Athyma reta moorei (Fruhstorfer, 1906)

Kirton, Laurence G., Tan, Horace, Phon, Chooi-Khim & Khew, Sin-Khoon, 2020, Discovery of the previously overlooked female of Athyma reta (Lepidoptera: Nymphalidae), and its taxonomic implications, Raffles Bulletin of Zoology 68, pp. 249-266 : 260-262

Athyma reta moorei female: Peninsular Malaysia —

Kedah : Langkawi (7 specimens: 5 ZRC, 2 MNM); Langkawi, Bukit Tembak (Chong-Arshad) — Selangor: Ampang Jaya ( MNM) ; Batang Berjuntai (ZRC); Bukit Tarik (2 specimens: Chong-Arshad, ZRC) ; Gombak (MZUM); Rantau Panjang (2 specimens: ZRC) ; Templer Park (2 specimens: MZUM, ZRC) — Pahang : Kuantan , Bukit Sekilau (Kirton); Fraser’s Hill (2 specimens: ZRC, FRIM) ; Genting (MZUM); Lanchang (Liew); Lata Jarum (Liew); Tanum, Sungai Yu Corridor (FRIM) — Negeri Sembilan : Kenaboi (2 specimens: MZUM) ; Seri Menanti (Chong-Arshad) — Johor: Batu Pahat (MZUM); Panti FR (3 specimens: FRIM) ; Skudai (Neo). Singapore — Nanyang (2 specimens: Tan) .

Description of the female of A. reta . The following is a first description of the female of A. reta . Upperside ground colour of wings black-brown from above vein 1a of the hindwing and on the whole forewing, with contrasting white cilia on the mid margins of each of spaces 1b–4 on the forewing and spaces 1b–7 of the hindwing, and marked with orange spots, bands and lines as follows. On the forewing: a streak running narrowly from the base of the wing into the lower half of the cell where it expands and is broken on its upper margin then tapers slightly at the end of the cell; an arrowhead-shaped marking in space 4 just beyond the cell, tapering towards mid vein 4 and always at least slightly convex at its upper margin in the first quarter of space 4; an irregular band comprising four spots from mid space 1a to the lower half of mid space 3; a series of submarginal spots starting in space 1a and running parallel to the termen to space 3, thereafter continued as a postdiscal band that arcs to the costa in spaces 4–6, flanked by a costal dash in space 10; a small submarginal spot or streak in space 4 forming an arc with subapical spots in spaces 5 and 6, flanked by a costal dash in space 8; a marginal line from space 1b to space 6, sometimes faintly present in spaces 1a and 7. On the hindwing: a subdiscal band from vein 1b to vein 8; a similar but narrower and more irregular postdiscal band; a marginal line from vein 1b to vein 8. Head black above with an orange-scaled collar. Palpi black above. Antennae black above with a deep orange-brown tip. Thorax black above with a transverse orange to yellow band next to the base of the orange cell-streak. Abdomen black above, covered with light orange and white hair-like scales on the first segment and orange scales on the second and third segments. Remaining segments black with sparse orange scales. Underside wing colour reflecting the colour and markings of the upperside but much paler orange-white, with heavy orange-white scaling over the ground colour, especially on the hindwing, and patches of brown scaling between the two orange hindwing bands. Head and palpi pale orange beneath. Antennae whitish beneath with the club deep orange-brown. Thorax ventrally clothed in whitish hairs. Legs pale orange-white; tibial and tarsal spines black-brown. Sternites of abdomen clothed in very pale orange scales.

The female of A. reta can be distinguished from the orange female form of A. nefte by the orange or yellow thoracic band, which is white in A. nefte . In the Sundanian region, to which it may be restricted, it is also reliably distinguished by the convex upper margin of the basal half of the cell-end arrowhead, which is concave in A. nefte . Other less reliable differences in the Sundanian region, which are described in more detail above are i) wider orange markings in A. reta , ii) a clearer submarginal spot in space 4 of the forewing upperside between the postdiscal and narrow marginal bands, iii) a generally stronger orange colour on the underside, iv) more orange scaling flanking the underside markings, and v) pale orange underside bands and spots, instead of almost white markings with a pink or pale orange tinge as in A. nefte f.-f. neftina.

Recognised subspecies of A. reta

The following subspecies of Athyma reta are recognised: syma (Frühstorfer, [1913]) – Nias

riamba ( Corbet, 1942) – Mentawai Islands

reta Moore, 1858 – Sumatra

mendica (Frühstorfer, [1913]) – Bangka Island

moorei ( Frühstorfer, 1906) – Southern Thailand, Peninsular Malaysia and Singapore

kresna Moore, 1858 – Borneo

retina ( Frühstorfer, 1906) – West Java

The name “ eurylenia ” attributed by Frühstorfer (1906) to Hagen (1898) as a subspecies of Athyma (“ Pantoporia ”) reta in Sipora is a misspelling and misdating of euryleuca Hagen, 1898, rightly considered by Corbet (1942) to be a subspecies of A. kanwa from Mentawai. The taxon adunora Kheil, described from Nias, was once placed as a subspecies of A. reta by Frühstorfer (1906), but is a subspecies of A. clerica Butler (see Eliot & Kirton, 2000; see also specimen figured in original description).

Misidentifications in the literature. The following specimens figured as females of A. reta are in fact males of this species: Frühstorfer (1913), pl. 124, row d, third fig. from left, reta syma, Nias — Tsukada (1985), pl. 143: fig.

24, reta moorei, Peninsular Malaysia, labelled as female in the plate but as male in the plate description; pl. 144: figs. 13–16, reta syma, Nias; figs. 18–20, reta riamba, Mentawai — Otsuka (1988), pl. 58, row a, second and third figs. from left, both reta kresna, Borneo.

The following specimens figured as females of A. nefte are in fact females of A. reta: Distant (1886) , Tab. (plate) 16, fig. 7, reta moorei (with near certainty), Peninsular Malaysia — Fleming (1975, 1983), pl. 45, fig. N 87 female f b, reta moorei, Peninsular Malaysia — Tsukada (1985), pl. 151: fig. 7, cf. subspecies reta, Belitung ; fig. 9, reta reta, Sumatra ; fig. 10 reta reta, Sumatra ; fig. 11, reta kresna, Borneo ; fig. 12, reta moorei, Peninsular Malaysia; fig. 14, reta kresna, Borneo — Otsuka (1988), pl. 59, row ‘a’, second and third figs. from left, both reta kresna, Borneo — Khew (2010, 2015), p. 112 (First edition), p. 116 (Second edition), upper inset fig., reta moorei, Singapore — Kirton (2014), p. 83, bottom left fig., reta moorei, Peninsular Malaysia (figure corrected in Second Edition, in press).

Implications to the relationships of species. Pinratana & Eliot (1996) attempted to assign species traditionally placed under Athyma in subgenera using names originally described as genera by Moore (1898). They placed A. kanwa , A. reta , A. nefte and four other species of Athyma in subgenus Tatisia Moore based on their closed forewing cell and hairy eyes. Prior to this, A. reta and allied species have also been placed in a common group with A. kanwa (in Evans, 1932) or placed in a systematic position that suggests it is closely related to this species (e.g., Corbet & Pendlebury, 1992). This is probably because the males of both A. reta and A. kanwa have the forewing cell-end spot separated from the cell streak and the forewing spot in space 2 separated from the spot in space 1b. In addition, the female of A. reta was thought to resemble the male, as in A. kanwa .

However, the discovery that the female of A. reta has orange markings, and an analysis of the morphology of its early stages, enables some new inferences on the relationships of the species. Firstly, A. reta is closely related to A. nefte and A. cama . The early stages of A. reta moorei closely resemble those of A. nefte subrata , which is compared alongside A. reta in this study, and has also been figured by Igarashi & Fukuda (2000) from Peninsular Malaysia and by Tan & Khew (2012) from Singapore. The two species also share a common hostplant, Glochidion zeylanicum var. zeylanicum . Both species share very similar larval characteristics with A. cama zoroastres Butler (Taiwan) for which the early stages have been illustrated by Igarashi & Fukuda (2000), and in common with this species they also exhibit sexual dimorphism.

Athyma reta , A. nefte and A. cama have a few early stage characters in common with A. selenophora laela (Frühstorfer) (Taiwan) , A. perius perius (Linnaeus) (Peninsular Malaysia), A. gutama teldeniya (Frühstorfer) (Palawan) , A. speciosa Staudinger (Palawan) and A. libnites libnites (Hewitson) (Sulawesi) , for which the early stages have been figured by Igarashi & Fukuda (2000). The same characters are seen in A. pravara helma (Frühstorfer) , A. clerica clerica and Pandita sinope sinope Moore , which have been bred by L.C. Goh (personal communication, photographs seen). The fifth instar larvae of all these species have narrow, elongated thoracic and abdominal setae that branch into three or four at their tips. They also have small peripheral conical head spines and small rounded frontal head tubercles. In the pupae of these species, the cephalic protuberances that encase the palpi are relatively short, flexed sideways and drawn to a fine-tipped point.

The larval and pupal stages of all the above species differ starkly from those of A. kanwa , which has thick and densely branched setae in the final larval instar and greatly elongated cephalic protuberances that encase the palpi in the pupa, resembling A. venata Staudinger from Palawan ( Igarashi & Fukuda, 2000). Athyma kanwa and A. venata also differ structurally from these other species in the adults, in having the origin of forewing vein 3 located on vein 4 beyond the lower discocellular vein, instead of located on the cubitus before or beside the lower discocellular vein. These clear structural differences in the early stages and adult indicate that A. reta and other allied species are not closely related to A. kanwa , with which they have in the past been grouped ( Pinratana & Eliot, 1996).

In view of the above, the name Tatisia , if applied as a species grouping at any infra-generic level, would likely include only A. kanwa (the type species of Tatisia ) and A. venata . The name Zabana Moore is available as an infra-generic name for A. nefte and allied species if required, since its type species, Athyma urvasi C. & R. Felder, is a male of A. nefte with white markings that are broader than usual. Most of the remaining species placed in Tatisia by Pinratana & Eliot (1996), including A. nefte , were originally placed in Pantoporia Hübner by Moore (1898) who considered the type species of this genus to be Athyma nefte , having overlooked that the type species was fixed by Scudder (1875) as Pantoporia hordonia ( Papilio hordonia Stoll ), as pointed out by Hemming (1967).

Recent molecular studies ( Dhungel & Wahlberg, 2018; Wu et al., 2018) have provided new insights into the relationships of species within the Limenitidini . These studies suggest that some of the species traditionally placed in Athyma merit being placed in genera of their own ( Tacola Moore ) or, in other cases, should be placed under Limenitis Fabricius (e.g., asura ). Conversely, they suggest that some species placed in other genera ( Sumalia Moore ) or genera of their own ( Pandita Moore ) are congeneric with Athyma . These findings broadly agree with the larval and pupal morphology of species for which the life histories are known. For example, all the species mentioned earlier that share the larval and pupal characters of A. reta are grouped within a common clade in the mitochondrial 37 gene analysis of Wu et al. (2018). However, the phylogenetic tree is less in agreement with the very divergent larval and pupal morphology of A. kanwa , a species included in the same clade. Clearly, further studies on adult and early stage morphology, host plants, gene sequences and behaviour will be needed to fully clarify the relationships of species in the Limenitidini . It is also certain that a revision of the subgeneric divisions of Athyma proposed by Pinratana & Eliot (1996) will be required.