Gergithoides nui Jérôme Constant & Hong-Thai Pham 2017, sp. nov.

Gergithoides nui sp. nov.

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Figs 3–5

Diagnosis

Gergithoides nui can be recognized by (1) the shape of the lateral process of the phallobase, with posterior spine strongly hooked anteroventrally and anteroventral spine strongly curved dorsally and elongate, (2) the ventral lobe of the phallobase, with dorsal margin emarginate on each side and indentated in middle, and (3) median posterior processes of phallobase pointed apically, and laterally emarginate subapically.

Etymology

“ Nui ” is the Vietnamese word for mountain. It refers to the mountainous origin of the type specimens and is used as a noun in apposition.

Type material Holotype

VIETNAM: ♂, dissected, right hind wing mounted, Fig. 3A–E [Coll. VNMN., Vietnam, Cao Bang prov., Pia Oac N.P., 10.viii.2012, Leg. H.T. Pham] (VNMN).

Paratype

VIETNAM: 1 ♂, same data as holotype (RBINS).

Description

MEASUREMENTS AND RATIOS. LT: ♂ (n = 2): 5.3 –5.4 mm. LTg/BTg = 2.0; BV/LV = 1.65; LF/BF = 1.28.

HEAD (Fig. 3A, C–D). Vertex broader than long in midline, brown with margins carinate; anterior margin convex, posterior one concave and lateral converging anteriorly; disc excavate, with obsolete tubercles. Side of head yellowish brown. Frons elongate and rugulose, brown; median carina yellowish, extending from dorsal margin down nearly to frontoclypeal suture; row of yellowish tubercles along dorsal and lateral margins, extending to level of base of eyes; lateral margins yellowish under eyes; lateral margin under eye and median carina on dorsal ⅓ bordered with dark brown. Clypeus black-brown, elevated medially. Scape short, ring-shaped, black; pedicel bulbous, brown. Labium dark brown, with last segment longer than broad and shorter than penultimate.

THORAX (Fig. 3A, C). Brown. Pronotum very short, with median carina, and anterior and posterior margins carinate; disc concave; row of yellowish tubercles along anterior margin extending on paranotal fields to level of base of eyes; another oblique row of 3 yellowish tubercles on each side of disc, parallel to anterior margin. Mesonotum short, slightly coriaceous, with obsolete median carina and obsolete impressed point on each side of disc; transverse carina along anterior margin yellowish; 4–5 yellowish tubercles grouped at each external angle; yellowish suffused marking on each side of scutellum; apex of scutellum marked with black. Tegulae brown.

TEGMINA (Fig. 3A, C). Strongly convex; broader than long when taken together in dorsal view; impressed at basocostal angle; subcoriaceous with dense reticulum of slightly raised veins and veinlets; main veins barely distinct basally; pale green-brown, with brown to black irregular markings; broad transverse dark brown patch at apical third; small black spot in middle of sutural margin.

HIND WINGS (Fig. 3E). Brown, unilobed, with veins darker, slightly shorter than tegmina. Venation reticulate, with main longitudinal veins distinct basally (C, ScP+R, MP, CuA); numerous cross-veinlets. Anal area absent. Costal and cubital margins sinuate, distal margin rounded.

LEGS (Fig. 3A–D). Elongate and slender, brown with black-brown line along externoventral margin of femora; black-brown line on ventral carinae of tibiae; base and apex of tibiae, apex of tarsi and apex of metatibial spines black-brown. Posterior tibiae with 2 lateral spines on apical ⅓ and 6 apical spines.

METATIBIOTARSAL FORMULA. (2) 6/8–9/2.

Male genitalia

Pygofer higher than broad and with posterior margin slightly rounded, protruding laterally in median ½, dorsal and ventral ¼ sinuate in lateral view (Fig. 4A); ventral margin rounded in lateral view (Fig. 4A). Gonostyli (Fig. 4A, C) elongate in lateral view, emarginate dorsally at base of capitulum and depressed at level of emargination; capitulum well developed, elongate and projecting dorsointernally; with small tooth on dorsal margin and a basolateral laminate process with anteroventral hook; convex externally at base of capitulum (Fig. 4C). Anal tube (Fig. 4A–B) nearly as broad as long, curved ventrally in lateral view, dorsoventrally flattened, with sides subparallel on apical half; apicolateral angles roundly projecting ventrally. Aedeagus strongly curved posterodorsally, rather simple (Fig. 4D, F). Phallobase with lateral process at basal half showing 2 spines; posterior spine strongly hooked ventroanteriorly, ventroanterior spine elongate, strongly curved dorsally, and slightly sinuate apically (Fig. 4E–F); phallobase with laminate process on each side, with right one more developed and projecting slightly further laterally than left one (Fig. 4D–F) and 2 median processes pointed apically, and lateral margin sinuate anteapically (Fig. 4E). Ventral lobe of phallobase broad, with apical margin emarginate on each side and indentated medially (Fig. 4E).

Biology

Gergithoides nui sp. nov. was collected in August on lower vegetation, in moist evergreen tropical mountain forest at an altitude between 1600 and 1900 m a.s.l.

Distribution

The species is currently recorded only from Pia-Oac National Park, Cao Bang Province (Fig. 5).