Orothalassodes Holloway, 1996

Han, Hongxiang & Xue, Dayong, 2011, Thalassodes and related taxa of emerald moths in China (Geometridae, Geometrinae), Zootaxa 3019, pp. 26-50 : 30

Orothalassodes Holloway, 1996

Orothalassodes Holloway, 1996 , Malay. Nat . J., 49 (3–4): 259. Type species: Thalassodes hypocrites Prout, 1912 , by original designation. SINGAPORE.

Description. Head: Identical to that of Thalassodes . Thorax: Hind tibia with two pairs of spurs in both sexes, not dilated, without hair-pencil and terminal extension in male. Wing pattern: Outer margin of both fore- and hind wings smooth or crenulated, sometimes slightly projecting at middle on hind wing, inner margin elongate. Apex of forewing pointed to blunt, that of hind wing slightly protruding, rounded. Wings bluish green (more bluish than Thalassodes ), diffused with white striations. Forewing with antemedial line indistinct, postmedial line punctuated, composed of series of dots on veins, often enlarged, forming white patch on inner margin. Hind wing with postmedial line similar to that of forewing; sometimes with white discal spot. Fringes of both wings sometimes reddish, appearing as white dots on vein ends. Venter paler than dorsum, streaks on dorsum discernible. Venation identical to that of Thalassodes . Abdomen: Dorsal side often with small white patches. Third sternite of male abdomen lacking setal patches. Eighth segment modified: sternite very broad, often expanded laterally, with blunt process, concave at middle or occasionally with sclerotized process; tergite very narrow, bifurcate posteriorly. Male genitalia: Uncus sclerotized, narrow and long. Socii narrow, of similar length to uncus. Gnathos with median process tapering, pointed or blunt. Valva usually simple, with a weak longitudinal setal patch at middle near costa; occasionally with ampulla (e.g. O. pervulgatus Inoue, 2005 ). Juxta sometimes with serrated sclerite at lateral sides of posterior. Saccus semicircular or tongue-like. Coremata absent. Aedeagus sclerotized and usually blunt terminally; vesica wrinkled, with pointed to blunt cornutus. Female genitalia: Shape variable. Sterigma wrinkled, sclerotized. Ductus bursae very short to long, often broad and with lateral lobe. Corpus bursae small to very large; bicornute signum sometimes present.

Diagnosis. On wing pattern, Orothalassodes can be distinguished from other three genera ( Thalassodes , Pelagodes and Remiformvalva) by the large white spot on the forewing postmedial line at the inner margin, or the white discal spot on the hind wing. Main characteristic features are in the modification of the eighth segment, which is more pronounced than in Thalassodes . Contrastingly the pair of slender lateral processes on the sternite and simple tergite in Pelagodes are absent in this genus. In the male genitalia, the usually simple valva is distinguishes the genus from the other three genera. In the female genitalia, the lateral lobe that is often present on the ductus bursae is also distinctive. However the narrow socii are similar to that of Thalassodes and the absence of setal patches on the third sternite and coremata is shared with Pelagodes and Remiformvalva.

Distribution. South-east Asia to South-west Pacific.