Six new species of Philiris Röber, 1891 (Lepidoptera, Lycaenidae) from Papua New Guinea

Abstract Six new species of the large lycaenid genus Philiris Röber, 1891 (Philiris petriei sp. n., Philiris bubalisatina sp. n., Philiris baiteta sp. n., Philiris radicala sp. n., Philiris hindenburgensis sp. n. and Philiris parsonsi sp. n.), from Papua New Guinea, are described and illustrated, as are the early stages of the former taxon, with Litsea sp. near callophyllantha K. Schum (Lauraceae) recorded as the larval food plant. The holotypes of all but the latter are deposited in the ANIC, with that of P. parsonsi located in the BMNH. The external facies and male genitalia of all new species are compared in detail to putative known related species, and the types of these, in nearly all cases, are also illustrated.


Introduction
Philiris Röber, 1891 is one of the most speciose genera in the Australian region, where it is confined to Maluku, New Guinea, the Bismarcks and eastern Australia, with a concentration on the mainland of New Guinea. The genus was revised by Tite (1963), who recognised 56 species and later in an unpublished thesis by Sands (1981a) who Diagnosis. Males of Philiris petriei sp. n. are readily distinguished from other species in the genus. P. petriei sp. n. is a large species with a forewing length that surpasses that of its putative congeners, P. harterti (Grose-Smith, 1894) and P. albiplaga (Joicey & Talbot, 1916). P. harterti occurs widely in mainland New Guinea (nominate in northern and western NG mainland; subspecies leucoma Tite, 1963 in eastern NG mainland). The holotypes of both taxa are illustrated here-in (see . P. harterti also occurs on Yapen Island, where it is known by ssp. melanoma Tite, 1963. P. albiplaga is restricted to the Schouten Islands (Biak and Mefor). Since the holotype is a female specimen (Figs 11,12), Tite (1963) designated one of two known males of P. albiplaga as a neallotype (Figs 9,10).
The shape of the fore wing in P. petriei is slightly rounded at the apex, whereas it is pointed in the other species, particularly so in P. harterti. The hind wing termen is weakly serrated near the tornus in P. petriei, unlike in related species and the cilia on the underside of the hindwing tornal area is continuously black, as in P. albiplaga, whereas Philiris adults (left side upperside and right side underside, where halved) and label data. 1 P. petriei holotype ♂upperside 2 P. petriei holotype ♂ male underside 3 P. petriei holotype ♂ label data 4 P. petriei paratype ♂ (halved) 5 P. harterti harterti holotype ♂ (halved) 6 P. harterti harterti holotype ♂ label data 7 P. harterti leucoma holotype ♂(halved) 8 P. harterti leucoma holotype ♂ label data 9 P. albiplaga neoallotype ♂(halved) 10 P. albiplaga neoallotype ♂ label data 11 P. albiplaga holotype ♀(halved) 12 P. albiplaga holotype ♀ label data 13 P. bubalisatina holotype ♂upperside 14 P. bubalisatina holotype ♂ underside 15 P. bubalisatina holotype ♂ label data. Scale bar = 10 mm. the cilia are mostly white in P. harterti and black only at the vein terminals. The underside of the forewing in P. petriei bears a large dark basal patch, not present in either P. harterti or P. albiplaga. The frons in P. petriei are black (Fig. 97), while they are rusty red and brown in P. harterti (Fig. 98) and P. albiplaga, respectively. The white area on the forewing above is much more reduced in P. petriei than in P. harterti and P. albiplaga, bearing more resemblance to the pattern in P. bicolor (Bethune-Baker, 1904), a species with red frons similar to P. harterti. In P. petriei, the forewing white patch is restricted to the inner margin and does not extend beyond vein 2, only marginally extending beyond 1b, while in P. harterti and P. albiplaga this white area continues beyond vein 2 and reaches, or exceeds, vein 3 and the edge of the cell. No obvious variation has been noted in the type series of P. petriei, with all specimens similar in size and maculation.
The male genitalia of P. petriei (Fig. 61) also show a relationship to both P. harterti (Fig. 62) and P. albiplaga (Fig. 71). However, the genitalia of the former species are larger than both P. harterti and P. albiplaga, and the sociuncus is narrowly V-shaped dorsally, whereas it is rather rounded in P. harterti and broadly U-shaped in P. albiplaga. The valva is triangular-shaped at the base in P. petriei, whereas it is bulbous in P. harterti and with conspicuous median lobes in P. albiplaga. The phallus is long and slender in P. petriei (Fig. 61c) and the vesica is boat shaped at its apex, whereas the phallus of P. harterti (Fig. 62c) is comparatively short and squat and the apex of the vesica is bifurcated symmetrically. The phallus of P. albiplaga is not clearly defined in either slide mounts of the Mefor Island male specimens but appears to be heavily sclerotized and the vesica is tongue-shaped (Fig. 71c).
Fore wing termen slightly convex but straight between veins 2 and 4, inner margin slightly convex; upperside with ground colour black, a restricted triangular area of white in the median and postmedian area, extending from the inner margin to midway between veins 1b and 2 and from about one-third along the termen to approximately 3mm from the termen at the tornus, white area suffused with light grey narrowly towards base, cilia black; underside uniformly white, with apical area and termen broadly suffused with brown, a large rhomboid-shaped patch of dark brown scales extending from base to median area, cilia black.
Hind wing slightly rounded, termen weakly serrated between veins 2 and 4; upperside with ground colour black, apical area broadly white and extending along costa to near base and to the middle of the hind wing, filling distal half of cell and discocellulars, cilia black except in apical area where they are white; underside uniformly white with weak brown suffusion broadly along termen, cilia black and longer in tornal area, white at apex. ♀: Unknown. Male genitalia (Fig. 61): Vinculum and tegumen ring broadly oval, sociuncus broad, socii with lateral margin rounded, socii weakly separated by V-shaped sinus, saccus tapered posteriorly, brachium tapered dorsally and slightly hooked at apex; valva long, symmetrical, triangular-shaped at base and tapered apically; phallus with prezonal section approximately equal in length to postzonal section, slender, with vesica apically flanged.
Etymology. This species is named in honour of Edward A. Petrie, Sydney, Australia, renowned for his expertise in Australian Lycaenidae, in particular their life histories.
Distribution. New Britain Island, Papua New Guinea. Ecology. When compared with those of the related P. harterti, the flight behaviour of P. petriei males differs in that the latter species generally flies on mountain tops (e.g. Fig. 84) from 1100 hrs until just after midday, whereas P. harterti does not normally appear in its hill top territories until about 1330. Males of P. petriei fly high, usually above six metres above the ground, whereas those of P. harterti generally fly much lower, between 1-4 metres above the ground. There appear to be two broods annually for the life cycle of P. petriei, with adults flying in November and December and again in April and May. Conversely, adults of P. harterti fly throughout the year in mainland New Guinea. Parsons (1998) recorded the life history of P. harterti on saplings of Litsea callophyllantha (Lauraceae). A pupal exuvia of a Philiris, presumed to be P. petriei, was located in the Whiteman Range, New Britain, by the author during January 2013 on a small plant of Litsea species. Some months later two eggs were located on the same plant and one was sleeved. Both eggs hatched after some days and developed very slowly through the winter months, reaching final instar during August. One of the larva pupated in late September (larval duration 121 days), emerging in early Oct (pupal duration 14 days). Owing to the lack of florescence (flowers and/or fruit), it has not been possible to identify the Litsea species on which the new species feeds, although similarly to L. callophyllantha, it appears to grow very slowly and remain as a sapling for years until an opening in the canopy creates an opportunity for the plant to flourish. The food plant of P. petriei is very different from the large leaved Litsea guppyi (F. Muell) F. Muell. Ex Forman., the food plant of Philiris siassi Sands, 1979(Müller 2002, which flies in the same habitats as P. petriei. The early stages of both P. harterti (Figs 93-96) and P. petriei (Figs 88-92) are exceptionally well camouflaged on their foodplant, with those of P. petriei even more so than the larvae and pupae of P. harterti. The early stages are quite distinct between the two taxa, with the pupa of the new species being much less speckled and with more irregular dark patches than in P. harterti. The anterior of the pupa of P. petriei lacks the very long setae present in P. harterti. The mature larvae of the two taxa differ in that that of P. petriei is brown while the larva of P. harterti is greenish and the setae are much coarser in the latter species. The early stages of P. petriei are described below.
Egg (Not illustrated): Approximately 0.5 mm diameter, white, domed, wider than high, intricately sculptured. Similar to those of other Philiris taxa examined.
Third Instar (Not illustrated): c. 7.0 mm in length, 1.5 mm wide, similar to second instar but with lateral margin brown rather than green.
Fourth Instar (Fig. 89): c. 10.0 mm in length, 2.5 mm wide, flattened, flanged laterally, centrally deep green with broad light brown margins, finely speckled with white, with long light brown setae on margins.
Pupa (Figs 91,92): 13 mm in length, 4.5 mm wide, light brown with dark brown irregular mottled patches, particularly on eyes and surrounding the wing cases, fine short setae (<1 mm long) anteriorly and on abdomen.
Similarly to the larva of P. harterti, the first two instars feed on the underside epidermis of the leaf of the food plant, sheltering concealed within these shallow depressions which become feeding scars on the foliage. The third instar larvae chews troughs from the stem of the food plant, within which it eventually rests, progressively increasing the size of the trough to accommodate the sheltering larva. At this stage the larva also chews right through the leaf, creating holes. Eventually, the larva pupates within the trough, where it is remarkably well concealed.
Remarks. P. petriei may possibly be restricted to the island of New Britain within the Bismarck Archipelago. Substantial surveying of pristine habitats by the author in New Ireland from sea level to the highest elevations has not yielded any specimens of this taxon. The insect may also be confined to upland habitats, with all specimens taken above 950m. It appears to be a rather rare species, possibly due to the scarcity of its larval food plant. Diagnosis. Philiris bubalisatina is unlike any known species, its external facies showing affinities with the Philiris marginata (Grose-Smith, 1894), P. fulgens (Grose-Smith & Kirby, 1897) and P. helena (Snellen, 1887) groups. The wing shape of P. bubalisatina is highly acute, with a long pointed forewing and a remarkably elongate hind wing. The forewings are more exaggeratedly pointed than in P. vicina (Grose-Smith, 1898), P. marginata (holotypes; Figs 18, 19, 77 and 20, 21, 76, respectively) (both P. marginata group) and P. fulgens (holotype; Figs 22, 23, 78), even 'subspecies'

Philiris bubalisatina
septentrionalis Joicey & Talbot, 1916 (holotype;Figs 24, 25, 79). The fore wing upperside is a bright shining lilac-blue, which is more bluish on the hind wing and the dark margins are very broad, while that on the hind wing is of hairline thickness. The underside of P. bubalisatina is unique in Philiris, being a pale buff-cream, with a yellowish hue. Unlike other species with non-white undersides (essentially those in the helena group), e.g. P. apicalis Tite, 1963 (holotype;Figs 26, 27, 80 and subspecies ginni Müller; Fig. 28), that of P. bubalisatina is semi-glossy rather than matt. There is no black spot at the inner margin of the hind wing underside. There appears to be little variation in the type series of P. bubalisatina, although one paratype from the Upper Sepik has a slightly shorter fore wing length and the shape of the fore wing is slightly more convex than in the other specimens.
The male genitalia of P. bubalisatina is also highly distinctive and does not closely resemble those of any known Philiris. The bulbous valvae with lateral appendages are unusual and are only otherwise shared with P. lavendula Tite, 1963 (holotype;Figs 16, 17, 75). However the sociuncus in the male genitalia of the latter species is deeply incised and the valvae are much more acute than in P. bubalisatina. P. bubalisatina and P. lavendula have dissimilar external facies, with the former species having a broad forewing upperside border with a shining lilac-purple ground colour and a buff-coloured underside, whereas P. lavendula has a much narrower upperside border, a matt purple ground colour and a white underside. The wing shape of the two taxa also differ markedly.
Forewing termen nearly straight, inner margin straight, apex pointed; upperside with ground colour black, a large area of shining purple-lilac extending from base to near end of cell and postmedian area to approximately 2mm from termen at tornus, cilia black; underside uniformly glossy pale buff-cream with apical area suffused with dark scales, darker basal patch at inner margin, cilia narrowly black.
Hindwing elongated towards tornus, slightly produced near tornus at veins 2, 3 and 4; upperside shining purple-blue (more bluish than fore wing shining area) and narrowly bluish-white nearest to costa, termen narrowly (<1mm) black, costa light brown above vein 7 and midway between cell and vein 8, merging with dark termen between veins 7 and 6, inner margin broadly brown to vein 1b, cilia black; underside uniformly glossy pale buff-cream with dark brown scaling near termen, cilia narrowly black, broader at tornus and at ends of veins 2, 3, and 4.
Male genitalia (Fig. 63): Vinculum and tegumen ring oval, tapered towards sociuncus, sociuncus rather broad, socii with lateral margin square-shaped, dorsally rounded, socii weakly separated by V-shaped sinus, saccus tapered posteriorly, brachium tapered dorsally and slightly hooked at apex; valva symmetrical, bulbous at base with long appendage stemming from lateral margin; phallus large, with zone of intricate cornuti in post-zonal section, vesica apically flanged. ♀: Unknown. Etymology. The name is a combination of the Latin word 'bubalinus', for the colour buff, reflecting the unusual pale yellowish-brown hue to the underside, and 'satina', which refers to the satin lustre to the underside.
Distribution. West Sepik and Western Highlands Provinces, Papua New Guinea. Ecology. All specimens of P. bubalisatina were taken at, or just before, midday as they perched momentarily on foliage overhanging rapid torrents, several metres above the ground. The taxon has a remarkably rapid and robust, wide-ranging flight, which is rather Hesperiid-like.
Remarks. Since it is difficult to accurately determine, the correct nomenclatural positioning of P. bubalisatina would be assisted by information about its life history and larval food plants. Several Philiris larvae were found in the general type locality area and some were reared to adult (e.g. P. violetta (Röber, 1926), P. praeclara Tite, 1963 and P. harterti). It is not known if larvae of the new species were present among individuals that were not able to be reared to adult due to time constraints. A molecular phylogeny of the genus Philiris will undoubtedly better resolve its taxonomic position. 4 ♂♂ labelled the same as the holotype (1 ♂ AM, 1 ♂ BMNH, 2 ♂♂ CJMC); 3 ♂♂ labelled "Papua New Guinea, Baiteta, Madang Prov. 5°00'S, 145°44'E, 380m, 6 August 1987, D.P.A. Sands (on loan to ANIC); 1 ♂ labelled the same as last but 31 July 1987 (on loan to ANIC); 1 ♀ labelled "nr. Oetakwa R., Snow Mts., Dutch N. G., up to 3500 ft., x. xii. 1910 (Meek)" (BMNH).

Philiris baiteta
Diagnosis. Philiris baiteta is a distinctive species that was previously confused with the related P. hypoxantha (Figs 34,35). The type specimen of P. hypoxantha from south-western Papua Province could not be located but the description (in German) by Röber (1926) is detailed and he describes the wings above as 'monotonously sepiabrown with low shine ' Röber (1926, p. 375, translated).
A single female of P. baiteta in the BMNH (Fig. 32, 32) was recognised tentatively as a 'form' of P. hypoxantha by Tite (1963) who also added comment that its significance could not be assessed until more material became available. This is obviously the true female belonging to P. baiteta. P. baiteta is readily distinguished from P. hypoxantha by the large area of creamwhite in the costal and subapical area of the hindwing upperside. Both wings above are uniformly brown in P. hypoxantha. The underside of P. baiteta is cream-yellow, with a broad cream border to the greyish area on the inner margin of the forewing. Conversely, in P. hypoxantha, the underside is bright yellow.
The unusual male genitalia of P. baiteta (Fig. 64), P. hypoxantha (Fig. 66) and P. hemileuca (Fig. 65) emphasise a close relationship of the three taxa, yet each show vast differences in their morphology, in particular the shape of the valva. In all three species the valva is sharply tapered to a spike anteriorly. In both P. hemileuca (Fig. 65b) and P. baiteta (Fig. 64b) an additional posterior dorso-lateral spike is present, which is much longer and more pronounced in the latter species than in P. hemileuca. The phallus of the three species also exhibit notable differences with P. hypoxantha bearing an apically enlarged vesica (Fig. 66c), which is bifurcated in P. hemileuca (Fig. 65c), yet rather abruptly terminated in P. baiteta (Fig. 64c). Parsons (1998) noted that the male genitalia of P. hypoxantha bear some resemblance to those of P. vicina (Fig. 77), especially in the shape of the valvae and aedeagus.
Fore wing termen nearly straight, inner margin straight, apex pointed; upperside with ground colour dark uniform brown, cilia brown; underside pale yellow-cream, grading through white towards inner margin where the area between the inner margin and vein 2 and the cubitus are light grey-brown, cilia dark brown.
Hind wing slightly acute at tornus; upperside with ground colour dark uniform brown, a large cream-white apical area extending from base to beyond vein 6 into space 5 but not connected to termen; cilia dark brown except at apex where they are cream; underside uniformly pale yellow, cilia as in upperside.
♀: (Figs 32, 33), Forewing length 14.5 mm, antenna 8 mm. Similar to male but larger, wings much more rounded. Forewing upperside with diffuse patch of cream white in median area between veins 2 and 4; forewing underside with brown area along inner margin not reaching termen. Hindwing upperside with cream-white patch slightly more extensive, reaching further into space 5.
Etymology. This species is named after the locality in Madang Province where Dr Don Sands, Brisbane, Australia, collected part of the type series, also recognising its distinction from the related P. hypoxantha.
Ecology. Both P. baiteta (Fig. 87) and P. hypoxantha were collected around midday as they settled on foliage some metres above the ground over a rapid flowing stream in precipitous terrain (Fig. 86), together with a number of other Philiris species. Both species exhibited a rapid, fluttering flight.
Remarks. P. baiteta appears to form a small group within Philiris also comprising P. hemileuca (holotype; Figs 36, 37) and P. hypoxantha (Figs 34, 35) and P. baiteta appears to fall midway between the two. All species have been taken in the Hindenburg Range area, Western Province, where P. hemileuca occurs above about 1500m, while P. hypoxantha and P. baiteta have been taken together at around 1000m. The latter two species have also been taken flying together elsewhere, in the Snow Mountains, where A. Meek even collected both species on the same day. Diagnosis. Philiris radicala is unique within Philiris, with its very unusual colouration in the male upperside and matt white underside ground colour and dark border to the underside termen in both sexes. The taxon shows some relationship to P. intensa (Butler, 1876) (Holotype; Figs 44, 45 and female; Fig. 46), with which it flies in the Hindenburg Range, although the latter species is more commonly encountered below 500m, while P. radicala flies between 700-1100m. The male upperside of P. intensa is a deep, bright, shining sky blue, whereas that in P. radicala is an iridescent turquoise (green-blue). The dark border to both wings on the upperside of the male P. radicala is much broader than in P. intensa and the border of the forewing is straight, forming a line between the postmedian section of the costa and the tornus, while this border is curved in P. intensa. The female upperside of P. radicala bears very large white median patches on both wings, unlike P. intensa and the discocellulars of P. radicala are distinctly dark brown. On the underside of both sexes the ground colour is an unusual powdery matt white, the termen of both wings is heavily blackened, particularly at the vein ends, and dark scaling occurs in the subterminal area. These features are not present in P. intensa.
Description. ♂ (Figs 38-40): Forewing length 17 mm, antenna 9 mm (holotype). Head, palpus and thorax dark grey dorsally, white ventrally, abdomen dark grey dorsally, white ventrally, frons dark grey with white eye ring; legs white with black areas on tibiae; antenna shaft black, ringed conspicuously with white between segments, apex of club tipped with brown.
Fore wing termen slightly convex, inner margin very slightly bowed near base, apex slightly rounded; upperside bright shining turquoise, costa and termen broadly black, 2mm wide at tornus but up to 5mm wide at apex, the boundary between the dark border and shining turquoise area is straight between veins 2 and 8, cilia white but broadly black at vein ends, giving chequered appearance; underside matt white with apical area suffused with black scales, termen and vein ends distinctly black, cilia as in upperside.
Hind wing rounded; upperside bright shining turquoise, termen broadly black (2 mm wide), between inner margin and vein 1a dark brown-black, grading to light grey-brown basally, apex broadly black, costa broadly light grey, basally grey-brown, cilia white but broadly black at vein ends, giving chequered appearance; underside matt white, subterminal area narrowly suffused with black scales, termen and vein ends distinctly black, cilia as in upperside.
Fore wing termen slightly convex, inner margin very slightly bowed near base, apex slightly rounded; upperside dark brown-black, large area of white extending from base along inner margin to postmedian area and occupying about two-thirds of cell, margins of this pale patch suffused with powder blue, costal half of discocellulars heavily brown-black, intruding into pale area, cilia as in male; underside as in male.
Hind wing rounded; upperside dark brown-black, apical area broadly grey-white, cell and basal area along vein 1b grey-white with powder blue suffusion, inner margin and basal part of costa light grey-brown, discocellulars heavily brown-black, intruding into pale area, cilia as in male; underside as in male.
Etymology. The name 'radicala' reflects the extraordinary colouration of the male upperside and overall divergent morphology of this species.
Distribution. Western Province, Papua New Guinea. Ecology. Males of P. radicala were taken around midday and early afternoon as they settled at the tops of tall saplings, between 8-10 metres above the ground, in small clearings created by tree falls in very steep terrain. Females were recorded in similar areas, where they fed at the small white flowers of an unidentified tree. Conversely, males of P. intensa, flying at the same localities but generally at a lower altitude, were always seen to fly within 2-3 metres above the ground in areas of regrowth proximal to streams. Diagnosis. Philiris hindenburgensis is a small species with rounded wings that is unique among those species in the genus with predominantly purple-blue uppersides to the males, in bearing a very broad dark border to the costa and inner margin of the hindwing upperside where the purple-blue is essentially restricted between veins 2 and 6. The broad forewing border that is parallel to the termen is also a feature of the males of P. satis Tite, 1963 (Holotype;Figs 50, 51, 81), P. oreas Tite, 1963 (Holotype;Figs 52, 53, 82) and P. albihumerata Tite, 1963 (Holotype;Figs 54, 55, 83). However, these taxa all have glossy white undersides with a large, prominent black spot on the inner margin of the hindwing underside. In P. hindenburgensis, the underside is a light grey-white and the spot on the inner margin is merely represented as a barely recognisable brown smear.

Philiris hindenburgensis
The male genitalia of P. hindenburgensis are highly distinctive and do not resemble those of any known Philiris species. The sociuncus is long and tapered such that the socii are not obviously separated and the lateral margin of the socii is concave. The valvae in P. hindenburgensis are most unusual, with long, slightly asymmetric appendages stemming from the lateral margin of the bulbous base.
Description. ♂ (Figs 47-48): Forewing length 15.5 mm, antenna 8.5 mm (holotype). Head, palpus and thorax dark grey dorsally, light grey ventrally, abdomen dark grey dorsally, light grey ventrally, frons dark grey with white eye ring; legs light grey with black areas on tibiae; antenna shaft black, ringed conspicuously with white between segments, apex of club brown.
Fore wing termen slightly convex, inner margin very slightly bowed in middle, apex slightly rounded; upperside dull frosty purple-blue, termen broadly dark brownblack and of even width (1.5 mm wide), cilia dark brown black; underside uniformly light grey-white, a small dark brown basal patch near inner margin, cilia light grey but dark brown-black at vein ends.
Etymology. This species is named after the type locality, the monumental Hindenburg Wall.
Distribution. Western Province, Papua New Guinea.

Philiris parsonsi
Diagnosis. Philiris parsonsi is a distinctive species, presently known only from the unique male holotype, which Parsons (1998) illustrated as an undescribed species. He compared the external facies and male genitalia to P. angabunga Bethune-Baker, 1908 (Holotype;Figs 59, 60), within the Philiris refusa (Grose-Smith, 1894) group. However, the shape of the forewing and the colouration and maculation of both wing surfaces are unlike any of the described species within that species group. The forewing of P. parsonsi is more elongated than in other species and the dark border is much narrower, with the exception of P. biplaga and P. pagwi Sands, 1979, which have borders parallel to the termen and broader at the tornus, respectively, while that in P. parsonsi is widest at the apex. The upperside ground colour in P. parsonsi is an unusual pale lilac colour and there are white scales present in the median area of the forewing, not present in other species. The underside configuration of black spots is more complex  than in other species and bears a total of ten individual markings, whereas a maximum of five spots are present in any other species (that for P. maculata Sands, 1981).
The male genitalia of P. parsonsi (Fig. 73) is also distinctive, the tegumen ring being very squat and squared dorsally when compared with that of P. angabunga (Fig.  74). The socii in P. parsonsi are widely spaced and the valvae are smaller than those of P. angabunga and rounded, whereas those of P. angabunga are triangular-shaped.
Fore wing termen very slightly convex, inner margin very slightly bowed near base, apex slightly rounded; upperside pale lilac-blue, a scattering of white scales in median area, largely concentrated, but not restricted to, the area between veins 2 and 4, apical area broadly dark brown-black, border 5 mm wide at apex, narrowing evenly to meet tornus, cilia dark brown; underside dull white, cell with a large black spot (approximately 1.5 mm wide) about two thirds from base, two smaller obscure brown-black spots surrounding this spot, slightly closer to base and junction of cubitus with vein 3, discocellulars black, forming an elongated spot, cilia white, dark brown-black at vein ends.
Hind wing rounded; upperside pale lilac-blue, costa and inner margin dark, termen very narrowly dark brown (hairline thickness), cilia dark brown; underside dull white, two large (approximately 1.5 mm diameter) black spots in cell, about two thirds from base, a much smaller spot close to upper spot on basal side, a large black spot between veins 1a and 1b and another obscure dark brown spot of similar size between veins 1b and 2, both spots about one third from base, discocellulars black, forming an elongated spot, cilia as in forewing underside.
♀. Unknown. Etymology. Named after the collector of the holotype, Dr Michael Parsons, California. Distribution. Western Highlands Province, Papua New Guinea. Remarks. The unique holotype was taken in a creek by Parsons (pers. comm. 2013), flying together with P. angabunga. Although not listed on the specimen label, Parsons (1998) noted that the creek is known as Wara [Tok Pisin for River] Pimbi.

Discussion
The distinctive black and white colour of both sexes of the species in the P. harterti species-group was noted by Sands (1981a). Parachrysops was originally erected for Philiris bicolor based on its red frons and wing venation but Sands (1981a) proposed that Parachrysops be subsumed within Philiris based on the two fore-mentioned characters being shared with P. harterti. Philiris petriei is very unusual within the group in that it possesses black frons, as opposed to the typical red frons.
Although Sands (1981a) proposed that P. hypoxantha and P. hemileuca be placed in their own species group, Parsons (1998) suggested, due to the colour above, in particular P. hemileuca, a relationship to the harterti species group.
There were two syntypes of P. hemileuca in the original description by Jordan (1930), described as Candalides hemileuca. The lectotype designated by Parsons (1998) is in poor condition when compared to the other syntype.
The genitalia slide preparation of the lectotype (then yet to be designated) by Bennett in 1955 for the work of Tite was significantly distorted (examined by the author) and was not illustrated by Tite (1963). Interestingly, Jordan (1930), in his description of P. hemileuca, well-illustrated the genitalia of this species, only then known by the two syntypes, of which only one (later designated the lectotype by Parsons (1998) was dissected. Therefore, Jordan obviously made drawings from the genitalia before it was mounted by Bennett. Jordan (1930) particularly noted the apically teethed claspers (valvae) of P. hemileuca.
This work has further high-lighted areas of butterfly endemism in Papua New Guinea. In particular, expeditions within the mountains comprising the central cordillera of New Britain Island have yielded other recent noteworthy discoveries (Müller 2013;Müller and Wills 2013 and references there-in). The Hindenburg Range and Star Mountains in Western Province also host a number of recently described taxa (Lachlan 1999(Lachlan , 2000 and the Upper Sepik Basin supports a number of distinctive butterfly taxa, yet to be described (C. Müller, unpublished).