Microperla qinlinga Chen, 2019

Huo, Qing-Bo & Du, Yu-Zhou, 2019, Microperla qinlinga Chen reviewed with supplementary illustrations and the description of the nymph, Zootaxa 4706 (3), pp. 427-438 : 428-429

Microperla qinlinga Chen, 2019

Small size, body length 5.7–7.2 mm, forewing length 8.0–9.0 mm, hindwing length 7.0–8.0 mm. General color dark brown ( Fig. 2 ); body covered by fine setae, pores black. Triocellate, anterior ocellus very small. Gena pale brown. Pronotum width twice its length, dark-colored with rugosities ( Fig. 3 ).

Male: Abdomen with obvious lateral sclerites after emergence, two pale spots present on terga 1–3 ( Fig. 4 ). Anterior margin of tergum 10 strongly sclerotized, the sclerite becoming wider bilaterally; posteromedial half of tergum 10 sclerotized, curved upwards and forwards, terminal rounded and bearing several black setae ( Fig. 5 ). Aedeagus as a complex tridimensional structure, membranous, without any spines or sclerites. Aedeagus divided into three lobes: the basal lobe wide and possess a pair of “sheep horn-shaped” lateral arms; the middle lobe constricted ventrally with a pair of processes and the apical lobe expanded into two large lateral lobes and a small median-ventral lobe ( Fig. 6 ).

Female: Similar in habitus to male. Subgenital plate large and broad, posterior margin rounded with a median notch, variable, sometimes entire in some individuals ( Fig. 7 ).

Mature nymph: Body length ca. 5.8 mm. Gills absent. Body covered with pale hair. Head capsule wide approximately 1.1 mm. Anterior ocellus tiny, often indistinguishable ( Figs. 8–9 ). Lacinia short, fingerlike, with short brush on the inner edge; thin and ossified on apex with a row of serrations. Galea with a huge, developed crescent hairbrush. Mandible short, inner side with a basal tooth and two apical teeth; the first apical tooth shorter than M. brevicauda ( Uchida & Isobe 1989) . A row of fine hairs between the second apical tooth to the basal tooth ( Fig. 10 ). Paraglossae shorter than glossae ( Fig. 11 ). Thoracic segments wide and rounded. Forewing pads almost triangular, short; forewing pads separated by a distance about 2X width, hindwing pads directly fused and not divergent from midline. Paraprocts short, nail shaped, covered with long setae ( Fig. 12 ). Cerci about 12 segments, half the length of the antennae, with setal fringe ( Fig. 13 ).

Material examined: 5♂♂, 8♀♀, 2 nymphs, China, Shaanxi Province, Xi’an City, Zhouzhi County, Qinling Mountains , Huaerping , 1280 m, 33°50.636′N, 107°49.969′E, 2019-IV-23, leg. Huo Qing-Bo, Shen Yue ; 6 nymphs, Xi’an City, Zhouzhi County , Qinling Mountains , Heihe National Forest Park, 818 m, 33°53.406′N, 108°0.349′E, 2019-III-18, leg. Huo Qing-Bo, Zhao Meng-Yuan

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Remarks: Mature nymphs emerged on rocks along an unnamed river ( Figs. 14–15 ). It was observed that some emerging nymphs began to molt to adults exiting the river during the emergence peak ( Fig. 16 ). These pre-emergent adults were often swept away by the river current before successfully completing emergence. Fortunately, most emergent adults fully expanded their wings and moved safely to nearby dry rocks.

Figures

FIGURE 2. Microperla qinlinga, adult habit.

FIGURE 3. Microperla qinlinga, head and pronotum.

FIGURE 4. Microperla qinlinga, male abdomen. A: light spots on terga 1–3; B: abdomen, dorsal view; C: abdomen, lateral view.

FIGURE 5. Microperla qinlinga, male terminalia. A: dorsal view; B: lateral view; C: ventral view.

FIGURE 6. Microperla qinlinga, aedeagus. A, D: lateral view; B, E: lateral-vertical view; C, F: vertical view.

FIGURE 7. Microperla qinlinga, female, subgenital plate. A: abdomen contracted; B: abdomen expanded.

FIGURE 8. Microperla qinlinga, nymph habit.

FIGURE 9. Microperla qinlinga, nymph. A: head and pronotum, dorsal; B: head and pronotum, ventral; C: mesothorax and metathorax, dorsal; D: mesothorax and metathorax, ventral; E: outline of nymphal head and thorax.

FIGURE 10. Microperla qinlinga, mouthpart of nymph. A–B: left mandible, dorsal and ventral; C–D: left lacinia, dorsal and ventral.

FIGURE 11. Microperla qinlinga, labium of nymph, ventral.

FIGURE 12. Microperla qinlinga, terminalia of nymph. A: dorsal; B: ventral.

FIGURE 13. Microperla qinlinga, cerci of nymph.

FIGURE 14. Habitat of Microperla qinlinga, an unnamed river in Huaerping, Zhouzhi County, Shaanxi Province, China.

FIGURE 15. Exuvia of Microperla qinlinga on rocks during emergence.

FIGURE 16. A–F: Microperla qinlinga, adult eclosion.