Neocybaeina 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 : 105-107

Neocybaeina Bennett gen. nov.

Cybaeina (in part) Chamberlin and Ivie 1937: 225, fig. 65.

“New genus #2” Bennett 2005: 88, figs 22.37, 22.39, 22.44; Bennett 2017: 99, figs 23.37, 23.39, 22.44.

Type species. Cybaeina xantha Chamberlin and Ivie 1937 . Etymology. The genus name, feminine in gender, means “new Cybaeina ”.

Diagnosis. Distinguishing specimens of Neocybaeina gen. nov. from other Cybaeinae except Rothaeina gen. nov. is explained in the diagnosis of Cybaeina . The females of Neocybaeina gen. nov. and Rothaeina gen. nov. are readily separated by vulval characters: in Neocybaeina gen. nov. ( Figs 37–39, 41–42), the spermathecal stalks are short and slender and the spermathecal bases bulbous (and easily differentiated from the stalks) while in Rothaeina gen. nov. ( Figs 67–69, 71–74, 76–79, 81–83) the stalks are slender but elongate and convoluted and the bases slender, of similar diameter to the stalks (and, thus, difficult to differentiate from the stalks).

In addition, specimens of both sexes of Neocybaeina gen. nov. have four pairs of conspicuous elongate, usually overlapping macrosetae ventrally on tibia I while those of Rothaeina gen. nov. usually have five ( Fig. 2). Aside from this difference, the males of these two genera are difficult to differentiate: see discussion in the diagnosis of Cybaeina . The combination of the following characteristics of the male pedipalp of Neocybaeina gen. nov. and Rothaeina gen. nov. will help to differentiate them. In the male of N. xantha comb. nov. (the single species of Neocybaeina gen. nov. with a known, described male) ( Figs 29–30) the tegular apophysis of the genital bulb is relatively simple and linear with the distal arm short (about as long as wide) and the proximal arm elongate and straight with a simple angular tip. Furthermore, in the male of N. xantha comb. nov. the patellar apophysis ( Figs 18, 31–34) is elongate (about as long as the width of the patella), relatively smoothly tapered, and with peg setae concentrated at the tip. In the males of Rothaeina gen. nov. the tegular apophysis ( Figs 43–51, 60–63) is more complex with the distal arm elongate, usually curved, and often enlarged and the proximal arm elongate but often curved or with an otherwise more complex tip. Additionally, in the males of Rothaeina gen. nov. the patellar apophysis ( Figs 53–59, 62, 64–65) is short (length less than the width of the patella) or, if about as long as the width of the patella, then the apophysis has either a distinct prominence on its distal margin ( Fig. 59) or a small group of peg setae dorso-basally ( Fig. 62).

Description. As for Cybaeus and in genus diagnosis in this paper. Additional descriptive characters presented here. Small- to medium-sized spiders, carapace lengths averaging 1.96 mm (males) and 1.73–1.89 mm (females); females usually smaller than males. Legs pale yellow to light reddish brown, unmarked. Ventral tibia I macrosetae pattern 2(+1p)-2-1p-2-2-0. Abdomen gray, patterned (occasionally pale, unmarked). Colulus a low swelling marked by two clumps of very few setae.

Male: See diagnosis of genus and description of N. xantha comb. nov. for male sexual characteristics.

Female: Epigyne ( Figs 36, 40) simple with single inconspicuous transverse atrial opening anteriorly, atrial opening may be paired and very small ( Fig. 39). Vulva ( Figs 37–39, 41–42) with copulatory ducts very short, heavily sclerotized, separated and proceeding anteriorly or posteriorly from atrial openings; spermathecal heads at anterior end of vulva with primary pores usually on anterior margin of heads; spermathecal stalks short; Bennett’s glands usually conspicuous.

Composition and distribution. ( Fig. 84) Neocybaeina gen. nov. is endemic to a small area encompassing southwestern Oregon, U.S.A. from the upper (southern) reaches of the Willamette Valley to the California border. We recognize two species: N. burnetti spec. nov. (male unknown) and N. xantha comb. nov. Both are rarely encountered.