Theridion hemerobium Simon, 1914

Knoflach, Barbara, Rollard, Christine & Thaler, Konrad, 2009, Notes on Mediterranean Theridiidae (Araneae) – II, ZooKeys 16 (16), pp. 227-264 : 249

Theridion hemerobium Simon, 1914

Figs 57-58

Material examined. Greece: Peloponnesos, Nafplio, Argos , brookside, 1 ♂ ( CTh), 22.6.2000, leg. J. Buchar.

Description, identification. Differentiation from the closely related, larger T. pictum see Levi (1957a, sub T. berkeleyi ), Blick et al. (1993), Bosmans et al. (1994), Roberts (1995), Nentwig et al. (2003), Almquist (2005). For additional citations and synonyms see Platnick (2008).

Male palp ( Figs 57-58 ). Palp less elongated and considerably smaller than in T. pictum , length of tibia and tarsus ca. 0.4 mm (versus ca. 0.7 in T. pictum ). Tibia rather broad at base as compared with distal rim, about 0.7 of distal width in ventral view, thus little constricted. Shape of conductor and median apophysis diagnostic. Prolateral tip of median apophysis closer to tip of conductor than in T. pictum . Embolus short, distal part 0.12 mm long ( T. pictum 0.3 mm, see Knoflach 1998).

Distribution. Theridion hemerobium is widespread in North America ( Levi 1957a) and Europe ( Bosmans et al. 1994; Anthes 2000). From Greece it was hitherto not known ( Bosmans et al. 1994; Anthes 2000; Bosmans and Chatzaki 2005). The present finding bridges a distribution gap in southeast Europe, though its occurrence is not surprising. A further record comes from Bulgaria ( Deltshev 1992); the easternmost one from Israel ( Levy 1998). Interestingly, the species has so far not been mentioned from Russia ( Mikhailov 1997, 1998). T. hemerobium occurs stenotopically on the vegetation in wetlands and on banks of lakes, ponds and running water ( Anthes 2000) and also colonises human-made structures in these habitats, e.g. bridges and fences ( Jones 1994; Daws 2003).

Figures

Figures 57-62. Theridion hemerobium Simon from Peloponnese (57-58). Heterotheridion nigrovariegatum (Simon) from Uzbekistan, Surchan Darja (59). Theridion musivum Simon from France, Vaucluse (60) and Gabas (61-62). Male palp, ventral (57, 59, 60, 61), prolateral view (58, 62). 57-58 and 61-62 drawn at same scale. Scale lines: 0.2 (57-59) and 0.1 (60-62) mm.