Hemacroneuria trilobata, Mo & Wang & Li, 2020

Mo, Raorao, Wang, Guoquan & Li, Weihai, 2020, The first record and a new species of the genus Hemacroneuria from Guangxi of China (Plecoptera: Perlidae), Zootaxa 4780 (2), pp. 396-400 : 396-399

Hemacroneuria trilobata sp. nov. ( Figs. 1–3 )

Adult habitus ( Figs. 1 a–1b). General color dark brown. Head brown with a large dark brown to black trapezoidal marking with an anterior triangular notch anterior from occiput medially and anterior of tentorial callosities to brown M-line; a subtrapezoidal dark brown median marking between central M-line and clypeus. Triocellate, anterior ocellus much smaller, distance from posterior ocellus to compound eye ca. 1.5X as wide as distance between posterior ocelli. Antennae brown and palpi paler. Pronotum brown, subtrapezoidal, widest at anterior margin about 1.5X of its length, corners obtuse and lateral margins circularly rounded, with lighter rugosities and contrasting whitish lateral margins. Legs uniformly brown. Wings brown but costal area pale, veins dark brown. Abdomen brownish with darker terminalia; cerci brown.

Male ( Figs. 1–3 ). Forewing length ca. 14.9 mm. Tergum 10 with a pair of posterolateral lower knobs laterally to large rounded sensilla basiconica patches separated by a dark brown, longitudinal, strongly sclerotized median strip, and with a triangular median sclerite ( Fig. 1c ). Paraprocts strongly curved forward, rectangular, with a slightly outcurved sharp outer tip; outer portion triangular, apparently sclerotized, while inner portion membranous; laterally subtriangular with an acute tip ( Figs. 1 c–d, 2a, 2c). Hammer large, transversely rounded, and covered by indistinct granules, slightly elevated in lateral view, positioned over midlength of the sternum ( Figs. 2 b–c).

Aedeagus ( Figs. 2d , 3 ) [incompletely everted] membranous, tubular in shape, apparently apex abruptly constricted to an apical lobe. Basal portion in ventral view with many distinct transverse wrinkles. Apical half with many longitudinal and transverse wrinkles, brownish and bilobed due to the widely indented anterior margin, posteriorly with a saddleshaped structure visible well in ventral view (left one broken and seemingly knee-like in lateral view) between two ventrolateral lobes. Subapical portion with a pair of small, rounded ventrolateral lobes. The single median apical lobe tubular, ca. 2X length of lateral lobes, cover with many longitudinal wrinkles.

Female. Unknown.

Distribution. China (Guangxi Zhuang Autonomous Region).

Type material. Holotype male ( HIST), Guangxi Zhuang Autonomous Region, Tianlin County, Cenwanglaoshan , “stopping pad”, 24°29.25' N, 106°23.48' E, 1849 m, 2013.V.8, Meicai Wei, Genyun Niu.

Etymology. The specific name refers to three lobes of aedeagus. “Tri” in Latin means three and “lobus” means lobe.

Remarks. The male of the new species appears most similar to H. spatulata ( Wu, 1948) described from Sichuan Province of southwestern China, in sharing similar rectangular paraprocts in dorsal aspect. However, both the paraprocts and hammer differ. In H. trilobata , the paraprocts are triangular with acute apex in lateral view and the hammer is transversely rounded, whereas in H. spatulata , the paraprocts are subrectangular with wide apex in lateral view and the hammer appears more rounded (see figs. 16–17 in Wu 1948).

Among the well described species, the new species is also similar to H. ovalis Li, Mo & Murányi, 2019 described from Zhejiang Province of eastern China along the East China Sea in having a similar pronotum, tergum 10 and similar brownish ventral area in the apical half of aedeagus. However, the new species can be easily distinguished from H. ovalis by the rectangular paraprocts in dorsal view. In H. ovalis , the paraprocts are largely triangular. In addition, hammer of H. trilobata is transversely rounded while that of H. ovalis by is rounded (compare fig. 6b in Li et al. 2019 and Fig. 2b ).

Figures

FIGURE 1. Hemacroneuria trilobata sp. nov. (male). a. Habitus, dorsal view. b. Head and pronotum, dorsal view. c. Terminalia, dorsal view. d. Paraprocts, dorsocaudal view.

FIGURE 2. Hemacroneuria trilobata sp. nov. (male). a. Paraprocts, lateral view. b. Hammer, ventral view. c. Terminalia, lateral view. d. Partially everted aedeagus, ventral view.

FIGURE 3. Hemacroneuria trilobata sp. nov. (aedeagus). a. Dorsal view. b. Ventral view. c. Lateral view.