Eustigmaeus formosus, 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 : 2-7

1. Eustigmaeus formosus sp. n. ( Figs 1­7 )

Locus typicus. North Poland. Tczew province. “Opalenie Górne” Reserve, near Mala Karczma village. Oak­hornbeam forest (Notation: “JUDO 9 A...­G”).

The research place has been traced in Tilio­Carpinetum forest, fragment with Tilia cordata, Quercus robur, Acer platanoides and Carpinus betulus . In wealthy and heterogeneous fleece the most important were: Aegopodium podagraria, Galeobdolon luteum, Hepatica nobilis, Majanthemum bifolium and Mercurialis perennis . Besides, there are plant species which are quite rare in regional scale, or species which are lawfully protected: Platanthera bifolia, Asarum europaeum, Asperula odorata and Equistemum pratense .

Sampled material: plants fragments, litter, soil, moss from fallen logs as well as from bark of trees.

Specimens. Holotype: female, slide N o 9A / P­1 (coll. date: 31 Jun. 1999). Paratypes: female, 9E / P­1 and female, 9E / P­5 (coll. date 0 5 Mar. 2000).

Type repository. Holotype is kept in ZMH. Both paratypes are deposited in DAM.

Etymology. The Latin word “ formosus ” means “shapely”, “beautiful”.

General character. The species of “ pinnatus ” group ( Kaźmierski 2000): sabre­shaped dorsal setae, three pairs of aggenital setae (ag), genu II with four setae, including thornshaped famulus k.

Description of holotype, female (slide N o 9A / P­1).

Idiosoma. Relatively large (in comparison with other Eustigmaeus species), broadly oval ( Fig. 1 ). Length: 425, width: 321. Ratio of length to width (from measurements of all the specimens) = proportion index: 1.32 ­ 1. 37. Shields: P, HY (embraced also the ventral side) and SA. Cuticle broad, strongly sclerotized. Ornamentation: composed of multiangular “meshes” equal in largeness, with irregulary outlined “craters” inside of all the polygons. The bottoms of “craters” dotted by alveolae ( Fig. 5 ). All the idiosoma is covered with ornament ( Fig. 1 ), together with ventral side and coxisternal regions ( Fig. 4 ), thus, only trochanteres and the remaining leg segments are deprived of polygons. Eyes rounded ( Fig. 1 ), more­less as large as single polygon, situated between setae be and ce. Caudal setae (li = d, e, le) straight or at least only slightly bended, sharp, strongly serrated ( Figs.1, 3 ), shorter and broader than the remaining dorsal setae. The latter are sabre­shaped ( Figs.1, 2 ), sharp on the ends and rough only (without serration). Length of setae: ae ­ 88, be ­ 107, ce ­ 80, de ­ 85, he ­ 72, a ­ 71, b ­ 95, c ­ 95, la ­ 76, li ­ 68, lm ­ 79, e ­ 39, le ­ 31. Ventral side ornamented. Lack of sternal shields (SP and SM). Ventral chaetotaxy: 3 (1a, 3a, 4a). Genital chaetotaxy: (3 ­ 3). Setae ge situated on smooth genital plates. Setae ag set on the ornamented cuticle (ag3 ­on the lips) ( Fig. 5 ).

Gnathosoma . Basal part hidden under the anterior projection of aspidosoma ( Fig. 4 ). The length of subtly bent cheliceral stylets: 40. Palps ( Fig. 6 ): tibial claw strong, thick, terminally rounded (blunt), with downed tip, additionally with short and stout thorn on its base. Palpal tarsus (= “thumb”) rather slender, approximately as long as claw, ended by trident ­ trifurcate eupathidium (p). Besides, five different in length and shape setae, as well as small, proximal solenidium occur. A complete palpal chaetotaxy is: [0 ­ 3 ­ 4+claw with thorn ­ 5+(p)+]. The shape and localization of setae ­ as in Fig. 6 .

Legs. Relatively short. Chaetotaxy: I (2 ­ 1 ­ 6 ­ 3+ k ­ 5+ p + ’’ ­ 13+), II (2 ­ 1 ­ 3+1 ­ 3+ k ­ 6 ­ 9+), III (2 ­ 2 ­ 3 ­ 1 ­ 6 ­ 7+), IV (2 ­ 1 ­ 2 ­ 1 ­ 6 ­ 6+). Apotele with two claws and empodium. Empodiae composed of main stem and three bifurcate chetoids (=rylets), divided on very base. They look like three pairs of hairs, the tips of which are forked additionally on their very ends. Detailed organotaxy of leg I ( Fig. 7 ) from trochanter to tarsus (symbols of trochanteral and femoral setae are newly proposed): trochanter ­ trv (nude); femur ­ bfl’’ (slightly serrated), tfv (nude), tfl’ (nude), tfl’’ (slightly serrated), tfd’, tfd’’ (both strongly serrated); genu ­ l’, l’’, d (all strongly serrated), famulus k (in form of thick thorn); tibia ­ v’, v’’ (both nude), l’, l’’ (both strongly serrated), d (strongly serrate), solenidiae p and ’’.The latter one is distinctly longer and more developed than the basal solenidium p.Tarsus ­ three pairs of eupathidials: (ft), (tc) and (p), three pairs of normal setae: (pl), (at), (u), single seta vs and long solenidium I. Symbol at for anterials is used instead of Grandjean’s designation a ­ for avoid a homonym (Setae (a) are dorsal setae). All tarsal setae nude. One of four setae on femur II is much shorter, in form of narrow thorn.

Differentiating diagnosis. The new species is similar in total view to Eustigmaeus pinnatus ( Kuznetzov, 1977) . The main differences between both closely related species are as follow:

Dimensions. The new species is larger: holotype: length 425 / width 321, paratypes females: 440 / 321 (Holotype of E. pinnatus : 330 / 265).

Proportions. The new species is narrower: ratio of length to width: 1,32 ­ 1,37 (Holotype of E. pinnatus : 1,24).

The shape of setae. The new species has two categories of dorsal setae: broadly lanceolate, shorter and strongly serrate caudal setae (li, e, le) and sabre­shaped, longer and narrower, unserrated the remaining ones (All the dorsal setae of E. pinnatus are about equally shaped, in form of broad sabres with serration).

Genital chaetotaxy. The new species: (3 ­ 3), E. pinnatus : (4 ­ 3). However, some of specimens of E. pinnatus from Poland have three pairs of ge setae ­ in oposition to Kuznetzov’s description ( Kuznetzov 1977) (Individual variability?).

Figures

FIGURE 4. Eustigmaeus formosus sp. n., female (holotype) ­ ventral view.

FIGURES 1 ­ 3. Eustigmaeus formosus sp. n., female (holotype). 1 ­ dorsal view; 2 ­ aspidosomal seta be; 3 ­ opisthosomal seta e.

FIGURES 5 ­ 7. Eustigmaeus formosus sp. n., female (holotype). 5 ­ genital region; 6 ­ palp (right); 7 ­ right leg I, paraxial view.