Tactusa nieukerkeni Fibiger, 2010

FIBIGER, MICHAEL, 2010, Revision of the Micronoctuidae (Lepidoptera: Noctuoidea) Part 3, Taxonomy of the Tactusinae, Zootaxa 2583 (1), pp. 1-119 : 23-24

Tactusa nieukerkeni Fibiger , new species

( Plate 2 , figure 6; male genit. plate 13, figure 2)

Material examined. Holotype: male, Vietnam, Vinh Phuc, Tam Dao , UTM 48 Q Wj 6773 ( WGS84 ), 1000 m, 26.ix.2003, leg. E.J. v. Nieukerken & C. Vd Berg, genit. prep. 5798 M. Fibiger, coll. RMNH.

Taxonomic notes. T. nieukerkeni is a member of the T. nieukerkeni species-group, which has a blackish triangular or quadrangular patch between the antemedial and postmedial lines, the typical Tactusa ampulla, and prominent features listed under the species-group and below.

Diagnosis. Imago (external). Wingspan: 13 mm.

Forewing: ground colour light yellow, with acutely-angled blackish patch in upper medial area, black subterminal area and a small black patch on costa between medial patch and apex.

Crosslines: only subterminal and terminal lines indicated; former inwardly outlined by light yellow, latter by interneural black spots.

Reniform stigma: well marked, white, outlined black.

Male genitalia. Tegumen: narrow.

Vinculum: strongly built.

Saccus: long; strongly built, prominently V shaped.

Fultura superior: membranous.

Valva: slightly asymmetrical, left one broader.

Ampulla: forming a cross with axis of valva; slightly asymmetrical, broadest by valva, dorsal arm with long, spinelike, pointed process (apo.).

Digitus: present, narrowly triangular, rounded at tip (apo.).

Juxta and anellus plate: fused (in preparation broken dorsally).

Phallus: long, S shaped, coiled.

Vesica: apically with four, small, narrow, pointed cornuti (apo.).

Female genitalia. Unknown.

Differential diagnosis. T. nieukerkeni differs from all other Micronoctuidae from SE Asian and Oriental regions in shape of ampulla, with long spine, narrow, apically blunt digitus, and four small, narrow cornuti in vesica of phallus.

Distribution. Known from one specimen from N Vietnam.

Figures

PLATE 2. Figures 1–8. Tactusa species, adults. 1, 2, T. nilssoni, male holotype, Thailand, Phuket, and female paratype, with same data; 3, T. ostium, female holotype, Thailand, Nakhon Naoyk; 4, T. peregovitsi, male holotype, Vietnam N, Nghe Aniwan; 5, T. flavoniger, female holotype, Laos, Vientiane; 6, T. nieukerkeni, male holotype, Vietnam, Vinh Phuc; 7, T. topi, male holotype, China, Guangdong, Canton; 8, T. incognita, male holotype, Thailand, Nakhon Naoyk.