Platyja sumatrana

Zilli, Alberto & Vos, Rob de, 2021, The sumatrana species group of the genus Platyja with descriptions of four new species (Lepidoptera: Erebidae), Fragmenta entomologica 53 (2), pp. 391-410 : 395

Platyja sumatrana sub-group

Platyja sumatrana ([C. & R.] Felder & Rogenhofer, 1874) (Figs 16, 25-26, 30)

Ophisma sumatrana [ C. & R.] Felder & Rogenhofer, 1874. In: Felder C. et al., [1865]-1875, Reise der Österreichischen Fregatte Novara um die Erde in den Jahren 1857, 1858, 1859 unter den Befehlen des Commodore B. von Wüllerstorf-Urbair (Zoologischer Theil) 2 (2) Lepidoptera (Atlas) : Erklärung der Tafel CXVI, pl. 116, fig. 5. Locus typicus: Sumatra. Holotypus ♂ (by ‘likely’ monotypy), in NHMUK [examined: actually, a chimaera of glued pieces as usual by Felder’s technicians] .

= Platyja sumatrana magnimargo Holloway, 1976 . Moths of Borneo with special reference to Mount Kinabalu: 34, pl. 13, fig. 161. Locus typicus: [Borneo, Mt Kinabalu] Park H [ead] Q[uarters]. Holotypus ♀ (by original designation), in NHMUK [examined].

Distribution. Indochinese-Sundan species known from Vietnam, Malay Peninsula (from Southern Thailand to Singapore), Sumatra and Borneo ( Roepke, 1951; Holloway, 1976, 2011; and original data) ( Fig. 76 ).

Diagnostic remarks. Unmistakable species. The male has much shorter antennal rami than other relatives and is of deep dark blackish brown colour, with weakly expressed pattern, postmedial line of forewing just barely visible and reduced to a few black dots, narrow bright white adterminal bands on both wings, and strongly tetragonal hindwing. On the underside black colour predominates too, but there are broad white patches in correspondence of forewing apex and basal area of hindwing, and also the fringes are white. On the upperside, the female is similarly patterned to the male but with much wider, dirty white adterminal bands, especially on forewing, and its ground colour can vary from chocolate to dark blackish brown; on the underside it is pale lilac brown with sparse pinkish white sprinkles and minute pinkish white streaks where the uniformly bowed postmedial lines and veins cross. The male and female genitalia are as illustrated in figures 49, 70 and 75. Their most outstanding features are the small rounded apical process of valvae, the long, arched, banana-shaped apical process of the right plate of juxta, the short scaphium lying on a partly separate lobe overlapping tuba analis, the very long midventral cleft of the lodix that almost reaches the base of sternum A7, where the two lateral lobes interlock via the ‘scale-fold’ system described in the general morphological and taxonomic remarks above, and the post-ostial prolongation of the dorsal wall of the ductus bursae, which is particularly long and narrow.

Taxonomic remarks. The description by Holloway (1976) of Platyja sumatrana magnimargo as of a wider-banded subspecies was likely driven by the filiform antenna artifi- cially glued by Felder’s technicians onto the male holotype of sumatrana , so that at a first glance this seems to be a female, and absence of other females of this sexually di- morphic species at the NHMUK at the time of its description. This taxon was eventually subsumed into nominate sumatrana by Holloway (2005) himself.

Figures

Fig. 76 – Distribution of species of the Platyja sumatrana-group (populations from New Britain and Rook Island [= Umboi, Siassi] combined as vityaz s.l.; see explanation in text).