Danaus chrysippus, FROM WALLACEA

Smith, David A. S., Lushai, Gugs & Allen, John A., 2005, A classification of Danaus butterflies (Lepidoptera: Nymphalidae) based upon data from morphology and DNA, Zoological Journal of the Linnean Society 144 (2), pp. 191-212 : 201-203

FORMS OF D. CHRYSIPPUS FROM WALLACEA

Corbet (1940) established the type locality of the nominotypical form of D. chrysippus ( Linnaeus, 1758 as Papilio chrysippus ) as Canton, China. In his species-level review of Danaus, Talbot (1943) classified all D. chrysippus from Arabia eastwards to the Malay Peninsula, Borneo, the Philippines and China as ssp. chrysippus . He distinguished three further Indo-Pacific subspecies, bataviana (Moore) , cratippus (Felder) and petilia (Stoll) , as replacing forms distributed eastwards and southwards across Wallacea (the Malay and Indonesian Archipelago) to IJ/ PNG, Australia and Fiji ( Lushai et al., 2005a).

There are problems with the ambit, relationship, biogeography and correct name for D. chrysippus ssp. bataviana . Moore (1883: pl. XXX1, fig. 1) described ‘ Limnas alcippoides n. sp. ’ from Nepal that had white on the hindwing, though rather less than in alcippus from West Africa, and, on the forewing, a broad subapical bar comprising [five] conjoined white spots [in spaces 4–6, 8–9], an enlarged spot below the bar [in space 3 (Cu 1a)], and a bold submarginal white spot in the orange area [of space 2 (Cu 1b)]. This description fits specimens from Penang south to the Singapore Strait in the Malay Peninsula, collected, bred or observed by us (N = 172, DASS unpublished).

Furthermore, the description embraces an OUMNH collection (N = 35) from Kuala Lumpur, West Malaysia, made by W. A. Lambourne in 1920–1. It should be noted that the latter is labelled ‘ Danaida chrysippus bataviana Moore , subspecies alcippus Cramer’. In all these specimens, and similar ones from the same area, housed in the Natural History Museum, London (NHML) (N = 7) and the Muséum National d’Histoire Naturelle, Paris (MNHNP) (N = 6), the white area on the hindwing fully matches in extent that found in African alcippus. This suggests that Moore’s alcippoides type from Nepal was heterozygous (Aa) at the A locus, which determines hindwing white ( Clarke et al., 1973; Smith, 1998). Moore’s description also applies to specimens with full white hindwings in the NHML (N = 29) and MNHNP (N = 3) collected from Sumatra and Nias Island before 1935.

Moore (1883) also described but gave no figures for ‘ Limnas bataviana n. sp. ’ from Java and ‘ Limnas bowringi n. sp. ’ from Hong Kong. The former resembled alcippoides except that the hindwing was brown, whereas bowringi had an orange hindwing and ‘subapical band composed of somewhat larger spots’. Both bataviana and bowringi had a second submarginal ‘lower spot’ [in space 1b (1 A + 2 A) of the forewing], as in 42% (N = 105) of alcippoides examined by us from the Malay Peninsula.

Having examined large collections from Malaysia and Indonesia in the OUMNH, NHML and MNHNP (N = 478), we now propose that four forms (including gelderi (Snellen) from Sulawezi), are minor variants of a single subspecies. Whereas alcippoides (white hindwing: Malay Peninsula, Sumatra and its neighbouring small islands), bataviana (brown hindwing: Java and the Greater Sunda Islands) and gelderi (white marks on hindwing: Sulawezi) have some geographical integrity, bowringi occurs as a morph throughout the Far East. Although the name alcippoides has priority by pagination over bataviana and bowringi , Moore’s (1883) description of bataviana and the type locality (Java) best fits the material we have examined. The names bowringi , alcippoides and gelderi remain relevant for these distinct varieties.

In January 1996, one of us (DASS) undertook a Danaus transect, following the west coast of the Malay Peninsula from the Thai border in the north to the Singapore Strait in the south. Although not uncommon, chrysippus s.s. and bataviana are local in Malaysia, generally occurring in isolated but sometimes dense colonies where their food-plant, Calotropis gigantea , is established ( Corbet & Pendlebury, 1992; DASS, unpublished). In the north-western province of Kedah (including Langkawi Island), all records (N = 240) were for D. chrysippus chrysippus . Only one hybrid individual with any white on the hindwing (genotype Aa) was taken. In contrast, from Penang southwards all sightings and captures (N = 250) were bataviana f. alcippoides , thus confirming Corbet & Pendlebury (1992). There was no sign of an anticipated hybrid zone.

These records may be compared with per cent frequencies in pre-1935 museum collections from the Malay Peninsula south of Kedah, Sumatra and Nias Island: orange hindwing (A-) 59.0, hybrid phenotype (Aa) 7.2, white hindwing (aa) 33.8 (N = 237). Pre-1904 percent frequencies are: A- 76.3, Aa 5.5, aa 18.2 (N = 55). These data suggest that heterozygotes were scarce pre-1935, indicating that chrysippus chrysippus and bataviana have always been substantially isolated, as they are today. It is clear, both from local records ( Morishita, 1985) and analysis of museum material, that bataviana has largely displaced chrysippus c hrysippus during the 20th century, both in peninsular Malaya north to Kedah and in Sumatra and Nias Island. The late D. F. Owen (pers. comm.), who visited Sumatra in 1986, saw only white hindwinged forms of both bataviana and its mimic Hypolimnas misippus . Thus we believe the geographical range of bataviana f. alcippoides (genotype aa) has expanded west and north through the twentieth century to displace chrysippus chrysippus (genotype AA) from Sumatra, its offshore islands and the Malay Peninsula north to Kedah.

Although bataviana has generally been considered a subspecies of D. chrysippus ( Talbot, 1943; Morishita, 1985), it clusters unequivocally with dorippus-2 ( Figs 2A , 3) and is now best treated as a disjunct race of D. dorippus . Since D. chrysippus ssp. cratippus has a geographical range (Lesser Sunda Islands and Molluccas) parapatric to and sandwiched between those of bataviana and petilia , it too may be a subspecies of dorippus or possibly of petilia . The colour pattern of cratippus is intermediate between those of its two neighbours, indicating the possibility of east–west gene flow from the Sahul Shelf ( Australia and IJ/ PNG) across Lydekker’s Line to Wallacea; however, in the absence of DNA data, its status and relationships remain unclear.

A REVISED NOMENCLATURE FOR THE AFRICAN FORMS

Figures

Figure 2. A, single most parsimonious tree based on amalgamated mtDNA 12S rRNA (344 bp†) and COI (676 bp†) genes (Appendix 2) for the genus Danaus, rooted by outgroups Tirumala septentrionis and T. limniace (†values before alignment). Tree statistics: characters in matrix 1025, variable informative characters 54, parsimony informative characters 139, heuristic search length 304, consistency index (CI) = 0.80, homoplasy index (HI) = 0.20, retention index (RI) = 0.81, rescaled consistency index (RCI) = 0.65. Bootstrap replicates/Bremer Support values are shown for each node where significant. Branch lengths are drawn proportional to nucleotide changes and indicated in parentheses. The MP topology depicted here is congruent with the MP strict consensus, NJ and ML algorithms not shown. ML branch significance is P <0.01 unless marked *. See Table 1 for provenances and sample sizes. B, single most parsimonious tree based on morphological, biochemical and colour gene characters (Appendix 1A, B) for the genus Danaus, rooted by outgroups T. septentrionis and T. limniace (characters from T. petiverana, T. hamata and T. ishmoides were used to fill gaps); †character alignment was fixed to character). Tree statistics: characters in matrix 67†, variable uninformative characters 8, parsimony informative characters 59, heuristic search length 95, CI = 0.84, HI = 0.16, RI = 0.90, RCI = 0.75. Other notes as in (A). C, one of 11 most parsimonious trees based on amalgamated nDNA 18S rRNA (525 bp†) and EF1-a (400 bp†) genes for the genus Danaus, rooted by outgroups Amauris niavius and A. ellioti (†values before alignment). Tree statistics: characters in matrix 926, variable uninformative characters 19, parsimony informative characters 24, heuristic search length 52, CI = 0.83, HI = 0.17, RI = 0.72, RCI = 0.60. Other notes as in (A).