Sundaroa Gen. n.
Type species: flaveofusca Swinhoe
Sundaroa is described to accommodate a number of species misplaced in Aroa and
Euproctis. Indeed, all Oriental Aroa are probably misplaced (see Orgyiini
and Parvaroa Gen.n). The African type species of Aroa, discalis Walker,
lacks tymbals in the male abdomen, has the uncus divided into two simple,
tongue-like valves, and has a curved aedeagus with a variably scobinate vesica.
The build is delicate, with rather deep, rounded forewings. Both wings
tend to be brightly coloured in shades of yellow, orange, brown and black. All
species have large black discal spot on the forewing. The venation is similar to
most Nygmiini, and has M3 + CuA1 stalked in the hindwing. Sexual dimorphism
varies from very slight to extreme.
The male abdomen lacks tymbals. The genitalia have several bizarre and
diagnostic features that necessitate mounting them in a lateral position as for
butterflies: the uncus is long to very long, with a pair of dorsal projections
at its base; the valves are very small, narrow, rather digitate; the aedeagus is
short, asymetrically Y-shaped, with spines at the apex of the larger distal arm;
the base of the aedeagus is also bifid.
The female has unusually shaped ovipositor lobes with the dorsal angles
distinctly produced. The pseudopapillae are well developed. The sterigma is
strongly sclerotised but the ductus and bursa are small, flimsy, the latter with
The genus appears to be restricted to Sundaland and is most diverse in
Borneo. As well as those species discussed below, it also includes S. mirma Swinhoe
comb. n. (Sumatra). Many species are day-flying.
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