Porrhomma terrestre ( Emerton, 1882 )

Růžička, Vlastimil, 2018, A review of the spider genus Porrhomma (Araneae, Linyphiidae), Zootaxa 4481 (1), pp. 1-75 : 63

Porrhomma terrestre ( Emerton, 1882)

Figs. 55A–F .

Tmeticus terrestris Emerton, 1882 — Emerton (1882): p. 57, Pl. XVII, Fig. 6 (descr. ♂).

Microneta clavata Emerton, 1917 — Emerton (1917): p. 265, Fig. 17.3 (descr. ♂, not ♀); examined and synonymised by Bishop & Crosby (1938).

Sciastes terrestris — Bishop & Crosby (1938): p. 79, Pl. 5, Figs. 54–56 (♂, descr. ♀).

S. terrestris — Kaston (1948): p. 211, Pl. XXXI, Figs. 683–684 (♂ ♀); ♂ redrawn from Emerton (1882).

Porrhomma gertschi Hackman, 1954 — Hackman (1954): p. 31, Figs. 111–119 (descr. ♂ ♀); new synonymy.

P. terrestris — Ivie (1967): p. 130.

P. terrestre — Paquin & Dupérré (2003): p. 148, Figs. 1632–1633 (♂ ♀).

Material examined. CANADA. Porrhomma gertschi Hackman , holotype Ƌ, Deer Lake, NFld., 30 May 1951, C.H. Lindroth ; allotype ♀, Deer Lake , NFld., 30 May 1951, C.H. Lindroth ( CNC) .

Other material examined. CANADA: Manitoba, Fort Whyte , 12 Dec 1974, 1 ♀, leg. C.W. Aitchison ; Glenlea , 10 mi S of Winnipeg, 1 Jul 1973, 1 Ƌ 1 ♀, leg. J. Redner & C . Starr. Newfounland, Deer Lake , 30 May 1951, 1 Ƌ 1 ♀, leg. C.H. Lindroth. Nova Scotia, Cape Breton Highlands National Park, Lone Shieling, 25 Jun 1983, 1 Ƌ, leg. Y. Bousquet. Ontario, Kinburn, 11 Oct 1967, 1 ♀, leg. J.E.H. Martin; Cochrane , 48°46'N, 80°14'W, 17 Jul 2003, 1 Ƌ, Canadian Forest Service, Sault Ste. Marie ( CNC). USA: Alaska, Primrose Camp , 60.20°N, 149.20°W, 24 Aug 1968, 1 ♀, leg. W. Ivie. Connecticut, New Britain, 41.40°N, 72.45°W, 10 Feb 1958, 1 ♀, leg. A.J. Nappi. Massachusetts, Lexington, 42.36°N, 71.12°W, Oct 1933, 1 Ƌ 1 ♀, leg. W.J. Gertsch. New Jersey, Jamesburg, 40.22°N, 74.26°W, 26 Apr 1964, 1 ♀, leg. J. & W. Ivie. New York, Ithaca, 42°N, 76°W, May, 2 ♀, leg. C.R. Crosby. South Dakota, Pennington County, Keystone , 43.55°N, 103.26°W, 14 Jul 1959, 1 ♀, leg. C.C. Hoff (AMNH).

Diagnosis. Small species (CW <0.60 mm), Fe I–II without dorsal spines. Embolus short, reaching to the tip of AP ( Fig. 55B ), epigynum and vulva of most simple type ( Fig. 55C–F ). Native in North America.

Description. ♀ (from Fort Whyte, Canada, Manitoba, 12 Dec 1974). Carapace brown, 0.57 mm wide, eyes normal, PME–PME = 1.1 ( Fig. 55A ). Abdomen brown-grey. Fe without dorsal spines. Ti I with one prolateral and one retrolateral spine, Ti II with one retrolateral spine. Tm Mt I = 0.40, Mt I/CW = 0.80.

Spermathecae (♀ from Kinburn, Canada, Ontario, 11 Oct 1967) start at the midway of the ascending part of copulatory ducts. Main sacks are in contact and directed to the abdomen. They end at the base of appendices in the caudal view. Appendices are oriented towards the abdominal wall ( Figs. 55C–F ).

Ƌ (from Glenlea , Canada, Manitoba, 1 Jul 1973). Embolus short with a broad velum ( Fig. 55B ).

Variation. Ƌ ♀. Carapace 0.52–0.62 mm wide. Fe without dorsal spines, one prolateral spine sometimes present. Tm Mt I = 0.34–0.40, Mt I/CW = 0.71–0.82 (n = 5).

Comments. Bishop & Crosby (1938) examined the material of T. terrestris collected by J.H. Emerton, and the species is generally accepted, although the structure of the genitalia is hardly known. Emerton (1917) has incorrectly associated the male and female; the female is Oreonetides rotundus Emerton, 1913 ( Bishop & Crosby 1938; Buckle et al. 2001). The figures of the male palp drawn by Emerton (1882, 1917) and Paquin & Dupérré (2003) represent only the outline of the palp, lacking details of embolic division; the figure of Kaston (1948) is redrawn from Emerton (1882). The drawing of Bishop & Crosby (1938) did not present the embolus in detail.

Ecology. Under leaves, in detritus.

Global distribution. North America after Buckle et al. (2001) and this paper. See Fig. 56 .

Figures

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 54. Global distibution of Porrhomma rosenhaueri.

FIGURE 55. A–F, Porrhomma terrestre. A, carapace of female from Fort Whyte, Canada, Manitoba, frontal view. B, embolic section of male from Glenlea, Canada, Manitoba. C, epigynum of female from New Britain, U.S.A., Connecticut. D–F, vulva of female from Kinburn, Canada, Ontario, ventral, caudal and dorsal. Scale bars, 0.1 mm.

FIGURE 56. Global distibution of Porrhomma terrestre.