Holostaspis ambigua, Babaeian & Mašán & Halliday, 2019

Babaeian, Esmaeil, Mašán, Peter & Halliday, Bruce, 2019, Review of the genus Holostaspis Kolenati, 1858 (Acari: Laelapidae), Zootaxa 4590 (3), pp. 301-341 : 306-308

Holostaspis ambigua sp. nov.

( Figs 1–9 )

Specimens examined. Holotype. female, NE Slovakia, Bukovské Vrchy Hills , Ulič Village (48°57'44" N, 22°25'34" E), meadow, in anthill of Lasius flavus (Fabricius, 1782) ( Hymenoptera , Formicidae ) under Quercus palustris , altitude 280 m, August 17, 1999, coll. P. Mašán . Paratypes. four females, with the same data as in holotype [these four specimens from Ulič Village were previously published under the name Hypoaspis (Pneumolaelaps) montana by Fenďa & Mašán (2003)] . The holotype and two paratypes are deposited at the Institute of Zoology, Slovak Academy of Sciences, Bratislava , Slovakia, and two other paratypes at the Acarological Collection, Jalal Afshar Zoological Museum, Faculty of Agriculture, University of Tehran, Karaj, Iran.

Diagnosis (female). Dorsal shield inversely ovoid, regularly tapering from level of r5, with uneven reticulate ornamentation on lateral regions, bearing 39 pairs of setae and one unpaired accessory setae between J1–J5; dorsal setae mostly short, smooth and similar in length, with tips not reaching bases of following posterior setae; setae Z5 and S5 longest, at least twice as long as most of other dorsal setae (Z5 = S5 = 2.5 x J5). Sternal shield as long as wide, mostly smooth, except a few irregular liniae/ridges in anterior region. Anal shield subtriangular, with anterior margin straight and anterolateral angles widely rounded; postanal seta slightly thicker and longer than adanals. Peritremes relatively long, anteriorly reaching level between z1–s1. Epistome subtriangular, with rounded or pointed apex. Fixed digit of chelicera with two shallow teeth, movable digit edentate.

Description. FEMALE (N=4)

Dorsal idiosoma ( Fig. 1 ). Dorsal shield ovoid, 475–525 µm long and 320–350 µm wide, covering most or all of idiosoma dorsally (sometimes leaving exposed a 10–15 µm strip of soft integument posterolaterally), smooth medially, with uneven lineate-reticulate ornamentation on lateral areas, bearing 39 pairs of setae: 22 pairs (j1–j6, z1–z6, s1–s6, r2–r5) in podonotal area and 17 pairs (J1–J5, Z1–Z5, Px2–Px3, S1–S5) in opisthonotal area and one unpaired accessory seta between J1–J5; with at least 21 pairs of discernible pore-like structures (four pairs of gland pores and 17 pairs of lyrifissures). All dorsal shield setae simple, smooth and short, except S2–S4 slightly longer, and S5 and Z5 longest. Lengths of some dorsal shield setae: j 1 23–26 µm, z 1 8–11 µm, J 4 25–31 µm, J 5 21–26 µm, Z5 52–58 µm, S4 41–47 µm, S5 49–55 µm.

Ventral idiosoma ( Fig. 2 ). Tritosternum with short columniform base (19–25 µm) and pilose laciniae (60–63 µm). Sternal shield subquadrate, 100–115 µm in length and width, widest at level of coxae II–III (146–158 µm), with convex anterior and slightly concave posterior margin; surface smooth, or weakly reticulate in anterior portion; setae short, with tips not reaching bases of following ones (st 1 24–27 µm, st2 and st 3 29–32 µm); lyrifissures iv1 and iv2 slit-like. Metasternal setae (st 4 29–34 µm) and associated lyrifissures iv3 on soft integument; endopodal platelets III–IV subtriangular, narrow and free from sternal shield. Epigynal shield tongueshaped, elongate, slightly bulging at level between st5 and Zv 1, 203–223 µm long and 117–127 µm wide (103–112 µm at level of st5); anterior hyaline margin broadly convex, extending to level between sternal setae st2 and st3; posterior portion with lineate ornamentation pattern forming usually eight elongate cells; genital setae (st 5 31–34 µm) inserted on mediolateral margins and associated lyrifissures iv5 on soft integument; soft integument with two pairs of small sclerites, one close and lateral to Zv1, and another farther, at level between iv5 and Zv1. Metapodal platelets suboval. Anal shield 73–81 µm long and 71–77 µm wide, triangle-shaped, with lineate-reticulate pattern (predominated by semicircular lines) on anterior portion; postanal seta 31–39 µm long, negligibly thickened and slightly longer than adanal setae (24–27 µm); cribrum with narrow band of spicules. Lateral and opisthogastric soft integument with 16 pairs of setae. Poststigmatic section of peritrematal shield narrow, tapered posteriorly.

Gnathosoma ( Figs 3–5 ). Epistome ( Fig. 3 ) subtriangular, sharply or obtusely pointed, rarely bipointed. Corniculi short and narrow, with a bump or protuberance on lateral margin, more or less horn-like; internal malae abutting each other, median projections narrow, with smooth margins, with dense laterobasal fimbriae; labrum blade-like, reaching tip of palpgenu ( Fig. 4 ). Deutosternal furrow narrowed posteriorly, with six transverse rows of denticles, each with 4–16 denticles. Lengths of hypostomal and palpcoxal setae: h 1 17–21 µm, h 2 12–15 µm, h 3 27–31 µm, pc 17–19 µm. Shape and dentition of chelicera as in Fig. 5 ; lengths of cheliceral articles: the second segment 80–100 µm, fixed digit 22–24 µm, movable digit 22–27 µm.

Legs ( Figs 6–9 ). Tarsi I–IV each with a pair of claws and pulvillus. Lengths of legs: leg I 390–434 µm, leg II 285–320 µm, leg III 222–275 µm, leg IV 368–397 µm. Setae ad1 on femur I, II and IV thickened, setae pd on trochanter I, al on trochanter II, pl on trochanter III, ad1 on femur III, ad2 on femur IV and ad on trochanter IV slightly thickened.

MALE. Unknown.

Etymology. The specific name refers to the Latin adjective " ambiguus " (= uncertain) is referred to the fact that this species may be readily confused because it is intermediate in appearance between some other congeners, together representing a species complex whose members are difficult to delineate.

Remarks. The new species can be reliably recognised by the following combination of characters used in the identification key above: (1) setae Z5 and S5 similar in length and about 2.5 times longer than J5; (2) setae J5 relatively short, with their tips not reaching beyond posterior margin of dorsal shield; (3) soft integument with 16 pairs of setae.

Figures

FIGURES 1–5. Holostaspis ambigua sp. nov., female. 1. Dorsal idiosoma; 2. Ventral idiosoma; 3. Epistome, variant forms; 4. Ventral gnathosoma with palp; 5. Chelicera.

FIGURES 6–9. Holostaspis ambigua sp. nov., female. 6. Leg I; 7. Leg II; 8. Leg III; 9. Leg IV.