Veigaia incisilobata 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 : 8-11

Veigaia incisilobata Mašán , sp. nov.

( Figs 5–10 )

Material examined. Slovakia. Holotype. Female. Vtáčnik Mts.: Ostrý Grúň village, Hlboká dolina valley, 4 November 2003, beech forest (Fagion sylvaticae), 450 m a.s.l. Paratypes. Veľká Fatra Mts.: 1 female, Liptovské Revúce village, Rakytov Mt., 20 July 2004, dwarf pine forest (Pinion mugi), 1,560 m a.s.l.; Vtáčnik Mts.: 1 female, same data as holotype; Považský Inovec Mts.: 1 female, Hrádok village, Hrádocká dolina valley, 10 May 1998, oak forest (Quercetum) with beech ( Fagus sylvatica ), 600 m a.s.l.; Strážovské vrchy hills: 1 female, Zliechov village, Strážov Nature Reserve, 25 March 1999, beech forest (Fagion sylvaticae), 950 m a.s.l.; Bulgaria. Stara Planina Mts.: 2 females, Balkanets village, 26 April 2006, old beech forest (Fagion sylvaticae), 1,250 m a.s.l.

Description (Female). Dorsal idiosoma ( Fig. 5 ). Dorsal shield divided into two separate shields. Podonotal shield projecting deeply into opisthonotal, separated from it by V-shaped juncture, elongated, conspicuously longer than wide (length 490–550 µm, width 315–390 µm), subheptagonal, widely rounded anteriorly, tapered and sphenoid posteriorly, with delicate reticulate pattern on surface, and 21 pairs of simple spine-like setae, setae r4 outside shield. Most podonotal setae subequal in length (25–34 µm in specimens with shorter setae, 34–45 µm in specimens with longer setae), only s1, s2 and r5 markedly shorter (s1 and s 2 12 –15 µm, r 5 16–20 µm), j1 and r3 longer (j1 52–59 µm, r3 46–57 µm). Dorsal setae smooth or pilose (in specimens from Bulgaria, all dorsal setae with fine pilosity). Anterior part of podonotum fused with peritremes, peritremes with slightly expanded anterior ends located between setae j1. Opisthonotal shield bilobate, deeply invaginated anteromedially, widely rounded laterally, truncate to slightly concave posteriorly, 315–400 µm wide and 73–85 µm long along the midline, distinctly reticulated, bearing 18 pairs of simple spine-like setae. Podonotal setae j 6 in unusual posterior position to anteriormost opisthonotal setae. Opisthonotal setae subequal, 17–33 µm in length. Dorsolateral and ventrolateral soft cuticle with five pairs of slightly enlarged spatuliform setae (28–42 µm in specimens with shorter setae, 43–50 µm in specimens with longer setae).

Ve n t r a l idiosoma ( Fig. 6 ). Presternal sclerites subtriangular, with delicate transverse striation. Sternal shield oblong, with massive anterolateral corners, well sclerotized, posterior margin indistinctly and obscure, finely reticulated on surface, slightly concave anteriorly and posteriorly, bearing three pairs of sternal setae (st1 39–43 µm, st 2 27–30 µm, st 3 28–32 µm) and two pairs of lyrifissures; st2 slightly stouter than other sternal setae. Metasternal plate fused with endopodal sclerite, bearing seta st4 (31–35 µm) and a lyrifissure, anteriorly connected to posterolateral corner of sternal shield. Genital shield elongated, subtriangular, regularly reticulate, bearing three pairs of setae (st5 35–38 µm, Jv1 32–37 µm and Zv 1 23–28 µm), fused with ventral shield in metapodal region. Ventral shield subtrapezoid, bowl-shaped, with free anterolateral corners, delicately reticulate, with four pairs of ventral setae only slightly differentiated in length (Jv2 and Jv 3 21–26 µm, Zv 2 27–31 µm and Zv 3 30–37 µm). Peritrematal shields reduced to very narrow strips along outer margin of peritremes. Posterior ends of peritremes free, not fused with ventral shield, distinctly widened, axe-shaped. Punctiform organs in metapodal regions each usually with six pores, sometimes seven. Anal shield suboval to subtriangular, slightly wider than long (length 75–77 µm, width 82–86 µm), finely reticulated, carrying three circum-anal setae, post-anal seta minute. Membranous integument with 12–13 pairs of setae (posteriormost setae 13–23 µm in length and pilose), (excluding the five longer spatulate pairs), and a pair of minute poststigmatic setae. Ventral setae all simple, needle-like and mostly smooth.

Spermathecal structures. Coxae IV without well differentiated or sclerotized structures, no spermathecal structures visible.

Gnathosomal structures. Cheliceral digits as in Fig. 9 . Tectum ( Fig. 10 ) with distally serrated and bifurcated central projection, lateral cusps usually with 3–4 denticles on anterolateral margin.

Legs. All legs with a well developed pretarsus and ambulacral apparatus including pulvillus and two claws. Trochanter IV with a distinct dorsal and posterior protuberance; all other segments smooth and without protuberances. Tibia IV with a long and upright dorso-distal sensory macroseta (85–96 µm). Tarsus I 134–161 µm, tibia I 88 –121 µm, tarsus IV 157–179 µm and tibia IV 94 –120 µm.

Etymology. The name of this species is derived from Latin " incisus " (cut into) and " lobatus " (lobed), and refers to the distinctive opisthonotal shield, which consists of two large lobes separated by a conspicuous anterior incision.

Notes. The form and position of the podonotal and opisthonotal shields are very good specific diagnostic characters for this new species. No other known species of Vei g ai a has the podonotum so deeply incised into the opisthonotum. In general appearance, V. incisilobata is most similar to V. nemorensis -like species, in the arrangement of the ventral structures: genital and ventral shields fused in metapodal regions, posterior ends of peritrematal shields free and not connected with anterolateral corners of ventral shield, ventral shield bearing four pairs of subequal setae, and anal shield with three circum-anal setae.

The species shows a relatively large degree of intraspecific variability in the form, length and position of some idiosomal setae. There are apparent trends towards elongation of dorsal setae and reduction of their pilosity, together with changes in position of certain setae ( Figs 5 , 7, 8 ). Three main patterns of chaetotaxy can be distinguished: (1) Slovakian specimens with longer and smooth dorsal setae, some podonotal setae reaching the bases of following setae, setae s5 aligned with s4–s6, and s3–s6 aligned with s4–s5 ( Fig. 5 ); (2) Slovakian specimens with longer and densely pilose dorsal setae, some podonotal setae reaching the bases of following setae, setae s5 not aligned with s4–s6, and s4 not aligned with s3–s6 ( Fig. 7 ); (3) Bulgarian specimens with shorter and densely pilose dorsal setae, no podonotal setae reaching the bases of following setae, setae s5 not aligned with s4–s6, and s5 not aligned with s3–s6 ( Fig. 8 ).

Figures

FIGURES 5 – 6. Vei ga ia incisilobata sp. nov., Female. 5. Dorsal idiosoma, form with longer and smooth setae (specimen from Slovakia); 6. Ventral idiosoma. Scale: 100 µm.

FIGURES 7 – 10. Veigaia incisilobata sp. nov., Female. 7. Posterolateral region of podonotum, form with shortened and pilose setae (specimen from Slovakia); 8. Dorsal idiosoma, form with short and pilose setae (specimen from Bulgaria); 9. Chelicera, dorsal view; 10. Tectum. Scales: 100 µm: Figs 7 – 9; 50 µm: Fig. 10.