Nesticus furtivus Gertsch, 1984

Hedin, Marshal & Milne, Marc A., 2023, New species in old mountains: integrative taxonomy reveals ten new species and extensive short-range endemism in Nesticus spiders (Araneae, Nesticidae) from the southern Appalachian Mountains, ZooKeys 1145, pp. 1-130 : 1

Nesticus furtivus Gertsch, 1984

Fig. 48B, D

Nesticus furtivus Gertsch, 1984: 27, figs 97-99; Hedin and Dellinger 2005: 12, figs 15, 16.

Material examined.

New collections from type locality: USA - Tennessee, Hamilton Co. • ♀; Raccoon Mountain Caverns , se Chattanooga ; 28 Mar. 1993; M. Hedin, M. Wolinsky leg.; • ♂; Raccoon Mountain Caverns ; 25 Jul. 2000; M. Hedin, D. Wood, B. Delllinger, S. Perlacky leg.; MCH 00_137; • ♀; Raccoon Mountain Caverns ; 19 Aug. 2005; M. Hedin, R. Keith, J. Starrett, S. Thomas leg.; MCH 05_063; Non type material: - Marion Co. • ♀; Hugden Branch Cave (TMN 127); 17 Apr. 2016; K.S. Zigler, P.R. Heald leg.; KSZ 15-570 .

Diagnosis.

Closely related to Nesticus barri , but the males differ in that the tip of the N. furtivus paracymbial dorsal process is finely forked, the shape of the basal tegular fork is broader (rather than blade-like), and the apical tegular fork is reduced and lacking a distinct tip (Fig. 48B ). Female N. furtivus have a distinctly wide median septum that narrows to a conspicuous tip posteriorly (Fig. 48D ).

Variation.

The Hugden Branch Cave female specimen, representing the second known location for this species, is troglomorphic with an epigynum that closely matches females from the type locality.

Distribution and natural history.

This troglomorphic species is known from two nearby caves from a single mountain in southeastern Tennessee, near Chattanooga (Fig. 49 ; Hedin and Dellinger 2005: fig. 1; Carver et al. 2016: fig. 2).

Carver et al. (2016) provide important natural history, reproductive biology, and abundance data for this rare species, extending earlier observations of Hedin and Dellinger (2005).

Figures

Figure 48. Nesticus barri and N. furtivus genitalia. N. barri - Tennessee, Marion Co., Tate Spring Cave, MCH 04 _ 050, ♂ palp ventral (A), epigynum ventral (C). N. furtivus - Tennessee, Hamilton Co., Raccoon Mountain Caverns, SE Chattanooga, MCH 00 _ 137, ♂ palp ventral (B), epigynum ventral (# 1660) (D).

Figure 49. Distribution of Nesticus barri and Nesticus carteri groups. Type localities designated with yellow circles. State boundaries and major cities shown for geographic context. Dashed lines circumscribe known species distributions.