizontally for at least 30 m, with some puddles.Most specimens were wandering when collected (Fig. 9) except two which were caught under stone.Dongodytes (Dongodytes) baxian, sp.nov.
(Figs 10-13) Holotype: male, Baxian Dong, a limestone cave in Baxian Park, at suburb of Du'an for about 8 km, 108.13'281 ''E / 23.91'404''N, 150 m, 26 April, 2010, Louis Deharveng leg., in SCAU.Diagnosis.Small sized for Dongodytes, elongate and slender beetle; reddish brown, head, thorax covered with long and sparse setae, surface smooth, elytra glabrous; abdominal ventrites shortly pubescent; head a little more stout than other members of Dongodytes (s.str.), with only the anterior pair of supraorbital pores, the posterior ones wanted, with a few irregularly located setae; frontal furrows rather long; protarsomere 1 not modifi ed in male; aedeagus very short and stout, with apical portion short and obtuse, and parameres narrow and slender, subequal in length, each with four long setae at apex.

Description
Length (including mandible): 7.3 mm.Yellowish brown, palpi, antennomeres 5-11, and tarsi pale; surface moderately shiny, smooth on head and prothorax, faintly rugose on elytra; head and pronotum covered with long and sparse setae.Microsculptural meshes fi ne transverse or oblique lines on head and pronotum, irregularly polygons on elytra.
Head (Fig. 10) very long and narrow, HL/HW=3.1;widest at about the level of antennal articulation, and gradually narrowed to neck posteriorly; neck constriction quite elongate, base of neck evidently convex, ring-shaped; dorsal surface moderately convex; frontal furrows moderately long and well defi ned; with only anterior pairs of supraorbital pores, and a few irregularly located setae; labrum emarginated at frontal margin, clypeus quadrisetose; mandibles slender, and well developed; eyes effaced; mental tooth evident, faintly bifi d at tip; palpi slender, labial palpomere 2 with two setae at inner side.Antennae long and slender, evidently extending over elytral apices; antennomere 1 with a long preapical setae and a few sparse shorter ones, other antennomeres with denser pubescence; antennomere 1 short and stout, 3.4 times as long as wide; antenomeres 1 and 2, and 3 and 4 subequal in length, respectively.
Elytra (Fig. 11) very slender, and narrow, widest at a little before 3/5 from base; EW/PW=2.0,EL/PL=2.8,EL/EW=2.0;sides well bordered throughout, smooth and not serrated; with very slight shoulders, feebly sinuate behind and almost straight before the faint shoulders; surface strongly convex exception of base area which is distinctly depressed; striae obsolete except for striae 1 and 3 which are more or less evident; stria 3 with two setiferous pores at 5/7 and 1/2 from base, respectively; marginal umbilicate pores similar to those in D. fowleri Deuve and D. grandis Ueno; without scutellar striole.
Underside of head and thoraxes smooth and glabrous, with sparse and long setae; abdominal ventrites shortly pubescent.Apical abdominal ventrite with two pairs of preapical setae; ventrites IV-VI each with a pair of setae at median portion.
Male aedeagus (Figs.12-13) with the median lobe small, and short, but stout and well sclerotized, slightly membraneous on apical dorsal part, base orifi ce wide, apex shortly broad, inner sac armed with a very large, well-defi ned sclerotized copulatory piece, which is about 1/3 as long as the median lobe; in dorsal aspect, apex broad, gently protrude and rounded, slightly membraneous at tip; parameres long and slender, each with four long setae at apex.
Remarks.D. baxian sp.nov. is very similar to D. fowleri and D. grandis Uéno, but easily distinguished from them by the following characters: (1) aedeagus stouter and broader, parameres more elongate and slender; (2) pronotum covered with sparse and long setae; and (3) elytral sides slightly but obviously sinuate behind the very slight shoulders.
Etymology.This new species is named after its type locality: Baxian Dong.In Chinese, Ba Xian refers to the eight immortals, viz.Zhang Guolao, Lu Dongbin, Cao Guojiu, Zhong Liquan, Li Tieguai, Han Xianzi, He Xiangu and Lan Caihe, who are symbols for good fortune.