Nihonogomphus schorri Do & Karube

Do, Manh Cuong & Karube, Haruki, 2011, Nihonogomphus schorri sp. nov. from Huu Lien Nature Reserve, Lang Son Province, Vietnam (Odonata: Gomphidae), Zootaxa 2831, pp. 63-68 : 64-67

Nihonogomphus schorri Do & Karube , sp. nov.

Material. Holotype ɗ: Vietnam, Lang Son Province, Huu Lien Nature Reserve, Boc stream in Lan Chau community, alt. 250 m, 9.VI.2008, Do Manh Cuong leg. Deposited in Vietnam National Museum of Nature, Hanoi. Paratype ɗ, same stream as for the holotype, 14.V.2009, M. Hämäläinen leg. Deposited in Kanagawa Prefectural Museum of Natural History, Odawara.

Etymology. The species is named after Mr. Martin Schorr, Treasurer of International Dragonfly Foundation (IDF), who has supported the first author in many ways in his studies of Vietnamese dragonflies.

Description of the holotype male. A medium sized dragonfly with black body furnished with yellow-greenish markings.

Head: Occiput black with long black setae and semicircular yellow marking behind. Vertex black with domed prominence above each lateral ocellus. Antefrons rather protrusive laterally, faintly excavated mid-dorsally and mostly greenish. Postclypeus black, anteclypeus light brown; labrum wholly black. Mandible black with yellowgreenish marking at base. Labium black, genae greenish ( Fig. 1 ).

Thorax: Prothorax entirely black ( Fig. 2 ). Mesepisternum black with broad upside-down 7-shaped greenish markings ( Fig. 3 ). Dorsal carina with yellow spot in anterior part ( Fig. 2, 3 ). Mesepimeron and metepisternum black with broad greenish marking covering nearly entire mesepimeron, the marking connected with metepisternum marking which occupies anterodorsal part and anterior border, stopping above stigma. Metepimeron largely greenish, with thick black anterior margin ( Fig. 2 ).

Wings: Fw with 17 Ax, 14 Px. Pterostigma dark brown, rear margin covers 7 cells. Arculus about 1/3 distance between second and third Ax. Cu crossing proximal to first Ax. No cross-vein in triangle, subtriangle or supratriangle ( Fig. 4). Hw with 12 Ax, 15 Px. Rear margin of dark brown pterostigma covers 6 cells. Arculus approximately opposite second Ax. Cu crossing proximal to first Ax. Cross-veins lacking from triangle, subtriangle and supratriangle. Anal loop with one cell ( Fig. 5).

Legs: Front legs black with large yellowish-green marking along outside of femur. Middle and hind legs entirely black.

Abdomen: Moderate in size for the genus. Black with greenish yellow markings. S1–2 black with middorsal stripe and stripe on lower half yellowish-green. S3 with pair of anteroventral markings, S4–7 each with pair of semicircular yellowish-green spots at upper base. S8–9 entirely black, S10 with large yellowish-green marking on posterior half. In ventral view, from tip of S7 to tip of S8, abdomen gradually enlarges, reaching widest point at tip of S8, then narrowing gradually from base of S9 to tip of S10.

Anal appendages: Cerci yellowish-brown, thick at base and curved inward and downward at about apical 1/3 ( Fig 6, 7, 8 ). In dorsal view, an inner nodule at midpoint of each cercus, after that the cercus strongly curves inward ( Fig. 7, 8 ). In lateral view, cercus robust and simple, thick at base with a slight ventral nodule at base. Cerci narrow gradually from base, with slight downward curve and simple obtuse apex with slight downward projection ( Fig. 6 ). In ventral view, tips of cerci folded and convex, with ventral ridge ( Fig. 9, 10 ). Epiproct dark brown, making a Ushape with divergent tips ( Fig. 10 ). In lateral view, arises from S10, then curves sharply upward at 2/3 length; apices rounded ( Fig. 6 ).

Genitalia: Anterior hamule with pronounced shoulder, basal part broad and robust and apical part slender and curved ( Fig. 11 ). Posterior hamule broad at base, tapering to slightly curved point ( Fig 12 ). Vesica spermalis with prominent posterior lobe on basal segment ( Fig. 14 ) and two long, pale, diverging flagella on distal segment ( Fig. 13, 14 ). In ventral view, the distal segment bifurcated into two parts at one third apically, each part ended with a long flagella ( Fig. 13 ).

Measurements of male: Abdomen (incl. appendages) 45.0 mm. Hw 32.5 mm.

Female: No female specimens available, but the following characters are visible in the available photo ( Fig. 16 ) taken at the type locality. Thorax markings similar to the male. In dorsal view, abdomen black with markings as follows: segments 1–2 with middorsal greenish stripe that continues to base of S3; 4–7 with pair of dorsolateral yellowish dots; S8–9 entirely black; S10 black at base, yellowish at tip. Cerci entirely yellowish.

Habitat. The adults of this species were found on a rather open lowland stream in a region with secondary forests, at an elevation of about 250 m. The stream beds have some vegetation. The stream is about 4–6 m wide with muddy and sandy bottom. Water is quite clean and flow is moderate.

Figures

FIGURE 16. Nihonogomphus schorri female, Huu Lien, Vietnam, 9 June 2008 (photo by Manh Cuong Do).

FIGURES 1 – 3. Nihonogomphus schorri, male holotype. (1) Head; (2) Synthorax, lateral view; (3) Synthorax, anterior view.

FIGURES 6 – 10. Nihonogomphus schorri, male holotype. (6) S 10 and anal appendages, lateral view; (7) S 8 – 10 and anal appendages, oblique dorsal view; (8) S 10 and anal appendages, dorsal view; (9) Apical part of left cercus, ventral view; (10) Anal appendages, ventral view.

FIGURES 11 – 15. Nihonogomphus schorri, male holotype (except Fig. 15). (11) Anterior hamule; (12) Posterior hamule; (13) Distal segment of vesica spermalis, ventral view; (14) Vesica spermalis, lateral view; (15) N. bequaerti distal segment of vesica spermalis, ventral view.