Cybaeina dixoni Bennett, 2023

Bennett, Robb, Copley, Claudia & Copley, Darren, 2023, Revision of the western Nearctic spider genus Cybaeina including the description of Neocybaeina gen. nov. and Rothaeina gen. nov. (Araneae: Cybaeidae: Cybaeinae), Zootaxa 5318 (1), pp. 97-129 : 102-103

Cybaeina dixoni Bennett spec. nov.

Figs 5 , 10–11 , 14–15 , 25–28

Type material. U.S.A.: Oregon: Holotype male. Curry County, two miles north of Brookings , 31(sic). ix.1959, V.D. Roth ( CAS) . Paratypes. Curry , 4♀, 2 mi. N of Brookings, 31(sic). ix.1959, V.D. Roth ( CAS) ; 1♀, Carpenterville , 31(sic). ix.1959, V.D. Roth ( CAS) ; Jackson, 1♀, Ashland Watershed , 15.vi.1998, R.W. Peck et al. ( RBCM) .

Etymology. The specific epithet is a patronym honouring the late blues and jazz lyricist and bassist William (Willie) James Dixon.

Diagnosis. Distinguishing specimens of C. dixoni spec. nov. from those of C. confusa is discussed in the diagnosis of the latter. Pedipalpal characters distinguish males of C. dixoni spec. nov. from those of C. minuta : in C. dixoni spec. nov. ( Figs 10–11 , 14–15 ) the patellar apophysis is broad in retrolateral view with nine peg setae aligned dorsoventrally and the medial component of the retrolateral tibial apophysis is a distinct ledge with a small, slender, acuminate distal tip; in C. minuta ( Figs 12–13 , 16–17 ) the patellar apophysis is very small and tipped with two peg setae while the medial component of the retrolateral tibial apophysis is a simple stout, acuminate process. Females of C. dixoni spec. nov. and C. minuta are distinguished by vulval characters: in C. dixoni spec. nov. ( Figs 26–27 ) the copulatory ducts loop once around the spermathecal stalks and Bennett’s glands are prominently visible in dorsal view; in C. minuta ( Figs 23–24 ) the copulatory ducts loop about 2.5 times around the spermathecal stalks and Bennett’s glands are inconspicuous, obscured by the posterior loops of the copulatory ducts and spermathecal stalks.

Description. As in diagnosis and description of the genus and the diagnoses of C. confusa and this species. Additional descriptive characters presented here.

Male: (n=1). Patellar apophysis short and stout in retrolateral view ( Figs 10 , 14 ). Tegular apophysis ( Fig. 5 ) with distal arm long (about twice as long as width at base), distad, tapered; proximal arm with elongate, acuminate prolatero-ventrad tip.

Measurements (n=1). Holotype CL 2.00, CW 1.73, SL 1.07, SW 1.05.

Female: (n=6). Atrium ( Fig. 25 ) positioned medially on epigyne. Vulva ( Figs 26–27 ) with copulatory ducts contiguous at atrium then diverging prior to looping around spermathecal stalks; heads of spermathecae continuous with rest of vulva, primary pores on prolateral surface of heads; spermathecal stalks elongate, well sclerotized, twisted within loops of copulatory ducts; Bennett’s glands prominent near junction with relatively large, rounded spermathecal bases (about 1/2 length of vulva); fertilization ducts broad basally.

Measurements (n=5). CL 1.93–2.08 (2.02), CW 1.50–1.60 (1.56), SL 1.04–1.14 (1.08), SW 0.99–1.04 (1.01).

Distribution and natural history. ( Fig. 28 ). Cybaeina dixoni spec. nov. is rarely encountered in, and apparently restricted to, a small area of southwestern Oregon, U.S.A. where it has been recorded from Curry and Jackson Counties. All but one of the specimens were collected in 1959. A single specimen was recorded in 1998. One female was collected in June; the other specimens were collected in late September and early October.

Figures

FIGURE 28. Distributions of Cybaeina species. Cybaeina confusa, C dixoni spec. nov., and C. minuta. AB—Alberta, AZ— Arizona, BC—British Columbia, CA—California, ID—Idaho, MO—Montana, OR—Oregon, NV—Nevada, UT—Utah, WA— Washington.

FIGURES 3–7. Cybaeina species, males (3 C. confusa from Cascadia, Oregon; 4 C. confusa from unknown locality; 5 C. dixoni spec. nov. from Brookings, Oregon; 6–7 C. minuta from Kyuquot, British Columbia), left pedipalp. 3, 5–6 Genital bulb, ventral. 4, 7 Tegular apophysis and embolus, retrolateral. Cy—cymbium, DA—distal arm of tegular apophysis, E—embolus, PA—proximal arm of tegular apophysis, Ti—tibia, TR—tegular ridge.

FIGURES 8–13. Cybaeina species, males (8–9 C. confusa from Cascadia, Oregon; 10–11 C. dixoni spec. nov. holotype; 12–13 C. minuta from Kyuquot, British Columbia), left pedipalp. 8, 12 Tibia and distal portion of patella, retrolateral. 10 Tibia and patella, retrolateral. 9, 11 Tibia and patella, dorsal. 13 left half of patella, dorsal. Cy—cymbium, dRTA—distal component of retrolateral tibial apophysis, mRTA—medial component of retrolateral tibial apophysis, PTA—patellar apophysis, Ti—tibia. Note: in Figs 8–9 the mRTA terminates distally in a basally articulated macroseta; in Figs 10–12 the distal end is a short rigid spine-like process.

FIGURES 14–18. Cybaeina and Neocybaeina gen. nov. species, males (14–15 C. dixoni spec. nov. holotype; 16–17 C. minuta from Kyuquot, British Columbia; 18 N. xantha comb. nov. from near Bridge, Oregon), left pedipalp retrolateral. 14, 16 tibia and distal tip of patellar apophysis.15, 17 medial component of retrolateral tibial apophysis.18 distal tip of patellar apophysis.Arrows indicate medial component of retrolateral tibial apophysis (14–17 single shafted arrows), distal component of retrolateral tibial apophysis (14, 16 double shafted arrows), unknown contaminant on dorsal surface of patellar apophysis (18 dashed arrow).

FIGURES 22–27. Cybaeina species, females (22–24 C. minuta from Tofino, British Columbia; 25–27 C. dixoni spec. nov. from Brookings, Oregon), copulatory organ. 22, 25 Epigyne, ventral. 23–24, 26–27 Vulva (23, 26 ventral; 24, 27 dorsal). BG—Bennett’s gland, BS—base of spermatheca, CD—copulatory duct, HS—head of spermatheca, SS—stalk of spermatheca. Unlabelled arrows indicate atrial openings (22, 23, 25–26).