Tactusa rima Fibiger, 2010

FIBIGER, MICHAEL, 2010, Revision of the Micronoctuidae (Lepidoptera: Noctuoidea) Part 3, Taxonomy of the Tactusinae, Zootaxa 2583 (1), pp. 1-119 : 15-16

Tactusa rima Fibiger , new species

( Plate 1 , figure 2; male genit. plate 12, figure 1)

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. 5800 M. Fibiger, coll. RMNH.

Taxonomic notes. T. rima is a member of the T. sumatrensis species-group, which has a blackish-brown quadrangular patch between the antemedial and postmedial lines.

Diagnosis. Imago (external). Wingspan: 12 mm.

Forewing: ground colour light yellow, suffused with brown patches and lines.

Crosslines: dorsal part of antemedial and postmedial lines brown, subterminal pale, margined proximally by blackish patches, all extending weakly to costa; terminal line marked by interneural black spots (apo.).

Reniform stigma: well marked; white.

Hindwing: dark grey, with indistinct discal spot.

Underside: unicolorous grey.

Male genitalia. Tegumen: narrow, considerably narrower than vinculum and saccus (in illustrated prep. split dorsally, and right arm broken by connection to vinculum).

Vinculum: strongly built.

Saccus: short, strongly built, broadly U shaped.

Fultura superior: membranous.

Valva: asymmetrical; right side broader; left side with large, dorsally directed saccular process (apo.).

Ampulla: forming a cross with axis of valva; strongly asymmetrical; right one very large on dorsal side; ventral side a short flap; right ampulla much shorter but higher (apo.).

Digitus: absent, but a prominent, asymmetrical bar present on apical half of costa (apo.).

Juxta and anellus plate: totally fused, with large hole for phallus; asymmetrical.

Phallus: short and very broad; upturned subapically (apo.).

Vesica: without cornuti, but with a sclerotised patch (apo.).

Female genitalia. Unknown.

Differential diagnosis. T. rima differs from other Micronoctuidae from SE Asian and Oriental regions in highly asymmetrical ampullae, prominent costal bar, prominent saccular process on left valva, and short, broad, subapically upturned phallus.

Distribution. Known from one specimen from N Vietnam.

Figures

PLATE 1. Figures 1–7. Tactusa species, adults. 1, T. major, female holotype, Thailand N, Chiang Mai; 2, T. rima, male holotype, Vietnam N, Vinh Phuc; 3, T. sine, male holotype, Vietnam N, Da Lat; 4, T. sumatrensis, male holotype, Indonesia, North Sumatra; 5, T. schnacki, male holotype, India NE, Assam; 6, T. parasumatrensis, male holotype, Indonesia, North Sumatra; 7, T. trigonifera Hampson, 1898), male holotype, India NE, Assam.