Miscellaneous Genera I
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Ischyja Hübner

Type species: manlia Cramer, India.

Potamophora Guenée (type species manlia).

The species are all large with strikingly patterned but cryptic forewings and with pale blue or white flash coloration on the more uniform hindwings. There is some sexual dimorphism, the males tending to have more variegated and clearly marked forewings. The male hindwing venation is strongly modified with disruption and shortening of the cell, separation of M2 from the rest of the quadrifid system, the remaining three branches remaining closely associated before diverging relatively distally, almost as a trident in one species (inferna Swinhoe) but with the CuA branches stalked to beyond this point of divergence in the rest. The two anal veins are closely associated near the base, and the dorsum is thickly scaled. The wider spaces within this modified system are relatively thinly scaled and slightly translucent. The underside is more uniform, though the forewings as well as the hindwings have an irregular blue postmedial fascia; the hindwings are more extensively blue below in several species.

The male antennae are somewhat flattened in the vertical plane and broader towards the base; they are fasciculate. The antennae extend well beyond the centre of the forewing costa. The labial palps of both sexes are directed forwards, the third segment very slender but equal in length to the robust second.

In the male abdomen the eighth segment is only slightly modified, with the tergite narrowing distally slightly from a broad anterior margin and being slightly less sclerotised in a circular lacuna, and with the sternite being slightly broader, with its posterior margin broadly notched. The genitalia have a balland-claw apex to the uncus, and a scaphium is present. The juxta, possibly modified from the inverted ‘V’ type, is diamond- or flask-shaped with, ventrally, a vertical, central, narrow, less sclerotised strip between two shallow flanges. The valves are robust, broadly based, narrowed distally beyond an angle in the ventral margin, and without accessory processes. The aedeagus has a transversely oriented, somewhat convolute vesica that bears three or so small sclerotisations with spines as well as more general scobination. The male genitalia are very uniform in structure throughout the genus, and species are usually more clearly identified from facies features.

The female genitalia (
hagenii Snellen, paraplesius Rothschild) have the seventh sternite reduced, its posterior margin slightly cleft and associated with the ostium. The ductus is very short, sclerotised, laterally scrolled. The ductus seminalis arises at the very base of a corrugated and scobinate basal section of the corpus bursae. This section is swollen centrally and twice as long as the distal, ovate section, from which it is separated by a constriction. The ovate section is more weakly scobinate and without corrugation.

The genus extends throughout the Indo-Australian tropics to as far east as the
Solomons, but is possibly most diverse in Sundaland. There are 11 species in Borneo.

A number of authors (Moore, 1884-1887 (with illustration); Gardner, 1947; Tanahara & Tanahara, 2000; Bell (MS)) have described larvae attributed to I. manlia, and one was illustrated by Kuroko & Lewvanich (1993). Confusion of the identity of manlia, and the presence of I. marapok sp. n. with it in the Indian Subregion make it difficult to ascertain which species may have been involved, so these descriptions and the host plants recorded are treated here in a generic context. Bell (MS) suspected, from the variety of larval forms in India, that more than one species was involved (see below); material from his collection in BMNH included specimens of marapok and hemiphaea Hampson.

The larva illustrated by Kuroko & Lewvanich is a semi-looper, though the prolegs on A3 appear to be only slightly reduced. Gardner (1947) noted numerous external setae on the prolegs, an unusual feature in the quadrifine Noctuidae. The body tapers forward through the thorax to the head, and segments A1 and A2 have pairs of tubercles dorsally, and there are dorsal humps on A7 and A8, the latter large and bearing a pair of tubercles. The body is a variegated golden brown with a fine, paler reticulation. There are transverse violet grey bands anterior to the tubercles on A2 and A3.

Moore (1884-1887) and Gardner (1947) referred to dark speckling, purplish variegation, and irregular marking with black streaks. Bell (MS) described various colour forms: light pinkish brown, suffused and reticulated with pale chocolate brown above a blackish dorsal line, this suffusion fading dorsally and with the ventral surface black and green; with a white subdorsal spot at anterior of A3 but generally more blackish and variegated; similar to the previous but greyish.

The pupa has a bluish-white bloom (Gardner, 1947), noted also in other species by H.S. Barlow (
pers. comm. and see below).

The host plants recorded (Bell, MS; Robinson
et al., 2001) are: Achyranthes (Amaranthaceae); Mangifera (Anacardiaceae); Ananas (Bromeliaceae); Canarium (Burseraceae); Terminalia (Combretaceae); Shorea (Dipterocarpaceae); Castanopsis, Quercus (Fagaceae); Cinnamomum (Lauraceae); Bauhinia, Dalbergia, Xylia (Leguminosae); Aglaia (Meliaceae); Malus (Rosaceae); Cupania, Cupaniopsis, Litchi, Nephelium (Sapindaceae); Vitis (Vitaceae). Tanahara & Tanahara, 2000 noted Cinnamomum and Stauntonia (Lardizabalaceae) as natural hosts on Okinawa I., but found the larvae would accept Rosa, Eriobotrya (Rosaceae), Diospyros (Ebenaceae) and Mussaenda (Rubiaceae) in captivity.

Adults of a species identified as
manlia were recorded as piercing fruit in Thailand (Bänziger, 1982; Kuroko & Lewvanich, 1993). The species may come more readily to fruit bait than to a light-trap, hence comments on rarity that follow are relative within the genus but possibly not comparative outside it. S.J. Willott (unpublished data) recorded several species in moderate frequency in lowland forest near the Danum Valley Field Centre; such records were all from samples made in the understorey.

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