Protarcys caudata Klapálek, 1912

Mo, Raorao, Li, Weihai & Murányi, Dávid, 2025, Protarcys Klapálek, 1912, the senior synonym of Neofilchneria Zwick, 1973 (Plecoptera: Perlodidae), Zootaxa 5618 (1), pp. 68-78 : 70-72

Protarcys caudata Klapálek, 1912

( Figs. 1A–D , 2 , 3A , 4A–D )

Protarcys caudata Klapálek, 1912: 9 (original description of the male and female); Wu 1935: 300 (catalog); Wu 1938: 31 (monograph, with the reproduction of the original figures); Claasen 1940: 117 (catalog); Illies 1966: 375 (revised combination); Li & Murányi 2015: 52 (type locality information); Yang & Li 2018: 52 (catalog); DeWalt et al. 2024 (catalog).

Arcynopteryx (Protarcys) caudata Klapálek, 1912 : Ricker 1943: 8 (new combination); Ricker 1952: 81 (catalog).

Diagnosis. Forewing with irregular reticulation between the apical part M veins. Male: finger-like process of hemitergum 10 short, tip rounded; joint of the epiproct lever arm indistinct; aedeagus with arrow-shaped dorsal armature, lacks lobes. Female: subgenital plate prolonged in a wide triangular apex without an incised tip. Egg: shape oval, collar separated from chorion, bearing one indistinct row of FCIs, rim distinctly flanged.

Material examined. Syntype 1 male, CHINA: Sichuan Province, Ya’an City, Baoxing County, 30°22′ N, 102°49′ E, 1000 m, 1870, leg. A. David (Labels: MUSEUM PARIS / MOUPIN / A. DAVID 1870; caudata / Klapálek; black label; TYPUS (red label)) ; Syntype 1: same locality and data (Labels: MUSEUM PARIS / MOUPIN / A. DAVID 1870; caudata / Klapálek; black label; COTYPE (red label)) ; Syntype 1 female: Sichuan Province, Garzê Tibetan Autonomous Prefecture, Luding County, Dadu (Lu) River, Luding Bridge along Chengwu Road , 29°54.8′ N, 102°13.8′ E, 1310 m, 14–15 Apr 1893, leg. G.N. Potanin (Labels: Cычуан, р. Тун / мостъ Лютинчао / Потан 14–15IV93; caudata / Klapálek; black label; COTYPE (red label)) .

Redescription

Male ( Figs. 1A–B ). Medium sized, macropterous forewing length 11.0 mm. General color dark brown, with bright yellow pattern on head and pronotum. Head brown, triocellate and with big, bulging eyes; posterior ocelli set closer to eyes than to each other. Occipital region pale, with distinct rugosities; area between the three ocelli dark, tentorial callosities and M-line distinct; wrinkles present between M-line and the lateral margins. Long submental gills present. Palpi brown, scape and pedicel dark brown, rest of antennae broken. Pronotum square, as wide as long, narrower than head with eyes. Its ground colour dark brown, with distinct bright yellow longitudinal stripe; rugosities are dark and distinct. Legs dark brown with pale apical ring on femora. Wings with dense crossveins, irregular reticulation present between the apical part of R and M veins on the forewing, and between the R veins on the hindwing.

Abdomen entirely dark brown ( Fig. 2 ). First three segments widely separated into terga and sterna, fourth and fifth narrowly separated; an obscure gill vestige can be noticed between the first tergum and sternum. Tergum 9 and sternum 9 unmodified. Tergum 10 full divided into hemiterga, which are mostly dark but inner portion lighter anterior to hemitergal process, and the light area bear sparse sensilla basiconica. The process of hemitergum finger-like, short and pointed medially, slightly raised in lateral view. Epiproct with huge, bicolored basal anchor connected to short lateral arms, and strong, upcurved lever arm; epiproct tip is missing for the holotype; lateral stylets lacking; paragenital plates forming brown colored, apically diverging strip-like sclerites. Sternum 10 is forming a short, dark subgenital plate. Everted aedeagus is a long tube, constricted in the apical half, then dilated apically. The apical half is fully armed with dense spines, mostly small and short, but long, spike-like and golden colored spines cover the dorsoapical portion, forming an arrow-shaped patch. Cerci as long as the body, cercomeres cylindrical.

Female ( Figs. 1C–D ). Generally similar to male, macropterous forewing length 14.0–15.0 mm. Head is lacking for the female syntype collected together with the male syntype. Head pattern of the other female, collected at the Luding Bridge, has more marked color pattern than the male.

Abdomen brown to dark brown ( Fig. 3A ). Sterna 7–8 covered with uniform long hairs. Subgenital plate on sternum 8 prolonged in a wide triangular apex, covering basal half of sternum 9. Sternum 9 is uniformly dark. Paraprocts triangular, cerci similar to the male.

Egg ( Figs. 4A–D ). 0.45–0.55 mm long, 0.35–0.40 mm wide (n = 18). Shape oval, cross section round, no longitudinal ridges visible. Hatching line inconspicuous. Micropyles placed in an equatorial line, not raised, each located at the meeting of ditches between follicular cell impressions (FCIs). Chorion with ornamentation of penta- and hexagonal FCIs. Collar round, separated from chorion by a shallow ditch, bearing one indistinct row of FCIs, rim distinctly flanged, edge wavy. Anchor cannot be studied in detail.

Distribution. China (Sichuan Province).

Affinities. This species, P. lutescens and P. cheni are distinguished from the other three species by having irregular reticulation between not only the R, but the apical part of the M veins of the forewing (although the wing venation is not specified for P. erberi ). Unfortunately, the epiproct tip of the single available male of P. caudata is broken, and distinction from the other two species with short finger-like process of hemitergum 10 (the Himalayan P. uncata and P. erberi ) is a bit problematic but possible on the basis of the lever arm and the shape of the hemitergal tip, as discussed in the key above. The aedeagus is distinctly different from P. cheni and P. wanglanga by lacking lobes but having arrow-shaped armature of golden spines; unfortunately, the aedeagus remains unknown for the other two species. The female of P. caudata is the only known Protarcys with a simple triangular subgenital plate that is lacking an apical incision. The triangular subgenital plate is similar to P. lutescens , but that species has a shallow apical incision, and the leg of P. lutescens is similarly colorful as of the third Sichuan species, P. wanglanga . The egg of P. caudata distinctly differs from that of P. lutescens by having a flanged collar that is well separated from the chorion.

Figures

FIGURE 1. Protarcys caudata Klapálek, 1912 and P.lutescens Klapálek, 1912, adult habitus A–B. Holotype male of P. caudata. C–D. Paratype female of P. caudata from Luding Bridge. E–F. Holotype female of P. lutescens. A, C, E. Habitus and labels. B, D, F. Head and pronotum, dorsal view, B and F with lateral part of head showing submental gill, ventral view. Scale 1 mm, for Figs. B, D, F.

FIGURE 2. Protarcys caudata Klapálek, 1912 holotype, male genitalia A. Terminalia, dorsal view. B. same, lateral view. C. Aedeagus, lateral view. D. Hemitergal lobes and uneverted epiproct, dorsal view (epiproct tip lacking). E. Apical half of aedeagus, dorsal view. F. same, ventral view. Not to scale.

FIGURE 3. Protarcys caudata Klapálek, 1912 and P. lutescens Klapálek, 1912, female terminalia in ventral view A. Paratype female of P. caudata from Luding Bridge. B. Holotype female of P. lutescens, setation omitted, coloration showed only for segment 9. Not to scale.

FIGURE 4. Protarcys caudata Klapálek, 1912 and P. lutescens Klapálek, 1912, eggs A–D. Paratype female of P. caudata from Luding Bridge. E–F. Holotype female of P. lutescens. A, E. Lateral view. B. Collar end, lateral view. C. Collar end, caudal view. D, F. Chorion detail with micropyles.