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Rusicada Walker Gen. 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This account contains much of the material in an unpublished review of the genus by the author that was referred to by Galsworthy (1997) and Holloway & Nielsen (1999).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,
Rusicada was 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:

Rusicada fulvida Guenée comb. n. = inducens Walker

Oriental tropics and subtropics to Japan, Sumatra and Java

Rusicada mafalui Bethune-Baker comb. n.

Papua New Guinea

Rusicada albopunctata Bethune-Baker comb. n.

New Guinea, Bismarcks, Solomons

Rusicada schistosema Hampson comb. n.

Seram, Queensland, New Guinea, Solomons, Vanuatu

Rusicada privata Walker comb. n. = commoda Butler

China, Korea, Japan, Vietnam (Zilli, 1999), Thailand (VK) – introduced to eastern U.S.A.

Rusicada metaxantha Walker comb. n.

N.E. Himalaya, Vietnam (Zilli,1999)

Rusicada lineosa Walker comb. n.


Rusicada fructusterebrans Bänziger comb. n.

N. Thailand

Rusicada fulminans Bethune-Baker comb. n.

New Guinea

Rusicada vulpina Butler comb. n. = nagalia Mabille & Vuillot

Fiji, ?Samoa

Rusicada sp. n. (slide 11946)

N. Thailand

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.

External appearance

1 Forewing ground colour orange 2
 Forewing ground colour mainly brown or vinous, though perhaps with orange or reddish patches or tinge 11
2 Posterior lobe of forewing reniform smaller than the anterior 3
Posterior lobe of reniform equal to or larger than the anterior 5
3 Average line of zigzag anterior part of forewing postmedial oblique to costa nigritarsis
Average line of anterior part of postmedial more or less at right angles to the costa 4
4 Posterior lobe of forewing reniform markedly darker and forewing ground dull yellowish orange (Australian specimens of revocans could key out here) fulvida
Posterior lobe of forewing reniform only slightly darker and forewing ground reddish orange revocans
5 Forewing reniform with small lobes separated by a marked constriction; forewing margin rounded; pale orbicular large, often almost 1mm in diameter, cream-coloured vulpina
Forewing reniform with moderate lobes separated by only a slight constriction; forewing margin angular; orbicular a minute white dot 6
6 Forewing reniform with posterior lobe larger, filled with paler grey or dark brown  7
Forewing reniform with lobes roughly equal, filled with ground colour 8
7 Forewing antemedial more or less evenly curved; hindwings reddish; Papuan Subregion schistosema
Forewing antemedial irregular; hindwing brown; Oriental combinans
8 Hindwing margin produced slightly centrally prima
Hindwing margin more or less evenly rounded 9
9 Posterior half of forewing postmedial more or less straight, evenly concave distad or only slightly wavy; E. China, Japan, Vietnam privata
Posterior half of postmedial distinctly wavy 10
10 Length of forewing costa greater than 20mm leucolopha
Length of forewing costa less than 20mm metaxantha
11 Forewing margin excavate between apex and central angle; orbicular white dot prominent albopunctata
Forewing margin straight or only slightly excavate between apex and central angle; orbicular white dot minute 12
12 Posterior part of postmedial evenly curved, pale, colinear with basal edge of reniform lineosa
Postmedial not as above 13
13 Forewing marginal angle rounded; reniform with black dots distally; New Guinea (if Fiji, then vulpina) mafalui
Forewing marginal angle square, reniform obscure 14
14 Line of anterior half of forewing postmedial meets costa obliquely 15
Line of anterior half of postmedial meets costa more or less at right angles 16
15 Reddish brown; orbicular white dot present nigritarsis
Dark brown; orbicular not white fructusterebrans
16 Forewing markings obscure; rich reddish deep brown fulminans
Forewing markings obvious; vinous greyish brown or dark brown, sometimes with orange patch centrally by posterior half of postmedial 17
17 Forewings dark brown; line of posterior part of postmedial not contiguous with basal edge of reniform but well basal to it sp. 11946
Forewings vinous greyish brown, sometimes with orange suffusion; line of posterior part of postmedial more or less contiguous with basal edge of reniform albitibia

Male genitalia (aedeagus vesica must be everted).

1 Setose projections from anellar attachment to aedeagus asymmetrical, usually only one large one; valve coremata with setal bases pale; juxta robust, strongly bifid 2
Setose projections on aedeagus two, more or less symmetrical; valve coremata with setal bases dark-centred; juxta weakly bifid or entire, planar. 6
2 Valve with subapical lobes or projections 4
Valve without subapical ornamentation
3 Valve heavily sclerotised, ventral angle acute, curved; two subapical projections on valve: a large subdorsal rounded one and a smaller elongate angled subventral one; uncus square apically, constricted subapically; eighth sternal corema double albopunctata
Valve only lightly sclerotised, ventral apical angle blunt central subapical projection to valve a transverse flange; uncus tapering apically; eighth sternal corema single mafalui
4 Juxta bifurcations extend almost to apex of valve, apically curved; basal projections from vesica rugose, directed basad nigritarsis
Juxta bifurcations straight, terminating well short of apex of valve; one projection from base of vesica a robust, distally directed spine 5
5 Anellus projection long, slender, only heavily setose at apex revocans
Anellus projection broad, moderate, evenly and extensively setose fulvida
6 Juxta with lobes lateral to a longer, central, notched process sp. n. 11946
Juxta otherwise 7
7 Juxta distinctly bifid 8
Juxta entire or slightly lobed apically 9
8 Uncus apically excavate; aedeagus with two smaller anellus projections in addition to two normal ones and two prominent long spines arising from within the anellus structure schistosema
Uncus tapered apically; aedeagus with only two anellus projections, with two or three slender spines arising from within the anellar structure combinans
9 Juxta apically squarish, broadest at apex 10
Juxta apically rounded, narrower at apex 12
10 Cornutus in aedeagus vesica a lobe bearing several spines privata
Cornutus simple, unspined 11
11 Long spines associated with anellar structure as in 7; largest vesica cornutus acute metaxantha
No long spines in anellar structure; largest vesica cornutus apically bulbous   prima
12 Valve ornamentation a sclerotised band extending to the ventral margin subapically, where it is coarsely scobinate lineosa
Valve ornamentation not marginal if present 13
13 Valve with central subapical projection oblique 14
Valve with central subapical projection vestigial or transverse 16
14 Central projection of valve moderately oblique; uncus long, tapering fructusterebrans
Central projection more longitudinal than transverse; uncus short, somewhat swollen subapically 15
15 Aedeagus vesica with one cornutus long, curved, almost reaching exterior angle of everted vesica leucolopha
Aedeagus vesica with both cornuti short, blunt, directed more towards interior angle of everted vesica fulminans
16 Valve with central subapical projection reduced, merely a more sclerotised area vulpina
Central subapical projection of valve transverse albitibia

Female genitalia

1 Two posterior, finely setose lobes of lamella postvaginalis as long as, or longer than broad, separated by a deep, usually narrow cleft; sclerotisation at base of ductus bursae moderate to weak, separate from lamella vaginalis 2
Lobes of lamella postvaginalis broader than long at base, separated by only a shallow, angular cleft; sclerotisation at base of ductus bursae extensive, continuous with that of lamella vaginalis 12
2 Cleft of posterior lobes terminating in a posteriorly directed pocket 3
Cleft of posterior lobe equal to exterior margin, terminating simply 11
3 Ductus bursae with sclerotisation centrally 4
Ductus bursae with sclerotisation only basally or not at all 5
4 Ductus bursae with central sclerotisation associated with an angle privata
Ductus bursae not angled metaxantha
5 Base of ductus distinctly swollen, connected to pocket of lobes (2) by a broad band of sclerotisation lineosa
Base of ductus unswollen or only slightly so, connected to pocket of lobes by only a weak band of sclerotisation 6
6 Pocket of lobes much larger (deeper) than lobes albitibia
Pocket of lobes smaller than lobes 7
7 Sclerotisation present in ductus bursae distal to basal constriction 8
No sclerotisation so present 10
8 Pocket and lobes flanked by a pair of semicircular flanges sp. n. 11946
Pocket and lobes not flanked by flanges 9
9 Lobe pocket much smaller than lobes; anterior margin square, posterior margin shallowly cleft prima
Lobe pocket almost as large as lobes; anterior margin hastate, posterior margin rounded, deeply excavate leucolopha
10 Depth of pocket at sides less than one third length of interior cleft, its lip only slightly concave vulpina
Depth of pocket at sides about half length of interior cleft, its lip deeply concave fulminans
11 Lobes mostly parallel-sided, set close together combinans
Lobes tapering, set slightly apart schistosema
12 Lamella postvaginalis with posteriorly directed sclerotised angle between the lobes; diverticulum on right of base of ductus bursae 13
Lamella postvaginalis without such an angle; no diverticulum on right of base of ductus bursae (but possibly on left) 14
13 Angle between lobes obtuse, somewhat rounded  fulvida
Angle between lobes acute revocans
14 Sclerotised base of ductus straight, simple nigritarsis
Sclerotised base of ductus expanded, convolute 15
15 Distal diverticulum from left of basal swelling on ductus; lamella postvaginalis lobes only weakly cleft (to less than half overall depth) mafalui
No distal diverticulum on ductus swelling; lamella postvaginalis lobes cleft to more than half overall depth albopunctata

Fig 2.
Cladogram of relationships of species of Rusicada, with summaries of distribution.

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).

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