Hemacroneuria violacea Enderlein, 1909

Huo, Qing-bo, Zhu, Bin-Qing & Du, Yu-Zhou, 2021, New illustrations, new species and new combination of Hemacroneuria Enderlein (Plecoptera: Perlidae) from China, Zootaxa 5032 (4), pp. 563-576 : 564-571

Hemacroneuria violacea Enderlein, 1909

( Figs. 1–13 )

Hemacroneuria violacea: Enderlein 1909: 395 . Holotype male: Tonkin, Vietnam.

— Stark & Sivec 2008: 174 — Murányi & Li 2016: 189 — Yang & Li 2018: 46.

Kiotina violacea: Claassen 1940:156 —Illies. 1966: 343—Du 1999: 318.

Acroneuria violacea: Zwick 1973: 491 — Du, Sivec & He 1999: 63.

Supplementary description: Adult wings nearly black with metallic green and blue luster. Body generally black, with similar luster to wings, except the ventral arolium, ventral first two tarsomeres, and membranous junction between the ventral thoracic segments are bright yellowish ( Figs. 1–6 ).

Adult male: Aedeagus membranous, composed of a long, thick tube at base, the apex abruptly expanded to a wide stem with two pairs of lateral arms and one apical lobe (partially extruded). The apical lobe bears many distinct transverse wrinkles and thick hairs. Much of the aedeagal surface covered with ventral microtrichia and cuticular asperities ( Fig. 4 ).

Adult female: Shape of the subgenital plate in our materials same as the figures in Zwick (1973, Fig. 6 ).

Egg: Length ca. 0.47 mm, width ca. 0.34 mm. Outline chicken-egg shaped, collar small, projecting well above posterior pole. Chorion coarsely punctate throughout, without ridges; a paler ring lacking punctations near anterior pole ( Fig. 6 ).

Nymph: Triocellate, anterior ocellus highly reduced. Compound eyes small, only 20 % of lateral head length. General color reddish brown, without obvious pattern ( Figs. 7–9A ). Pronotum smooth on surface, completely fringed with long bristles along lateral margins. Legs with sparse dorsal fringes on femora and tibiae but rather heavily armed with stout setae. Thoracic and anal gills well developed; more than 5 branches present on each gill ( Fig. 8 ). Paraprocts large, apex finger-like and pointed ( Figs. 8G ).

Lacinia triangular, bidentate, five coarse spines below the second tooth, a row of long fine hair from base of spines to articulation of lacinia. Mandible with five stout, short cusps, from basal cusps three rows of stout spines occupy the molar region, two extending on the ventral surface and a third composed of longer spines on the medial surface. Paraglossae flat, inverted triangular, ca. twice the length of glossae. Glossa short, apex with thick fine hairs.

Material examined: 8♂♂, 4♀♀, 2 nymphs, 10 shed skins, China, Fujian Province, Wuyishan City, Mount Wuyi ( Wuyishan ), on the way from Saiyan to Tongmu Village , 726m, 27°44'46"N, 117°40'29"E, 2021-IV-13, leg. Huo Qing-Bo, Xiang Ya-Nan , Zhu Bin-Qing, Chen Zhi-Qiang ; 1♂, 1♀, China, Guangxi Zhuang Autonomous Region ,, Jinxiu Yao Autonomous County, “Jinzhong highway”, 1100m, 1999-V-10, leg. Xiao Hui ; 1♂, China, Guizhou Province, Tongren City, Mount Fanjing ( Fanjingshan ), Yamugou stream, 27.80°N, 108.73°E, 2019-VI-9, leg. Hu Zheng-Kun ; 1♂, China, Guangdong Province, Shaoguan City, Nanling National Forest Park , 2021 (specimen picked from a collection of local Malaise trap, data and collector unknown) .

Distribution: China (Fujian, newly recorded in Guangdong, Guangxi and Guizhou); Vietnam.

Remarks: This work is the first to describe the nymph of H. violacea . Mandible of nymphs share the same shape with Hemacroneuria marginalis Stark & Sivec, 2008 . The interspecific differences are not apparent based on mouthparts. When this species emerges it is easily collected from rocks and bridges by streams ( Fig. 9 ). Specimens from the four geographical populations from China showed no visible intraspecific differences in morphology.

Figures

FIGURE 1. Hemacroneuria violacea from Fujian. Male, A: habitus (dorsal and ventral); B: head and pronotum.

FIGURE 2. Hemacroneuria violacea from Fujian. Male, A: wings; B: an aberrant male with forewing shorter but bearing more cross veins apically.

FIGURE 3. Hemacroneuria violacea from Fujian. Male abdomen, A: dorsal; B: ventral.

FIGURE 4. Hemacroneuria violacea from Fujian. Male, A: terminalia; B: hammer; C: aedeagus, dorsal; D: aedeagus, ventral.

FIGURE 5. Hemacroneuria violacea from Fujian. Female, A: habitus (dorsal and ventral); B: head and pronotum.

FIGURE 6. Hemacroneuria violacea from Fujian. Female, A–B: subgenital plate, two viations; C: mature egg; D: immature eggs.

FIGURE 7. Hemacroneuria violacea from Fujian. Shed skin, A: habitus; B: mandible; C: lacinia; D: labium, ventral.

FIGURE 8. Hemacroneuria violacea from Fujian. Nymph, A: head and pronotum; B: winpads; C: mouthpart, ventral; D: thoraxal gills, ventral; E–F: terminalia, dorsal and ventral; G: paraprocts, ventral.

FIGURE 9. Hemacroneuria violacea from Fujian. A–B: adults in/after emerging; C: stream in Wuyi Mountains, the habitat.

FIGURE 10. Hemacroneuria violacea from Guangxi. Male and female habitus with original collecting labels.

FIGURE 11. Hemacroneuria violacea from Guangxi, male and female terminalia (materials checked by Ignac Sivec). A–B: male tergaum 7–10, dorsal and ventral; C: female, subgenital plate, ventral.

FIGURE 12. Hemacroneuria violacea from Guizhou, male.A: habitus (photo taken by Hu Zheng-Kun); B: head and pronotum; C–D: male terminalia, dorsal and ventral.

FIGURE 13. Hemacroneuria violacea from Guizhou, male. A: tergum 10 and paraprocts, caudal view; B: hammer; C–E: aedeagus, dorsal, ventral, caudal in difference views.