Cybaeus aspenicolens Chamberlin & Ivie, 1932

Bennett, Robb, Copley, Claudia & Copley, Darren, 2021, Cybaeus (Araneae: Cybaeidae): the aspenicolens species group of the Californian clade, Zootaxa 4926 (2), pp. 224-244 : 228-230

Cybaeus aspenicolens Chamberlin & Ivie

Figs 1–4 , 11 , 16–17 , 20–22 , 41

Cybaeus aspenicolens Chamberlin & Ivie, 1932: 21 , figs 52–54. Roewer 1954: 89. Bonnet 1956: 1301. Roth & Brown 1986: 3. Copley et al. 2009: 372, fig. 6. World Spider Catalog 2020.

Type material. Holotype male and allotype female. U.S.A.: California: Tuolumne County, Aspen Valley, Yosemite National Park , 11.8.1931, W. Ivie ( AMNH), examined but subsequently lost . Neotype male here designated from original paratype series. U.S.A.: California: Tuolumne County, Aspen Valley, Yosemite National Park , 11.8.1931, W. Ivie ( AMNH), examined .

Other material examined. U.S.A.: California: Mariposa. 1♀, Bower Cave , 30.5.1959, “RG” ( AMNH); 1♀, 6 mi. S of Mather, 4.9.1958, V . D. Roth ( AMNH); 1³, Yosemite National Park, Buck Meadows , 15.9.1959, V . D. Roth & W.J. Gertsch ( AMNH); 1♀, Yosemite National Park, Lower Falls , 30.10.1981, V . F. Lee ( CAS); 2♀, Yosemite National Park, Spider Cave, Twilight Room floor, 2.3.2009, J. Krejca, L. McDermid, G. Stock, & R . Sas ( CAS); 1³ 3♀, Yosemite National Park, Strawberry Creek , 12.9.1959, V . D. Roth & W.J. Gertsch ( AMNH); 1³ (palpus only), Yosemite National Park, Wawona Camp , 17.9.1941, W. Ivie ( AMNH); Tuolumne. 2³ 8♀, 12 mi. E of Buck Mead- ows, 11.9.1959 (W.J. Gertsch & V . D. Roth ( AMNH); 4³ 4♀, Yosemite National Park, Aspen Valley, 11.8.1931, W. Ivie ( AMNH); 4³ 8♀, Yosemite National Park , Aspen Valley , 4.9.1958, V . D. Roth ( AMNH) .

Diagnosis. Cybaeus aspenicolens is grouped with C. blasbes and C. coylei spec. nov. in the informal aspenicolens subgroup. Distinguishing the aspenicolens and fraxineus subgroups is discussed in the aspenicolens species group diagnosis. Males of C. aspenicolens and C. blasbes are distinguished from males of C. coylei spec. nov. by the proximal arm of the tegular apophysis being clearly visible in ventral view ( Figs 3 , 6 ) and the patellar apophysis with two dozen or fewer large, conspicuous peg setae retrolaterally, 15 or fewer small peg setae dorsally, and retrolateral margin slightly concave distal to retrolateral peg setae group ( Figs 2 , 5 , 11–12 ) in C. aspenicolens and C. blasbes versus proximal arm deflected dorsally and mostly hidden in ventral view ( Fig. 9 ) and the patellar apophysis with 30 or more conspicuous peg setae retrolaterally, about two dozen small peg setae dorsally, and retrolateral margin smoothly rounded distal to retrolateral peg setae group ( Figs 8 , 13 ) in C. coylei spec. nov.

Males of C. aspenicolens and C. blasbes are differentiated by the number and morphology of the patellar apophysis peg setae and, less noticeably, by the morphology of the tips of the proximal arm of the tegular apophysis and the patellar apophysis. The patellar apophysis in male C. aspenicolens has two dozen large retrolateral peg setae and fewer than ten (usually four to seven) very small dorsal peg setae ( Figs 2 , 11 ) versus no more than 20 large retrolateral peg setae and usually at least 12 short but stout dorsal peg setae ( Figs 5 , 12 ) in C. blasbes . The tip of the proximal arm of the tegular apophysis is relatively short and only slightly twisted ( Figs 3–4 ) in C. aspenicolens versus somewhat longer and more strongly twisted ( Figs 6–7 ) in C. blasbes . Finally, the tip of the patellar apophysis is relatively short and blunt ( Figs 2 , 11 ) in C. aspenicolens versus blunt but relatively elongated ( Figs 5 , 12 ) in C. blasbes .

Females of C. aspenicolens and C. blasbes are characterized by an at least slightly sclerotized epigynum and a pronounced anterior ridge on the epigynal depression ( Figs 16, 18 ) versus an unsclerotized epigynum and no anterior ridge in C. coylei spec. nov. ( Fig. 14 ).

Females of C. aspenicolens can be distinguished from those of C. blasbes by the presence of a pair of small, sclerotized longitudinal flaps covering the atrial openings ( Fig. 16 ) and less reliably by the copulatory ducts frequently broadly joined along midline of vulva ( Figs 17 , 21 ) in C. aspenicolens versus atrial openings sclerotized but exposed and not covered by longitudinal flaps ( Fig. 18 ) and vulval ducts usually not joined medially ( Figs 19 , 23–24 ) in C. blasbes .

Description. Ventral macrosetae on tibia I usually 2–1p–2–1p–2.

Male: (n=13). Patellar apophysis ( Figs 1–2 , 12 ) large, bluntly rounded, slightly constricted near tip with about two dozen conspicuous, dentiform peg setae retrolaterally and less than ten very small, inconspicuous peg setae dorsally. Retrolateral tibial apophysis with inconspicuous short, broad cuticular spine anterodorsally ( Fig. 2 ). Proximal arm of tegular apophysis ( Figs 3–4 ) large, broad, C-shaped, and slightly deflected dorsally; tip retrolaterally directed, uncinate, truncate, and slightly dextrally twisted.

Measurements (n=12). CL 2.6–3.4 (3.0±0.3), CW 2.00–2.50 (2.19±0.17), SL 1.28–1.55 (1.39±0.08), SW 1.28– 1.53 (1.36±0.08). Holotype, neotype CL 3.0, 2.8; CW 2.23, 2.03; SL 1.43, 1.35; SW 1.38, 1.30.

Female: (n=24). Epigynal depression broad, strongly bordered anteriorly ( Fig. 16 ). Atrial openings covered ventrally by pair of longitudinal, angular, sclerotized flaps. Vulval ducts often contiguous along vulval midline except for small area anteriorly ( Figs 17 , 21 ), some specimens have non-contiguous ducts ( Figs 20–22 ). (Contiguous ducts may be a characteristic of older specimens (see Bennett 2006)).

Measurements (n=20). CL 2.8–3.5 (3.2±0.2), CW 1.93–2.43 (2.22±0.15), SL 1.33–1.60 (1.47±0.09), SW 1.26– 1.55 (1.41±0.08).

Distribution and natural history. Western slopes of the Sierra Nevada in and around western Yosemite National Park ( Fig 41 ). Type series specimens were collected from small, irregular webs under rotting logs and other objects on a hillside at about 6000’. Males have been collected in September.

Figures

FIGURE 41. Distributions of Cybaeus aspenicolens (yellow diamonds), C. blasbes (blue circles), C. coylei spec. nov. (green triangle). AZ—Arizona, CA—California, ID—Idaho, OR—Oregon, NV—Nevada, UT—Utah.

FIGURES 1–4. Cybaeus aspenicolens, male from Aspen Valley, Yosemite National Park, California, left palpus. 1 patella, tibia, and genital bulb, ventral; 2 patella and tibia, dorsal; 3 genital bulb, ventral; 4 genital bulb, retrolateral. DA—distal arm of tegular apophysis, E—embolus, LPS—large peg setae, PA—proximal arm of tegular apophysis, PTA—patellar apophysis, RTA—retrolateral tibial apophysis, SPS—small peg setae.

FIGURES 11–13. Cybaeus spp., males, left palpus, patellar apophysis, dorsal. 11 C. aspenicolens from Aspen Valley, Yosemite National Park, California; 12 C. blasbes from near Fish Camp, California; 13 C. coylei spec. nov., holotype.

FIGURES 14–19. Cybaeus spp., females, copulatory organ (14–15 C. coylei spec. nov. from Pinecrest, California. 16–17 C. aspenicolens from Aspen Valley, California. 18–19 C. blasbes from North Fork, California). 14, 16, 18 epigynum, ventral; 15, 17, 19 vulva, dorsal. AO—atrial opening, BG—Bennett’s gland, BS—base of spermatheca, CD—copulatory duct, HS—head of spermatheca, SS—stalk of spermatheca.

FIGURES 20–24. Cybaeus spp., females, copulatory organ, vulva (20–22 C. aspenicolens from Aspen Valley, California. 23 C. blasbes from Shaver Lake, California. 24 C. blasbes from North Fork, California). 20–21, 23–24 ventral; 22 dorsal.

FIGURES 5–7. Cybaeus blasbes, males, left palpus (5 from near Fish Camp, California. 6–7 from Shaver Lake, California). 5 patella and tibia, dorsal; 6 genital bulb, ventral; 7 genital bulb, retrolateral. PA—proximal arm of tegular apophysis.

FIGURES 8–10. Cybaeus coylei spec. nov., male holotype, left palpus. 8 patella and tibia, dorsal; 9 genital bulb, ventral; 10 proximal arm of tegular apophysis, posterior. Embolus dislodged from usual resting position in folds of tegular apophysis in Fig. 9. PA—proximal arm of tegular apophysis.