Eustigmaeus brevivestitus, Mierski, Andrzej Ka Ż & Czyk, Justyna Do Ñ, 2003

Mierski, Andrzej Ka Ż & Czyk, Justyna Do Ñ, 2003, Two new free living mite species of Eustigmaeus (Actinedida: Raphignathoidea: Stigmaeidae) from Poland, with new data of some other rare species of the genus, Zootaxa 198, pp. 1-16 : 7-14

2. Eustigmaeus brevivestitus sp. n. ( Figs 8­17 )

Locus typicus. North Poland. Tczew province. Gniew city. Xerothermic lawn on the slope of Vistula River Valley (Notation: “JUDO 10 A...­G”).

This place has been traced on high edge of Vistula River Valley, strongly exposited to the sun, with xerothermic plants. In wealthy composition of plant species the most often noticed are: Arrenathemum elatius, Bronnis inermis, Avenastrum pubescens, Vicia tenuifolia, Carduus acanthoides, Anthemis tinctoria, Falcaria vulgaris, Centaurea scabiosa. From the group of pretty interesting (=relatively rare) plant species should be mentioned: Ononius spinosa, Eryngium planum and Lathyrus tuberosus . The presence of ruderal plants as Echium vulgare, Cichorium intybus and Medicago x varia is connected with neighbourhood of the city.

Sampled material: dry soil from beneath of plants, also leaves and stalks of varying plants.

Specimens. Holotype: female, slide N° 10E / P­9 (coll. date: 0 5 Mar. 2000). Allotype: male, 10D / P­5 (30 Dec. 1999). Paratypes: female, 10D / P­7 (30 Dec. 1999), female, 10E / P­14 (05 Mar. 2000), deutonymph, 10G / P­7 (03 Jul. 2000) and larva, 10D / P­16 (30 Dec. 1999).

Type repository. Holotype is deposited in ZMH. Allotype and paratypes are deposited in DAM.

Etymology. The Latin word “ brevivestitus ” means “shortly covered”.

General character. The species of “ segnis ” group: sabre­shaped dorsal setae, one pair of aggenitals (ag), genu II with three setae (famulus k absent).

Description of holotype, female (slide No 10E / P­9).

Idiosoma. Short and relatively flat, broadly­pyriform in dorsal or ventral view ( Fig. 8 ). Length: 255, maximal width: 220 (For comparison: female paratype 1 from slide 10D/P­7: 258 ­ 227). Shields: P, (H), HY, SA. Shield ornamentation: reticulation without prominent „craters” and alveoli. Shield HY only slightly extends on the both sides of body. Eyes not large, located between setae be and ce ( Fig. 8 ). Dorsal setae relatively long and narrow, flat, sabre­shaped, with rather delicate but visible serration ( Fig. 9 ). Lengths: ae (strongly bent) ­ 60, be ­ 60, ce ­ 50, de ­ 53, he ­ 57, a ­ 58, b ­ 58, c ­ 60, la ­ 60, li ­ 64, lm ­ 64, e ­ 40, le ­ 32. Ventrum striated ( Fig. 10 ) with exception of nude intercoxal regions. Three pairs of intercoxal setae occur (1a, 3a, 4a). Lack of coalesced sternal shields (SP and SM). Genital chaetotaxy: (3 ­ 1). Setae ge situated on nude genital plates. Setae ag lie on striated cuticle ( Fig. 11 ).

Gnathosoma . Visible from above. Bases of chelicerae thick. Stylet of 30 in length. Palps strong, stout and long ( Fig. 12 ). Tibial claw thick, subtly narrowed at the tip, which is somewhat blunt and turned down. Additional, smaller, straight and bidentate claw (=thorn) is seting at the base of main claw. Palpal tarsus (=“thumb”) almost equal in length with claw, twice as long as broad. It is provided with five nude setae, proximal solenidium

and terminal trifurcate eupathidium (p). The latter is nearly as long as its segment. Palpal femuro­genu with two dorsal serrate setae and the third one, which is ventral, shorter and smooth. Palptrochanter with dorsallo­lateral sharp thorn seting on rounded „hillock”. Summing ­ palpal pattern is: [1 ­ 3 ­ 4+claw with thorn ­ 5+(p)+].

Legs. Stout and relatively long in comparison with many other Eustigmaeus species. Chaetotaxy: I (2 ­ 1 ­ 5 ­ 4 ­ 5+ p + ’’ ­ 13+), II (2 ­ 1 ­ 4 ­ 3 ­ 6 ­ 8+), III (2 ­ 2 ­ 3 ­ 1 ­ 6 ­ 7+), IV (2 ­ 1 ­ 2 ­ 1 ­ 6 ­ 6+). Apotele with two claws and empodium in shape of dumpy stem with three „Y”­shaped chetoids (= rylets). Rylets are long and slender, with each branch forked on its very end. Detailed organotaxy of leg I ( Fig. 13 ) from trochanter to tarsus: trochanter ­ trv (nude); femur ­ bfl’’ (nude), tfl’, tfl’’ (both nude), tfd’, tfd’’ (both strongly serrated); genu ­ l’, l’’, d’, d’’ (all four strongly serrated); tibia ­ v’, v’’ (both nude), l’ (serrate), l’’ (nude), d (strongly serrated), sharply ended solenidiae p and ’’. Solenidium ’’ shorter and less developed than proximal p. Tarsus ­ three pairs of eupathidials: (ft), (tc), (p), three pairs of remaining setae: (pl), (at), (u), single seta vs and solenidium I, which is long, bent and rounded distally. All tarsal setae are nude. Proximallo­dorsal setae on tibiae II, III and IV are distinctly shorter, acciculate and based on rounded convexities (= hillocks”) ­ as in E. segnis . Second seta on trochanter III very slender.

Male. Length: 264, width: 183. Shields and chaetotaxy like in female. However, all four pairs of tarsi provised in imposing, additional males solenidions m, which are based proximally, in dorso­adaxial position ( Fig. 14 ). In genital region well visible aedagus occurs ( Fig. 15 ).

Deutonymph. Length: 242. width: 170. Similar to female with exception of underdeveloped genital region: lack of internal sclerites and presence of three pairs of setae only (lack of ag) are characteristic for this stase.

Larva. The body rounded and dumpy ( Fig. 16 ). Length: 140, width: 130. Fourth pair of legs missing. Small, paired anogenital plate with three pairs of minute setae occurs. No coalesced dorsal opisthosomal shield HY, which is divided into central M (medial), posterior MLZ (mediozonal), and two lateral L. Medial shield embraces setae a and b, while mediozonal one embraces setae c, d and lm. Shields H lie lateroventrally, shield SA lies ventrally. Summing ­ larval pattern of shields is: P, (H), M, (L), MLZ and SA. Phanerotaxy patterns for the legs from coxae to tarsi are as follow: I (2 ­ 0 ­ 4 ­ 3 ­ 5+ p ­ 13+), II (0 ­ 0 ­ 3 ­ 2 ­ 5+1 ­ 8+), III (0 ­ 0 ­ 3 ­ 0 ­ 5+1 ­ 7+). Tibiae I without ’’, while p is well developed and strongly bent. Seta d on tibia I serrated. Seta l’ on tibia I slightly serrated. Tectals on tarsus I unequal in length ( Fig. 17 ). Coxa I with dorsal seta cxd in shape of short thorn based on thumb­like processus on very base of segment. Similar organ (trd) occurs in palptrochanter ( Fig. 16 ). Each tibia II and III with five normal and one minute seta.

Differentiating diagnosis. The new species is highly specific by some features, although it can be compared with Eustigmaeus segnis ( Koch, 1836) . Both species are similar by following combination of key­characters (excluding common features typical for “ segnis ” group):

Setae a longer than the distance of a ­b.

Ends of setae b reach the bases of setae c.

Setae li longer than the distance li ­li.

Setae c situated dorsally.

All dorsal setae serrated.

The differences are as follow:

Dimensions. Body length of females: 250­260 (length of E. segnis : ca 300 m).

Idiosoma more flat.

Shield HY only slightly extends on the sides of body ­ in opposity to HY in E. segnis ,

which is extending to the ventrum.

Fused sternal shields SP and SM absent (present in E. segnis ).

“Craters” without cavities (= alveolae), which are characteristic for E. segnis .

Length of setae b equal to b ­c distance (in E. segnis b distinctly longer than b ­c).

Femur II with four setae (in E. segnis ­ five).

Figures

FIGURE 10. Eustigmaeus brevivestitus sp. n., female (holotype) ­ ventral view.

FIGURE 13. Eustigmaeus brevivestitus sp. n., female (holotype) ­ right leg I, paraxial view.

FIGURES 8 ­ 9. Eustigmaeus brevivestitus sp. n., female (holotype). 8 ­ dorsal view; 9 ­ opisthosomal seta c.

FIGURES 11 ­ 12. Eustigmaeus brevivestitus sp. n., female (holotype). 11 ­ genital region. 12 ­ right chelicera and palp, dorsal view.

FIGURES 14 ­ 15. Eustigmaeus brevivestitus sp. n., male (allotype). 14 ­ left tibia, tarsus and apotel I, paraxially; 15 ­ aedagus, lateral view.

FIGURES 16 ­ 17. Eustigmaeus brevivestitus sp. n., larva. 16 ­ total aspect; 17 ­ left tibia, tarsus and apotel, paraxial view.