Amphinemura triquetra Zhao & Du, 2021

Zhao, Meng-Yuan & Du, Yu-Zhou, 2021, Two new species of Amphinemura (Plecoptera: Nemouridae) from Taiwan Province on the southeast coast of China, Zootaxa 4969 (3), pp. 573-580 : 576-577

Amphinemura triquetra Zhao & Du , sp. nov.

Type material: Holotype, 1♂, China, Taiwan Province , Nantoupuli–Aowanda, 1280m, 2012-X-21, leg. Ren Shun- Xiang ( ICYZU) . Paratypes, 1♂, the same data as the holotype ( ICYZU).

Adult habitus: Head dark brown, antennae brown; cervical gills highly branched; pronotum dark brown, anterior margin wider than posterior margin. Wings subhyaline, veins brown. Legs brown ( Fig. 6 ).

Male: Forewing length 6.3–6.4 mm, hind wing 5.1–5.2 mm. Tergum 9 slightly sclerotized, with a large midanterior indention, and concaved at median of posterior margin, with several spines laterally. Tergum 10 sclerotized mostly, forming a membranous concavity below the epiproct, with few small spines laterally ( Fig. 7A ). Hypoproct broad basally, tapering toward the rounded tip; vesicle slender, length 4 × width ( Fig. 7B ). Paraproct divided into 3 lobes, inner lobe slightly sclerotized, simple; median lobe broad and sclerotized basally, connected with a membranous portion which with several spines each lateral and narrowed to the tip; outer lobe dark, triangular basally, narrowed medially, with 4–5 spines on the triangular tip ( Fig. 7B, D ). Epiproct broad basally, tapering to the tip, dorsal sclerite membranous, with a notch apically; lateral arm sclerotized ( Fig. 7A, D ); ventral sclerite forming a median keel-shaped ridge, broad basally, bearing a whole row of horn-shape spines ventrally ( Fig. 7C ), tip of the keel reaching over dorsal sclerite forming a pair of small projections ( Fig. 7D ). Cerci membranous, with setae.

Female: Unknown.

Etymology: The Latin “ triquetra ” meaning triangular, refers to outer lobe of paraproct with triangular basal and tip.

Remarks: The male of the new species seems related to A. flavicollis Klapálek, 1912 . The two species share a similar epiproct, which is almost oval with a notch apically. However, the new species is quite distinct from A. flavicollis on ventral sclerite bearing a whole row of horn-shape spines and two small projections over dorsal sclerite, while the row of spines on ventral sclerite are less and small with only one short oblong projection apically in A. flavicollis . Comparing the paraprocts of the two species, it can be easily found that the median lobe of A. triquetra broad and sclerotized basally, connected with a membranous portion bearing several spines each lateral and narrowed to the tip, but A. flavicollis only bearing 6–7 long spines at the tip; while the outer lobe of A. triquetra darkly sclerotized with triangular basal and tip, bearing 4–5 apical spines, these features are absolutely absent in A. flavicollis .

Figures

FIGURE 6. Amphinemura triquetra Zhao & Du, sp. nov. Male, A: head and pronotum, dorsal view; B: prothorax and gills, ventral view.

FIGURE 7. Amphinemura triquetra Zhao & Du, sp. nov. Male terminalia, A: dorsal view; B: ventral view; C: lateral view; D: epiproct and paraproct, caudal view.