Rhopalopsole triseriata Qian & Du

Qian, Yu-Han & Du, Yu-Zhou, 2013, Two new species of Rhopalopsole (Plecoptera: Leuctridae) from China, Zootaxa 3599 (6), pp. 588-592 : 590-591

Rhopalopsole triseriata Qian & Du , sp. nov.

Figs. 4–6 .

Material examined. Holotype male, Sichuan Province, Luding County, Hailuogou, 2200m, 3 Jul. 2009, Leg. Qian Yu-han. Paratype male, Tibet, Motuo County, Beibeng, 780m, 17 Jun. 2009, Leg. Qian Yu-han.

Adult habitus. Head dark brown, wider than pronotum; hind ocelli much closer to the eyes than to each other, antennae and palpi dark brown. Pronotum dark brown, subquadrate, all angles somewhat rounded with black irregular stripes on surface. Legs dark brown. Wings hyaline, veins light grayish brown.

Male. Approximate measurement: forewing length 5.0mm, body length 5.5mm. Tergum 9 weakly sclerotized, distinctly wider than long, posterior margin with two narrow, distinctly sclerotized transverse bands; transverse bands more or less connected in the middle, and expand on each side ( Fig 4 ). Sternum 9 subgenital plate wider than long and rounded apically; basally, tongue shaped vesicle bears dense hairs ( Fig 5 ). Tergum 10 with strongly sclerotized lateral process rather thick basally, thin apically and ending a sharp point in lateral view ( Fig 6 ); midanterior sclerite sclerotized, distinctly wider than long, bearing two short obtuse lateral processes and one slightly longer middle process with expanded tip; tergum also bearing weakly sclerotized mid-posterior transverse sclerites ( Fig 4 ). Epiproct simple curved process with erect spine-line apical portion ( Fig 1 ). Subanal lobes long and upturned, in ventral aspect, two sides of subanal lobes folded inward, narrow basally and expanded apically, distinct longitudinal furrows cover the dorsal and ventral surface ( Fig 5 ). Cerci cylindrical and bent upward without a tiny apical spine ( Fig 6 ).

Female. Unknown.

Distribution. Sichuan Province, Xizang (= Tibet) Autonomous Region.

Etymology. Latin “ tri ” means three; Latin “ seriata ” means row. The species name refers to the shape of the mid-anterior sclerite of tergum 10.

Diagnosis. Rhopalopsole triseriata is a member of the R. magnicerca group ( Sivec et al. 2008, Stark et al. 2012, Li and Yang 2012), which currently includes 14 species, six of these known from China ( Li and Yang 2012). Males of the group are generally recognized by the moderately long, relatively stout posterolateral projections of tergum 10 and by a pair of sublateral raised areas on the posteromedian margin of tergum 9. The epiproct of the known species are small, hook-like projections and the cerci are upturned and lack terminal spines. Rhopalopsole triseriata appears distinct from the known members of this group in shape of the mesal sclerite, lateral process, and subanal lobe of tergum 10. In R. bispina ( Wu, 1949) , also known from Sichuan Province, this structure is broadly cordate in shape with only a weak suggestion of three lobes and lateral projections gradually and regularly tapering ending in a sharp ( Sivec et al. 2008), whereas in R. longispina, Yang & Yang (Yang & Yang 1991b) and R. emeishan Sivec & Harper (Sivec et al. 2008) , the three lobes of the sclerite are quite distinct, but in R. longispina , two sides of subanal lobes not fold inward. The shape of mesal sclerite and subanal lobes allies the new species most closely with R. emeishan Sivec & Harper, 2008 , because both have the median lobe bearing an expanded tip on a slender stalk, and in addition the subanal lobes are similar in ventral aspect. However, the lateral aspects of the processes of tergum 10 are quite different. In R. emeishan , a basal notch is present and lateral margins of the thinner process are parallel for most of its length, whereas in R. triseriata the basal notch is lacking and the thicker process has more rounded margins in the basal half.

The recent key to the Chinese species of R. magnicerca group by Li & Yang (2012) can be modified to include R. triseriata as follows:

1. Lateral projections of tergum 10 nearly parallel–sided in lateral view............................................. 2

–. Lateral projections of tergum 10 gradually tapering toward apex in lateral view.................................... 3

2. Male subanal lobe basally with well-defined sloping furrows, female subgenital plate only slightly produced, darkened areas

triangular......................................................................... R. lewolong Li and Yang –. Male subanal lobe basally with lateral margins smooth flap and apically with longitudinal furrows, female subgenital plate pro- duced into triangular apical extension, darkened areas irregular.......................... R. emeishan Sivec and Harper

3. Lateral projections of tergum 10 downcast medially in lateral view, subanal lobes with furrow area bulging and bulbous................................................................................... R. minutospina Li and Yang

–. Lateral projections of tergum 10 curved upward in lateral view, subanal lobes with furrow area concave or lacking distinct fur- row................................................................................................. 4

4. Lateral projections of tergum 10 with long and narrow in dorsal view, distal half gradually tapering into a sharp point...... 5

–. Lateral projections of tergum 10 relatively robust in dorsal view, apex with an abruptly sharpened point................. 6

5. Subanal lobes lacking a distinct furrow................................................. R. xui Yang, Li , and Zhu

–. Subanal lobes with a distinct furrow, folded inward......................................... R. triseriata Qian & Du.

6. Lower base of the lateral projections with a distinct indentation in males, female subgenital plate with a broad extension, trans- verse bar of sternum 8 entire................................................................. R. bispina (Wu)

–. Lower base of the lateral projections lacks an indentation in males, female subgenital plate with a narrower triangular exten- sion, transverse bar of sternum 8 split into two triangular lobes by medial membrane.......... R. longispina Yang and Yang

Figures

FIGURES 4 – 6. Rhopalopsole triseriata, sp. nov. 4. Terminal abdominal segments of male, dorsal view; 5. Terminal abdominal segments of male, ventral view; 6. Terminal abdominal segments of male, lateral view.

FIGURES 1 – 3. Rhopalopsole curvispina, sp. nov. 1. Terminal abdominal segments of male, dorsal view; 2. Terminal abdominal segments of male, ventral view; 3. Terminal abdominal segments of male, lateral view.