Tachycines (Gymnaeta) lingulatus, Lin & Huang & Luo, 2023

Lin, Chun, Huang, Shihui & Luo, Changqing, 2023, Description of five new species of the subgenus Tachycines (Gymnaeta) (Rhaphidophoridae: Aemodogryllinae: Aemodogryllini) from caves in Guizhou, China, Zootaxa 5389 (5), pp. 582-596 : 585-586

Tachycines (Gymnaeta) lingulatus sp. nov.

( Figs. 2 , 3 )

Description. Male. Body small-sized ( Figs. 2A–C ). Head. Vertex of head divided into two conical tubercles, bases of the well-developed tubercles drawn together, obtusely rounded apices separated ( Fig. 2D ). Eyes normal, not reduced ( Fig. 2D ).

Anterior margin of pronotum straight, posterior margin protruding backward, ventral margin arc-shaped ( Fig.

2E); posterior margin of mesonotum and metanotum protruding backward.

Legs. long and slender; coxae with small medial projections. Fore femur about 2.2 times longer than the pronotum, ventrally unarmed, internal genicular lobe with 1 small spine, external genicular lobe with 1 long spine; fore tibia ventrally with 1 inner spine and 2 outer spines, apex with 1 small outer spine on dorsal surface and 1 pair of long spines on ventral surface, between the paired ventral spines with 1 small spine. Middle femur ventrally unarmed, internal and external genicular lobes with 1 long spine respectively; middle tibia ventrally with 1 inner spine and 1 outer spine, apex with 1 pair of dorsal spines and 1 pair of ventral spines, between the paired ventral spines with 1 small spine. Hind femur ventrally unarmed; hind tibia dorsally with 66–74 inner spines and 63–69 outer spines, arrange in groups, ventral and dorsal surface with a pair of small sub-apical spines respectively, apex with 1 pair of long dorsal spines and 1 pair of long ventral spines; the longest dorso-apical spine not exceeding the dorso-apical spine of hind metatarsus ( Fig. 2F ). Hind metatarsus keeled beneath.

Abdomen. Sternites with rather short ventral projections. Epiphallus in the shape of “H”; median lobe of genitalia with 1 pair of apical lobules, divided by a visible notch; paired lateral sclerites developed; dorsal and ventral pairs of lateral lobes almost equal in length ( Figs. 2G, H ).

Female. General appearance similar to that of male ( Figs. 3A–C ). Ovipositor about half the length of hind femur; base of ovipositor broad, narrowing to apex; apex pointed and slightly curved upwards; almost indistinct denticles on ventral edge of distal part of inferior valves ( Fig. 3D ). Subgenital plate nearly ligule ( Fig. 3E ).

Coloration. Body light brown. Posterior margins of the tergites with distinct deep brown stripes. Head brown with dark brown tubercles. Eyes black. Hind femora with light brown stripes laterally.

Material examined. Holotype: 1♂, Shenxian Cave, Zhexiang Town , Zhenfeng County, Qianxinan Buyi Miao Autonomous Prefecture , Guizhou Province, 24.VIII.2020, coll. Changqing Luo, Shihui Huang & Xueli Feng. Paratypes: 5♂, 13♀, same data as the holotype .

Measurements (mm). Body: ♂ 11.80–14.72, ♀ 12.16–12.80; pronotum: ♂ 5.42–5.90, ♀ 5.20–5.32; fore femur: ♂ 10.90–12.90, ♀ 11.40–11.66; hind femur: ♂ 21.22–23.94, ♀ 21.08–22.58; ovipositor: ♀ 10.02–10.40.

Distribution. China (Guizhou).

Discussion. The new species is similar to T. (G.) chenhui ( Rampini & Di Russo, 2008) , but can be separated from the latter by several morphological features: the number of spines on the hind tibiae of T. (G.) lingulatus sp. nov. is higher than that in T. (G.) chenhui (30 inner and 36 outer spines). In addition, the shape of the female subgenital plate is different between these two species ( Figs. 3E ; 4A ).

Etymology. The name of the new species refers to the shape of the subgenital plate of female.

Figures

FIGURE 2. Tachycines (Gymnaeta) lingulatus sp. nov. (male). A. habitus, dorsal view; B. habitus, lateral view; C. habitus, ventral view; D. head, frontal view; E. pronotum, dorsal view; F. hind tarsus, lateral view; G. genitalia, dorsal view; H. genitalia, ventral view.

FIGURE 3. Tachycines (Gymnaeta) lingulatus sp. nov. (female). A. habitus, dorsal view; B. habitus, lateral view; C. habitus, ventral view; D. ovipositor, lateral view; E. subgenital plate, ventral view.

FIGURE 4. The shape of female subgenital plates of four Tachycines (Gymnaeta) species. A. subgenital plate of T. (G.) chenhui, after Rampini et al. (2008); B. subgenital plate of T. (G.) cavernus, after Jiao et al. (2008); C. subgenital plate of T. (G.) zorzini, after Rampini et al. (2008); D. subgenital plate of T. (G.) lalinus, after Feng et al. (2019).