Suwallia kawaii Li & Li, 2021

Li, Wenliang, Wang, Yingying, Wang, Ying & Li, Weihai, 2021, A new species of Suwallia Ricker, 1943 from Japan, and the identity of Alloperla teleckojensis Šámal, 1939 (Plecoptera: Chloroperlidae), Zootaxa 5040 (4), pp. 575-581 : 576-578

Suwallia kawaii Li & Li , sp. n.

( Figs. 1–2 )

Suwallia bimaculata ( Okamoto, 1912) : Song 2016: 85. (mitochondrial genome, misidentified).

Material examined. Holotype male ( HIST): Japan, Hokkaido, Ashoro town, Onnetô Lake , 2013.VIII.1, Cai & Wang; paratypes: 2 males, 2 females ( HIST & CAU), same data as holotype.

Adult habitus. Forewing length ca. 7.1 mm in males, female forewing length ca. 7.9 mm. Head with large median markings except for pale lateral margin, basal portion of the marking bowl-shaped, and anterior part nearly trapezoidal, apex with a triangular notch between a pair of small anterolateral extensions on frons.Antenna brownish to brown, with basal segments paler. Pronotum slightly rugose, generally dark brown with medial area brown, midline light brown; meso- and metanota with brown U-shaped marks. Wings hyaline and veins darker. Legs brown. Median abdominal stripe upside down triangular on each tergum and connecting before tergum 8.

Male terminalia ( Figs. 1b, 1c ). Abdominal stripe on terga 8-9 interrupted, and reduced in size as short, anteromedial dark brown sclerite on each tergum ( Fig. 1b ). Tergum 9 with anterolateral portion sclerotized, and medially moderately sclerotized before the slightly produced posterior margin. Tergum 10 with slender medial triangular sclerite. Hemitergal processes finger-shaped and anteromedially recurved. Epiproct knob-like, with a pair of sharp posterolateral spines ( Fig. 1b ). Aedeagus in dorsal and lateral aspects before eversion trapezoidal ( Figs. 1b, 1c ); membranous structures broken in males; armatures ( Fig. 2 ) consisting of triangular spines forming a plate-like structure with apical notch in posterior view, which extends from a triangular basal part in dorsal view seen through broken dorsal membrane ( Figs. 2a, 2c ).

Female: Median abdominal stripe interrupted between tergum 7 and ending at tergum 8. Subgential plate large, nearly trapezoidal, the basal portion attaching to sternum 8 across ca. 2/3 of width, mediolaterally slightly recessed, and apically slightly circularly produced, apex reaching to the posterior margin of sternum 9 ( Fig. 1d ). Paraprocts small and triangular.

Larva and egg. Unknown.

Distribution. Only known from the type locality.

Etymology. The species is named after Dr. Teizi Kawai, for his great contributions to Japanese stonefly fauna. Diagnosis and remarks. The new species is superficially similar to S. bimaculata ( Okamoto, 1912) because of the similar head pattern, epiproct, but it can be easily separated from that species externally by generally brown medial portion of pronotum and a large plate-like spinous area of everted aedeagus. In bimaculata , pronotum is pale between the lateral markings, and the spinous patch of aedeagus is acutely angled "V" shaped (fig. 4 D, Alexander & Stewart 1999). Their females also differ dramatically: in bimaculata , the subgenital plate covers half length of sternum 8 with recessed apex (fig. 4E, Alexander & Stewart 1999) whereas the plate in the new species overlaps sternum 8 with rounded apex.

The head pattern of new species is also similar to S. thoracica . But the midline of pronotum is light brown in S. kawaii ( Fig 1b ) while the pronotum is entirely dark in S. throacica . The hemitergal process of the S. kawaii has a posteromedian process while that of S. thoracica is parallel sided ( Fig. 1b ; figs. 22a, 22b, Alexander & Stewart 1999). The female subgential plate of S. kawaii is mediolaterally incised while S. thoracica is evenly curved. ( Fig. 1d ; fig. 22C, Alexander & Stewart 1999).

Figures

FIGURE 1. Suwallia kawaii sp. n. (a–c, male, d, female). a: Head and pronotum, dorsal view; b: Terminalia, dorsal view; c: Terminalia, ventral view; d: Female terminalia, ventral view.

FIGURE 2. Suwallia kawaii sp. n. (male). a: Extruded aedeagus, lateral view; b: Armatures of extruded aedeagus, posterior view; c: Extruded aedeagus, dorsal view.