Amphinemura yao Mo, Yang, Wang & Li, 2017

Mo, Raorao, Wang, Guoquan, Yang, Ding, Li, Weihai & Murányi, Dávid, 2021, Two new species and four unknown larvae of Amphinemurinae (Plecoptera, Nemouridae) from southern China, Zootaxa 5040 (1), pp. 77-101 : 89-94

Amphinemura yao Mo, Yang, Wang & Li, 2017

( Figs 11–14 )

Amphinemura yao Mo, Yang, Wang & Li, 2017: 278 . Holotype male (HIST), China, Guangxi, Jinxiu , Dayaoshan.

Complementary description of adults. Male ( Figs. 11A–C ). Tergum IX slightly sclerotized, with 2 paramedial groups of strong spines and hairs along mid-posterior margin. Slender vesicle of sternum IX claviform, length 4X of maximum width, constricted basally and slightly constricted medially. Hypoproct rectangular basally, gradually narrowing towards nipple-like tip. Tergum X sclerotized, a brown concavity presents below the epiproct, bearing a few strong spines on either sides of the concavity. Epiproct trifurcate, pentagonal, basally wide, with a pair of S-shaped lateral processes and a shorter median process; lateral processes strongly sclerotized, bearing relatively dense spines at apical half; median process strongly sclerotized except subapical part. Paraproct trilobed and simple without distinct spines and complex structures: outer lobe sclerotized, slender and hidden, much shorter than median lobe; median lobe large and strongly upcurved; inner lobe triangular, weakly sclerotized, mostly hidden by hypoproct.

Female ( Fig. 11D ). Sternum VII weakly sclerotized with a sclerotized semicircular pregenital plate; the plate slightly extending to sternum VIII and partly covering anterior part of subgenital plate. Sternum VIII weakly sclerotized, with wing-shaped subgenital plate with a posteromedial notch; the notch triangular in ventral view and anteriorly linked the sclerotized medial rod. Sternum IX moderately sclerotized, extending anteromedially, subtrapezoidal.

Description of mature larva. Measurements: Body length: 5.3–5.7 mm (excluding antennae and cerci). Habitus ( Figs. 12–13 ). Body relatively slender for genus, general colour brown, with some indistinct pattern on head, pronotum and abdomen; head, pronotum and abdomen slightly darker than thorax and legs, but wing pads dark brown ( Fig. 12 ). Antennae dark brown, scape and pedicel paler. Legs moderately long, width of hind femora> 1/4 of their length. The pronotum is rectangular with rounded corners, wider than long. Cervical gills long, inner and outer gills with 6 and 7 branches, respectively. Wing pads <2X as long as the corresponding segments. Abdomen relatively slender and uniformly brown, integument light matt brown, first 5 abdominal segments divided by pleura ( Figs. 12 , 14 ). Posterior margin of sternum IX of the male larva short triangular; posteromedial portion of tergum X paler, membranous and triangular, slightly protruded posteriorly with a rounded tip; paraprocts blunt ( Figs. 14 E–F ). Sternum VIII of female larva with a deep and wide posteromedial notch, adult subgenital plate well seen by transparency ( Figs. 14B–C ). Cerci long, with 23–24 cylindrical segments; length of the last 3 segments is> 3X of their width ( Fig. 14D ).

Setation ( Figs. 12–14 ). Head, antennae, and palpi with dense short setae. Pronotum covered with very short setae; marginal setae distinct and blunt, row continuous but setae shorter in anteromedial and posteromedial third, corners have setae as long as 1/13 of pronotum width ( Figs. 12 , 13A ). Setae on mesonotum and metanotum as long as longest marginal setae on pronotum; wing pads with short setae besides marginal ones. Legs with relatively dense setae that are variable in length.All tibiae bear sparse and indistinct swimming hairs as long as tibia width ( Figs. 12 , 13B–C ). Longest acute setae of all femora are about as long as half of the corresponding femur width; long setae not arranged in line, restricted to outer surface. Tarsi and claws normal. Tergal segments covered with short setae; row of posterior margin are of longer, thicker, blunt setae with different length, not erect in lateral view, longest nearly reaches half of segment length ( Figs. 12 , 14A ). Cercal segments with relatively sparse and moderately long setation; setae sparser and shorter on the basal segments ( Figs. 12 , 14D ). Cercomeres with strong setal whorls; medial cercomeres with an apical whorl of 8–12 acute setae that are longer than segment length, nearly parallel to cercomere; swimming hairs absent.

Material examined. CHINA: Guangxi, Laibing City, Jinxiu Yao Autonomous County, Dayaoshan National Natural Reserve , Yinshan Park ; 1130 m, 24°10’07’’ N, 110°14’38” E, 10 June 2020, Yan Lai, Raorao Mo, Qingcheng Yang et al. leg.: 1 pharate female larva, 7 ultimate larvae, 5 early instar larvae ( HIST) ; same locality and collectors, 8 June 2020, light trap: 2 male and 8 female adults ( HIST) ; same locality and collectors, 9 June 2020, light trap: 1 male and 1 female adult ( HIST) .

Distribution. China, Guangxi Zhuang Autonomous Region, known only from the Dayaoshan National Natural Reserve. Four years after of collection of the types, all life stages were successfully collected at the type locality, including mature and younger larvae. Mature larvae can be easily associated with adults by the transparent genitalia, both sexes of Amphinemura yao are identical to the original description.

Affinities. Similar to Amphinemura hamiornata , the larva of A. yao has no distinctive color pattern, and distinction from the known Chinese congeners must rely on combination of several setation characters: generally blunt setation, presence of long setae on the whole dorsal surface of hind femora, tergal row of setae moderately long and not erect in lateral view, cercal setation is moderately long and not erect, lack swimming hairs.

Figures

FIGURE 11. Amphinemura yao Mo, Yang, Wang & Li, 2017 (A–C male, D female) A. Head and pronotum, dorsal view. B. Terminalia, dorsal view. C. Terminalia, ventral view. D. Terminalia, ventral view. Scale bars: 0.1 mm.

FIGURE 12. Amphinemura yao Mo, Yang, Wang & Li, 2017 A. Pharate female larva. B. Ultimate male larva. C. Early instar larva. Scale bars: 1 mm.

FIGURE 13. Amphinemura yao Mo, Yang, Wang & Li, 2017 (Pharate female larva). A. Head and Pronotum, dorsal view. B. Right hind leg, outer face. C. Right hind leg, inner face. Scale bars: 1 mm.

FIGURE 14. Amphinemura yao Mo, Yang, Wang & Li, 2017 (A–C Pharate female larva, D–F Ultimate male larva) A. Abdomen, dorsal view. B. Abdomen, ventral view. C. Abdomen, lateral view. D. Right cercus, dorsal view. E. Terminalia, dorsal view. F. Terminalia, ventral view. Scale bars: A–D=0.5 mm; E–F=0.1 mm.