Aemene taprobanis Walker 1854

The Aemene taprobanis species-group

Diagnosis. The species-group is characterised by the combination of the following features in the male genitalia which is unique within the genus: (1) the presence of a short subbasal lobe of the costa; (2) the presence of two elongate and thin apical processes of the costa; (3) the long sacculus with a short (in certain species, reduced) distal process; and (4) the absence of a distal membranous lobe of the valva. In the female genitalia, the thin and helical appendix bursae is diagnostic. Additionally, the ductus bursae is elongate, sclerotised and dorso-ventrally flattened, and the corpus bursae bears round, elliptical or short ribbed band-shaped signa.

Description. External morphology of adults. Forewing length 9–13 mm in males and 9–14 mm in females. Male antenna shortly bipectinate or densely ciliate, female antenna sparsely ciliate. Head, thorax and wing colouration brownish or greyish. Forewing pattern brown. Subbasal line interrupted into spots. Antemedial and medial lines irregularly zigzagged or interrupted in certain species. Postmedial line irregularly zigzagged, strongly curved opposite the cell. Submedial line indistinct, often presented by subapical spot at costal margin. Terminal line interrupted into spots between veins. Cell with round or elliptical spot between antemedial and medial lines and reniform or round discal spot. Cilia monotonous, as forewing ground colour. Hindwing monotonous, in certain species with dark suffusion. Discal spot present in certain species, falcate, indistinct. Abdomen darker than thorax and head, in females densely covered with long hair-like scales apically. Male genitalia. Uncus elongate, slender, somewhat dilated medially or distally, with pointed claw-like tip. Tuba analis broad (ca. half of tegumen length), with heavily sclerotised stick-like scaphium. Tegumen with posterior halves of arms fused. Vinculum somewhat shorter than tegumen, U-shaped, with short corema anteriorly. Valva equal in length or somewhat shorter than tegumen-vinculum complex, tapered distally, with medially convex costal margin. Costa with short and rounded subbasal lobe and two triangular or thorn-like apical processes, in certain species with additional subapical process dorsally. Sacculus narrow and long, with short distal process directed dorsad, latter one may be reduced in certain species. Transtillae wide, fused. Juxta short but wide, transverse band-shaped, weakly sclerotised. Phallus large (longer than tegumenvinculum complex), somewhat curved, with short and rounded coecum. Vesica broad, globular, bearing fields of granulation and clusters of spine-like or triangular cornuti of various sizes. Basal plate of vesica ejaculatorius narrow but strongly elongate, heavily sclerotised. Vesica ejaculatorius distally twisted. Female genitalia. Papilla analis trapezoidal with rounded corners, weakly setose. Apophyses long and thin, anterior one equal in length to posterior one or somewhat shorter. Postvaginal area with two lateral subostial lobes. Ductus bursae elongate and narrow, somewhat dilated posteriorly, dorso-ventrally flattened, its posterior section weakly sclerotised while anterior one granulated. Posterior section of corpus bursae with sclerotised plates and clusters of spinules or short but robust triangular thorns; anterior section broader than posterior one, membranous with ribbed band-like and (or) round or elliptical signa. Appendix bursae originating postero-laterally, directed laterally, narrow, helical, bearing clusters of granulation or scobination.