Holoparasitus hemisphaericus ( Vitzthum, 1923 )

Witaliñski, Wojciech, 2006, New mites of the genus Holoparasitus Oudemans, 1936 from northern Austria and Karavanke (Acari: Parasitidae), Zootaxa 1320, pp. 15-27 : 17-22

Holoparasitus hemisphaericus ( Vitzthum, 1923) ( Figs. 1–21 )

Ologamasus hemisphaericus Vitzthum, 1923: 101 .

Holoparasitus absoloni ( Willmann, 1940) female, (as Ologamasus absoloni Willmann, 1940: 212 ), syn. nov.

Holoparasitus micherdzinskii Witaliński, 1981: 41 , synonymy by Witaliński & Skorupski, 2002: 55.

Material examined

Material deposited in the Zoologische Staatssammlung, München: holotype female, slide " V15 ", left­hand labelled " Ologamasus hemisphaericus Vitz. 1923 Ψ Hypost. Palpi Chel. B. 1 TYPUS " and right­hand labelled "Waidhofen/Thaya, N.­Öst. Muttergang v. Hylesinus fraxini Panz. leg: Wichmann det: Vitzthum", and slide " V22 ", left­hand labelled " Ologamasus hemisphaericus Vitzth. Ψ TYPUS " and right­hand labelled "Waidhofen, Thaja leg: Wichmann det: Vitzth. 25. 6. 1920 ", as well as female, slide originally labelled "13", right­hand " Olog. absoloni Ψ Det. C. Willmann" and left­hand "Abs. 775", and additionally labelled as follows " Ologamasus absoloni WILLMANN, 1940 = Holoparasitus absoloni ( WILLMANN, 1940) " " rev.: I. Juvara Bals, 1999" "1 f; Holotypus ".

Material collected by the author and deposited in the Zoological Museum, Jagiellonian University, Cracow: 22 females, 12 males (slides no. 1881–1890), 12.11.2004; Waidhofen a.d. Thaya, Austria, thick layer of moss under group of larches in spruce forest; 48 o 49.18' N, 0 15o 21.50' E, alt. ca. 650 m a.s.l.

Diagnosis

In the female, the endogynium is circular or oval in outline, with two lateral protrusions each bearing several spines directed adaxially and more or less anteriad; two lamellae protruding from the posterior margin of endogynium elliptical, covering most of the endogynial entrance; anterior margin of endogynial lamella convex; epigynial central prong right­angled and evenly but weakly pigmented; subapical epigynial structure with bipartite lateral protrusions, these located posteriorly, semicircular and not extending beyond epigynial margin, anterior protrusions hyaline, extending out of the epigynial margin.

In the male, sternal shield with prominent excipulum composed of three parallel thickenings with two depressions in­between and two additional anterolateral thickenings of sternal reticulation frequently forming an arc delimiting the excipulum anteriorly; cuticle of excipulum with well visible large pores forming a polygonal network; corniculi slender; spurs on Ge II and Ti II with concave margin, similar in shape, size and location.

Description

Female

Idiosoma well sclerotised, brownish, 520–570 x 685–755 µm (n=10). Length of podonotal setae: 33–37 μm (j 1), 28–32 μm (r 3), others 10–37 μm; opisthonotal setae very short, 6–8 μm; length of peritrematal groove 215–220 μm.

Ven te r. Presternal plate wide, narrower medially, lateral platelets wedge­shaped and free ( Fig. 1 ). Sternal reticulation ( Figs 1, 2 ) more pronounced in an area demarcated posteriorly by a line running through the second pair of pores (iv 2). Gland pores gv 1 present adaxially to setae st 3. Setae of sternogenital region finely barbed, 50 µm (st 1) to 65 µm (st 2, st 3) long.

Genital region. Paragynial shield ( Fig. 2 ) with posterior paragynial lobes relatively small and far from one another; metagynial sclerite semicircular; posterolateral protrusion “locking” epigynial plate minute, thickening of the underside of anterior paragynial edge facing coxa III absent. Central apex of epigynial shield ( Figs. 3, 4 ) less pigmented and close to right­angled in shape, lateral prongs large and acute. Subapical structure well pigmented, barrel­shaped in outline. Lateral protrusions bipartite; posterior projections are semicircular and well sclerotised, ending more or less at the margin of the epigynium and passing anteriad into less sclerotised hyaline protrusions extending out of the epigynial margin. Endogynium ( Figs 2, 5, 7 ) circular or oval in outline, with two lateral protrusions each bearing several spines directed adaxially and more or less anteriad. Rarely are spines located directly on the endogynium wall. Posterior margin of endogynium protruded into two leaf­shaped lamellae, partly overlapping and covering most of the endogynial opening. Hyaline endogynial lamella ( Figs 6, 8 ) with convex anterior edge extending between metagynial thickenings. Gland pores gv 2 in normally sclerotised cuticle. Opisthogaster bears eight pairs of ventral setae 22–39 µm long.

Gnathosoma . Gnathotectum trispinate, hypognathal groove with six clearly visible anterior rows of denticles and four posterior rows represented only by 1–2 lateral denticles. Palpcoxal setae finely barbed, hypostomatic setae simple. Distal half of the fixed digit of the chelicera with two teeth and a low tubercle in­between, in front of the pilus dentilis, followed by two larger teeth located on the internal (adaxial) side. There is a lamellar edge on the external (abaxial) side. Movable digit with three teeth. Pedipalp trochanter with seta v 1 simple and v 2 barbed distally.

Legs. Leg structure and setation unremarkable.

short, 7–12 μm; length of peritrematal groove 205–215 μm.

Ventral side ( Figs 9–11 ). Presternal plates small, triangular, with less sclerotised projections anteriad. Genital lamina prominent, located in a deep concavity in the anterior sternal margin; its anterior hyaline edge bilobate, lateral pointed projections relatively short and pigmented ( Fig. 11 ). Sternogenital shield with prominent excipulum ( Figs 9, 10 ) composed of three parallel sclerotised ridges; its cuticle shows large pores pentagonally or hexagonally arrayed. The excipulum is demarcated anterolaterally by thickened lines of sternal reticulation. Gland pores gv 1 at st 3 level, with terminally dilated channels directed laterally. Two pairs of thickenings behind excipulum are more or less discernible. Gland pores gv 2 in unmodified cuticle. Sternal setae length from 46 µm (st 1) to 35 µm (st 3), opisthogastric setae 22–30 µm.

Gnathosoma ( Figs 12–15 ). Gnathotectum ( Figs 12–14 ) trispinate, but lateral prongs tiny. Hypognathal groove with 10 or 11 rows of clearly visible denticles ( Fig. 15 ); of these, the most proximal row is frequently represented only by lateral denticles. Palpcoxal setae finely barbed, hypostomatic setae simple. Incisions present in cuticle behind hypostomatic setae. Corniculi slender. Chelicera ( Figs. 16, 17 ) with fixed digit narrow, concave in distal third, bearing a row of several tiny denticles; abaxially there is a semicircular incised lamella. Behind pilus dentilis, the ventral border of the digit forms a straight lamellar edge. Movable digit with 4–5 teeth in distal third followed proximally by a larger tooth. Arthrodial membrane with a well­pronounced brush­like process; synarthrodial membrane wavy. Pedipalp trochanter with seta v 1 simple, v 2 distally barbed.

Legs. Leg I, III, and IV unremarkable. Leg II ( Figs 18–21 ) with spurs as follows: the main spur on femur short, conical, with tubercle located ventrally at its base, and ending in a very small apical segment ( Fig. 18 ). Axillary process with apical part oval, larger than the apical segment of the main spur. Spurs on Ge II and Ti II with concave margin and similar in shape, size and location. Ventral seta on Ti II larger than that on Ge II. Coxa II bears anterolaterally a row of denticles, 7–9 plus 1; the row ends with a long tooth­like structure directed ventrally ( Figs 19, 20 ).

München, was designated as holotype by I. Juvara­Bals in 1999. This specimen is in a moderate condition, but available features (subepigynial structure, endogynium, sternum) strongly support synonymy with H. hemisphaericus (both types, kindly loaned to the author by Dr. L. Tiefenbacher and Dr. Eva Karl, were examined). The males determined by Willmann as H. absoloni belong in fact to Heteroparasitus tirolensis ( Sellnick, 1968) ( Karg 1971: 362) .

The only female determined and described by Micherdziński (1969: 363) as a female of H. intermedius ( Holzmann, 1969) was synonymised by Karg (1971: 362) with H. absoloni . However, the female of H. intermedius (Holzmann) sensu Micherdziński actually belongs to H. cornutus Juvara­Bals & Witaliński, 2000 (syn. nov., Micherdziński’s specimen examined).

Figures

FIGURES 1 – 8. Holoparasitus hemisphaericus (Vitzthum), female: 1 presternal plate and sternal shield; 2 genital region with paragynia, epigynium and endogynium; 3, 4 epigynium; 5, 7 endogynium; 6, 8 endogynial lamella. 1: slide no. 1881; 2: 1882; 3: 12 A; 4, 5, 6: 11 A; 7, 8: 1886. Scale bars: 0.1 mm.

FIGURES 9 – 17. Holoparasitus hemisphaericus (Vitzthum), male: 9 presternal plates and sternum; 10 excipulum; 11 genital lamina; 12 – 14 gnathotectum, dissected and pressed (12) or in situ (13, 14); 15 gnathosoma, ventrally; 16, 17 left and right chelicera. 9 – 11, 13: slide no. 1889; 12, 16, 17: 1885; 14, 15: 1890. Scale bars: 0.1 mm.

FIGURES 18 – 21. Holoparasitus hemisphaericus (Vitzthum), male: 18 femur, genu and tibia of leg II (most setae not shown); 19, 20 rows of denticles on anterolateral side of both coxae II; 21 spurs on Fe II, Ge II and Ti II, ventrally (arrow at anterolateral side). 18 – 20: slide no. 1884; 21: 1889. Scale bar: 0.1 mm.