Theridion pyrenaeum Denis, 1944

Knoflach, Barbara, Rollard, Christine & Thaler, Konrad, 2009, Notes on Mediterranean Theridiidae (Araneae) – II, ZooKeys 16 (16), pp. 227-264 : 254-255

Theridion pyrenaeum Denis, 1944

Figs 48-49 , 53-55 , 56

Material examined. Spain: Sierra Nevada, Veleta route, 2600 m, boulder fields, 3 ♂ 9 ♀ 1 subadult ♂ 1 subadult ♀ ( CTh), 18.7.1982 and 19.7.1982, leg. K. Thaler [Sp82-2, 82-7]. Sierra Nevada, Corral de Veleta, 3000 m, 1 ♀ ( MHNG), leg. K. Thaler [Sp82-5] . France: Pyrenees, Larruns, Arrens, E Col d’Aubisque , 1600 m, scree, 1 ♂ 4 ♀ 1 subadult ♂ 1 juvenile ( CTh), 14.7.1982, leg. K. Thaler [Py 82-11]. Pyrenees Orientales, Massif du Canigou, between Chalet de Cortalets and Cirque, 2200-2400 m, 1 ♀ ( NMW), 26.9.1983, leg. K. Thaler [F83-8] .

Description, identification. Denis (1944), Bosmans et al. (1994).

Taxonomic status. The statement of Bosmans et al. (1994: 238) ”.. further material of T. pyrenaeum is needed to allow a biometric study of some parts of the palp and epigyne to decide about the status of this species” indicates its close similarity to T. hannoniae and the arising problem of interspecific/intraspecific classification. This requirement remains. Judging from the present specimens, T. pyrenaeum is larger in body and leg size, although in the females this was not always clearly reliable ( Fig. 56 ). However, the dimensions of the male and female genitalia (cymbium length and width of epigynal cavity) from various locations show consistent differences.

Measurements. This is a similar, but larger, species compared to Theridion hannoniae ( Fig. 56 ). Males (n=4, min-max):Total length 2.2-2.5, carapace length 1.0, width 0.9-1.0, length femur I 1.8-2.2, tibia I 1.6-2.0 mm. Females (n=5, min-max): Total length 2.0-3.0, carapace length 0.8-1.0, width 0.8-1.0, length femur I 1.4-1.8, tibia I 1.1-1.5 mm.

Somatic features, colouration. Not distinguishable from Theridion hannoniae , see above.

Male palp ( Figs 48-49 ). Conformation of male palp: see T. hannoniae , as palpal elements do not differ in shape. Differentiation from T. hannoniae by larger dimensions: Cymbium 0.50-0.52 mm long (n=4). Distal embolus 0.38-0.40 mm long (n=2).

Epigynum /vulva ( Figs 53-55 ). Overall genital morphology as in T. hannoniae , distinguished by size and proportion of following parts: Epigynal cavity larger than in T. pyrenaeum , 0.12-0.15 mm wide (n=11), its width exceeding the distance to outside of ducts (x, Fig. 53 ). Receptacula seminis as long as or shorter than width of epigynal cavity.

Distribution. According to the current state of knowledge Theridion pyrenaeum appears to be endemic to western European mountain systems, in allopatry with the widespread T. hannoniae . Up to the present, T. pyrenaeum has been found only in the French and Spanish Pyrenees and Sierra Nevada ( Spain). There it is confined to the higher zones, between 2500 and 3130 m altitude in Sierrra Nevada, about 2000 m in the type region Andorra ( Denis 1957) and between 1600 and 2400 in the French Pyrenees (present paper). Ecological preference and altitudinal zoning resemble that of Theridion petraeum in the Alps.

Figures

Figure 56. Relationship of prosoma width and length of tibia I in Theridion hannoniae Denis and T. pyrenaeum Denis. Open symbols represent females, closed males.

Figures 45-49. Theridion hannoniae Denis from Corsica; Forêt de Bonifatu (45-46) and Italy, Venezia (47). Theridion pyrenaeum Denis from Spain, Sierra Nevada (48-49). Male palp, ventral (45, 48), prolateral (46, 49), retrolateral-ventral view (47). All figures drawn at same scale. Scale lines: 0.20 (45-46, 48-49), 0.10 mm (47).

Figures 50-55. Theridion hannoniae Denis from Mallorca (50, 52) and Italy, Toscana (51). Theridion pyrenaeum Denis from Spain, Sierra Nevada (53, 54) and France, Pyrenees (55). Epigynum/vulva, ventral (50-51, 54-55), dorsal view (52-53). Scale lines: 0.10 mm.