Rusicada WalkerGen. rev.

Type species: nigritarsis Walker.

Synonym: Gonopteronia Bethune-Baker (type species albopunctata Bethune-Baker, New Guinea to Solomons) syn. n.

This account contains much of the material in an unpublished review of the genus by the author that was referred to by Galsworthy (1997) and Holloway & Nielsen (1999). Though not fully illustrated, the keys presented should allow all known Indo-Australian species to be identified.

In that review, Rusicadawas retained as a subgenus of Anomis, but is here given full generic status for the reasons presented on p. 223. The species are relatively large and robust with variegated brick-red to brown or greyish and pale orange-red hindwings.

The male genitalia (see also p. 222) have deep valves that extend ventrally to a shallow saccus that has often a concave ventral margin. The valves have deeply based, slightly double coremata, and the Indo-Australian species usually have a slight fold or lobe at three-quarters from the valve base. The juxta is strongly developed, usually bifid distally (though this is reduced in one lineage), a feature shared with Cosmophila Boisduval. There are setose projections from where the anellus fuses with the aedeagus, and the aedeagus vesica has two reversed cornuti when everted. The male abdomen shares with Cosmophila and other members of the Anomis group a corema on the eighth sternite, but this is much more developed in Rusicada.

The female genitalia share with Cosmophila presence of two setose lobes arising from the posterior margin of the lamella postvaginalis. The corpus bursae is scobinate and corrugated, but lacks a signum.

The genus contains 17 Oriental and Australasian species of which six occur in as described later. The other 11 are as follows:

Keys to the Indo-Australian species are presented below, based separately on external appearance, male genitalia and female genitalia. The similarity of the external appearance of many of the species means that reliable diagnosis is best obtained from genitalia structures. However, distinction by female genitalia characters is least reliable for closely related species pairs such as revocans/fulvida, combinans/schistosema and the group prima/leucolopha/fulminans/vulpina, and it is recommended that external appearance and geography be used to confirm any diagnosis so made.

Numbers refer to presumed synapomorphies of each clade, listed below.

1. Setose projections from where anellus fuses with aedeagus. Vesica, when everted, with two reversed cornuti (reduced to one in many species). Sternite eight corema in male strong (present in Cosmophila and some allied species, but weak).
2. Single valve corema elongate along axis of valve. Setose projections from anellus well developed. Male forewing costal margin with one or two angles. Valve with slight fold or lobe centrally at three-quarters from base (lost, displaced or modified in several species).
3. Reversed cornuti reduced to one in vesica (also in privata though). Anellus projections asymmetric. Juxta stout, robust, broadly bifid (only slightly so in pair defined by 8, entire (bifurcations fused) in other members of sister group). Base of ductus bursae heavily sclerotised and sclerotisation continuous with lamella postvaginalis.
4. Valve central process lost (seen also in privata, metaxantha and to some extent in vulpina). Vesica of aedeagus with additional basal projections.
5. One basal projection on aedeagus vesica a distally directed spine. Angular projection from lamella postvaginalis between marginal lobes. Diverticulum basally on ductus bursae on right.
6. Dull brown coloration. Black dots distally on forewing reniform, one on anterior lobe, two on posterior lobe. Heavy sclerotisation and convolution of base of ductus bursae.
7. Valve apex bilobed. Setal bases on valve corema dark-centred.
8. Juxta bilobed rather than bifid. Gnathus apically divided, the bifurcations splayed. Base of ductus bursae spherically swollen. Reniform of forewing with posterior lobe larger, filled with pale or dark grey (also seen in the African pair; 10).
9. Juxta entire (some indication of fusion of bilobed structure in some species). Interior margins of lobes of lamella postvaginalis come together within a posteriorly directed pocket.
10. Juxta narrow, bifurcations close together. Eighth sternal corema strongly eversible.

The larvae are slender, cylindrical semi-loopers with the first of prolegs reduced. The primary setae are small, giving the body a glabrous appearance; the chaetotaxy was described by Gardner (1941). The larvae are solitary defoliators of a variety of plant genera, mainly in the family Malvaceae (Abutilon, Cissampelos, Gossypium, Hibiscus, Kydia, Sida, Thespesia, and Urena) and the related Tiliaceae (Grewia) and Sterculiaceae (Pterospermum, Sterculia, Waltheria), all Malvales.

The adults are primary piercers of soft-skinned fruit and secondary piercers of fruit with tougher skin (Bänziger, 1982); the development of barbs on the proboscis is generally more pronounced than in other genera of the Anomis complex (Bänziger, 1986).

Two Afrotropical species, leucosema Hampson and melanosema Berio, are also referable to Rusicada and probably form a sister-group to the Indo-Australian species as suggested by a cladogram presented by Holloway & Nielsen (1999). This is reproduced in Fig 2, with synapomorphies listed in the legend.

Two major clades are recognised. The nigritarsis clade is fully resolved and includes three widespread species (two recorded from Borneo) characteristic of open habitats as sister-group to a pair of species from New Guinea and neighbouring islands.

The second, much larger, combinans clade includes an unresolved group of ten species. Apparently derived traits within the group either also occur in combinans (long spines arising from within the anellar structure; valve projection transverse, almost a pocket) or otherwise lack congruence (obliqueness or loss of the valve projection; elongation of one vesica cornutus; square apex to juxta).