_(완료)인쇄본KJAE12-85.pdf678.0KB

 The oribatid mites (Acari: Oribatida) are associated with organic matter in most terrestrial ecosystem. They are one of the most numerically dominant arthropod groups in the organic horizons of most soils (Behan-Pelletier, 1999). Punctoribates Berlese, 1908 is a small genus in the family Mycobatidae, having 26 known species distributed worldwide (Bayartogtokh et al., 2000). Adults are small ball-shaped. They are mostly live in the leaf litter and upper soil horizon in terrestrial ecosystem (Rajski, 1968; Seniczak et al., 2006). However, some of them, such as Punctoribates sellnicki Willmann, 1928 live in wet habitats, including Sphagnum and other mosses at the edge of lakes (Seniczak and Seniczak, 2008).

 Two species of Punctoribates, P. punctum C. L. Koch, 1839 and P. insignis Berlese, 1910 have been recorded so far in Korea. The first species, P. punctum is mostly found in litter and soil of forest (Jung et al., 1998; Park et al., 1998; Lee et al., 2000), but the second species, P. insignis (=Puntctoribates manzanoensis Hammer, 1958) was reported from rice paddy field (Choi, 1995).

 We found the third species of Punctoribates collected from litter and soil in Seonginbong, Ulleung Island, Korea (Fig. 1). In this work we present a taxonomic diagnosis of the genus and species, and morphological characteristics with detailed illustration.

Fig. 1. The collection site of Punctoribates hexagonus Berlese, 1908 (Seonginbong, Ulleung Island, Korea).

Materials and methods

 The specimens were collected from of Seonginbong (37° 30′ 11.73″N, 130° 51′ 58.15″E; 700m elevation) Ulleung Island, Korea in August 2008 (Fig. 1). The site was mostly covered with trees of Taxus cuspidate Siebold et Zuccarini, Tsuga sieboldii Carriere, Acer mono var. savatieri Nakai. Oribatid mites were extracted by using a modified Berlese-Tullgren funnel for 72 hr with 30 watt bulb (Kim and Jung, 2008; Jung et al., 2010; Kim et al., 2010; Kim et al., 2011). The extracted mites were mounted on the slides using PVA mounting medium (Downs, 1943; BioQuip, Rancho Dominiquez, CA, USA). The terminology and measurements used in this paper is based on Weigmann (2006), Seniczak and Seniczak (2008), and Bayartogtokh (2010).

Systematic accounts

 Family Mycobatidae Grandjean, 1954
     Genus Punctoribates Berlese, 1908
     Syn. Minguezetes Subías et al., 1990

 Diagnosis. Adults small to medium in size (308~469 μm in length; 216~378 μm in width). Rostrum rounded, with or without lateral dens. Lamella well developed, but relatively narrow. Lamellar cusp well developed, but sometimes very small. Translamella usually present, but in rare cases inconspicuous. Interlamellar seta well developed, long, their insertions connected to each other by transverse ridge. Sensillus lanceolate, fusiform or club-shaped, but never capitates nor setiform. Enantiophysis between base of interlamellar seta and bothridium sigmoid or irregularly elongate oval in shape. Tutorium well developed, with distally pointed triangular cusp, closely appressed to prodorsum. Subcapitulum with well-developed mental tectum.. Anteromedian tectum of notogaster projecting forwards as a convex, concave or trapezoid process and covering the bases of interlamellar seta and transverse ridge between them. Posterior notogastral tectum undivided. Ten pairs of small, sometimes indistinct notogastral setae present, frequently some or all setae represented by microsetae or only by their alveoli. Octotaxic system expressed as four pairs of porose areas. Pteromorpha large, semimovable, with only posterior half hinged. Custodium short or absent. Circumpedal carinanot merging with custodium or discidium. Epimeral setation 3-1-3-3. Six pairs of genital, one pair of aggenital, two pairs of anal and three pairs of adanal setae present. Legs heterotridactylous, with lateral claws much thinner than empodial claw (Bayartogtokh et al., 2000).

Distribution. Palearctic, Nearctic, Neotropical, Oriental, Australian, Ethiopian regions (as described in Bayartogtokh et al., 2000) 

Punctoribates hexagonus Berlese, 1908 (Figs. 2-3)
Minguezetes hexagonus: Subías et al., 1990; Pérez-Iñigo,
1993; Pavlitshenko, 1994; Subías, 2004
육각사다리응애 (신칭) 

Fig. 2. Punctoribates hexagonus Berlese, 1908. (A) Dorsal aspect. (B) Ventral aspect.

Fig. 3. Punctoribates hexagonus Berlese, 1908. (A) Anterior notogastral tectum. (B) Interlamellar seta (in). (C) Sensillus (ss) and bothridium. (D) Notogastral seta lp and porose area A₁. (E) Genital plates with setae. (F) Anal plates and adanal setae.

 Diagnosis. Adult body length 355 μm and width 288 μm. Body color dark and chestnut brown. Prodorsum: tip of rostrum round; lamellar seta (le) narrow and rough. Interlamellar seta (in) similar in shape to le. Seta le relatively long, but shorter than seta in. All prodorsal setae barbed. Lamella narrow and shorter than translamella; sensillus (ss) with relatively long stalk and club-shaped or distally narrowed head, directed anteromedially. Notogaster: anterior notogastral tectum concave medially, fore-end of this tectum relatively short, sharp, middle part of tectum with “U” form; anterior notogastral tectum projected far forward, and covers partly lamella and translamella, bothridium (bo) and basal parts of setae in and le; The fore part of notogaster trapezoidal profile and hind part oval in outline, having ten pairs of setal pores and four pairs of porose areas, with Aa largest and elongated, which is positioned near setae lm and la, A₂ oval in shape and smaller than A₁. Pair of thickened bands associated with medial process. Ventral side: epimeral setation 3-1-3-3, genital plates with six pairs of genital setae (g), thin and smooth (four arranged on anterior and other two on posterior half of the plate), one pair of aggenital setae (ag), two pairs of anal (an)  and three pairs of adanal setae (ad), ad located close to the lateral margin of anal plate; legs heterotridactylous with a strong empodial claw and slimmer lateral claws.

Distribution. Palaearctic Region: Korea (new record), Siberia, Russian Far East, Kazakhstan, Mongolia, Japan; Europe; Oriental Region: Vietnam. (as described in Bayartogtokh, 2010) 

 Remarks. This species can be distinguished from P. insignis by the smaller size of anterior notogastral tectum and translamella covering prodorsum. It prefers salty soils (Rajski, 1968; Seniczak et al., 1985; Weigmann, 2006), and seemed to be related to the moist habitats (Seniczak and Seniczak, 2008). It also occurs in meadows (Bielska and Paszewska, 1995).

Key to adults of Punctroibates Berlese species in Korea

 1. Medial process of anterior notogastral tectum large, forming two lateral projections with a concave incision between them; lamellae, translamella and lamellar cusps small, poorly developed, situated underneath the notogastral tectum························································································2

 - Medial process of anterior notogastral tectum small, convex, without lateral projections; translamella and lamellar cusps large, well developed, extending well beyond notogastral tectum ································· P. punctum (C. L. Koch, 1839)

 2. Medial process of anterior notogastral tectum relatively small, partly covering prodorsum up to level of translamella; genital plates smooth; body relatively small, 330-366 μm in length, 270-318 μm in width ························································································· P. hexagonus (Berlese, 1908)

 - Medial process of anterior notogastral tectum relatively large, covering most of prodorsum beyond level of translamella; genital plates with longitudinal striations, body relatively large, 378-469 μm in length, 301-378 μm in width ·································································· P. insignis (Berlese, 1910)

Acknowledgement

 This study was funded by Rural Development Administration project (Project No. PJ9069992012). Jiwon Kim was supported by 2^nd stage “Brain Korea 21 program”, Andong National University from the Ministry of Education and Human Resources Development, Korea.