Tactusa spadix Fibiger, 2010

FIBIGER, MICHAEL, 2010, Revision of the Micronoctuidae (Lepidoptera: Noctuoidea) Part 3, Taxonomy of the Tactusinae, Zootaxa 2583 (1), pp. 1-119 : 33-34

Tactusa spadix Fibiger , new species

( Plate 4 , figure 5; male genit. plate 14, figure 3)

Material examined. Holotype: male, Laos, Vientiane Prov., Ban Van Eue, 15–31.v.1965, genit. prep. 3316 M. Fibiger, coll. BPBM.

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

Forewing: ground colour brown, with very large black triangular patch, including fringes, that extends from antemedial point on costa to apex and to tornal edge; a large, light-brown patch present inside large patch close to apex (apo.).

Crosslines: only terminal lines visible as blackish-brown interneural spots.

Reniform stigma: traceable, yellowish.

Hindwing: dark grey, with indistinct discal spot.

Underside: unicolorous grey.

Vinculum: well built.

Saccus: short, strongly built, broadly U shaped.

Fultura superior: membranous.

Valvae: asymmetrical, that on right prominently broader; right sacculus especially, with huge dorsal, triangular extension, setose at tip (apo.).

Ampulla: forming a cross with axis of valva; asymmetrical; broadest by valva; dorsal left arm broader, rounded; ventral arm equally broad throughout, with small, stout spines at tip (apo.).

Digitus: absent, but with heavily sclerotisation where place for base of a digitus (apo.).

Juxta and anellus plate: asymmetrical, fused, somewhat triangularly ventrally and rounded dorsally, with hole for phallus at right side by rounded edge (apo.).

Phallus: coecum rather short; broad at ductus ejaculatorius; tapered conelike to1/3, almost straight from there to tip (apo.).

Vesica: unarmed.

Female genitalia. Unknown.

Differential diagnosis. T. spadix differs from other members of second half of species-group in large blackish patch with light-brown patches and indistinct reniform stigma; in male genitalia, in huge triangular saccular process, absent digitus, shape of ampulla, ventrally triangular juxta-anellus plate and almost straightphallus.

Distribution. Known from a single specimen from S Laos.

Figures

PLATE 4. Figures 1–8. Tactusa, Conspica, and Tumula species, adults. 1, T. similis, female holotype, Thailand, Chiang Mai; 2, T. constrictor, male holotype, Laos, Vientiane; 3, T. assamia, male holotype, India NE, Assam; 4, T. discrepans, male holotype, Thailand, Chiang Mai; 5, T. spadix, male holotype, Laos, Vientiane; 6, T. pars, male holotype, Thailand W, Kanchannaburi; 7, Conspica inconspicua, male holotype, Thailand, near Ban Nam Lee Pattana; 8, C. parainconspicua, male holotype, Thailand, Chiang Mai.