Pimoa tehama, Hormiga, Gustavo & Lew, Stephen, 2014

Hormiga, Gustavo & Lew, Stephen, 2014, A new American species of the spider genus Pimoa (Araneae, Pimoidae), Zootaxa 3827 (1), pp. 95-100 : 95-99

Pimoa tehama new species

( Figs. 1 –3 )

Types. Male holotype and three female paratypes from USA, California, Tehama County: Blackjack Spr. N39.8311° W122.8665° 1350 m, headlamp search, 19.ix.2006, S. E. Lew (leg #4) (GH0739; digital images & illustrated GH 2007), male (California Academy of Sciences); same data as holotype (leg #3, GH0738, digital images 21.i.2008 GH), female (California Academy of Sciences); same data as holotype (leg #2) (GH0739), female (California Academy of Sciences); N39.833° W122.858° 1335–1560 m. FS Rd., M4 29.1 mi W of Paskenta, 25.vi. 2004, S.E. Lew, UC Berkeley EMEC 50,996 (illustrated GH), female (Essig Museum of Entomology, University of California, Berkeley).

Etymology. The species epithet is a noun taken in apposition from the Californian county of the type locality.

Diagnosis: Pimoa tehama n. sp. is most similar to P. laurae Hormiga, 1994 ( Hormiga 1994, figs. 390–402) and to P. edenticulata Hormiga, 1994 ( Hormiga 1994, figs. 409–419). Males of Pimoa tehama n. sp. can be most easily distinguished from those of P. laurae by the shape of the pimoid cymbial sclerite ( Fig. 2 A, D, PCS) in ectal view (more pointed in P. laurae ) and by the overall shape of the PCS. Pimoa tehama n. sp. differs from P. edenticulata by the presence of ventral tibial cuspules ( Fig. 2 B) and also by the overall shape of the PCS. Females of P. tehama n. sp. are diagnosed by their long, protruding epigynum ( Fig. 3 ), which is much shorter in P. laurae and more caudally cleaved in P. edenticulata .

Male (holotype; Figs. 1 D–F, 2 A–D). Total length 7.31. Cephalothorax 3.75 long, 2.91 wide, 1.92 high. Sternum 2.39 long, 1.77 wide. Abdomen 4.23 long, 2.66 wide. AME diameter 0.184. Clypeus height 3.10 times one AME diameter. Carapace with deep longitudinal fovea ( Fig. 1 D). Chelicerae with three prolateral and three retrolateral teeth; stridulatory striae subtle, scaly. Legs annulated. Femur I 8.38 long, 2.23 times the length of cephalothorax. Metatarsus I trichobothrium 0.91. Metatarsus IV trichobothrium present (apical). Pedipalp as in Fig. 2 A–D. Pedipalpal tibia with two prolateral and three retrolateral trichobothria ( Fig. 2 C, D).

Female (paratype, GH0738; Figs 1 A–C, 3 A–D). Total length 7.42. Cephalothorax 3.78 long, 2.84 wide, 2.01 high. Sternum 2.29 long, 1.59 wide. Abdomen 3.87 long, 3.29 wide. AME diameter 0.21. Clypeus height 2.50 times one AME diameter. Carapace with deep longitudinal fovea ( Fig. 1 C). Chelicerae with three prolateral and two retrolateral teeth; stridulatory striae subtle, scaly. Legs annulated. Femur I 6.13 long, 1.62 times the length of cephalothorax. Metatarsus I trichobothrium 0.93. Metatarsus IV trichobothrium present (apical). Epigynum as in Fig. 3 A–D.

Variation. Female cephalothorax length ranges from 3.08–3.78 and total length form 6.26–7.42 (n = 3).

Natural history. Pimoa tehama n. sp. is only known from the type series, and beyond the collection of these four individuals it has not been observed in nature. All three individuals were found in mixed conifer forest at around 1,350 meters elevation. The female from Blackjack Spring was found in a small horizontal sheet web typical of pimoids in a deep cut creek, and the male was found wandering in the same creek two years later. The other female was found hiding under bark, and may have been associated with a web that was destroyed when the bark was moved.

Distribution. Known from the Pacific Coast Ranges of northern California. The entire type series was collected in the Mendocino Range in Tehama County, between Corning and Covello. One of us (SL) has also collected P. edenticulata in the same area; these are the only pimoid species known from Tehama County, which also includes parts of other Pacific Coast Range mountains, parts of the Great Valley, and foothills of the Cascade Mountains.

Additional specimens studied: Only the type series.

Figures

FIGURE 1. Pimoa tehama new species, A – C, Female; D – F, male. A, E, Habitus, lateral. B, F, Habitus, dorsal. C, D, Prosoma, dorsal. Scale bars, 1.0 mm.

FIGURE 2. Pimoa tehama new species, A – D, Male palp (left). A, Ventral. B, Mesal. C, Ectal. D, Dorsal. Abbreviations: C, conductor; CDP, cymbial denticulate process; P, paracymbium; PEP, pimoid embolic process; PCS, pimoid cymbial sclerite; T, tegulum. Arrow points to alveolar sclerite. Scale bars, 0.5 mm.

FIGURE 3. Pimoa tehama new species, A – D, Epigynum. A, Ventral. B, Lateral. C, Dorsal. D, Dorsal (cleared). Abbreviations: FD, fertilization duct; S, spermatheca. Right pointing arrow, copulatory duct; left pointing arrow, copulatory opening. Scale bars, 0.5 mm.