Oreonetides minimus, Tanasevitch, 2017

Tanasevitch, Andrei V., 2017, A new Oreonetides Strand, 1901 from the Russian Far East (Araneae, Linyphiidae), Zootaxa 4318 (3), pp. 596-599 : 596-598

Oreonetides minimus new species ( Figs 1–10 )

Holotype male ( ZMMU), RUSSIA, Maritime Province (= Primorsky Krai), Ussuriysk District, environs of Timiryazevsky , 43.859493°N 131.898477°E, roadside bund with diverse herbs and Gramineae between wheat field and road; 20.IX.2016 ; A. Zaytsev et al. leg. Paratypes. 3 females (ZMMU), together with holotype. 1 male, 3 females ( MHNG), 1 male ( ZMMU), same locality, field of wheat; 20.IX.2016 ; A. Zaytsev et al. leg. 2 females ( ZMMU), same locality, field of soybean; 20.IX.2016 ; A. Zaytsev et al. leg. 1 male ( ZMMU), same locality, rice paddy; 20.IX.2016 ; A. Zaytsev et al. leg. 1 female ( ZMMU), Maritime Province, Khorol District, environs of Lugovoy , 44.549808°N 132.132833°E, soybean field; 22.IX.2016; A. Zaytsev et al. leg.

Type and other comparative material examined. Oreonetides badzhalensis Eskov, 1991: 1 female paratype (ZMMU), RUSSIA, Khabarovsk Province (= Khabarovsky Krai), Verkhnebureinsky District, Badzhalsky Mt. Ridge, 1000 m a.s.l., Mogda River, spruce forest, moss; VII.1989; D. Kurenshchikov leg. 1 female (ZMMU), Khabarovsk Province, Lake Evoron, larch forest; VI.1992; G. Ganin leg. (new record). 1 female (CAT), ca. 210 km NE of Chegdomyn, Bureya River Valley, 3.5 km downstream of confluence of Pravaya and Levaya Bureya rivers; 22.V.2003; A. Tanasevitch leg. 1 female (CAT), Amur Area, Selemdzhinsky District, right bank of Selemdzha River, upstream of Koboldo, steep rocky slope of a bald mountain, 52°58.855’N 132°44.401’E, 450–465 m a.s.l., mosses, leaf litter, plant debris among fallen birch trunks; 30.VI.2007; E. Veselova & A. Ryvkin leg. (new record). Oreonetides beringianus Eskov, 1991 : male holotype (ZMMU, No. TA-5407), RUSSIA, Magadan Area, Detrin River flow (right confluent of Kolyma River), 56 km upstream of river mouth, Vakkhanka Stream, flood-plain Populus and Chosenia forest; 13.VIII.1984; K. Eskov leg. 1 female paratype (ZMMU, No. TA-5408), same locality, 9.VII.1985, Y. Marusik leg. 4 female paratypes (ZMMU), same locality; 20.VI.1986; Y. Marusik leg. 1 female paratype (ZMMU, No. TA-5409), Chukotka Autonomous Region, 118 road-km from Egvekinot to Iultin, 6718’N 17 830’E, hill; 18.VI 1 989; Y. Marusik leg.

Name. The specific name is a Latin adjective meaning “the smallest, referring to the very small size of the new species.

Diagnosis. The new species can to be assigned to Oreonetides after Eskov (1984; 1991), as being similar to some Asian representatives (see below), according to the same chaetotaxy (2.2.2.1), and by some genitalia characters, i.e., the shape of the paracymbium (posterior pocket forming a ridge), boat-shaped radix, the presence of two lateral extentions in the embolus, as well as by the structure of the distal part of the scape. Oreonetides minimus new species seems to be the smallest among congeners (see Helsdingen 1981; Thaler 1981; Eskov 1984; 1991; Paquin et al. 2009; Wunderlich & Li 1995; Marusik et al. 2016) except for Oreonetides longembolus Wunderlich & Li, 1995 (the holotype, 1.15 long), which undoubtedly belongs to a different genus, as will be shown in our further studies.. The new species seems to be most similar to the Asian O. beringianus , which is known only from females ( Eskov 1991), but is considerably smaller: size 1.08–1.30 versus 1.88–2.00 in O. beringianus . Besides the size, O. minimus new species can be easily distinguished by the structure of the distal part of the scape: the stretcher in O. beringianus being long and conical versus much shorter and with parallel edges in the new species (cf. Fig. 11 and Fig. 10 ). The new species is also somewhat similar to another Asian congener, O. badzhalensis , which is known only from females as well ( Eskov 1991). In addition to body size (1.63–1.80), O. badzhalensis differs clearly by the more strongly protruding epigynum, as well as by the long stretcher expanded near the middle (cf. Fig. 12 and Fig. 10 ).

Description. Male paratype from Timiryazevsky. Total length 1.25. Carapace unmodified, 0.60 long, 0.46 wide, yellow to pale brown. Chelicerae 0.20. long. Legs yellow. Leg I, 1.50 long (0.45+0.15+0.39+0.27+0.24), IV, 1.54 long (0.45+0.15+0.41+0.30+0.23). Chaetotaxy: TiI–III with two dorsal spines, TiIV with one dorsal spine, length of spines about 1–1.5 diameter of segment. Femora and metatarsi unarmed. TmI 0.42. Metatarsus IV without trichobothrium. Abdomen 0.66 long, 0.47, pale grey. Palp ( Figs 1–8 ): Cymbium without posterodorsal outgrowth. Paracymbium Ushaped, with a large posterior pocket forming a ridge. Distal suprategular apophysis with a narrow, sharp pit hook. Radix boat-shaped. Lamella characteristica divided into two lobes similar in size. Terminal apophysis a narrow, slightly curved stripe. Embolus cup-shaped, with two lateral extentions: one long and narrow (LE 1 in Figs 3, 6–8 ), other one shorter and wider (LE 2 in Figs 3, 6–8 ); embolus proper bifid.

Female paratype from Timiryazevsky. Total length 1.29. Carapace 0.56 long, 0.42 wide. Chelicerae 0.21 long. Leg I, 1.39 long (0.40+0.18+0.32+0.27+0.22), IV, 1.51 long (0.44+0.18+0.38+0.29+0.22). TmI 0.40. Abdomen 0.75 long, 0.51 wide. Epigynum ( Figs 9, 10 ) slightly protruding, fertilization ducts wide, well visible through integument. Lateral lobes of distal part of scape well-developed, forming a narrow transverse stripe. Stretcher short, wide, with a large pit. Receptacles subspherical. Body and leg coloration, as well as chaetotaxy as in male.

Variation. The body size in males (n = 4) varies from 1.10 to 1.28, in females (n = 9) from 1.08 to 1.30, TmI is 0.40–0.43 in both sexes. The shapes of palp and epigyne component structures are more or less stable, tiny variations can be observed only in the form of the lobes of the lamella characteristica (cf. Fig. 4 and Fig. 5 ).

Distribution. The new species is known only from the southern part of the Maritime Province of Russia.

Figures

FIGURES 1 – 12. Oreonetides minimus new species, male and female paratypes from Timiryazevsky (1 – 10); O. beringianus Eskov, 1991 after Eskov (1991) (11); O. badzhalensis Eskov, 1991, specimen from Bureya River Valley (12). 1, Right palp, retrolateral view. 2, Paracymbium. 3, Embolic division. 4, 5, Lamella characteristica. 6 – 8, Embolus, different aspects. 9, Epigynum, ventral view. 10, 11, Epigynum, dorsal view. 12, Sketch of epigynum, dorsolateral view. Scale bars, 0.05 mm.