Tiso incisus, V. & Tanasevitch, 2011

Tanasevitch, Andrei V., 2011, Linyphiid spiders (Araneae, Linyphiidae) from Pakistan and India, Revue suisse de Zoologie 118 (3), pp. 561-598 : 590-591

Tiso incisus sp. n. Figs 89-96

HOLOTYPE: Ƌ, INDIA, Himachal Pradesh, Jutogh , 10 km W of Shimla, 2000 m a.s.l., leaf litter near foot of rock; 29.X.1988; leg. S. Vit [37].

PARATYPES: 13 Ƌ, 19 ♀; 5 Ƌ, 3 ♀ ( ZMMU), from same locality, collected together with the holotype . – 1 ♀, Himachal Pradesh , Kulu Valley , S of Manali, Chijoga, 1900 m a.s.l., hollow in Quercus ; 14.X.1988; leg. S. Vit [21]. – 1 Ƌ, 2 ♀, Uttar Pradesh , Garhwal, 10 km E of Dhanolti, 2450 m a.s.l., northern slope, Quercus forest, sifting litter; 21.X.1979; leg. I. Löbl [21b]. – 1 ♀, PAKISTAN, Swat District , S of Saidu-Sharif, Marghuzar, 1300 m a.s.l., sifting leaf litter under Platanus; 8. V.1983; leg. C. Besuchet & I. Löbl [2b]. – 1 Ƌ, 3 ♀, Malam Jabba , 2300 m a.s.l., Pinus forest, sifting litter under Pinus and Corylus; 9. V.1983; leg. C. Besuchet & I. Löbl [4c]. – 1 Ƌ, same, 2500-2600 m a.s.l., under stones; 18. V.1983; leg. C. Besuchet & I. Löbl [17a]. – 1 Ƌ, 5 ♀, same, 2500-2600 m a.s.l., Abies forest , sifting litter and moss; 18. V.1983; leg. C. Besuchet & I. Löbl [17b]. – 1 Ƌ, 3 ♀, Kalam , 2100 m a.s.l., Quercus forest, sifting leaf litter; 12. V.1983; leg. C. Besuchet & I. Löbl [9b]. – 7 ♀, Ushu Valley , upper reaches of Kalam River, 2300 m a.s.l., Cedrus forest, sifting leaf litter under Corylus; 15. V.1983; leg. C. Besuchet & I. Löbl [13b]. – 1 Ƌ, 1 ♀, above Miandam , 2400-2500 m a.s.l., Abies forest, sifting litter and moss; 17. V.1983; leg. C. Besuchet & I. Löbl [15b]. – 1 Ƌ, 1 ♀, same, 2400-2500 m a.s.l., Abies forest , sifting litter and moss; 17. V.1983; leg. C. Besuchet & I. Löbl [15b].

ETYMOLOGY: The species name means “incised”, “notched”, referring to the shape of the embolus.

DIAGNOSIS: The new species is characterized by the peculiar shape of the palpal tibia and the embolic division, as well as by the shape of the ventral plate of the epigyne.

DESCRIPTION: Male. Total length 1.40. Carapace 0.75 long, 0.58 wide, pale brown, unmodified, sulci absent. Chelicerae 0.23 long, unmodified. Legs pale brown. Leg I 1.88 long (0.55+0.20+0.45+0.38+0.30), IV 2.06 long (0.60+0.20+0.55+0.43+ 0.28). Chaetotaxy 1.1.1.1, spines weak, their length about same as diameter of segment or a little longer. TmI 0.44. Metatarsus IV without trichobothrium. Palp (Figs 89-94): Patella as long as cymbium, with a row of uniform short spines dorsally. Tibia strongly modified: elongated, slightly sigmoid, with several outgrowths different in size and shape. Paracymbium small and narrow, L-shaped. Distal suprategular apophysis long and wide, flat, apically pointed and bent 90º. Radical part of embolic division relatively large and flat. Embolus long, curved, with a notch near it base. Abdomen 0.78 long, 0.50 wide, pale grey.

Female. Total length 1.38. Carapace 0.68 long, 0.53 wide, unmodified. Chelicerae 0.23 long, unmodified. Leg I 1.64 long (0.48+0.20+0.38+0.30+0.28), IV 1.76 long (0.50+0.20+0.45+0.35+0.26). TmI 0.43. Abdomen 0.80 long, 0.55 wide. Epigyne and vulva (Figs 95-96): Ventral plate of epigyne long and narrow. Receptacles spherical, far apart from each other. Body and leg coloration, as well as chaetotaxy, as in male.

TAXONOMIC REMARKS: The new species seems to be most similar to the Holarctic T. aestivus (L. Koch, 1872) and can be easily distinguished by the structure of the embolic division: in T. incisus sp. n. the loop of the embolus is almost orthogonal to the main axis of the palp, whereas in T. aestivus the loop lies almost in the same plane; there are also other small differences in the shape of the palpal tibia and the embolic division. The female differs by the shape of the ventral plate of the epigyne: in T. aestivus the ventral plate is triangular, in T. incisus sp. n. it is as a narrow transversal stripe.

RANGE: Himalayan.

FIGS 97-100

Tiso (?) indianus sp. n., Ƌ paratype. (97-98) Right palp, retrolateral and prolateral views, respectively. (99) Palpal tibia, dorsal view. (100) Palpal tibia and paracymbium, lateral view.