Indonemoura spirocornua, Li, Weihai, Wu, Limin & Yang, Ding, 2017

Li, Weihai, Wu, Limin & Yang, Ding, 2017, Two new species of Indonemoura (Plecoptera: Nemouridae) from Yunnan Province of southwestern China, Zootaxa 4231 (2), pp. 289-295 : 290-294

Indonemoura spirocornua sp. nov.

(Figs. 6–10, 12)

Diagnosis. The median lobe of paraproct has a bifurcate apex consisting of two hooks of different sizes, the ventral hook being small and out-curved with sharp apical spine-like apex; the dorsal hook being larger and spiraled. Outer lobe of paraproct slender, finger-like in apical third with a tiny apical spine. Cerci are elongate, length at least 5X width.

FIGURES. 1–5. Indonemoura curvispina sp. nov. (male). 1. Terminalia, dorsal view. 2. Terminalia, ventral view. 3. Epiproct, dorsal view. 4. Epiproct, lateral view. 5. Paraproct, caudal view.

FIGURES. 6–10. Indonemoura spirocornua sp. nov. (male). 6. Terminalia, dorsal view. 7. Terminalia, ventral view. 8. Epiproct, dorsal view. 9. Epiproct, lateral view. 10. Paraproct, caudal view.

FIGURES. 11–12. Adult habitus, lateral view. 11. Indonemoura curvispina sp. nov. 12. Indonemoura spirocornua sp. nov.

Adult habitus (Fig. 12). Male forewing length ca. 8.8 mm, hindwing length 7.7 mm. Head and antennae dark brown; mouthparts dark brown and palpi lighter, compound eyes black. Thorax: pronotum dark brown, meso- and metanota slightly lighter, legs mostly brown with yellow pattern but foreleg black, hindleg femora with a wide yellow band between brown basal half and distal fourth, the band less patterned in midleg and obscure in foreleg, tibiae brown to grayish brown, distal portion lighter; wings subhyaline, membrane brownish with darker veins; Abdominal segments mostly brown except dark brown terminalia; hairs on abdomen mostly brownish.

Male Terminalia (Figs. 6–10). Tergum 9 weakly sclerotized, gently constricted medially, with two scattered tiny spines at the each side of the mid-posterior incision (Fig. 6). Sternum 9 with claviform vesicle, length ca. 3X width, stalk-like base and dorsolateral surface darkly sclerotized, ventral surface mostly membranous; hypoproct broad and subquadrate, slightly concave medially at base fourth, distal half tapering and apex tubular, covered by dense hairs (Fig. 7). Tergum 10 sclerotized, with deep longitudinal concavity beneath epiproct typical for the family, anterolateral margins bearing many spinules and a pair of upraised hump present mesolaterally. Cercus membranous with dense hairs, much elongate, length at least 5X width. Epiproct (Figs. 6, 8–9) slender and recurved, apex partially hidden by tergum 9 in natural position; basally parallel-sided except enlarged near apex, apex ovum-shaped with obscure incision in dorsal aspect, a pair of thin lateral sclerites extended from an apically divergent, trapezoid basal sclerite, lateral sclerites terminating in an expanded triangular apices subapically, surrounded membranous area basally subrectangular, together with the membrane at apical portion forming an arrow-shaped structure; ventral sclerite (Figs. 8–9) heavily sclerotized, broad and wider than dorsal sclerite at base and gradually narrowing toward apex after inserting in dorsal sclerite, in lateral aspect with a distinct apical ridge bearing a row of sharp spines. Paraprocts divided into 3 lobes (Figs. 7 & 10): inner lobe tiny and hidden by hypoproct then hardly observed; median lobe forming an evenly out-curved, darkly sclerotized, spine-like structure, apex bifurcate with two hooks of different size, the ventral one small and out-curved, base wide with sharp apical spine, dorsal one much larger and spiral, reminiscent of the horns of Argali sheep; outer lobe basally is a sclerotized strip around basal margin of cercus, distal portion forming a finger-like rod with a tiny ventroapical spine.

Female. Unknown.

Type material. Holotype male ( HIST), Yunnan Province, Nujiang Perfecture, Lushui County, Liuku Town (where both Perfecture and County people's governments are located), ca. 2 km W Xinzhai village, unnamed stream into Nu / Salween River , N25°80.8720', E98°87.5146', 1900 m, three days between 2012. VII.25–VIII.10, leg. Y.Q. Xi.

Etymology. The specific name refers to the large dorsoapical spiral-like horn of median lobe of paraproct, suggestive of the horns of Argali sheep. Distribution. China (Yunnan).

Remarks. The new species appears similar to I. curvispina , both sharing paraprocts with conspicuous curved apical spines. The holotype of I. spirocornua was collected with the holotype of I. curvispina . However, both species can be readily distinguished by the color pattern of the legs and details of the lobes of the paraprocts and the epiproct. Similar median paraproctal lobes occur in I. nyukmadongi ( Aubert 1967) and I. quadridentata ( Kimmins, 1950) . However, in I. nyukmadongi , the epiproct bears an apical flagellum (fig. 32, in Aubert 1967) absent in I. spirocornua (Figs. 8 & 9) and in I. quadridentata , the ventral sclerite of epiproct in lateral aspect has a much narrower subapical ridge and the larger branch of the median paraproctal lobe is only slightly curved apically (figs. 24-27, in Aubert 1967).