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 : 226

Key to the species of the Cybaeus aspenicolens group

1. Patellar apophysis broad, blunt; peg setae dimorphic, in two groups ( Figs 2 , 5 , 8 , 11–13 ). Proximal arm of tegular apophysis “C”-shaped, tip strongly retrolaterally directed, uncinate ( Figs 3–4 , 6–7 , 9–10 ). Atrium in a prominent epigynal concavity; atrial openings not obscured by anterior transverse epigynal ridge or hood ( Figs 14, 16, 18 ) ( aspenicolens subgroup)...... 2

- Patellar apophysis narrower, tapered; peg setae monomorphic, in single group ( Figs 25 , 29 ). Proximal arm of tegular apophysis relatively straight, not “C”-shaped, tip prolaterally directed, bifurcate (especially in retrolateral view) ( Figs 26, 28 , 30–33 ). Prominent epigynal concavity lacking; atrial openings at least partially obscured by anterior transverse ridge or hood ( Figs 34–35, 38–39 ) ( fraxineus subgroup)...................................................................... 4

2(1). Proximal arm of tegular apophysis strongly deflected dorsally, mostly hidden in ventral view ( Fig. 9 ) and visible only in posterior view ( Fig. 10 ). Patellar apophysis with about 30 or 40 conspicuous stout peg setae retrolaterally and approximately two dozen much smaller peg setae dorsally ( Figs 8 , 13 ). Anterior transverse ridge bordering epigynal depression absent or only weakly developed ( Fig. 14 ). No distinct sclerotized regions on epigynum..................... coylei Bennett spec. nov.

- Proximal arm of tegular apophysis only slightly deflected dorsally and clearly visible in ventral view ( Figs 3 , 6 ). Patellar apophysis with ± two dozen conspicuous peg setae retrolaterally and ±15 small peg setae dorsally ( Figs 2 , 5 , 11, 12 ). Anterior transverse epigynal ridge prominent ( Figs 16, 18 ). Some degree of sclerotization on epigynum....................... 3

3(2). Patellar apophysis with about two dozen retrolateral peg setae and less than ten (usually four to seven) very small dorsal peg setae in a loose cluster ( Figs 2 , 11 ). Tip of proximal arm of tegular apophysis very slightly twisted ( Figs 3–4 ). Atrial openings covered by pair of longitudinal flaps ( Fig. 16 ). Vulval ducts often broadly contiguous along vulval midline ( Figs 17 , 21 ).............................................................................. aspenicolens Chamberlin & Ivie

- Fifteen to 20 retrolateral peg setae and usually 12 to 15 short, stout dorsal peg setae in a tight cluster ( Figs 5 , 12 ). Tip of proximal arm of tegular apophysis strongly twisted ( Figs 6–7 ). Atrial openings usually not covered ( Fig. 18 ). Vulval ducts usually not contiguous ( Figs 19 , 23–24 ).................................................... blasbes Chamberlin & Ivie

4(1). In ventral view, proximal arm of tegular apophysis distinctly bifurcate, ventral tip of proximal arm prominent with broad rounded surface, dorsal tip angular ( Figs 26–27 , 32 ). Vulval ducts contiguous medially from atrium to spermathecal stalks ( Figs 35–37 )....................................................................... fraxineus Bennett spec. nov.

- In ventral view, proximal arm of tegular apophysis not distinctly bifurcate, with an inconspicuous narrow keel ventrally and a smoothly pointed tip dorsally ( Figs 30 , 33 ). Vulval ducts contiguous only along posterior portion of copulatory ducts ( Figs 39–40 )............................................................................ thermydrinos Bennett

Figures

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 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.

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 25–28. Cybaeus fraxineus spec. nov., males from vicinity of Ash Mountain, California, left palpus. 25 patella and tibia, dorsal; 26 genital bulb, ventral; 27 tegular apophysis and embolus, ventral prolateral; 28 genital bulb, retrolateral.Arrows indicate bifurcate tip of proximal arm of tegular apophysis.

FIGURES 29–31. Cybaeus thermydrinos, male from near Johnsondale, California, left palpus. 29 patella and tibia, dorsal; 30 genital bulb, ventral; 31 genital bulb, retrolateral.

FIGURES 34–40. Cybaeus spp, females, copulatory organ (34–36 C. fraxineus spec. nov. from vicinity of Ash Mountain, California. 37 C. fraxineus spec. nov. from Clough Cave, California. 38–39 C. thermydrinos from near Johnsondale, California. 40 C. thermydrinos from California Hot Springs, California). 34, 38 epigynum, ventral; 35, 39–40 vulva, ventral; 36–37 vulva, dorsal. CD—copulatory duct, ER—epigynal ridge or hood.

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 32–33. Cybaeus spp, males, left palpus, proximal arm of tegular apophysis (32 C. fraxineus spec. nov. from vicinity of Ash Mountain, California. 33 C. thermydrinos from near Johnsondale, California). Arrows indicate bifurcate tip of proximal arm of tegular apophysis.