Porrhomma oblitum ( O. Pickard-Cambridge, 1871 )

Růžička, Vlastimil, 2018, A review of the spider genus Porrhomma (Araneae, Linyphiidae), Zootaxa 4481 (1), pp. 1-75 : 48

Porrhomma oblitum ( O. Pickard-Cambridge, 1871)

Figs. 41A–F .

Linyphia oblita O. Pickard-Cambridge, 1871 — O. Pickard-Cambridge (1871): p. 432 (descr. ♂); examined and transferred by Jackson (1913).

Neriene pallipes O. Pickard-Cambridge, 1871 — O. Pickard-Cambridge (1871): p. 437 (descr. ♂); examined and synonymised by Jackson (1913).

Porrhomma oblitum — Jackson (1913): p. 39, Pl. II, Figs. 23 , 33 (♂ ♀); synonymy.

P. oblitum — Merrett (1994): p. 318, Figs. 5–6 (♀).

Material examined. CZECHIA: Lovosice, Lovoš Hill , 25 May –14 Jun 1980, 1 ♂; Lanžhot , Ranšpurk Reserve , 5 Jun 1996, 1 ♀; Sedlec , Lednické Rybníky Ponds Reserve , 16 Jul 1996, 1 ♀, leg. V. Růžička ( IECA). Šumava Mts. , Mrtvý Luh Reserve, 22 May 1980, 1 ♀, leg. A. Kůrka (CAK). Lanžhot, Soutok Reserve, 1996–1997, 5 Ƌ 5 ♀, leg. et coll. L. Kubcová . RUSSIA: Orenburskaya (= Orenburg) Area, Aytuar , 22 May 1997, leg. S.L. Esyunin, 4 Ƌ 6 ♀ ( PSU, No. 2840).

Diagnosis. Small species (CW <0.60 mm), Fe I–II without dorsal spines, AP has the form of a bird head, Sshaped ascending parts of copulatory ducts. It is closely similar to P. cambridgei , but it can be distinguished by pigmented body and normal eyes ( Fig. 41A ).

Description. ♀ (from Lanžhot, Czechia, 1 Oct 1996). Carapace brown, 0.57 mm wide, eyes normal, PME– PME = 0.8 ( Fig. 41A ). Abdomen gray. Fe without dorsal spines, Fe I with one prolateral spine. Ti I with one prolateral spine, Ti I–II with one retrolateral spine. Tm Mt I = 0.44, Mt I/CW = 0.72.

Ascending parts of the ducts are S-shaped. Spermathecae are formed behind the ascending part of the ducts. Long appendices can be seen on the epigynum ( Fig. 41C ) and vulva ( Figs. 41D–F ).

Ƌ (together with female). Embolus of middle length with a narrow velum. ARP has the form of a bird head ( Fig. 41B ).

Variation. Ƌ ♀. Carapace 0.53–0.61 mm wide. Tm Mt I = 0.37–0.45, Mt I/CW = 0.68–0.79 (n = 14).

Ecology. The species lives in wet open and forest habitats and is abundant in litter and under tree bark in floodplain forests ( Kubcová & Schlaghamerský 2002).

Global distribution. Europe after Helsdingen (2017) and this article. See Fig. 42 .

Figures

FIGURE 5. A–C, female vulva, lateral view. A, Porrhomma pygmaeum. B, Porrhomma microcavense. C, Porrhomma microps. Scale bars, 0.1 mm.

FIGURE 6. A–F, Porrhomma altaica new species from Altai Mts., Azutau Ridge. A, ♂ carapace, frontal view. B, embolic section. C, epigynum. D–F, vulva, ventral, caudal and dorsal. Abbreviations: A, appendix; AP, anterior process of the embolic plate; E, embolus; MS, main sack; PA, posterior apex of the embolic plate; V, velum. Scale bars, 0.1 mm.

FIGURE 23. A–F, Porrhomma errans from Chrast, Czechia. A, ♀ carapace, frontal view. B, embolic section. C, epigynum. D– F, vulva, ventral, caudal and dorsal. Scale bars, 0.1 mm.

FIGURE 33. A–C, tip of the embolus. A, Porrhomma microphthalmum from České Budějovice, Czechia. B, Porrhomma profundum from Domica Cave, Slovakia. C, Porrhomma microps from Horka nad Moravou, Czechia. Scale bars, 0.1 mm.

FIGURE 41. A–F, Porrhomma oblitum from Lanžhot, Czechia. A, ♀ carapace, frontal view. B, embolic section. C, epigynum. D–F, vulva, ventral, caudal and dorsal. Scale bars, 0.1 mm.

FIGURE 42. Global distribution of Porrhomma oblitum.