Veigaia pentachaeta Mašán, 2008

Án, Peter Ma Š, A, Peter Fen Ď & Mihál, Ivan, 2008, New edaphic mites of the genus Ve i g a i a from Slovakia and Bulgaria, with a key to the European species (Acari, Mesostigmata, Veigaiidae), Zootaxa 1897, pp. 1-19 : 11-13

Veigaia pentachaeta Mašán , sp. nov.

( Figs 11–14 )

Material examined. Bulgaria. Holotype. Female. Stara Planina Mts.: Petrokhan village, 20 April 2005, old beech forest (Fagion sylvaticae), 1,400 m a.s.l. Paratypes. 1 female, same data as holotype.

Description (Female). Dorsal idiosoma ( Fig. 11 ). Dorsal shield divided into two separate shields. Podonotal shield subequal in length and width (both between 360–380 µm), helmet-shaped, almost truncate or very slightly convex posteriorly, with conspicuous reticulate pattern on whole surface, and 21 pairs of simple spine-like setae, setae r4 outside shield. Most podonotal setae subequal in length (35–45 µm), only z1, s1, s2 and r5 distinctly shorter (15–21 µm), r2 moderately short (29–33 µm), j1 moderately elongate (45–50 µm), r3 elongate (66–71 µm). All podonotal setae with delicate pilosity, except r3 with stronger pilosity. Anterior part of podonotum connected with peritremes, peritremes with anterior ends between setae j1. Opisthonotal shield loaf-shaped, with widely rounded lateral margins, wider than long (length 203–215 µm, width 330–360 µm), anterior and posterior margins concave, surface distinctly reticulated, bearing 17 pairs of simple spine-like setae. Opisthonotal setae subequal in length, 34–42 µm. Dorsolateral and ventrolateral soft cuticle with six pairs of long slightly enlarged spatuliform setae (40–48 µm).

Ve n t r a l idiosoma ( Fig. 12 ). Presternal sclerites absent. Sternal shield slightly oblong, with markedly elongated and anteriorly directed anterolateral corners, well sclerotized and reticulated over whole surface, all margins distinct, anterior and posterior margins slightly concave, bearing three pairs of sternal setae (st1 43– 47 µm, st2 34–38 µm, st3 32–35 µm), two pairs of lyrifissures and a pair of simple pores. Metasternal plate fused with endopodal sclerite, bearing seta st4 (30–34 µm) and a lyrifissure, anteriorly connected to posterolateral corner of sternal shield. Genital shield subtriangular, regularly reticulate, bearing three pairs of setae (st5 and Jv 1 27–31 µm, Zv 1 7–10 µm), fused with ventral shield in metapodal regions. Ventral shield subtrapezoid, bowl-like, distinctly reticulate, with five pairs of setae conspicuously variable in length (Jv2, Jv3 and Zv 3 26–36 µm; Zv2 and Lv 3 7–10 µm), anterolateral corners of shield free, each corner fused only with small metapodal sclerite. Peritrematal shields well developed along whole length of peritremes, posteriorly free, not connected with ventral shield; posteriormost section of peritremes around stigmata slightly widened and rounded. Punctiform organs in metapodal regions each usually with 10 pores. Anal shield subtriangular, wider than long (length 85 µm, width 139 µm), finely reticulated, bearing a total of five setae; three circum-anal setae, post-anal seta minute, and an additional pair of very short pre-anal setae. Membranous integument with 8–9 pairs of short posterior setae in addition to the six pairs of long spatulate setae, and a pair of minute poststigmatic setae; posteriormost setae slightly shortened, sail-like, widened medially, and often finely pilose. All setae on ventral shields simple, needle-like and mostly smooth (only setae Jv2 and Jv3 with very delicate pilosity).

Spermathecal structures. Coxae IV without well differentiated sclerotized structures, spermathecal structures not visible.

Gnathosomal structures. Tectum ( Fig. 13 ) with distally serrated, bifurcate and apically pointed central projection, lateral cusps with denticulate outer margins. Cheliceral digits shortened and relatively thickened ( Fig. 14 ).

Legs. All legs with a well developed pretarsus and ambulacral apparatus including pulvillus and two claws. Distal venter of femur IV with two small and flat protuberances, all other segments smooth and without projections. Tibia IV with a long and upright dorso-distal sensory macroseta (127–139 µm). Tarsus I 148–157 µm, tibia I 104–115 µm, tarsus IV 223–241 µm and tibia IV 122–133 µm.

Etymology. The name of this species alludes to its distinctive feature of five setae on the anal shield (" pentachaeta ", Greek = with five hairs).

Notes. This species can be easily recognized because the dorsal idiosoma is covered by two separate shields, and the anal shield has five setae. No other described species of Vei g ai a has this combination of characters. The presence of five anal setae is known in most species from North America, but in all these species the dorsal idiosoma is covered by schizodorsal shield with mediolateral incisions. In Europe, only V. exigua - like species and V. bouvieri have five setae on the anal shield, but none of these have completely separate podonotal and opisthonotal shields.

V. pentachaeta occupies a special position amongst its congeners due to the presence of three pairs of poroid structures on the sternal shield. Two pairs of lyrifissures are adjacent to st1 and st2, and a pair of simple rounded pores is associated with st3 and situated close to the posterolateral margins of the sternal shield. The third pair of sternal pores is highly unusual among the Veigaiidae , and there is only one other species with similar poroidotaxy, V. bogdanovi known from Siberia ( Davydova, 1978). Both species are readily distinguishable, especially in the number of setae on the podonotal, opisthonotal, ventral and anal shields, the form of the tectum, and presence/absence of presternal plates and spermathecal tubular structures.

Figures

FIGURES 11 – 14. Vei ga ia pentachaeta sp. nov., Female. 11. Dorsal idiosoma; 12. Ventral idiosoma; 13. Tectum; 14. Chelicera, lateral view. Scales: 100 µm: Figs 11, 12; 50 µm: Figs 13, 14.