ZooKeys 119: 29–36, doi: 10.3897/ZooKeys.119.1629
A new species of the genus Epidamaeus (Acari, Oribatida, Damaeidae) from China
Lixia Xie, Maofa Yang, Rong Huang§
Institute of Entomology, Guizhou University; The Provincial Key Laboratory for Agricultural Pest Management of Mountainous Region, Guiyang, Guizhou, P.R. China, 550025

Corresponding author: Maofa Yang (yangmaofa@sohu.com).

Academic editor: Andre Bochkov

received 30 May 2011 | accepted 11 July 2011 | Published 15 July 2011

(C) 2011 Lixia Xie. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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The oribatid mite genus Epidamaeus Bulanova-Zachvatkina, 1957 from China is reviewed, and a list and key to all known species from China are provided. A new species, Epidamaeus conjungenus sp. n. is identified, and its morphological descriptions and illustrations are also given. The distinct characteristics of Epidamaeus conjungenus sp. n. is the coterminous ridge connected to the base of the notogastral setae. Pseudanal setae undulating attenuate, the proximal half with obvious, thorn-like barbs, the distal half smooth.


Epidamaeus, new species, checklist, distribution


Oribatid mites of the genus Epidamaeus Bulanova-Zachvatkina, 1957 are known to be very diverse throughout the Northern Hemisphere, especially in Europe and North America (Bayartogtokh 2004). Most species of this genus inhabit the litter of forests, mosses, decaying woods and organic soil layers, and primarily feed on decomposer or plant pathogenic fungi, therefore, they play an important role in regulation of the density of plant harmful fungi (Bayartogtokh 2000). Epidamaeus shows high taxonomic diversity in Europe and some parts of Asia. The genus comprises more than 70 species, that cosmopolitan distributed (Subías 2011). Up to now, only 6 valid species: Epidamaeus grandjeani, Epidamaeus cincinnatus, Epidamaeus elegantis, Epidamaeus longispinosus, Epidamaeus yunnanensis, Epidamaeus alticola from China were described (Wen 1990, Wang and Norton 1993, Enami et al. 1994, Wang and Cui 1996a, Chen et al. 2010), but the collection material from different vegetation zones of the country revealed species-richness as that in the other parts of the Palaearctic and Oriental Region. This may be related to the dynamic history of the area, which had a different climate and biota found throughout China.

In the present paper, a new species Epidamaeus conjungenus sp. n. were described from Henan Provinces. In addition, a list and key to all known Chinese species were present.

Material and methods

Measurements and descriptions are based on specimens mounted in temporary cavity slides that were studied using a light microscope equipped with a drawing attachment. Body length is measured in lateral view, from the tip of the rostrum to the posterior edge of the ventral plate. Length of leg segments, including the portion inserted into the next segment, is measured in the lateral aspect. The number of specimens measured does not always equal the number of specimens examined because structures are sometimes indiscernible under the circumstances where the specimens are not slide-mounted.

Terminology generally developed by Grandjean (1960) as applied by Norton (1979). All type specimens and other material studied are kept in Oudemans’ fluid and deposited in the Institute of Entomology, Guizhou University, Guiyang, China (GUGC).

Epidamaeus Bulanova-Zachvatkina, 1957


Type species:

Oribata bituberculata Kulczynski, 1902 (Bulanova-Zachvatkina 1957a)


Body reddish brown, medium sized, light to dark. propodolateral apophyses P mostly absent, but rarely present; the formation of tubercles of Prodorsum varied: usually only Ba or Da present, 3 pairs of tubercles (Ba, Bp, Da) is rare present as Damaeus; La tubercle can also be present, but weak and indistinct in dorsal view, and never in combination with Ba (as in Kunstidamaeus); E2a and E2b missing, Va and Vp rarely present occasionally. SS usually bristle-shaped, in shorter than ss (to 3/4 as long), bristle-shaped, mostly thin. Spinae adnata (Sa) usually present (subgen. Epidamaeus) or absent (subgen. Akrodamaeus); The length of legs medium to long; Tibiae I-IV without setae d; Setal mostly formula of genua I-IV: 4-4-3-3, rarely 4-4-4-4; Associated setal (setae d) formula of genua I-IV: 1-1-1-0; Setal formula of trochanters I-IV: l-1-2-1; Additional ventral seta v2” on I and IV missing. 6 g, 1 ag, 2 on, 3 ad. (Weigmann 2006)


Palaearctic, Oriental, Nearctic, Neotropical and Australian regions.

Species of genus Epidamaeus from China

Epidamaeus alticola Wang & Cui, 1996

Epidamaeus alticola Wang and Cui 1996a: 321; 1996b: 258.

Material examined.5♂♂, 4♀♀, China, Qinghai Prov., Xining City, Huzhu National Geological Park(36°57'11"N, 102°28'55"E), from litter under Pteridophytes, 2384 m a.s.l., 23 August 2009, coll. Lixia Xie (GUGC)

Distribution. China (Qinghai).

Epidamaeus cincinnatus Wang & Norton, 1993

Epidamaeus cincinnatus Wang and Norton 1993: 312; Wang et al. 2000: 323.

Material examined.11♂♂, 6♀♀, China, Hebei Prov., Chengde City, Mt. Wuling (40°36'50"N, 117°28'57"E), from litter under birch, 1362m a.s.l., 25 August 2010, coll. Lixia Xie (GUGC)

Distribution. China (Beijing).

Epidamaeus elegantis Wang & Norton, 1993

Epidamaeus elegantis Wang and Norton 1993: 316-318; Wang et al. 2000: 311.

Material examined.6♂♂, 3♀♀, China, Fujian Prov., Wuyishan City, Mt. Wuyi (27°45'19"N, 118°02'56"E), from litter under the chestnut trees , 278m a.s.l., 4 August 2008, coll. Zehong Meng (GUGC)

Distribution. China (Fujian, jiangxi).

Epidamaeus grandjeani Bulanova-Zachvatkina, 1957

Epidamaeus grandjeani Bulanova-Zachvatkina 1957b: 1794-1796; Wen 1990: 119; Wang et al. 2000: 256.

Distribution. China (Jilin), Russia (Tatarstan).

Epidamaeus longispinosus Wang & Norton, 1993

Epidamaeus longispinosus Wang and Norton 1993: 314-316; Wang et al. 2000: 310–311.

Material examined.4♂♂, 5♀♀, China, Fujian Prov., Wuyishan City, Mt. Wuyi (27°45'24"N, 118°02'46"E), from litter of coniferous forest, 263m a.s.l., 5 August 2008, coll. Zaihua Yang (GUGC)

Distribution. China (Fujian, Jiangxi).

Epidamaeus yunnanensis Enami, Aoki & Hu, 1994

Epidamaeus yunnanensis Enami et al. 1994: 43–46; Aoki et al. 2000: 6.

Material examined.2♂♂, 3♀♀, China, South of Guizhou Prov., Maolan National Nature Reserve (25°19'26"N, 107°55'59"E), from litter under Podocarpus, 819m a.s.l., 16 Sep. 2007, coll. Zaihua Yang (GUGC); 7♂♂, 6♀♀, China, Yunnan Prov., Dali City, Mt. Cang (25°38'38"N, 100°09'53"E), from litter under the pine, 1950m a.s.l., 18 December 2008, coll. Yi Yan (GUGC)

Distribution. China (Yunnan, Guizhou).

Key to species from China. .
1 Propodolateral apophysis (P) present, having tubercles (La) Epidamaeus yunnanensis Enami, Aoki & Hu
Propodolateral apophysis (P) absent, not having tubercles (La) 2
2 Notogastral setae cincinal, genital seta g6 far from g5 Epidamaeus cincinnatus Wang & Norton
Notogastral setae not cincinal, genital setae normal for genus 3
3 Sensillus (ss) aciculiform, aggenital seta (ag) lies between Anal aperture and genital aperture Epidamaeus elegantis Wang & Norton
Sensillus (ss) rod-like or flagellate, aggenital seta (ag) normal for genus 4
4 Sensillus (ss) rod-like, seta c1 longer than other notogastral setae Epidamaeus alticola Wang & Cui
Sensillus (ss) flagellate, seta c1 not longer than other notogastral setae 5
5 Notogastral setae leafy, Spinae adnatae rod-like Epidamaeus grandjeani Bulanova-Zachvatkina
Notogastral setae not leafy, Spinae adnatae not rod-like 6
6 Coterminous ridge connected to the base of the notogastral setae; Spinae adnatae not long and spinous Epidamaeus conjungenus sp. n.
Coterminous ridge not connected to the base of the notogastral setae; Spinae adnatae long and spinous Epidamaeus longispinosus Wang & Norton
Material examined.

Holotype (female in Oudemans’ fluid ), China: Luoyang city, Mt. Baiyun (34°23'25.18"N, 111°01'23.15"E), Henan province, from litter, 2100 m a.s.l., 16 Aug. 2008, coll. Li-xia Xie. Paratypes. Five adults (2 males, 3 females), with same data as holotype.


The specific name “conjunctus” is from Latin, and refers to the conjunct ridge.


Prodorsal tubercles Da, Ba, Bp present. Sensillus smooth, short, with conspicuous bars. Sa triangular, long and acuminate. Sp small, triangular. Enantiophysis E2 and V present. Vp bearing seta 3b. The setae of notogaster acuminate, radially directed. Leg setation as follows, femora 7-6-4-4; genua 4-4-3-2; tibiae 4-4-3-3; tarsi 21-18-18-15.


Body length 913 (holotype), 913- 932 (mean 924, 6 paratypes); body width 605 (holotype), 602- 623 (mean 610, 6 paratypes). Males slightly smaller than females: body length of males holotype and 2 paratypes) 886- 902 (mean 894), body width of males 584- 592 (mean 588); body length of females (4 paratypes) 906- 914(mean 910), body width of females (4 paratypes) 596- 624 (mean 610).

Integument. Microtuberculate on all enantiophyses and apophyses, rostrum, lateral prodorsum and around leg acetabula. Cerotegument granules, thick, dense on most of body and legs, except digital part of tarsi. Notogaster with exuvial scalps, legs segments and lateral part of body with dense fungus micelles and adherent debris.

Prodorsum. Tubercles Da and Bp well developed, broadly rounded; Ba represented as high ridge. Propodolateral apophysis (P) absent. A ridge presents the side of prodorsum. Setae ro (175–183 μm) and le (216–221 μm) long, smooth, with conspicuous barbs; mutual distance of pairs le slightly less than that of ro (1.0:1.1). Interlamellar setae (96–104 μm), dark brown, with small barbs. Exobothridial setae (94–98 μm) smooth, relatively tenuous, attenuate. Sensillus (225–232 μm), with conspicuous barbs, undulating attenuate. Comparative length of prodorsal setae: ex < in < ro < le < ss.

Notogaster. Almost circular, slightly longer than wide. Anterior and posterior margins broadly rounded in dorsal view. Spinae adnatae large, directed anterolaterad in dorsal view, distance between their bases approximately equal to that between tubercles Bp. Notogastral setae of c-, l- and h-series inserted on distinct tubercles. Setae relatively smooth, brown, acuminate. Comparative length: lm < lp < la = h3 < h2 < h1= c1 = c2 . The respective lengths: 88–94μm, 107–110 μm, 137–142 μm, 147–154 μm and 167–172 μm. Setae c1, c2 and la directed anterodorsad, other setae radially directed. A conjoint ridge connected to base of all notogastral setae. Mutual distance of setae c2 twice that of c1. Pseudanal setae undulating attenuate, the proximal half with obvious, thorn-like barbs, the distal half smooth. Comparative length: ps1> ps2 > ps3.

Ventral region. Epimere I with medial pit and associated groove. Enantiophyses E2 and V well developed, broadly triangular in ventral view. Tubercle Vp bearing epimeral seta 3b. Parastigmatic tubercle Sa long, acuminate and triangular. Sp triangular, distinct in ventral view. Length of lateral aspect Sp twice as broad as Sa. Discidium acuminate, smaller than Sp, directed posterolaterad. Ventral setae faintly barbed. Setae 3c, 4d very long, flagelliform. Epimeral setation: 3-1-3-4. Anogenital region normal, seta ad3 close to anal valves. Fissure iad minute, represented by small, inconspicuous pore in lateral corner of valve. Anal aperture appreciably equal to genital aperture.

Gnathosoma. Infracapitular mentum slightly wider than long, without noticeable microtubercles. Hypostomal setae a, h and m thin, slightly barbed; seta a relatively short. Chelicera rather strong, fixed and movable digits with three blunt teeth; setae cha and chb conspicuously barbed. Palpal setation: 0-2-1-3-8 including solenidion ω.

Legs. Relative lengths (I-IV): 1: 0.84: 0.95: 1.1. Leg IV 1.1 times ventral body length; Femur IV 1.44 times length of trochanter IV. Formulae of leg setation and solenidia: I (1-7- 4- 4- 21) [1-2-2], II (1-6-4-4-18) [1-1-2], III (2-4-3-3-18) [1-1-0], IV (1-4-3-3-15) [0-1-0]; Each solenidion on genu I - III coupled with a respective seta d, seta d longer than solenidion on genu I-III. Solenidion φ1 on tibia I flagelliform, and 2.2 times longer than φ2.


Known only from the type locality.


Epidamaeus conjungenus sp. n. can be readily distinguished from most of known species of Epidamaeus by the coterminous ridge connected to the base of the notogastral setae. Pseudanal setae undulating attenuate, the proximal half with obvious, thorn-like barbs, the distal half smooth. Parastigmatic tubercle Sa very long, acuminate, Discidium(di) acuminate. The strong Spinae adnatae (Sa). The Prodorsum of this new species is somewhat similar to Epidamaeus verrucatus described by >Enami and Fujikawa (1989), but the setae of notogaster of new species are smooth, and lack of Propodolateral apophysis (P) and present tubercles Da and Bp.

Figure 1.

Epidamaeus conjungenus sp. n. A adult, dorsal view (100 μm) B adult, ventral view (100 μm) C leg I (100 μm) D leg IV (100 μm).

Table 1.

Leg setation and solenidia of Epidamaeus conjungenus sp. n.

Legs Trochanter Femur Genu Tibia Tarsus
I v d, l’, l’’, v1’ v1’’ bv’’, v2’’ d, σ, l’, (v) φ1, φ2, l’, l’’, (v) ft’, ft’’, pl’, pl’’, (v), ω1, ω2, ε, (pv), (tc), (it), (p), (u), (a), s
II v d, l’, l’’, bv’’, (v) d, σ, l’’, (v) φ, (l), (v) ft’, ft’’, (v), ω1, ω2, (pv), (tc), (it), (p), (u), (a), s
III l’, v’ d, l’, ev’, v’ d, σ, l’, v’ d, φ, l’, v’ ft, v’, pv’’, pv’, (tc), (it), (p), (u), (a), s
IV v d, l’, ev’, v’ d, l’, v’ φ, l’, (v) ft’’, (v), (pv), (tc), (p), (u), (a), s

We would like to express our heartfelt thanks to Roy A. Norton (College of Environmental Science and Forestry, State University of New York, Forestry Drive, Syracuse, New York, U.S.A) and Sergey G. Ermilov (Laboratory of Entomology, Center of Independent Examinations-NN, Nizhniy Novgorod, Russia) for their encouragement to our research and fervidly sending documents. Thanks are also due to all the people who participated in the specimens’ collection, for their friendly help and eager cooperation.

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