Psilochorus rockefelleri Gertsch 1935
Creators: name: Slowik, Jozef
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Pholcidae
Psilochorus
Psilochorus rockefelleri

description: Psilochorus rockefelleri Gertsch, 1935
Figs. 138–147, 193
Types. Ψ holotype, from south of Flagstaff (35.19 N, 111.65 W), Coconino County, Arizona, USA; coll: F E Lutz, 22-Jul-1934, AMNH. Not examined.
Specimens examined. 71 ɗ, 114 Ψ; CANADA, British Columbia, Frasier Plateau, 1 Ψ, Beecher's Prarie, D Maddison & D J Williams 80-114, MCZ 68020, 16-Jul-1980, MCZ; USA, Arizona, Cochise County, 1 ɗ, 2 Ψ, 1 Mi W Montezuma Pass, Huachua Mtns, W J Gertsch, 06-Sep-1950, AMNH [odd spur]; 3 ɗ, 5 Ψ, 18 Mi E Douglas, 26-Mar-1963, CU; 5 Ψ, 36 mi E Douglas, 28-Mar-1963, CU; 1 Ψ, 8 mi E apache, 28-Apr-1963, CU; 5 Ψ, Astin Spring 18 mi E Douglas, Durden B & C, McCoy C J, 8 Apr 1965, DMNS ZA.1941; 1 ɗ, 3 Ψ, Carr Canyon, Huachuca Mtns, 31-Jul-1949, AMNH; 10 ɗ, 10 Ψ, same locale, 03-Jun-1952, AMNH; 1 Ψ, same locale, B Malkin, 16-Sep-1952, AMNH; 1 Ψ, same locale, B Malkin, 29-Aug-1952, AMNH; 3 ɗ, 1 Ψ, same locale, [odd spur], 03-Jun-1952, AMNH; 5 ɗ, 5 Ψ, Carr canyon, in Pines, Huachuca Mtns, W J Gertsch, 09-May-1961, AMNH; 1 Ψ, Chiracahua Mtns, Portal Pk. VD Roth, 30-Jun-1984, CAS; 1 ɗ, 3 Ψ, Chiricahua Mtns, Rustler Park, Platnick, MCZ 33233, 2-Aug-no year, MCZ; 4 Ψ, Garden Canyon, Huachuca mtns, WJ & J W Gertsch, 31-Jul-1949, AMNH; 3 ɗ, 1 Ψ, same locale, WJ & J W Gertsch, 31-Jul-1949, AMNH [odd spur]; 10 ɗ, 10 Ψ, same locale, WJ & J W Gertsch, 31-Jul-1949, AMNH; 1 ɗ, Gray Hawk Nature Center, cottonwood/willow 2, Soykan C, May 2005, DMNS ZA.13583; 2 Ψ, Head of Carr Canyon, Huachuca Mtns, W S Creighton, 1-3-Aug-1951, AMNH; 1 ɗ, Huachuca Mtns, Brynt, lot 424, 01-Dec-1933, AMNH; 1 Ψ, same locale, O Bryant, 33-425, no date, AMNH; 3 Ψ, Lower Carr Canyon, W J Gertsch, 21-Jul-1955, AMNH; 1 ɗ, 1 Ψ, Montezuma Pass, Huachuca Mtns, 04-Jun-1952, AMNH; 1 ɗ, 1 Ψ, Portal, 05-Jul-1972, DPI; 1 ɗ, Portal, Saul Frommer, 26-Jul-1973, EM; 3 Ψ, Rucker Cyn, Chiricahua, 26-Apr-1963, CU; 2 Ψ, Rustlers Park, 14 mi E SWRS, F ennik, 12-Aug-1972, CAS; 1F, SW research station, 24-Mar-1963, CU; 1 ɗ, 1 Ψ, SW research station, 5 mi W Portal, 30-Dec-1899, CAS; 1 Ψ, same locale, 29-Sep-1966, CAS; 3 Ψ, SWRS 4 mi SW Portal,Durden B & C, 6-Apr-1965, DMNS ZA.1944; 10 ɗ, 10 Ψ, Upper Carr Canyon, Huachuca Mtns, W J Gertsch, 22-Jul-1955, AMNH; 5 ɗ, 1 Ψ, Cochise County, 03-Jul-1952, AMNH; Coconino County, 1 ɗ, 1 Ψ, Lakeview Campground. L. Mary, C E Griswold & R Jackson, 15-May-1974, EM; Graham County, 2 Ψ, Angel Orchard, Mt Graham, B & VD Roth, 10-Sep-1984, CAS; 2 Ψ, Pinaleno Mtns, Hospital Flat, B V Roth, 04- Sep-1980, CAS; Navajo County, 1 ɗ, Pine Forest, SW of Forestdale, 30-Dec-1899, AMNH [odd spur]; Pima County, 1 ɗ, 1 Ψ, Baboquivar Mtns, Picnic area nr Kitt Peak Obs., W Maddison 85-065, MCZ 67960, 20-Jun- 1985, MCZ; 2 ɗ, 2 Ψ, Mt Lemon, 4.8 Km S Summerhaven, Canta Catalina Mtns, H L Levi, MCZ 68016, 13- Apr-1997, MCZ; Santa Cruz County, 1 Ψ, Madera Canyon, Santa Rita Mtns, Aleen Ivie,, 10-Sep-1941, AMNH; 2 Ψ, Same locale, H L Levi, Juniper oaks sycamores, 12-Apr-1997, MCZ; Yavapai County, 1 ɗ, 10 mi W Ash Fork on Hwy 66, 29-Jun-1966, CAS; New Mexico, Catron County, 2 ɗ, 3 Ψ, 5 mi E Glenwood, 30- Apr-1963, CU; Grant County, 3 ɗ, 2 Ψ, Bear Creek, Pinos Altos, 10-Aug-1975, DPI; 1 ɗ, 6 Ψ, 11 mi N Silver, McMillian Campground, Vogel B, 15-Aug-1973, DMNS ZA.9091; 1 ɗ, 3 Ψ, Iron Creek Campground, 12 mi W Kingston, Vogel B, 2-Aug-1972, DMNS ZA.8078.
Diagnosis. Specimens may be distinguished by: males spur short and wide, curving inward and pointed in dorsal view (Fig. 138), spur is located on the proximal half of the chelicerae and is equal to or less than half of the cheliceral length (Fig. 139), procursus tip squared off with a dorsal step (Fig. 142) epigynum with two prominent ridges on the MEP which are as wide as tall (Fig. 145), narrow PEP projection (Fig. 144).
Male: (N=5) Total length: 2.65 ± 0.27; carapace length: 1.12 ± 0.09; carapace width: 1.15 ± 0.07; leg 1: 18.26 ± 0.92 (5.11 ± 0.32 + 0.44 ± 0.05 + 5.36 ± 0.25 + 6.14 ± 0.35 + 1.21 ± 0.05); tibia 2: 3.61± 0.20; tibia 3: 2.92 ± 0.18; tibia 4. 3.87 ± 0.22: 18–20 leg I tarsal segments; femur1/carapace length: 4.59 ± 0.40; RT at 11.0–16.0%; DT at 6.7–8.6%. Color typical for the genus. Spur short, located on the proximal half of the chelicerae, tip pointed (Fig. 138). Procursus distal area slightly swollen, dorsal step in distal area, end square with a small triangular apical apophysis (Fig. 142). Bulb apophysis bifurcate, the prolateral tip curving across the bulb to a rounded point, the retrolateral tip is broad with a weak point directed ectally (Figs. 140, 141). No retrolateral tab.
Female: (N=5) Total length: 2.88 ± 0.18; carapace length: 1.07 ± 0.01; carapace width: 1.13± 0.05; leg 1: 15.86 ± 1.78 (4.36 ± 0.51 + 0.38 ± 0.04 + 4.81 ± 0.56 + 5.17 ± 0.66 + 1.14± 0.06); tibia 2: 3.32 ± 0.57; tibia 3: 2.54± 0.31; tibia 4: 3.31 ± 0.28. 18–19 leg I tarsal segments; femur1/carapace length: 4.09 ± 0.34; RT at 13.1–15.1%; DT at 7.6–10.0%. Color typical for the genus. No AEP. MEP with two mesal ridges (Fig. 145). Ridges short, touching, triangular bulge located anteriorly of apophysis' in ventral view (Fig. 144). PEP low, oval, with PEP projection, dmPEP small, separate.
Remarks. The male spur of this species appears similar to P. topanga which they differ in the shape of the tip of the procursus and bulb apophysis. The spur also tends to be longer. Females may be confused with P. hesperus which has 4 ridges, and P. concolor new species, which has taller more conical ridges and an AEP. The British Columbia record is one female which may have been transported (MCZ 68020). This species was the most variable in the development of the genitalic features. The retrolateral tip of the bulb apophysis was found to occasionally curve ventrally making it difficult to see. Spurs of males were found which were: long and narrow, very thick and bulbous, represented as mere bumps, or were absent. Several were found with the spur on each chelicerae being of a different shape. Females varied in the development of the triangular bulge on the MEP. In some females the bulge would not be visible. No other species was this variable and the above mentioned diagnostics should be used cautiously. As indicated before, multiple specimens may be needed for a positive identification.
Distribution. Arizona, New Mexico.
description: Published as part of Slowik, Jozef, 2009, A review of the cellar spider genus Psilochorus Simon 1893 in America north of Mexico (Araneae: Pholcidae), pp. 1-53 in Zootaxa 2144 on pages 38-39, DOI: 10.5281/zenodo.188626