Thagria unibasispinosa, sp. nov.

(Plate 3A, Figs. 132–138)

Length, Male 8.50 mm; female unknown

External morphology. Moderately large, somewhat robust species. General color dark brown to black with numerous pale yellow markings on forewings; crown ivory, suffused spot medially near anterior margin and surrounding ocelli; eyes light translucent brown; pronotum black, bullae yellow; mesonotum black; forewings light brown with numerous ivory irregular shaped markings (Plate 3A); clypeus light yellowish brown, dark markings on clypellus, lorae and genae. Head much narrower than pronotum, anterior margin obtusely rounded; crown broad, wider than eye width, produced distally about ¼ of entire length, lateral margin convergent basally, depressed medially; pronotum large, slightly longer than crown; mesonotum large, nearly twice as long as pronotum; forewings typical; clypeus long, broad, constricted at base of antennal sockets, narrowed to truncate apex; clypellus short, broad but with base narrower than clypeus at juncture of clypeal suture, slightly inflated basomedially, apex expanded laterally.

Male genitalia. Pygofer in lateral view with short, very broad caudoventral lobe and segment X with concealed ventral processes (132), caudodorsal margin in dorsal view with moderately long, paired digitate processes (Fig.133); aedeagus in dorsal view symmetrical, long, exceeding midlength of ventral paraphysis, single prominent process basally (Figs. 134, 135); ventral paraphysis symmetrical, long, broad in basal 3/4, tapered toward apex (134, 135); style in dorsal view very long, extended beyond apex of ventral paraphysis, with prominent spine basad of middle, in lateral view slightly curved ventrally in distal 1/3, apex obliquely truncate with few small teeth apically (Figs. 136); connective typical; style in dorsal view very long with subbasal process on lateral margin (Fig. 137); dorsal connective in dorsobasal view broadly U shape, rami very narrow, attached distally to base of ventral process of segment X (Fig. 133); subgenital plate with tuft of long microsetae apically (Fig. 138).

Material examined. Holotype male. Vietnam, Tam Dao Mts., June 1991, V. Novotny (B11) (349 SP) (Brit. Mus. 1994 – 29) (BMNH)

Etymology. The name is descriptive for the single basomedial process on the dorsal margin of the ventral paraphysis.

Remarks. This species is unique having a single basal process on the ventral paraphysis and a subbasal spine on the style, all of which will separate it from all other species in the group having a narrow flat, basal clypellus and symmetrical aedeagus and ventral paraphysis.