Epicrius simoni, Án, Peter Ma Ò, 2008

Án, Peter Ma Ò, 2008, The family Epicriidae in Slovakia: annotated faunal synopsis and description of a new species of Epicrius (Acari, Mesostigmata, Epicriidae), Zootaxa 1880, pp. 48-68 : 59-60

Epicrius simoni sp. nov.

( Figs 3–8 )

Material examined. Holotype (Ψ) – 16 October 1991, NE Slovakia, Laborecká Vrchovina Highland, Niżný Komárnik Village (49°22'N, 21°41'E), virgin fir-beech forest (Abieti -Fagetum); paratypes (2 ΨΨ) – 30 October 1997, NE Slovakia, Bukovské Vrchy Hills, Uličské Krivé Village, Rožok Forest (48°58'N, 22°28'E), virgin beech forest (Fagion sylvaticae), 600 m.

Description (Female). Dorsal idiosoma ( Fig. 3 ). Idiosoma subglobular, widely oval to subcircular in outline, longer than wide (length 660–705 µm, width 490–530 µm). Dorsal shield entire, covering whole dorsal surface, richly ornamented with noduliform tubercles forming a distinct network; sculptural tubercles bi- and trispinate. Dorsal surface bearing 28 pairs of setae varying in thickness and length; setae j3, j5, J2, J3, z4 and s1–s4 needle-like and conspicuously shortened (shortest dorsal setae 27–31 µm); setae z5 intermediate; all other dorsal setae distinctly thickened, extremely elongate, spine-like, often undulate distally and with delicate pilosity on surface (longest dorsal setae 195–220 µm). Glandular structure between setae s6 and S3 hypertrophied, rounded, and placed together s6 on one common area enclosed by the row of nodules.

Ve n t r a l idiosoma ( Fig. 4 ). Presternal platelets well differentiated, small, suboval, each bearing a sternal seta st1 with associated poroid structure. Sternal shield subquadrate to subrectangular, situated between coxae II and III, straight anteriorly, concave posteriorly, slightly sinuous on lateral margins, with three pairs of setae (st2–st4). Genitiventral shield relatively large, quadrangular, slightly convex anteriorly and posteriorly, slightly constricted close to genital setae st5, bearing two pairs of setae (st5, Zv1). Wide posterolateral surfaces (almost whole opisthogastric region) covered by shield overlapping from dorsum; the shield in opisthogastric region with inner margins closely adjacent or abutting each other, widely rounded, and with five pairs of ventral setae (Jv3, Jv4, Zv2–Zv4), excluding setae Jv5 visible from dorsal view, and marginal R setae (altogether seven pairs of marginal r and R setae present). Anal shield free anteriorly (posterior margin not clearly visible and perhaps fused with dorsal shield), with small elongated anus, three circum-anal setae and a pair of pre-anal setae (Jv2). Ventral setae Jv1 placed on membraneous integument between genitiventral and anal shields. Exo-, endo- and metapodal integument densely sculptured with microspicules; all ventral shields smooth, without distinct sculptural ornamentation or structures (ventral nodules absent). Peritrematal regions with conspicuous stigma and small poroid structure, peritremes absent.

Gnathosomal structures ( Figs 5–7 ). Chelicera chelate-dentate, with weak dentition of digits ( Fig. 5 ). Hypostome with four pairs of setae ( Fig. 6 ), corniculi slender and digitiform, deutosternum with two transversal rows of denticles in medial area. Tectum subtriangular and denticulated on anterior margin, larger denticles situated close to apex ( Fig. 7 ). Palp with normal setation, palptarsal apotele 3-tined.

Legs. Legs with six free segments, terminal segment incompletely separated into metatarsus and tarsus. Legs II–IV terminated in multi-lobed pulvillus and two claws. Legs I the longest, lacking ambulacral apparatus on tarsus I ( Fig. 8 ). Tarsus I (305–320 µm long) with five specialized sensory setae (macrosetae) ventrolaterally: these setae with undistinct club-like tips. Legs bearing stout, spinose and finely barbed setae mostly inserted on distinct bases. Setation of segments of legs I-II-III-IV as follows: coxae 2-2-2-1, trochanters 6-5- 5-5, femora 13-13-8-8, genua 13-11-10-10 and tibiae 14-10-9-10.

Etymology. The species is named in honour of my son Šimon, who was born recently.

Notes. The new species can be easily distinguished from the other known Epicrius species by the chaetotactic pattern of the dorsal shield: dorsal setae of the medial rows are heterogeoeous in length: setae j1, j2, j4, j6, J4 and J5 are strongly elongated while setae j3, j5, J2 and J3 are strongly shortened; by the chaetotaxy of the interscutal membrane between the genitiventral and anal shields (opisthogastric cuticle with only a pair of setae Jv1), and the structure of the dorsal tubercles (tubercles with longer, slim and obtuse protuberances).

E. simoni is the most similar to E. magnus Solomon, 1984 , known from the Călimani Mountains in Romania ( Solomon 1984), by the almost identical shape of setae and sculptural nodules placed on dorsal surface, and form and arrangement of ventral shields. These species can be separated as follows: E. simoni – dorsal shield 660–705 µm long; anterior dorsal setae j5 and z6 strongly reduced in length and with tips never exceeding beyond the area enclosed by sculptural nodules; posterior dorsal setae J3 shortened and at least three times shorter than adjacent setae j6, Z2, Z3 and J4; lateroventral extensions of dorsal shield wide, with adjacent margins in opisthogastric region; E. magnus – dorsal shield 770 µm long; anterior dorsal setae j5 and z6 moderately reduced in length and with tips exceeding beyond the area enclosed by sculptural nodules; posterior dorsal setae J3 well developed and subequal with adjacent setae j6, Z2, Z3 and J4; lateroventral extensions of dorsal shield narrow and widely separated in opisthogastric region.

Ecology. The distribution area of this new species reaches the territory of Slovakia only marginally in the north-easternmost part of country ( Fig. 1 ), where it occurs very rarely in virgin forests with beech and fir (Fagion sylvaticae and Abieti -Fagetum). From the zoogeographical viewpoint it is probably an East Carpathian endemic element of the European fauna.

Figures

FIGURE 1. Known distribution of epicriid species in Slovakia (dotted area represents Pannonian flora distribution).

FIGURES 3 – 4. Epicrius simoni sp. nov., female. 3. Dorsal idiosoma, with detail of sculptural nodules; 4. Ventral idiosoma. Scale: 100 µm.

FIGURES 5 – 8. Epicrius simoni sp. nov., female. 5. Cheliceral digits; 6. Ventral hypostome; 7. Tectum; 8. Tarsus I. Figures not to scale.