Acroneuria axana, Chen, 2020

Chen, Zhi-Teng, 2020, New species of Acroneuria (Plecoptera: Perlidae) from central Vietnam, Zootaxa 4722 (1), pp. 59-67 : 60

Acroneuria axana sp. nov.

Figs. 2–4 .

Adult habitus ( Fig. 2 ). Three ocelli. General color yellow. Head slightly wider than pronotum, with a dark ocellate stigma; anterior ocellus smaller than posterior ones. Antenna dark brown and slender, subequal in length to the abdomen, apical segments paler. Pronotum pale, with obscure rugosities, anterior corners sharp. Wing membrane subhyaline, veins pale; apices of wings dark. Coxae pale; distal part of femur, tibia and tarsi dark brown. Cercus pale, apical segments dark.

Male ( Figs. 2–4 ). Body length 17.0–18.0 mm; forewings length ca. 21.0 mm, hindwings length ca. 18.0 mm. Tergum 9 without sensilla basiconica. Tergum 10 with a large, heart-shaped sensilla basiconica patch. Paraprocts sclerotized, long triangular and upcurved, apically hooked. Posterior margin of sternum 9 with a rounded hammer. Aedeagus ( Figs. 4D, E ) membranous and short, apical half widened with a rounded rim, apex with a large elliptical lobe and a smaller lobe; median area of lateral aspects spinulose.

Female. Unknown.

Type material. Holotype: male, Vietnam: Quang Nam Province, Tay Giang District, Axan Commune, Song Kool River , 15.83 N, 107.31 E ( Fig. 1 ), 1300m, July–August 2019, light trap (ICJUST) . Paratypes: 4 males, same data as holotype (ICJUST) .

Etymology. The species is named after its type locality, Axan Commune. The name is used as a noun.

Remarks. The new species is similar to A. nobilitata and A. apicalis by sharing the dark wing tips ( Klapálek 1909, Stark & Sivec 2008). In A. axana , the hammer is more rounded than the “elliptical” one in A. nobilitata ; the paraprocts are distinct, which are less developed in A. nobilitata ( Klapálek 1909) ; locality of A. axana in central Vietnam is distant from type locality of A. nobilitata in Lang Son Province of the northeastern boarder of Vietnam ( Fig. 1 ). Unfortunately, the aedeagus of A. nobilitata is still undescribed. When compared with A. apicalis , the aedeagus of A. axana is much shorter and wider, without the large apical projection as in A. apicalis (see fig. 3 in Stark & Sivec 2008); the locality of A. axana is also distant from the type locality of A. apicalis, Vinh Phu Province of the northeastern boarder of Vietnam ( Fig. 1 ).

Figures

FIGURE 1. Type localities of species of Acroneuria from Vietnam. The same locality is indicated by the same color.

FIGURE 2. Acroneuria axana sp. nov., A. Male habitus, dorsal view; B. Male habitus, ventral view.

FIGURE 3. Acroneuria axana sp. nov., A. Male terminalia before NaOH treatment, dorsal view; B. Male terminalia before NaOH treatment, ventral view; C. Male terminalia before NaOH treatment, enlarged view.

FIGURE 4. Acroneuria axana sp. nov., A. Male terminalia after NaOH treatment, dorsal view; B. Male terminalia after NaOH treatment, ventral view; C. Male terminalia after NaOH treatment, lateral view; D. aedeagus, dorsal view; E. aedeagus, ventral view.