Tactusa trigonifera ( Hampson, 1898 ) FIBIGER, MICHAEL, 2010

FIBIGER, MICHAEL, 2010, Revision of the Micronoctuidae (Lepidoptera: Noctuoidea) Part 3, Taxonomy of the Tactusinae, Zootaxa 2583 (1), pp. 1-119 : 19-20

Tactusa trigonifera ( Hampson, 1898) , new combination

( Plate 1 , figure 7; male genit. plate 12, figure 5)

Tolpia trigonifera Hampson, 1898 . Supplementary paper to volumes in “Fauna of British India” part II. Journal of Bombay Natural History Society xi: 440. Type locality: [ India NE], Assam, Khasis .

Material examined. Holotype: male, [ India NE], Assam, Khasis , genit. prep. BM 17006 M. Fibiger, coll. BMNH.

Taxonomic notes. This taxon is not listed in Poole (1989), because it was not in the “card index” in BMNH (M. Honey pers. comm.). T. trigonifera is a member of the trigonifera species-group, which has a blackish triangular or quadrangular patch between the antemedial and postmedial lines; the typical Tactusa ampulla; and a prominent, long, heavily sclerotised anellus, which is still totally fused to juxta.

Diagnosis. Imago (external). Wingspan: 12 mm ( Hampson (1898) gave wingspan as 14 mm).

Forewing: ground colour yellowish brown, with acutely-angled blackish patch in upper medial area, a blackish costal patch in basal area and a black terminal area.

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

Reniform stigma: well marked, white.

Hindwing: dark grey, with indistinct discal spot.

Underside: unicolorous grey.

Male genitalia. Tegumen: relatively broad (apo.).

Vinculum: strongly built.

Saccus: short; strongly built, broadly U shaped.

Ampulla: forming a cross with axis of valva; slightly asymmetrical, with one spinelike seta on outer distal corner (apo.).

Digitus: present; thornlike, inwardly directed (apo.).

Juxta and anellus plate: fused; anellar plate triangular and heavily sclerotised.

Phallus short and straight; upturned by carina with a spinelike extension (apo.).

Vesica: with spinules but no cornuti.

Female genitalia. Unknown.

Differential diagnosis. T. trigonifera differs from other Micronoctuidae from SE Asian and Oriental regions in five autapomorphies of male genitalia listed above; see also under T. schnacki .

Distribution. Known from one specimen from NE India, Assam. In Hampson’s handwritten manuscript, species no. 1734, he includes also a male paratype from Upper Assam, collected by William Doherty in 1895, but this is a different Tactusa species , T. assamia , see below.

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.