A stunning new species of Jamides Hübner, 1819 (Lepidoptera, Lycaenidae), with notes on sympatric congeners from the Bismarck Archipelago, Papua New Guinea

Abstract Jamides vasilia sp. n., from montane West New Britain Province, Papua New Guinea, is described and illustrated. The new species is strongly divergent from other known Jamides Hübner, 1819 in possessing a high antenna-forewing length ratio, long androconia on the hindwing upperside and a strongly convex forewing inner margin in the male. It is compared by external structures, male genitalia and mtDNA sequence data to putative related species in the cyta group of Jamides. Notes on various Jamides taxa from the Bismarck Archipelago are also provided, with Jamides pseudosias (Rothschild, 1915) and Jamides reverdini (Fruhstorfer, 1915) recorded from New Britain for the first time.


Introduction
Jamides Hübner, 1819, butterflies, commonly known as Caeruleans, belong to the subfamily Polyommatinae. The genus is distributed throughout much of the Oriental, Australian and Pacific region tropics (Rawlins et al. 2014) and comprises approximately 60 described species, with a concentration in South East Asia and New Guinea. (Hirowatari 1992) recognised 57 species and additional species have been described by Tennent and Rawlins (2012), and Takanami (1994). From approximately west to east, Kunte et al. (2015), Corbet and Pendlebury (1993), Treadaway and Schröder (2012), Rawlins et al. (2014), Parsons (1998), Tennent (2002) and Tennent (2006) identified six species for India, 16 for the Malay Peninsula, 16 for the Philippines, 21 for Maluku, 15 for Papua New Guinea, eight for the Solomon Islands and nine for the remainder of the South West Pacific, respectively. Hirowatari (1992) proposed two groups and eight subgroups for Jamides. He noted that, together with members of the genus Nacaduba Moore, 1881, there is exceptional diversity of the male genitalia valva and their morphology is useful in placing species and making phylogenetic inferences about the group.
The new species introduced herein is exceptionally distinct from all other Jamides species. A number of other phenotypically distinct butterflies have recently been recorded from West New Britain Province (Müller 2013(Müller , 2014Müller and Wills 2013), the type locality of the new species.

Materials and methods
Examination of type and other relevant material was carried out in various institutions (as listed below). Adult specimens were photographed using a Nikon D300s Digital SLR Camera with a Nikon AF-S VR Micro-Nikkor 105mm f/2.8G IFED Macro lens and Nikon R1C1 Close-up Kit Flashes Speedlights. RAW images were edited using Adobe Photoshop CS6. Editing included alignment, auto contrasting and removal of background. A standardised procedure was followed with photography and image editing to ensure consistency of image output. Genitalia were extracted following maceration of abdomens in 10% KOH at room temperature for 36 hours. Genitalia were photographed in glycerol using the fore-mentioned camera body adapted to a Meiji Techno EMZ-5TR-P-FOI Trinocular Stereozoom Microscope, with OPTEK FL95E Fibreoptic Illuminator and twin arm optical fibre. Individual images were taken with the remote acquisition software DIYPhotoBits Camera Control 5.2. Sliced genitalia photographs were stacked and concatenated using the software Helicon Focus 6.0 and edited in Adobe Photoshop CS6. The plates were assembled in Adobe InDesign CS6 and the phylogeny tree in CorelDRAW X6. Genitalia were stored in small glycerolfilled vials pinned beneath the specimen.
Descriptions of external facies follow that of the numerical vein system of Corbet and Pendlebury (1993). Nomenclature of genitalic descriptions follows the same reference.
Individual sequence properties were assessed using MEGA, version 4.1 (Tamura et al. 2006). Bayesian analyses of the dataset were carried out using MrBayes, version 3.0b4 (Ronquist and Huelsenbeck 2003). Three independent Bayesian runs at temperature settings in the range 0.2-0.4 were performed on the data using metropolis coupled Markov chain Monte Carlo simulations, from one to 5 million generations each, and tree sampling every 100 generations. Bayesian topology and branch posterior probabilities were computed by majority rule consensus after deleting the first 1000 000 generations (10 000 trees) as 'burn-in', after confirming that likelihood values had stabilized prior to the 100 000th generation.
Sequences were uploaded to GenBank (http://www.ncbi.nlm.nih.gov/genbank/) and are listed for each individual in the phylogenetic tree presented in Fig. 59. Additional sequences of Jamides taxa (also listed in the tree) were downloaded from Genbank and manually aligned with the dataset. Where possible, the species identity of the latter sequences was checked through the BOLD online database image gallery (http:// www.boldsystems.org/). Diagnosis. Both sexes of Jamides vasilia are highly distinctive and cannot be confused with any other known species. The uppersides of both sexes are brighter and more reflective than those of other species in the genus, the ground colour of the male in particular rivalling Morpho butterflies in intensity and radiance. The male of J. vasilia is unusual from a structural perspective, having long antenna (versus forewing length) that extend well beyond the cell and reach the postmedian area. The antenna/forewing length ratio is ~0.6, whereas in all other known Jamides species the antenna of the male is approximately half the length of the forewing. The shape of the male forewing is unique in that the tornus and inner margin are rounded, the latter being convex while in all other Jamides species the inner margin is straight. Also peculiar in the male is the large purple-brown patch occupying the costal one-third of the hindwing upperside. This patch is adorned with long androconial hairs (up to 5 mm in length). No other known Jamides bears such prominent structures. The male forewing upperside bears a thick terminal black border, tapering towards the tornus, not present in other species. On the underside, both sexes are easily recognised by the curved striae that are well displaced between veins on both wings and the two apical black spots on the hindwing are more rounded and pronounced than in other taxa. The area of orange bordered by metallic blue on the hindwing underside is extensive in both sexes, particularly the female, and extends from the inner margin all the way to space 5. The male forewing underside has the entire median area grey-white between the inner margin and vein 2.

Abbreviations
The male genitalia of J. vasilia is unusual, bearing long teeth-like processes on the inner margin of the valva, with a spine-like process at the apex of the valva.
Description. ♂ Forewing length 15.8mm (Holotype), Antenna length 9.5mm (Holotype). Head grey; antenna long and extending well beyond end of cell, black ringed with white; thorax blue scaled on upperside, grey beneath; abdomen dark grey with blue scales near base on upperside; legs black with white between segments.
Forewing upperside brilliant metallic sky blue, darkening slightly towards termen and apex, a prominent black termen border widening to ~1.5mm at apex; cilia black. Forewing underside deep grey-brown; inner margin broadly pale grey-white (in spaces 1a and 1b), with some metallic sky blue scales along vein 1b; termen narrowly white; a narrow grey-brown subterminal band, narrowly edged with white that forms triangular marks on basal edge; a postmedian band of similar colour to ground colour, about 2mm wide, narrowly edged with curved white on outside margin and with corresponding dark brown on inside margin, band is strongly displaced at veins by approximately 1mm, towards base in spaces 6 and 7 and incrementally towards base towards inner margin in spaces 2, 3 and 4; a median band at end of cell, approximately 1.5mm wide, curved and edged with white and dark brown as in postmedian band; cilia dark brown.
Hindwing rounded, with 2.5mm long, black tail at vein 2, tipped with white. Hindwing upperside brilliant metallic sky blue, darkening slightly towards termen; a large purple-brown patch, clothed with long androconia along costa and in median area, occupying much of spaces 6 and 7 as well as part of cell and space 5; termen narrowly black; a series of diffuse black-dusted and indented subterminal spots, as well as two small black spots at tornus near intersection of vein 1b. Hindwing underside deep grey-brown; inner margin narrowly white, interspersed with black at vein ends; a large black apical spot (1.5mm diameter) in space 6 and another apical spot of similar colour and dimensions in space 7, both spots rimmed narrowly with white; two large subtornal black spots in spaces 2 (approx. 1mm across) and 3 (approx. 0.4mm across) and smaller, less regular black spots in spaces 1b and 4, each of these spots broadly edged along veins with metallic sky blue and basally with bright orange, and then fine white arcuate lines; an additional arcuate white subterminal line in space 5 linking the subapical and subtornal black spots; a postmedian band similar to that on the forewing underside, curved and strongly displaced at veins; a median band edged with white and dark brown at end of cell; a basal band approximately 1mm wide, edged narrowly with white, displaced at either side of cell; cilia dark brown.
Forewing with inner margin straight. Forewing upperside bright lustrous sky blue, darkening towards termen; apex of termen and apex broadly and sharply edged black (2.5mm and 8mm wide, respectively). Forewing underside similar to male, ground colour slightly paler and inner margin only narrowly white-grey and without blue scales, postmedian band extending to vein 1b, white edging to bands slightly wider and more diffuse.
Hindwing rounded, with black, white-tipped tail at vein 2 (approx. 4mm long). Hindwing upperside bright lustrous sky blue, darkening towards termen; inner margin broadly black, basally transitional to brown, with narrow blue scaling along edge of space 6 and 7 adjacent to cell; a row of black subterminal spots (each averaging 0.6mm diameter) in spaces 2, 3, 4 and 5; two irregular black subtornal lines in spaces 1a and 1b, subparallel to termen; inner margin narrowly white. Hindwing underside similar to male, ground colour slightly paler, orange bordering subterminal spots wider and very extensive, reaching from the inner margin to space 5.
Male genitalia. Vinculum and tegumen ring broadly oval; sociuncus divergent; socii with lateral margin rounded, socii distinctly separated by straight, perpendicular sinus; saccus of even thickness, brachium widely bowed dorsally, yet sharply bent laterally, tapered dorsally; valva elaborate, hollowed, with serrated margin and teeth-like processes on inner margin, long narrow process stemming from near base of valva, weakly clubbed with pointed ventral surface on club; phallus with prezonal section approximately one tenth the length of postzonal section, slender, with apical rounded pencil-like process.
Etymology. This enigmatic and exquisite new butterfly is named in honour of the author's wife, Vasilia (Vicki) Savvas (Muller). Vicki has always supported the author's obsession in butterfly research, despite the many sacrifices both on and off the field.
Distribution. New Britain Island, Papua New Guinea. Ecology. Adults of J. vasilia inhabit moss forest and appear to have a more rapid, erratic flight than other members of the genus. Two females were initially observed flying around the base of a Syzygium R.Br. ex Gaertn. (Myrtaceae) sapling and resembled those of the lycaenid Arhopala thamyras (Linnaeus, 1758). The particular Syzygium plant had numerous, highly active, medium-sized brown ants present on the lichencovered trunk but no early stages of Jamides could be located either on the foliage, trunk or in leaf litter surrounding the base of the plant. In the upper parts of the Whiteman Range (Figs 60, 61), J. vasilia flies with several other Jamides taxa, including J. reverdini (Fruhstorfer, 1915), J. pseudosias (Rothschild, 1915), J. cyta (Boisduval, 1832), J. allectus (Grose Smith, 1894), J. soemias Druce, 1891 and J. amarauge Druce, 1891. At lower elevations in the same mountain range, J. celeno (Cramer, 1775), J. aetherialis (Butler, 1884) and J. nemophila (Butler, 1876) are abundant.
Remarks. The phylogeny of Jamides, presented in Fig. 59, comprises representative species from each of Hirowatari's eight subgroups of Jamides, with the exception of the monotypic J. celebica (Eliot, 1969). In the Bayesian phylogeny, J. vasilia is recovered in a deeply diverged clade also comprising J. cyta and J. nitens Joicey & Talbot, 1916. There is no significant variation in the type series of J. vasilia, with all specimens similar in size and shape. The male exhibits very slight variation in the width of the terminal black border.
The extent of distribution of J. vasilia on New Britain Island is not known. Based on the distribution of other endemic butterfly taxa on the island, it is unlikely to be restricted to the Whiteman Range, although no specimens have been observed during surveying, at a range of altitudes, of the Nakanai and Bainings Mountains, in central and east New Britain, respectively. J. vasilia appears to be a rare species. Remarks. The type (?types) of Jamides cyta (Boisduval, 1832) (1817). The type/s of J. cyta have not been located. However, the description by Boisduval is clear, as follows:
Il a le port et la taille d'Elpis, auquel il resemble beaucoup. Nouvelle-Irlande." Translated, this states that the insect (presumably a male), has "Wings a shiny silvery blue; the hindwings with a small tail; underside of the four [wings] with several broken white stripes; the hindwings additionally having a marginal band of black spots, of which the three adjacent [closest] to the abdominal [inner] margin are marked with fawn and golden green. It has the appearance and size of Elpis [Jamides elpis (Godart,[1824])], which it closely resembles. New Ireland." The description above is pertinent only to the male of J. cyta. The author has surveyed several sites throughout New Ireland, close to the localities visited by the Astrolabe, and found J. cyta to be particularly common at all of the lowland sites. Toxopeus (1930), followed by Riley and Corbet (1938), recognised that cyta was the correct species name to be applied to the species known as Catochrysops amphissa (C. & R. Felder, 1860). Prior to that time, several subspecies of what are now known to represent J. cyta were described under amphissa, in particular several taxa from Maluku described by Fruhstorfer (1916). J. cyta amphissa is now known to be restricted to northern Maluku (Rawlins et al. 2014). Ribbe (1899: 228) proposed the name Lycaena amphissina var. malaguna for specimens collected in New Britain, Duke of York Islands and New Ireland. This taxon was considered by D' Abrera (1977: 355) to be a junior synonym of Jamides cyta cyta and Takanami (1989: 50) designated a male lectotype from New Ireland (Neu-Mecklenburg) and recorded three paralectotypes. Both the lectotype and a female paralectotype are here-in illustrated (Figs 16-21).
Nominate cyta from the Bismarck Archipelago is highly distinct from the New Guinea mainland subspecies amphissina Grose Smith, 1894 (not to be confused with amphissa from Maluku), in that the Bismarck specimens are larger and brighter, with much more pronounced orange on the hindwing underside. Bismarck cyta taxa may be further separated in that females from New Britain possess more extensive and brighter blue on the upperside than those from New Ireland and may warrant subspecific status. The types of J. cyta amphissina are illustrated in Figs 25-30 and both sexes of J. cyta cyta from the Bismarcks are also figured (Figs 22-24).  J. cyta is an easily recognised species, the male bearing a pale blue-white upperside and both sexes bear a row of triangular subterminal black spots on the hindwing underside. Note that the illustration of the male J. 'cyta' (as Jamides 'cytus') in Parsons (1998) is in fact that of J. pseudosias.

Remarks.
In the Bismarcks J. pseudosias was known only from one pair taken at an unspecified locality in New Ireland by A. F. Eichhorn in November 1923, which are held in the NHM (Figs 13, 14). A female taken at the type locality of J. vasilia is also figured (Fig 15), representing the first record from New Britain.
J. pseudosias is readily distinguished from its congeners by its long hindwing tail, which is at least 1.5 times that of related species in New Guinea and by the rich blue colour of the male upperside. The forewings of the male are narrower and the apex more rounded than in related species. The forewing underside median bar and postmedian band are continuous across vein 3, though slightly oblique, giving the band a curved appearance. Note that Parsons (1998) illustrates a male of this species as that of J. cyta (as J. 'cytus'; see under J. cyta in this work).
Remarks. Jamides reverdini was previously known from the Bismarcks from just a single specimen from New Ireland, which Parsons (1998) considered to be possibly mislabelled. Additional material is here recorded from close to sea level near Poronbus in New Ireland and from both the Whiteman Range (approximately 1000m) and Bainings Mountains (2000m), in West and East New Britain Provinces, respectively. Therefore, the taxon has a notably extensive vertical range in the Bismarck Archipelago. In northern mainland New Guinea, for example in the Upper Sepik, J. reverdini is most commonly observed below 500m (pers. obs.) This insect is unique in its comparatively large size, bright silvery blue upperside and boldly patterned underside. On the underside, the ground colour is a distinct deep grey and, like J. pseudosias, the forewing median bar and postmedian band are connected at vein 3. J. reverdini is easily separated from J. pseudosias by, among other forementioned features, the shape of the subterminal band on the hindwing underside. In J. reverdini, this band constitutes a series of rectangular markings bordered heavily with white, whereas in J. pseudosias these markings are distinctly triangular.

Discussion
Jamides vasilia exhibits significant disparity from other members of Jamides. The male wing shape, with rounded tornus and convex inner margin, is unique, as is the black, tapering terminal border. On the forewing underside of the male the inner margin is broadly white-grey, relative to the remainder of the wing, a feature apparently unique in the genus. Also in the male, the hindwing upperside bears conspicuous androconia (Fig. 53), covering a purple-brown patch. Such prominent androconia are either absent or poorly developed in related species (Figs 54-58). The underside bands of both sexes are very curved and displaced at veins, unlike other Jamides taxa. J. vasilia is exceptionally bright, the male with the upperside luminescence possibly unmatched in Indo-Pacific Lycaenidae.
The male genitalia of J. vasilia (Fig. 46) are equally distinct and are unlike any of its congeners (Figs 47-52). The exaggerated teeth-like projections of the valva (Figs 46h, 46i) are unique. The dorsal projection of the valva is characteristic of the genus  Jamides and in Indo-Pacific Polyommatinae appears to be shared only with the genus Callictita Bethune-Baker, 1908.
That J. vasilia was phylogenetically recovered, as a result of Bayesian Inference, within a clade of Jamides also comprising J. cyta and J. nitens is perhaps unexpected, considering that J. vasilia is phenotypically very different from either of these taxa. Indeed, there is significant genetic divergence (in COI barcode) between J. vasilia and J. cyta or J. nitens. However, a potential similarity between J. vasilia and J. cyta is that the latter has been recorded feeding on Syzigium in Australia (Braby 2000) and, based on adult female behaviour (see Remarks section), is possibility the food plant of J. vasilia. J. nitens (Figs 38-43) is one of the, otherwise, brightest Jamides taxa. Parsons (1998) noted that J. nitens exhibits a deeper blue than related species in Papua New Guinea. Although the male upperside rich sky blue appears to be constant in all specimens, both sexes exhibit some degree of variability of the amount of white suffusion bordering the striae on the underside (hence three males of J. nitens are figured, see Figs 38-42).
J. vasilia is a montane species, having been recorded from 850 to 1050m. An additional female was observed at 700m in the Whiteman Range. Of the related Jamides taxa, J. nitens is also a montane insect, Parsons (1998) recording it from 1200-1800m, although the author has recorded this species from the Mianmin Range from as low as 550m. J. cyta is typically a lowland species and is rarely recorded above about 500m, although it has been seen very occasionally up to 900m in the Whiteman Range (pers. obs.). Parsons (1998) records J. cyta from sea level to 700m. J. reverdini and J. pseudosias appear to be predominantly montane in New Britain, the former being seen by the author at over 2,000m in the Bainings Mts, East New Britain Province. However, in mainland New Guinea, both species tend to occur in the lowlands. In the Solomons, J. areas (Figs 31-37) is generally a lowland species and the species was found to be fairly common at Uepi Island, New Georgia Group, at sea level during 1986 (pers. obs.). It is unknown to what extent, if any, vertical elevation separation has played in the role of Jamides diversification in the New Guinea region.
Various phylogenetic analyses produced a range of trees for the Jamides dataset. Indeed, in several, including Neighbour-Joining, Maximum Likelihood and Maximum Parsimony, the resultant tree suggested that J. vasilia is sister to all assessed Jamides species groups and that it may represent a separate genus. Given the variable results from the different methods, COI alone is clearly not an adequate tool and additional sequencing of nuclear gene fragments would undoubtedly assist in better resolving the phylogenetic position of the new taxon.
several of the author's trips to the UK. Geoff Martin and Blanca Huertas (NHM) allowed the study of material in their care. Ullasa Kodandaramaiah, Kerala (India), sequenced certain material. Yusuke Takanami, Japan, provided photos of lectotypes held in MNHU and SMT. Jean Weiner, AM, improved the translation of Boisduval's description of Catochrysops cyta. Zsolt Bálint (Hungarian Natural History Museum, Hungary) and Oskar Brattström (University of Cambridge, UK) reviewed the manuscript.