Costicoma, CHOI, 2000

CHOI, SEI-WOONG, 2000, A Cladistic Analysis of the Therini: A New Synonym of the Cidariini (Lepidoptera: Geometridae, Larentiinae), American Museum Novitates 3295, pp. 1-26 : 19-21

Costicoma , new genus

TYPE SPECIES: Perizoma exangulata Warren, 1909 .

DIAGNOSIS: Species of Costicoma can be characterized by the forewing with blackish central fascia medially and dorsally greatly tapered, the valva with sclerotized costa and long hairs on the middle of costa, cornuti absent from vesica, and the female genitalia having the corpus bursae with a large, threadlike signum.

DESCRIPTION: Antenna filiform in both sexes. Frons mixed with ochreous and brownish scales. Labial palp short. Legs dark brownish, foreleg tarsal joints distinct with ochreous scales. Metathorax dorsum with blackish tufts. Forewing basally dark brown; basal line dentate, slanted; central fascia blackish, costally bulged; subterminal line whitish, scalloped; apical streak blackish. Hindwing whitish, basally tinged with blackish scales; postmedial line blackish. Male genitalia. Uncus long, basally tapering. Tegumen dome-shaped. Saccus rounded, medially expanded. Anellus lobe long, rod shaped, apically with long hairs. Transtilla thin, round- ed, sclerotized. Valva slender; costa slender, distally with long hairs; sacculus membraneous. Aedeagus cylindrical with large, saclike vesica; cornutus absent. Female genitalia. Papillae anales simple. Anterior apophyses about 3 ⁄ 5 length of posterior apophy- ses. Sterigma membraneous, antrum broad, funnel-shaped. Ductus bursae short with a colliculum. Corpus bursae large, subovate, with a long, threadlike signum.

DISCUSSION: There are four autapomorphies: uncus long (character #12-1); ventral edge of sacculus flat (#27-1); vesica large, saclike (#33-0), signum large, threadlike (#47-3), and wall of corpus bursae with netlike sclerotizations (#48-3).

Costicoma exangulata is similar to Cidaria deletaria Hampson in the male genitalia having long hairs on the costa, but differs in the wing pattern and female genitalia (Choi, 1998a). Results here place C. exangulata as the sister taxon to P. corussarium , and the basal clade is supported by two apomorphic characters: blackish metathorax and thin, round transtilla. This taxon was included in the Therini (Prout, 1938) , but is distinct from other species of Therini based on several apomorphic characters (Choi, 1998a): costa of valva strongly sclerotized with long hairs; large saclike vesica without a cornutus; os- tium bursae broad; colliculum present; signum large, threadlike, and wall of corpus bursae with netlike sclerotization. Differences in wing pattern and genitalia separate exangulata from its sister genus Paradysstroma , suggesting a new genus, Costicoma . It is only known from northern India.

ETYMOLOGY: The name refers to long hairs on the costa in the male genitalia, Costa (Costa) + Hairs ( Coma ).