Holoparasitus rhombogynialis, Witaliñski, Wojciech, 2006

Witaliñski, Wojciech, 2006, New mites of the genus Holoparasitus Oudemans, 1936 from northern Austria and Karavanke (Acari: Parasitidae), Zootaxa 1320, pp. 15-27 : 22-25

Holoparasitus rhombogynialis sp. nov. ( Figs. 22–41 )

Material examined

Holotype female (slide no. 1358), 31.07.2000, ca. 2 km north of Loibl Pass, Karavanke mountains, Austria, 46o 26.70' N, 0 14o 15.80' E, alt. ca. 1000 m a.s.l., litter in beech forest with spruce admixture; 3 females, 2 males paratypes (slides no. 1357, 1359, 1360), ibid.; 1 female, 1 male paratypes (slide no. 1351), 31.07.2000, ca. 4 km south of Loibl Pass, Karavanke, Slovenia, 46o 24.65' N, 0 14o 16.50' E, alt. ca. 900 m a.s.l., litter in mixed forest (beech, ash, fir, spruce, larch). Types were collected by the author and Dr. M. Skorupski, Agriculture University, Poznań, Poland, and are deposited in the Zoological Museum of the Jagiellonian University, Cracow, Poland.

Diagnosis

In both sexes the gnathotectum is trispinate.

In the female, the endogynium is rhombic in ventral perspective, with two lateral groups of spines, the majority of which are directed backwards; two lamellae protruding from the posterior endogynial margin leaf­shaped, i.e. narrowing apically; anterior margin of endogynial lamella undulate and concave medially; epigynial central prong weakly pigmented (more so terminally), its margins shallowly concave; anterior part of lateral protrusions of subapical epigynial structure hyaline and membranous.

In the male, the excipulum has a ridge­like central thickening, the lateral thickenings usually form cuticular lids covering margins of excipular depressions; anterolateral thickenings of sternal reticulation frequently form lids similar to those of excipulum; setae st 1 are located on thickenings; two pairs of distinct button­like thickenings present at the level of sternal pores iv 3 and setae st 3; corniculi extended proximally; spurs on Ge II and Ti II differ in shape and orientation, that on Ti II arcuate in ventral perspective and located at the margin of less sclerotised cuticle.

Description

Female

Idiosoma brownish, 490–510 x 635–725 µm (n=4). Length of podonotal setae: 29–33 μm (j 1), 30–33 μm (r 3), others 11–34 μm; opisthonotal setae very short, 8–13 μm; length of peritrematal groove 224–228 μm.

Ven te r. Presternal plate and lateral platelets as in H. hemisphaericus ( Figs 22, 23 ). Sternum relatively longer than in H. hemisphaericus : its width (measured between second leg openings) to length (measured axially) ratio does not exceed 1.9, whereas in H. hemisphaericus it is greater than 2.2. Left and right parts of sternal reticulation line running through the second pair of pores (iv 2) usually arcuate ( Fig. 22 ). Gland pores gv 1 present. Setae of sternogenital region: 60–61 µm (st 1), 64–67 µm (st 2), 64–65 µm (st 3), 50–52 µm (st 4).

Genital region. Paragynial shields as in H. hemisphaericus . Central prong of epigynial shield ( Fig. 24 ) weakly pigmented, but more so terminally; its margins shallowly concave. Subapical structure with arcuate lateral thickenings. Lateral protrusions semicircular and well sclerotised, ending at epigynium margin and passing anteriad into membranous protrusions. Endogynium ( Figs 25, 27 ) rhombic in ventral perspective, with two lateral groups of spines directed mostly backwards. From the posterior endogynial margin, two leaf­shaped lamellae protrude anteriad and somewhat ventrally, thus visibly shorter in ventral perspective ( Fig. 27 ). Posterior part of endogynium is covered ventrally by endogynial lamella with anterior margin undulate and concave medially ( Fig. 26 ). Gland pores gv 2 in normal cuticle. Opisthogaster with eight pairs of ventral setae 29–46 µm long.

Gnathosoma . Gnathotectum trispinate ( Fig. 28 ), corniculi conical. Hypognathal groove with ca. 10 very weakly pronounced rows of denticles. Palpcoxal setae barbed, hypostomatic setae simple. Chelicera ( Fig. 29 ). Fixed digit with two teeth in front and two behind the pilus dentilis, followed by two parallel lamellar edges, similar to those in H. hemisphaericus . Movable digit with three teeth. Pedipalp trochanter with seta v 1 simple and v 2 barbed distally.

Legs. Leg structure and setation unremarkable, except for Co I bearing ventrally two clearly visible tubercles ( Fig. 30 ).

Male

Idiosoma brownish, 385–420 x 595–600 µm (n=2). Length of podonotal setae: 26–29 μm (j 1), 27–29 μm (r 3), others 8–22 μm; opisthonotal setae very short, 8–13 μm; length of peritrematal groove 205–209 μm.

Ven te r ( Fig. 32 ). Presternal plates small, triangular. Genital lamina ( Fig. 33 ) weakly sclerotised, located in a deep concavity of anterior sternal margin, flanked by tubercular protrusions; its anterior hyaline edge circular, lateral acute projections not discernible, and microsclerite under lamina well sclerotised. Excipulum on sternogenital shield prominent ( Fig. 32 ), composed of three largely parallel sclerotised ridges, of these the lateral ones are slightly arcuate and form lamellar protrusions (lids) covering the excipulum depressions laterally. The cuticle of excipulum shows distinct pores, but their pattern is similar to that in other areas of the sternum. Anterolaterally, the excipulum is flanked by thickened lines of sternal reticulation, also forming lamellar cuticular lids. On the posterior ends of these thickenings gland pores gv 1 are present, whereas more prominent reticulation runs anteriad, ending in thickenings located close to the bases of setae st 1. Two pairs of buttonlike thickenings behind excipulum are present. Gland pores gv 2 in normal cuticle. Approximate length of sternal setae: 44–46 µm (st 1), 46 µm (st 2), 33–39 µm (st 3), 35–37 µm (st 4), the length of opisthogastric setae is 20–33 µm.

Gnathosoma . Gnathotectum ( Figs 34, 35 ) trispinate as in female. Hypognathal groove with 10–11 rows of clearly visible denticles; palpcoxal setae barbed, hypostomatic setae simple and inserted on piece of cuticle separated by incisions. Corniculi extended in proximal part ( Fig. 36 ). Chelicera ( Figs. 37, 38 ) with fixed digit straight and narrow, in distal third with thin dentate lamella located on adaxial side. Movable digit with four to six teeth followed by larger tooth proximally. Arthrodial membrane with brush­like process, synarthrodial membrane wavy. Pedipalp trochanter with seta v 1 simple and shorter than v 2, which is barbed. Femur with broad elevation located ventrally at level of anterolateral seta.

Legs. Coxa I with two tubercles located ventrally ( Fig. 31 ). Leg II with spurs as follows ( Figs 39–41 ): the main spur on femur short and conical, ending in a low, roundish apical part; ventral seta inserted at base of spur on weakly pronounced elevation. Axillary process slightly curved, larger than apical segment of main spur. Spurs on genu and tibia differ in shape and orientation: the spur on genu straight with slightly concave edge, oriented obliquely in ventral perspective. Spur on tibia arcuate, located at the border of less sclerotised cuticle and oriented axially in ventral perspective ( Fig. 40 ). Ventral seta on Ti II larger than that on Ge II. Coxa II bears anterolaterally 8 + 1 denticles in fan arrangement ( Fig. 39 ). Legs III, and IV unremarkable.

Figures

FIGURES 22 – 29. Holoparasitus rhombogynialis sp. nov., female: 22, 23 presternal plate and sternal shield; 24 epigynium; 25, 27 endogynium; 26 endogynial lamella; 28 gnathotectum; 29 chelicera. 22, 27: slide no. 1357; 23: 1351; 24 – 26, 28, 29: holotype, 1358. Scale bars: 0.1 mm.

FIGURES 30 – 36. Holoparasitus rhombogynialis sp. nov.: 30, 31 ventral aspect of coxa I and trochanter I in female (30) and male (31) (arrow at anterolateral side). Male: 32 presternal plates and sternum with excipulum; 33 genital lamina; 34, 35 gnathotectum; 36 corniculus, ventrally. 30: slide no. 1357; 31 – 34, 36: 1351; 35: 1360. Scale bars: 0.1 mm.

FIGURES 37 – 41. Holoparasitus rhombogynialis sp. nov., male: 37 chelicera; 38 ibid., crushed; 39 coxa, trochanter, femur, genu and tibia of leg II (only the position of most setae is marked); 40 femur, genu and tibia of leg II in ventral perspective (arrow at anterolateral side); 41 Fe II, ventrally, another aspect. 37 – 39: slide no. 1360; 40: 1357; 41: 1351. Scale bars: 0.1 mm.