(Figs. 25, 68)

Type material. Holotype: female, Thailand, Prov. Chiang Mai, Sop Kha 20–23 km NW, 1–2 km S Kop Dong, 1650–1800 m, 13.ix 1999 (Szabó A. & Z. Czere leg.), genitalia slide RKY 7613. The holotype is in the collection of G. Ronkay, Budapest, to be deposited to HNHM, Budapest, Hungary.

Diagnosis. The new species is externally close to S. basiviridis, but differs by somewhat narrower shape of wing, mossy-green coloration of forewing and sharp, distinct wing pattern with prominent 8-shaped reniform and twin ante- and postmedial line. Female genitalia close to S. basiviridis, differing by narrower antrum, sclerotized band in ductus bursae, sclerotized cervix bursae, wider bursae and by presence of sclerotized patch in anterior part of bursa copulatrix. Probably it belongs to the same species group as S. basiviridis. Male unknown.

Description. Adult (Fig. 25). Wingspan 27 mm. Head and thorax green, thoracic crest present; ground color of forewing dark, mossy-green, wing pattern sharp, distinct; basal field prominently yellowish white, green in costal area, basal line as two black dots; subbasal field with black suffusion, forming black dash in central part; antemedial line twin, formed by thin black lines; medial field mossy-green, more greenish in costal area; orbicular rounded, formed by black bordering line; reniform 8-shaped, white inside, bordered by black line; medial line distinct, thin, black; postmedial line twin, arising from costal area near medial line, strongly incurved outward, then following inward the ventral margin; subterminal field brownish-green, terminal field mossy-green; subapical streak in costal area prominently black; other subapical streak lies under wing apex; subapical area with pale, salad-green suffusion; terminal line expressed as row of large black dots; cilia brownish-green. Hindwing yellowish-grey in central part, dark brownish grey around terminal margin; discal spot traceable; cilia pale, greyish-yellow.

Female genitalia (Fig. 68). Papillae anales rather large, apophyses anterior 1/3 longer than the posterior ones; antrum very large, with central sclerotized plate, which widens before ostium, somewhat constricted in mid part, extending proximally and having rhomboidal proximal end; it is separated from ductus bursae by narrow membranous patch; cervix bursae with sclerotized band; bursa copulatrix rather large, sack-like with sclerotized and ribbed anterior part, forming sclerotized extension.

Distribution. (81). North Thailand. The species is known only from its type-locality, where it occurs in mountains at elevations of 1650–1800 m.

Etymology. The species name is derived from the word “ Siam ” (ancient name of Thailand).