Two new species of Holoparasitus Oudemans, 1936 from Europe (Parasitiformes: Parasitidae)

Two new mite species, Holoparasitus calpetanus n. sp. from Gibraltar and Holoparasitus fanes n. sp. collected in the Dolomites (North-East Italy) are described. Holoparasitus calpetanus n. sp. is considered to be a member of the Holoparasitus mallorcae species-group. A new Holoparasitus crassisetosus species-group is defined; H. fanes n. sp. is morphologically close to this group.


INTRODUCTION
The genus Holoparasitus (Oudemans 1936) contains 55 species, including the two described in the present paper. These are predatory mites mainly inhabiting mosses and forest litter in the Holarctic region. Some taxonomic descriptions and revisions of type specimens have been published in recent years Skorupski 2002, 2003a, b;Witaliński 2004;Juvara-Bals and Witaliński 2006;Witaliński 2006;Witaliński and Skorupski 2007;Juvara-Bals 2008). A character set in the genus Holoparasitus was well defined by Hyatt (1987). This large genus is not divided into subgenera, although more than half of the species have been allocated to six groups of species: Holoparasitus annulus group (2 species), caesus group (4), hemisphaericus group (2), mallorcae group (20), peraltus group (2), and calcaratus group (7).
The morphological terminology follows Hyatt (1987) and Juvara-Bals (2008). http://www1.montpellier.inra.fr/CBGP/acarologia/ ISSN 0044-586-X (print). ISSN 2107-7207 (electronic) 211 + FIGURE 1: Holoparasitus calpetanus n. sp., female: A -Gnathotectum; B -Chelicera, adaxial aspect; C -Praesternal plate with lateral platelets; D -Sternal shield; E -Paragynium; F -Epigynium; G -Endogynium covered with endogynial lamella as visible between paragynia; H,I -Different aspects of endogynia, endogynial lamella not shown; J-L -Endogynium with endogynial lamella; M -Endogynial lamella, endogynium not shown; N -Dissected endogynium in dorsal perspective: this is a tube with a closed posterior tip directed in situ dorsally or postero-dorsally and with an anterior oval entrance. The endogynial lamella is visible below the endogynium as it covers the endogynium from the ventral side. Diagnosis -In both sexes gland pores gv1 are present and pores gv2 are located on the surface of the flat cuticle; the gnathotectum is trispinate. In the female, the anterior wavy margin of the presternal plate is finely dentate; sternal shield has a fine granular band running axially; the endogynium is a narrow, ventro-dorsally oriented tube, visible in ventral perspective as a very small ring between the posterior paragynial lobes, sometimes open on one or both sides when the endogynial tube is obliquely oriented; the ventral margin of the endogynium in most specimens bears a triangular lamellar protrusion, located asymmetrically; ventrally, the endogynium is covered by a delicate endogynial lamella, dentate at the anterior margin. In the male, the corniculi have a prominent dent in the distal half; the hypostome has a narrow thickening ending anteriorly at the level of the corniculi bases; the pedipalpal femur bears a rectangular tubercle located anteroventrally, close to the anterolateral seta; the main spur on the femur II ends at the same level as the axillary process; spurs on genu II and tibia II are different, that on genu II is conical and close to the distal margin of the segment, that on tibia II is broad, low in the lateral perspective, and ending before the distal margin of the segment; the spur on tibia II has a margin shorter than its basal part.
Legs -Leg I, III, IV unremarkable. Leg II (Fig. 2I-K) as follows: coxa II with a ridge of 5-6 denticles anterolaterally, accompanied by a basal denticle; the main spur on the femur ending at the same level as the axillary process; spurs on genu II and tibia II different, that on genu II conical and located close to the distal margin of the segment, that on tibia II broad, low in the lateral perspective and ending before the distal margin of the segment; its margin shorter than the basis as a result of the distally located incision (Fig. 2J). Remarks -Holoparasitus calpetanus n. sp. belongs to the Holoparasitus mallorcae species-group, which is characterised as follows (Juvara-Bals 2008). In females, (1) presternal plate bears denticles or granules, especially at the anterior margin, lateral platelets free; (2) sternum with an axial reticulated or granular band; (3) the thickening of the anterior paragynial edge facing coxa III absent; (4) fixed cheliceral digit with five denticles; (5) gv2 in unmodified flat cuticle. The first two character states are usually present together, but in a few species only one of them is present. In males, (1) hypostome with the tongue-shaped, sclerotised central part, extended in many species antero-laterally between the corniculi; (2) hypostomatic setae on a piece of cuticle separated by incisions of soft cuticle; (3) sternogenital shield without an excipulum; (4) leg II: coxa II possesses anterolaterally denticulate ridge and a basal denticle, femoral main spur and axillary process thumb-like and short.
Holoparasitus calpetanus is included in the Holoparasitus mallorcae species-group since both females and males show all species-group character states. On the other hand, the female of H. calpetanus differs from other species belonging to the species-group by the following characteristics: in H. algiersensis Juvara-Bals, 2008 and H. eivissa Juvara-Bals, 2008 gv1 glands are absent. Holoparasitus calpetanus differs from H. siculus (Berlese, 1906), as the central prong of the epigynium in this species is evidently elongate. In contrast to all other species of the H. mallorcae species-group, the endogynium in H. calpetanus is tubular and narrow, whereas in the remaining species it is large and sac-  (Berlese, 1906) by a gnathotectum with an acute central prong and regular lateral prongs, whereas from H. mahnerti Juvara-Bals, 2008 by the absence of a basal protrusion on the axillary process of femur II. Corniculi with prominent dents on their distal halves distinguish H. calpetanus from H. mallorcae Juvara-Bals, 1975 and H. variabilis Juvara-Bals, 2008, both showing corniculi with medium-sized dents on proximal halves.

Holoparasitus fanes n. sp. (Figures 3-5)
Zoobank: 5326BC8D-B3D4-450C-B686-7F7B4F836AA0 Diagnosis -In both sexes gland pores gv1 are present, and pores gv2 are located in unmodified flat cuticle. In the female, the gnathotectum is trispinate, presternal plate is ribbon-shaped, only slightly narrowed medially, with obliquely cut ends, no denticles or corrugation are present; lateral platelets free and wedge-shaped; sternal plate reticulation pronounced, axial granular or reticulated band absent, anterior sternal margin concave between st1 setae and frequently with small concavities laterally to sternal pores iv1; posterior paragynial lobes in close proximity, metagynial sclerite heavily sclerotised and located close to adaxial edge of paragynium, its antiaxial margin straight whereas the adaxial margin forms a rounded protrusion matching the concavities in the anterior subapical thickening of the epigynium; epigynial central prong much wider than the subapical structure, which is narrow and anteriorly tripartite, with lateral hyaline protrusions rounded and extending slightly beyond the central prong margins; endogynium very small in ventral perspective, with heavily sclerotised roundish structure located centrally, and the lateral parts bearing minute denticles; anteriorly, endogynium forming a lamellar protru-sion. In the male, the gnathotectum the solid central prong is rounded apically, lateral prongs absent; corniculi conical; hypostome normal; hypognathal groove clearly visible; chelicera fixed digit straight and edentate with a characteristic lamellar protrusion laterally, movable digit solid and curved adaxially, bearing one dent; pilus dentilis minute, settled in orifice in lateral protrusion of fixed digit; palpcoxal setae scarcely pectinate and hypostomatics simple; palp trochanter with stout simple seta v1 and longer seta v2 barbed terminally, both setae located in close proximity and separated by a prominence; palp femur with ventral tubercle near the anterolateral seta; sternal shield with a regular reticulation except the roundish area between coxa II and coxa III, where the reticulation is weak and the cuticle porous; genital lamina rounded, located in a concavity of the sternal margin, and flanked by the sclerotised prominences; apical segment of femur II main spur circular in the ventral perspective, axillar process wedge-like, spur on genu II moderate, the one on tibia II -low, roundish and broad; genu II extended anterolaterally in the distal part. Gnathosoma -Gnathotectum trispinate (Fig.  3A), corniculi conical. Hypognathal groove narrow, with ca. ten weakly pronounced rows of denticles. Palpcoxal and hypostomatic setae simple. Chelicera (Fig. 3B). Fixed digit with two denticles in front of pilus dentilis, one larger and lamellar, covering pilus dentilis, and two small denticles behind pilus dentilis; the latter are located somewhat below the digit edge, which is lamellar and arcuate. The movable digit bears three teeth, pedipalp trochanter with seta v1 simple, v2 longer and barbed distally; femur and genu setation unremarkable.
Genital region -Paragynial shields (Fig. 3E) reticulated, posterolateral protrusions well developed, roundish or sometimes asymmetrical. Posterior paragynial lobes in close proximity. Adaxial paragynial edge thickened and metagynial sclerite heavily sclerotised, located close to the adaxial paragynial edge; antiaxial margin of metagynial sclerite straight or slightly curved, adaxial margin forming a rounded protrusion matching concavity in the anterior subapical thickening of the epigynium (Fig. 3E). Thickening facing coxa III is absent. Central prong of epigynium (Fig. 3F,G) with convex margins, wider than the subapical structure, which is narrow and anteriorly tripartite. Lateral hyaline protrusions are rounded and extend only slightly beyond the margins of the central prong. Endogynium (Fig. 3H,I) is small, with heavily sclerotised roundish structure located centrally and with the lateral, less sclerotised parts bearing minute denticles; anteriorly, endogynium forms a lamellar tongue-like protrusion directed anteriorly and fre-quently indented apically. Gland pores gv2 in unmodified flat cuticle. Opisthogaster with eight pairs of ventral setae 15 -42 µm long.
Legs -Leg structure and setation unremarkable.
Legs -Leg I, III, IV largely unremarkable, with simple setae, but anterolateral setae on trochanter I and trochanter II, which are thicker and pectinate distally (Fig. 4H). Leg II (Fig. 5C-E) spurred as follows: apical segment of femur II main spur circular in the ventral perspective, whereas the axillar process wedge-like; spur on genu II moderate, that on tibia II low, roundish and broad. genu II is extended anterolaterally in the distal part (Fig. 5D,E).
Distribution -Both species of this group are found in the central part of Italy, Tuscany, whereas H. digitiformis is also found in Sardinia (Juvara-Bals and Witaliński 2000).
The female of H. fanes can be distinguished from the H. crassisetosus species-group by the anteriorly tripartite, rather than rounded, thickening of the subapical epigynial structure. In the male, a porous area in the sternum center is present only in H. fanes. Moreover, the corniculi are conical and tibia II regularly spurred. These characteristics differentiate H. fanes from H. inornatus (Berlese, 1906) and H. intermedius (Holzmann, 1969), both species with indented corniculi. H. megacalcaratus Schmölzer, 1995 possesses conical corniculi, but with only a single, large main spur on femur II.