Indonemoura annamensis, Fochetti, Romolo & Ceci, Massimo, 2016

Fochetti, Romolo & Ceci, Massimo, 2016, Indonemoura annamensis — a new species of stonefly from Vietnam (Plecoptera: Nemouridae), Zootaxa 4121 (1), pp. 85-88 : 85-88

Indonemoura annamensis sp. n.

( Figs. 1–4)

Material examined. Holotype ♂: Vietnam, Tua Thien Hue Province, Bach Ma National Park, surr. Hotel Morin, m 1300/1400, 16,2° N; 107,85° E, 23/28.V. 2014. The holotype, preserved 75% ethanol is deposited in the Vietnam National Museum of Nature, Hanoi, Vietnam.

Adult habitus. Forewing length 7.6 mm, hindwing length 6.7 mm. General color dark brown. Head and antennae dark brown; pronotum slightly paler. Legs and palpi uniformly light brown. Abdomen and cerci pale brown.

Male. Epiproct long, trifurcate distally; dorsal sclerite basally wide, divided into a pair of heavily sclerotized processes, curved outward subapically, bearing a few strong spines on their tip ( Figs.1, 3); ventral sclerite, basally large, then narrowing to a thin process which is ventrally subtriangular and of plough-like aspect ( Fig. 4 ). Paraprocts long, curved and enlarged subapically, terminating in a point ( Figs. 2, 3, 4 ), bearing a few strong spines at curvature. Outer and mesal paraproct lobes slender, subequal in length and both bent sharply near apex ( Fig. 2); inner lobe short and somewhat club shaped. Tergum 9 and 10 without conspicuous sensilla patches. Vesicle of normal length, slightly widened subapically ( Fig. 2); hypoproct long, enlarged at ⅓ of its length, tapering towards the slightly rounded apex.

Female: Unknown.

The single male here described was collected with a few female specimens and with also a single male of an unidentified species. These females cannot be associated with the new species.

Affinities: The epiproct of male of I. annamensis is distinctive within the genus, not similar to any other described species. The only Indonemoura species that shares a similar epiproctal dorsal sclerite with heavily sclerotized processes is I. voluta Li & Yang, 2008 , a species known from China (Guanxi Zhuang Autonomous Region of southern China). Indonemoura annamensis can be easily distinguished from I. voluta by the ventral epiproctal sclerite, plough-like in I. annamensis , flat in I. voluta , and by the shape of the paraprocts, shorter not ending in a point in I. voluta .

Etymology. The species name refers to the Annamese Mountains, a mountain range of eastern Indochina, which extends through Laos, Vietnam, and a small area in northeastern Cambodia, where the Bach Ma National Park is located, the type locality of the new species.

Diagnosis. The male of I. annamensis does not possess several small tubercles located adjacent to the epiproct on tergum 10 that are present in five of the regional ( Vietnam, Thailand) species ( Sivec & Stark, 2010). However, among the other three Vietnamese species only I. angulata shares this character. Including the peculiar epiproct, I. annamensis is a distinctive taxon as compared to other known species from Thailand and Vietnam, for which a provisional identification key was provided by Sivec & Stark (2010).

Figures

FIGURE 4. Indonemoura annamensis sp. n. Epiproct, dorsal (above) and ventral (below) sclerites, and paraproct (20 X).