Pimoa Chamberlin & Ivie, 1943

Wang, Bing, Meng, Qingzhen, Yao, Zhiyuan & Zhang, Xiaoqing, 2025, Notes on three closely related species of the genus Pimoa (Araneae, Pimoidae) from Southwest China, Zoosystematics and Evolution 101 (1), pp. 119-126 : 119-126

Genus Pimoa Chamberlin & Ivie, 1943

Pimoa : Chamberlin and Ivie 1943: 9; Hormiga 1994: 4; Hormiga and Lew 2014: 1 ; Mammola et al. 2016: 1.

Note.

In 1943, Chamberlin and Ivie erected the genus Pimoa , which included four pimoid North American species that had previously been placed within the genus Labulla Simon, 1915 , plus three new North American species. Then, Hormiga (1993) synonymized Louisfagea Brignoli, 1971 , with Pimoa , raised Pimoinae Wunderlich, 1986, to family rank, and brought an end to the history of pimoids being placed in different families.

Diagnosis.

Pimoa (total length ranges from 4.00–12.0 mm) is larger in size than Nanoa (1.42–1.65 mm). The males of Pimoa can be distinguished from Nanoa by the long and membranous pimoid embolic process and the elongate cymbial denticulate process with many cuspules (vs. the pimoid embolic process absent and short cymbial process only with one strong cuspule) (Fig. 2 ; Hormiga et al. 2005: figs 1, 2). The females of Pimoa can be distinguished from Nanoa by the absence of a ventral scape-like septum (vs. epigynum with a distinct septum) (Fig. 3 A ; Hormiga et al. 2005: figs 3, 5).

Composition.

The 85 Pimoa species are known from the northern hemisphere, with 14 from the western Nearctic, four from the western Mediterranean ( Italy, France, and Spain), two from Pakistan, seven from India, nine from Nepal, and 49 from China ( WSC 2024).

Type species.

Labulla hespera Gertsch & Ivie, 1936 , from California, USA.

Identification keys to three closely related species from Southwest China

Males

Females

Figures

Figure 2. Left palp of Pimoa shimian sp. nov., holotype A. Prolateral view; B. Ventral view; C. Retrolateral view. Abbreviations: AS = alveolar sclerite; C = conductor; CDP = cymbial denticulate process; E = embolus; MA = median apophysis; P = paracymbium; PCS = pimoid cymbial sclerite; PEP = pimoid embolic process; T = tegulum. The blue arrow represents the tegular apophysis. Scale bar: 0.50 mm (A – C).

Figure 3. Epigyne and habitus of Pimoa shimian sp. nov., female paratype and male holotype A. Epigyne, ventral view; B. Vulva, dorsal view; C. Schematic course of internal copulatory duct system, ventral view; D. Schematic course of internal copulatory duct system, dorsal view; E. Male habitus, dorsal view; F. Female habitus, dorsal view; G. Female habitus, ventral view. Abbreviations: CD = copulatory duct; CO = copulatory opening; DP = dorsal plate of the epigyne; FD = fertilization duct; S = spermatheca; VP = ventral plate of epigyne. Scale bars: 0.10 mm (A – D); 1.00 mm (E – G).

Figure 4. Pimoa bomi (A, C, E), P. reniformis (B, D, F) A, B. Prolateral view; C, D. Ventral view; E, F. Retrolateral view. Abbreviations: AS = alveolar sclerite; C = conductor; CDP = cymbial denticulate process; E = embolus; MA = median apophysis; P = paracymbium; PCS = pimoid cymbial sclerite; PEP = pimoid embolic process; T = tegulum. A, C, E were modified from Xu et al. (2021). Scale bars: 0.30 mm (A – F).

Figure 5. Pimoa bomi (A, B, E, F), P. reniformis (C, D, G, H) A, C. Epigyne, ventral view; B, D. Schematic course of internal copulatory duct system, ventral view; E, G. Vulva, dorsal view; F, H. Schematic course of internal copulatory duct system, dorsal view. Abbreviations: CD = copulatory duct; CO = copulatory opening; DP = dorsal plate of the epigyne; FD = fertilization duct; S = spermatheca; VP = ventral plate of epigyne. A, B, E, F were modified from Xu et al. (2021). Scale bars: 0.30 mm (A – H).