Tactusa biartus Fibiger, 2010

FIBIGER, MICHAEL, 2010, Revision of the Micronoctuidae (Lepidoptera: Noctuoidea) Part 3, Taxonomy of the Tactusinae, Zootaxa 2583 (1), pp. 1-119 : 29-30

Tactusa biartus Fibiger , new species

( Plate 3 , figure 7 (imago), 8 (wing preparations); male genit. plate 13, figure 5)

Material examined. Holotype: male, Thailand NW, Chiang Mai, Doi Suthep-Pui Nat. Park , San K, 1540 m, 22.iv.–6.v.1994, leg. I.J. Kitching et al., BMNH (E) 1994-97, wing prep. 3198 & genit. prep. 3403 M. Fibiger,

coll. BMNH.

Diagnosis. Imago (external). Wingspan: 11 mm.

Wing venation: in both wings, typical for Micronoctuidae (see plate 3, fig. 8).

Forewing: relatively short and narrow; ground colour yellowish, with basal-costal patch and dorsomedial, triangular patch; yellowish between basal and antemedial lines, and between triangular patch and subterminal line; subterminal and terminal areas, including fringes, blackish brown, except for beige costal patch (apo.).

Crosslines: subterminal line indicated, white; terminal line weakly marked.

Reniform stigma: invisible (apo.).

Hindwing: whitish, with indistinct discal spot.

Underside: unicolorous grey.

Abdomen: whitish with black crest dorsally on first segment.

Male genitalia. Tegumen: relatively strongly built.

Vinculum: even more strongly built.

Saccus: short; strongly built, V shaped.

Fultura superior: membranous.

Valvae: slightly asymmetrical, one on right broader.

Ampulla: forming a cross with axis of valva; prominently asymmetrical; slightly upturned; broadest by valva; arms relatively broad, dorsal arm shorter, broader; apically with small, stout spines, and ventral arm longer, narrower, tapered (apo.).

Digitus: absent (apo.).

Juxta and anellus plate: slightly asymmetrical, fused, constricted medially (apo.).

Phallus: strongly enlarged by ductus ejaculatorius, tapered from middle, and distally forming a long, narrow, curved, smoothly upturned cylinder.

Vesica: unarmed.

Female genitalia. Unknown.

Differential diagnosis. Given under T. artus .

Distribution. T. biartus known only from N. Thailand.

Figures

PLATE 3. Figures 1–8. Tactusa species, adults. 1, T. jeppeseni, female holotype, India NE, Assam; 2, T. bechi, female holotype, India NE, Assam; 3, T. dohertyi, male holotype, Indonesia, Java Centr.; 4, T. minor, female holotype, Thailand N, Chiang Mai; 5, T. tranumi, female holotype, Vietnam N, Vinh Phuc; 6, T. artus, male holotype, Thailand N, Chiang Mai; 7, 8, T. biartus, male holotype, Thailand N, Chiang Mai, and wing prep. 3198, with same data.