Aroana Bethune-Baker

Type species: olivacea Bethune-Baker, New Guinea.

Synonym: Ectogoniella Strand (type species pangraptalis Strand, Taiwan = baliensis Hampson; see below), syn. n.
Poole (1989) placed this genus in the Acontiinae, its current placement in the BMNH curation. However, Edwards in Nielsen et al. (1996) placed it within a broad concept of the Catocalinae, associated with genera of the Throana Walker and Saroba Walker generic groups of Holloway (2005). Sugi, in Inoue et al. (1982), placed Ectogoniella in the Ophiderinae.

The wing shape and facies are definitive, the former having the distal margins of all wings with a central angle, and crenulation posterior to this angle. The ground colour is a pinkish grey or, in the type species, a deep, rich green fasciated with brown that occurs also as a more extensive trapezoid on the forewing costa between the postmedial and submarginal. The discal marks are black, that of the forewing lunulate or a chevron, that of the hindwing bipunctate; there may be an orbicular dot on the forewing. The underside is a more uniform pinkish grey with the fasciae finer and more clearly defined. The type species has extensive areas of the wings flecked with pale blue. The labial palps are moderate, upturned, and the male antennae are sparsely ciliate with a few longer bristles amongst smaller ones.

The male abdomen has the eighth segment short and modified. The tergite is round to oval or slightly bilobed on its posterior margin, and with two short, triangular, widely separated apodemes on the anterior margin. The sternite is widely and obtusely notched, shorter than the tergite, and with patches of hair scales on each side. The genitalia have the valves robust, somewhat triangular, and divided slightly into costal and saccular parts distally as illustrated. There is a moderate saccus. The aedeagus is short with a small vesica that lacks ornamentation.

The female genitalia have the ostium set within the eighth segment, with pockets on each side; the apodemes are absent or vestigial, located on these pockets. The ductus bursae is sclerotised basally and distally as in Eublemma (see p. 159), but the base of the corpus bursae is not coiled, though usually having an area of sclerotisation. There is a constriction distal to this sclerotisation, with an oblique and incomplete ring of spines distal to the constriction. This ring is similar to that of Arasada (p. 118), though it is complete and not oblique in that genus.

On balance these features suggest that the genus is best placed in the Aventiinae.

The genus, as strictly defined above, consists of the type species and those discussed below. Edwards in Nielsen et al. (1996), included two further Australian species in Aroana that were not listed there by Poole (1989): ochreistriga Bethune-Baker; hemicyclophora Turner. Both were originally described in Zethes Rambur, ochreistriga from New Guinea. The facies of both is not consistent with placement in Aroana, nor are the male genitalia of ochreistriga.