Scirites pectinatus Emerton 1911
Creators: name: Dupérré, Nadine
name: Paquin, Pierre
Publisher: name: Zenodo
Year: 2007
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Linyphiidae
Scirites
Scirites pectinatus

description: Scirites pectinatus (Emerton 1911)
(Figs 1 –9, 18)
Dicymbium pectinatum Emerton 1911: 389, plate I, figs. 8, 8a–d
Tapinocyba exigua Hackman 1954: 17, figs. 37–41; Aitchison-Benell & Dondale 1992: 216, 223 (S). Scirites pectinatus (Emerton), Bishop & Crosby 1938: 70, figs. 31–34 [in part]; Kaston 1948:209; Levi et al. 1958: 48; Aitchison-Benell & Dondale 1992: 223; Hutchinson & Bélanger 1994: 211; Paquin et al. 2001:28; Buckle et al. 2001:139 [in part]; Draney & Buckle 2005:149, fig. 35.263
Type material.— Dicymbium pectinatum Emerton, TYPE SPECIMEN LOST. Label 1: Dicymbium pectinatum Em., Lake Winnepesaukee, Three Mile Island N.H., October 10 1909, J.H. Emerton Coll. MCZ 22574. Belknap County: Lake Winnepesaukee, Threemile Island [43.6737N, 71.4242W]. Holotype: male. Label 2: specimen lost, 1958.
— Tapinocyba exigua Hackman, EXAMINED. Label 1: Tapinocyba exigua Hackman / holotype CNC. Label 2: Millertown Junction, Nfld, 22.viii.1949, E. Palmn. Label 3: det. Leech 1966, epigynum missing, 14.vi.1966.
Material examined.— Canada: Alberta: George Lake, 16 km West of Busby [53.95N, 114.10W] 1ɗ 06.v.1999, pitfall, C. Buddle (DBC); Wagner Natural Area, 6 km West of Edmonton [53.55N, 113.47W] 5ɗ 16.v.–03. vi.1985, 2 ɗ 03.vi.–11. vi.1985, 1 ɗ 1Ψ 11.vi.–25. vi.1985, 2 ɗ 26.vi.–02. vii.1985, 1 ɗ 2Ψ 02.– 09. vii.1985, 1 ɗ 28.viii.–10.ix.1985, pan trap, A. Finnamore & T. Thormin (DBC); Manitoba: Riding Mountain National Park, Clear Lake [50.89N, 100.25W] 1ɗ 08.–28.vi.1979, pitfall, beaver meadow, S.J. Miller (MCZ); Riding Mountain National Park, Bison enclosure [50.89°N, 100.25°W] 1ɗ 04.–17.vii.1979, D.B.
Lyons (CNC); Riding Mountain National Park, near Refuse Pit [50.89°N, 100.25°W] 1ɗ 15.vi.1979, 2ɗ 2Ψ 28.vi.1979, 1ɗ 02.viii.1979, pitfall, aspen stand, S.J. Miller (CNC); Riding Mountain National Park, 1 km east of Clear Lake [50.89°N, 100.25°W] 2ɗ 1Ψ 08.vi.1979, 4ɗ 1Ψ 08.–28.vi.1979, pitfall, beaver meadow, S.J. Miller (CNC); Riding Mountain National Park, east escarpment [50.89°N, 100.25°W] 2ɗ 06.vi.1979, 1ɗ 25.vi.–20. vii.1979, 1 Ψ 20.vii.–01.viii.1979, pan trap, deciduous forest, S.J. Miller (CNC); New Brunswick: Kouchibouguac National Park [46.86N, 64.98W] 1ɗ 05.vii.1977, 1Ψ 03.vii.1977, bog, J.R. Vockeroth (CNC); Kouchibouguac National Park [46.86N, 64.98W] 1ɗ 26.v.1977, woods, S.J. Miller (CNC); Kouchibouguac National Park [46.86N, 64.98W] 1ɗ 15.vi.1977, mixed woods, J.H. Redner (CNC); Kouchibouguac National Park [46.86N, 64.98W] 1Ψ 23.vi.1977, sweeping, roadside, S.J. Miller (CNC); Kouchibouguac National Park [46.86N, 64.98W] 1Ψ 23.vi.1977, field edge, S.J. Miller (CNC); Kouchibouguac National Park [46.86N, 64.98W] 2ɗ 05.vii.–01.viii.1978, edge of bog, sphagnum, S.J. Miller (CNC); Kouchibouguac National Park [46.86°N, 64.98°W] 2Ψ 11.viii.1978, litter under dead fish, D.B. Lyons (CNC); Fundy National Park [45.62°N, 60.03°W] 1Ψ v.1969, pitfall, T.R. Renault (CNC); Acadia Forest, 15 miles [20 km] east of Fredericton [45.95°N, 66.17°W] 2ɗ 28.v.–13. vii.1970, 1 ɗ 29.vii.1969, soil, T.R. Renault (CNC); Newfoundland: Terra Nova National Park [48.60N, 53.78W] 1ɗ 06.vi.1980, pitfall, (CNC); Nova Scotia: Coldbrook [45.07N, 64.58W] 1Ψ vii.1959, pitfall, pine wood, C.D. Dondale (CNC); Ontario: Lake Temagami, Point west, Ko-Ko- Ko Bay [46.98N, 80.05W] 8ɗ 12Ψ 15.–25.viii.1946, W. Gerstch, W. Ivie & T.B. Kurata (AMNH); Lake Temagami, Island 1024 [46.98°N, 80.05°W] 4ɗ 4Ψ 15.–25.viii.1946, W. Gerstch, W. Ivie & T.B. Kurata (AMNH); Lake Temagami, Bear Island [46.98°N, 80.05°W] 1ɗ 16Ψ 15.–25.viii.1946, W. Gerstch, W. Ivie & T.B. Kurata (AMNH); Qu é bec: Abitibi-Ouest, Duparquet [48.50N, 79.23W] 1ɗ 15.vi.1995, sifting, Jack pine litter, P. Paquin, (CPAD); Saskatchewan: Besnard Lake [55.41N, 106.00W] 4ɗ 10.–14.v.1977, pitfall, forest, Don Buckle (DBC); USA: Pennsylvania: Bucks County, north east of Jamison, Horseshoe Bend, Neshaminy Creek [40.28N, 75.21W] 3ɗ 5Ψ x.1954, W. Ivie (AMNH).
Diagnosis.— The males of S. pectinatus are distinguished from S. finitimus n.sp. by the presence of a well sclerotized marginal suprategular apophysis (absent in S. finitimus n.sp., Figs 4, 12); a large paracymbium bearing 2 long and 1 short setae contrasting with the smaller paracymbium bearing only 2 short setae in S. finitimus n.sp. (Figs 5, 13); a palpal tibia nearly as wide as long, bearing 3 small ectal spines in S. pectinatus whereas in S. finitimus n.sp. the palpal tibia is longer than wide without spines (Figs 6, 14). Females of S. pectinatus with a posterior margin of ventral epigynal plate V-shaped projecting posteriorly to about the middle of the dorsal plate while that of S. finitimus n.sp. is U-shaped and projecting posteriorly only a short distance; openings to copulatory ducts closer together in S. pectinatus (Figs 7, 8) than in S. finitimus n.sp.
Description.— Male (n=5): Total length: 1.29–1.47; carapace length: 0.55–0.59; carapace width: 0.48– 0.51; carapace smooth, shiny, light brown to brown, carapace border sometimes suffused with dark grey, 2–3 erect setae along midline, cephalic eye region somewhat raised and flat (Fig. 2). Sternum brown, lightly suffused with grey. Chelicerae light brown, promargin with 1 large and 4 small teeth, retromargin with 4 denticles. Cheliceral stridulatory organ not visible. Abdomen uniformly coloured, light to dark grey, densely covered with decumbent hairs. Legs light yellow with a tinge of orange, tibia I–IV with one dorsal macroseta; metatarsus I with dorsal trichobothrium, Tm I 0.52–0.55, metatarsus I with 7 curved megaspines, Tm IV absent. Palpal tibia rather short and wide, with three small spines on the ectal side (Fig. 6) and a small curved, sclerotized apophysis (Figs 5, 6); embolic division rather simple, embolus tip spine-like; tailpiece elongate projecting basally; tegulum (T) rather large, protegulum with protegular papillae, suprategulum bearing a membranous (DSA) and well sclerotized marginal suprategular apophysis (MSA), fundus visible (Figs 3, 4); paracymbium bearing 2 long and 1 short setae (Fig. 5).
Female (n=5): Total length: 1.36–1.49; carapace length: 0.57–0.59; carapace width: 0.46; carapace coloration as in male, 4–5 erect setae along midline. Coloration of sternum and chelicerae as in male; promargin of chelicerae with 1 large and 4 small teeth, retromargin with 5 denticles. Cheliceral stridulatory organ not visible. Abdomen as in male. Legs coloured as in male, tibia I–IV with one dorsal macroseta; metatarsus I with dorsal trichobothrium, Tm I 0.55–0.60, Tm IV absent. females epigynal plate well sclerotized somewhat rectangular (Fig. 7); posterior edge of ventral plate V-shaped reaching half way through the dorsal plate; spermathecae rounded situated each side of the junction of ventral plate and dorsal plate (Figs 7, 8); copulatory ducts comma-shaped (Figs 8, 9).
Distribution.— Alberta to Nova Scotia within Canada, and in North-East USA in Pennsylvania (Fig. 18).
We could not examine Emerton’s type specimen but we included the type locality on the distribution map (indicated by a black star) that fits well in the known distribution of the species. The record from Washington given by Buckle et al. (2001) refers to S. finitimus new species.
Habitat.— The records from field, meadow, bog, deciduous and conifer forests suggest that the species is a generalist, mainly found in boreal type habitat.
Remarks.— The holotype vial was found, but the specimen is missing since 1958 as indicated by a label found in the vial. Fortunately, the illustration of the palpal tibia in dorsal view in the original description provided by Emerton (1911:plate I, fig. 8b) easily allows the recognition of the species and its distinction from S. finitimus new species. Bishop & Crosby (1938) provided illustrations for S. pectinatus but the orientation and details of the figures they provided (plate IV, figs 31–34) do not allow the separation of the two species. These authors list a few localities for S. pectinatus, including McLean (New York), Montauk Point (New York), and Three Mile Island (New Hampshire) the latter being the type locality of S. pectinatus. We were able to locate and re-examine some specimens collected by Bishop & Crosby from McLean deposited in the spider collection of Cornell University, which is on permanent loan to the AMNH. After examination, we easily conclude that specimens from McLean - McLean Bog is the complete name - were misidentified and indeed correspond to S. finitimus. The specimens collected at Montauk Point could not be found and therefore, this locality for S. pectinatus should be considered with caution as these authors did not distinguish the two species.
We also attempted to examine the female holotype of Tapinocyba exigua Hackman 1954, a synonym of S. pectinatus, but the epigynum is missing as mentioned on an additional label found in the vial. Without this structure, it is difficult to reject or confirm the synonymy of Aitchison & Dondale (1992). However, the detailed illustrations of the female genitalia provided by Hackman in the original description (1954, figs. 40– 41) allow us to accept this synonymy without further investigation.
description: Published as part of Dupérré, Nadine & Paquin, Pierre, 2007, Revision of the North American genus Scirites (Araneae, Linyphiidae), pp. 47-58 in Zootaxa 1460 on pages 49-52, DOI: 10.5281/zenodo.176406