Neoperla falcatata, Mo & Wang & Li & Murányi, 2021

Mo, Raorao, Wang, Guoquan, Li, Weihai & Muranyi, David, 2021, Two new species and one new record of Neoperla (Plecoptera, Perlidae) from Guangxi Zhuang Autonomous Region, China, ZooKeys 1056, pp. 191-206 : 191

Neoperla falcatata sp. nov.

Figs 3 , 4 , 5 , 6

Type Material.

Holotype: male (NMP), China: Guangxi Zhuang Autonomous Region, Shangsi County, Shiwandashan National Forest Park, forested river valley, 290-360m, 21°54.4'N, 107°54.2'E, 5-9.IV.2013, light trap, leg. M. Fikáček, J. Hájek and J. Růžička. Paratypes: 2 males (NMP), 1 female and 1 male (mating pair, HIST), same data as for holotype.

Diagnosis.

This species is characterized by a median dark brown oval area on the head. The aedeagus is sickle-shaped, mostly covered with mixed armatures of spines and spinules. Females of this species have a small truncate tab-like subgenital plate of sternum 8.

Description.

Adult habitus (Figs 3 , 4 , 5A , 6C ). Body color brown. Head brown, with a dark brown subtrapezoidal stigma on anterior part of frons and a distinct median dark brown oval area covering the posterior ocelli; mouthparts brown, palpi paler, antennae dark brown; biocellate, the distance between ocelli ca. 1.5 × the diameter of each ocellus; head slightly wider than pronotum. Pronotum rectangular, brown, with scattered darker rugosities; anterior corners sharp, posterior corners rounded. Wings brownish and transparent, veins dark brown; legs brown except femora yellow-brown at base; cerci dark brown.

Male (Figs 3 , 4A , 5 , 6A ). Forewing length 10.0-10.5 mm. Hindwing length 8.3-8.8 mm. Posterior process of tergum 7 trapezoidal, covered with many basiconic sensilla. Tergum 8 with a tongue-shaped upcurved process, with many basiconic sensilla at apex. Tergum 9 with two paramedial patches of long hairs, without sensilla patches. Hemitergal processes of tergum 10 sclerotized, slender, finger-like, S-shaped: basally incurved, curved outward medially but incurved again apically, nearly extending to tongue-shaped process of tergum 8 (Fig. 5B, D, E ). Aedeagus mostly membranous, sickle-shaped (Figs 5C, F , 6A ). Aedeagal tube plump, straight, distinctly sclerotized basally and dorsally, with many spinules on dorsal surface (Fig. 5F ). Aedeagal sac ca. 2.0 × as long as tube, membranous, strongly curved ventrad, forming an open loop with a blunt tip; ventral surface fully armed with spinules; dorsal surface of basal half covered with brownish spines; distal half mostly covered with larger brown dorsal spines before spinous apex (Figs 5C, F , 6A ).

Female (Figs 3 , 4B , 6B-D ). Forewing length 13.8-14.5 mm. Hindwing length 12.2-12.8 mm. Generally similar to male. Posteromedial portion of sternum 8 slightly produced, forming a small, rectangular subgenital plate with a truncate tip.

Etymology.

The name refers to the sickle-shaped aedeagus. The Latin “falcatus” means sickle-shaped.

Distribution.

China (Guangxi).

Ecology.

Shiwandashan National Forest Park is located in the southwest of Shangsi County of Fangchenggang City, Guangxi, and it belongs to the Shiwanda Mountains. The adults of the new species fly in spring and occur at low altitude. Other accompanying stoneflies were: Amphinemura hamiornata Li & Yang, 2008, Neoperla shangsiensis sp. nov., N. yentu Cao & Bae, 2007, N. yao Stark, 1987, an unidentified Neoperla sp. found only as a female, Rhopalopsole cestroidea Li, Murányi & Gamboa, 2017, and Togoperla perpicta Klapálek, 1921.

Remarks.

The new species shares a similar shape of the aedeagus with Neoperla nigromarginata Li & Zhang, 2014 from Henan Province, central China. However, the new species can be easily separated from the latter by the markings on the head and pronotum (see Li and Zhang 2014: fig. 1a). The new species can also be distinguished from N. nigromarginata by the hemitergal processes of tergum 10 and details of tergum 7. In N. falcatata , the hemitergal processes of tergum 10 are longer and nearly extend to the process of tergum 8, and tergum 7 only bears a trapezoidal posterior process, whereas in N. nigromarginata the hemitergal processes of tergum 10 are short and only extend to the posterior margin of tergum 9, and tergum 7 has a pair of upraised, nipple-shaped processes in addition to the distal subquadrate process. Additionally, both species can be distinguished by details of the aedeagal armature (see Li and Zhang 2014: figs 1d, 2). Additionally, the aedeagal sac of N. nigromarginata bears paired apical flagella, whereas in the new species the aedeagal sac lacks the apical flagella.

Finally, the female subgenital plates of the two species have different details. In N. falcatata , the posterior margin of the subgenital plate is truncate, while in N. nigromarginata the posterior margin of the subgenital plate has a slightly emarginate tip.

Figures

Figure 3. Neoperla falcatata sp. nov. (mating pair). Scale bar: 2.0 mm.

Figure 4. Neoperla falcatata sp. nov. A male adult habitus, dorsal view B female adult habitus, dorsal view. Scale bars: 2.0 mm.

Figure 5. Neoperla falcatata sp. nov. (male) A head and pronotum, dorsal view B terminalia after being cleared, dorsal view C apical half of aedeagal sac, dorsal view D terminalia after being cleared, lateral view E terminalia after being cleared, oblique lateral view F aedeagus, lateral view. Scale bars: 0.5 mm (A-C); 0.2 mm (D-F).

Figure 6. Neoperla falcatata sp. nov. A tip of aedeagal sac, dorsal view B female subgenital plate, ventral view C female head and pronotum, dorsal view D female terminalia, ventral view. Scale bars: 0.1 mm (A, B); 1.0 mm (C, D).