Pholcophora americana Banks, 1896

Huber, Bernhard A., Meng, Guanliang, Valdez-Mondragón, Alejandro, Král, Jiří, Ávila Herrera, Ivalú M. & Carvalho, Leonardo S., 2023, Short-legged daddy-long-leg spiders in North America: the genera Pholcophora and Tolteca (Araneae, Pholcidae), European Journal of Taxonomy 880 (1), pp. 1-89 : 14-17

Pholcophora americana Banks, 1896

Figs 3A , 4–8 , 33A–B

Remark

For synonymy, type material, and redescription, see Huber (2000).

Diagnosis

Easily distinguished geographically by being the only representative of Pholcophora (and of Ninetinae ) in the western USA and Canada ( Fig. 2 ); morphologically distinguished from similar congeners ( P. mexcala ; P. mazatlan sp. nov.; P. papanoa sp. nov.) by shape of male cheliceral apophyses ( Fig. 5A– B ; directed towards frontal rather than upwards, without proximal humps, relatively short), by tip of procursus ( Fig. 5C–E ; semi-transparent process widening distally), and by epigynum (main epigynal plate posteriorly strongly indented, Fig. 6A, C ).

Material examined (new records)

USA – Colorado • 3 ♀♀, in pure ethanol; Lookout Mountain near Golden , ‘sites 1 & 2’; 39.73° N, 105.24° W; 2220–2230 m a.s.l.; 6 Jul. 2016; B.A. Huber leg.; one female used for SEM, two prosomata used for molecular work; ZFMK USA16 • 2 ♂♂, in pure ethanol; same collection data as for preceding; vouchers of Ávila Herrera et al. (2021); ZFMK Kra55–56 . – California • 2 ♂♂, 5 ♀♀, 1 juv., in pure ethanol; Mono County, Inyo Nat. Forest ; 37.80° N, 118.38° W; 15 Jun. 2003; P. Paquin and N. Dupérré leg.; under wood debris in pine forest; ZFMK G089 • 1 ♂, 1 ♀; Plumas County, Lassen National Forest , Warner Creek Campground ; 40.3625° N, 121.3081° W; 1540 m a.s.l.; 18 May 2015; K. Schneider leg.; beaten from fallen pine cones; ZFMK Ar 23944. – Idaho • 1 ♀, in pure ethanol; Custer County, Salmon-Challis Nat. Forest , Kinnikinic Creek Road ; 44.278° N, 114.408° W; 19 Sep. 2003; P. Paquin and D. Wytrykush leg.; scree under Picea glauca forest; ZFMK G090 . – Montana • 1 ♂, 2 ♀♀, 1 juv., in pure ethanol; Missoula County, Lolo Nat. Forest , near Salmon Lake; 47.072° N, 113.384° W; 18 Sep. 2003; P. Paquin and D. Wytrykush leg.; under rocks, scree; ZFMK G092 . – Oregon • 2 ♂♂, 2 ♀♀, 1 juv., in pure ethanol; Josephine County, Siskiyou Nat. Forest , Briggs Valley Road ; 42.337° N, 123.610° W; 23 Sep. 2003; P. Paquin and D. Wytrykush leg.; ZFMK G091 .

Description (amendments; see Huber 2000)

Male

Measurements of a male from Hat Creek, California: carapace width 0.95; tibia 1 length: 1.75; distance PME-PME 75 µm; diameter PME 80 µm; distance PME-ALE 30 µm; distance AME-AME 20 µm; diameter AME 60 µm; diameters of leg femora 0.20–0.23, of leg tibiae 0.11–0.12. Clypeus unmodified, clypeus rim to ALE 0.30. Chelicerae as in Fig. 5A–B ; distances between cheliceral stridulatory ridges 2.5–2.7 µm. Procursus as in Fig. 5C–E , with distinctive transparent element distally; genital bulb as in Fig. 5F–H . Legs with few vertical hairs; prolateral trichobothrium absent on tibia 1. Tibia 1 length in 14 males (incl. specimens measured in Huber 2000): 1.50–1.75 (mean 1.62).

Female

In general similar to male but sternum without pair of anterior humps, and chelicerae without stridulatory files. Tibia 1 in 15 females (incl. specimens measured in Huber 2000): 1.25–1.70 (mean 1.48). Epigynum and internal female genitalia as in Figs 6–7 , apparently without median receptacle, without or with very small pore plates.

Distribution

Widely distributed in the western USA, ranging into SW Canada (British Columbia) ( Fig. 2 ). The map in Fig. 2 includes many records from British Columbia that were first shown in a map in Bennett (2014: fig. 5). A list of locality names was later published online in the Checklist of the Spiders ( Araneae ) of British Columbia (http://staff.royalbcmuseum.bc.ca/). The Canadian dots in Fig. 2 are based on coordinates of specimens digitized at the Royal British Columbia Museum that were kindly provided by C. Copley (pers. com. Feb. 2017).

Natural history

Surprisingly, nothing is known about the biology of this widespread spider beyond some basic habitat data taken from labels. It has usually been found under rocks, wood debris, and other objects on the ground, often in pine forests. The most northern records (British Columbia) suggest that this species tolerates very cold winters, with occasional temperatures below -10°C.

Figures

Fig. 3. Pholcophora Banks, 1896, live specimens. A. P. americana Banks, 1896, male from USA, Colorado, near Golden.B–E. P. mazatlan Huber sp. nov., males and females with egg-sacs from Mexico, Guerrero, N of Mazatlán. F–G. P. papanoa Huber sp. nov., male and female from Mexico, Guerrero, S of Papanoa. H–I. P. texana Gertsch, 1935, male and female with egg-sac from Mexico, Hidalgo, SW of Jacala. J–K. P. tehuacan Huber sp. nov., male and female with egg-sac from Mexico, Puebla, SE of Tehuacan. L. P. “Mex354”, female with egg-sac from Mexico, Puebla, SE of Tehuacan.

Fig. 4. Pholcophora americana Banks, 1896, male from USA, Colorado, near Golden (ZFMK Kra55). Left palp, prolateral, dorsal, and retrolateral views. Abbreviations: b = genital bulb; co = coxa; fe = femur; p = procursus; pa = patella; ta = tarsus; ti = tibia; tr = trochanter. Scale bar = 0.3 mm.

Fig. 5. Pholcophora americana Banks, 1896, males. A–E. From USA, Montana, Lolo Nat. Forest (ZFMK G092). F–H. From California, Inyo Nat. Forest (ZFMK G089). A–B. Chelicerae, frontal and lateral views. C–E. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views. F–H. Left genital bulb, prolateral, dorsal, and retrolateral views. Scale bars = 0.3 mm.

Fig. 6. Pholcophora americana Banks, 1896, females. A–B. From USA, California, Inyo Nat. Forest (ZFMK G089).C–D. From Colorado, near Golden (ZFMK USA16). Epigyna, ventral and lateral views. Abbreviations: ep = epigynum (main epigynal plate); pep = posterior epigynal plate. Scale bar = 0.3 mm (all at same scale).

Fig. 7. Pholcophora americana Banks, 1896, cleared female genitalia. A–C. From USA, California, Inyo Nat. Forest (ZFMK G089). D–F. From Colorado, near Golden (ZFMK USA16). A, D. Ventral views. B, E. Dorsal views. C, F. Detail of median internal structures. Scale bars: A–B, D–E = 0.3 mm; C, F = 0.1 mm.

Fig. 8. Pholcophora americana Banks, 1896, female from USA, Colorado, near Golden (ZFMK USA16). A. Prosoma, frontal view. B. Right spinnerets. C. Anterior lateral spinneret. D. Detail of tibia 1. E. Detail of metatarsus 4. F. Tarsal organ on tarsus 1. G. Tarsal organ and slit sensillum on tarsus 3. H. Tarsal organ on tarsus 4. Scale bars: A = 100 µm; B–E, G = 10 µm; F, H = 2 µm.

Fig. 33. Pholcophora internal female genitalia, median sections of main transversal internal sclerite. A–B. P. americana Banks, 1896, females from USA, California, Inyo Nat. Forest (ZFMK G089) and Colorado, near Golden (ZFMK USA16). C–D. P. mazatlan Huber sp. nov., females from Mexico, Guerrero, N of Mazatlán (ZFMK Ar 23943). E–F. P. papanoa Huber sp. nov., females from Mexico, Guerrero, S of Papanoa (ZFMK Ar 23945). G–H. P. “Mex354”, females from Mexico, Puebla, SE of Tehuacan (ZFMK Mex354). I–J. P. texana Gertsch, 1935, females from Mexico, Hidalgo, SW of Jacala (ZFMK Ar 23952). K–L. P. tehuacan Huber sp. nov., females from Mexico, Puebla, SE of Tehuacan (ZFMK Ar 23949). M. Pholcophora? “Car544”, female from Puerto Rico, Isla Mono (USNM ENT 783464). N. Pholcophora? “Cu12-325”, female from Cuba, Santiago de Cuba, Siboney (ZFMK Cu12- 325). Scale bar = 0.1 mm.

Fig. 2. Known distributions of ‘true’ Pholcophora Banks, 1896 (orange marks) and of presumably misplaced Caribbean ‘Pholcophora’ and of Papiamenta Huber, 2000 (red marks). Dominican amber species currently placed in Pholcophora are represented by an “F” in a pink square. Our molecular data suggest that Caribbean ‘Pholcophora’ are more closely related with the genus Papiamenta than with true Pholcophora. Barcoded specimens of Pholcophora americana Banks, 1896 are marked with an “x” and accompanied by the vial code (see Table 1 for details).