Falcuna nouabaleensis, Takano, 2024

Takano, Hitoshi, 2024, Descriptions of three new species of Lycaenidae (Lepidoptera: Papilionoidea) from Parc National de Nouabalé-Ndoki, Republic of Congo with additional notes on little-known species, Zootaxa 5496 (2), pp. 214-230 : 216-218

Falcuna nouabaleensis sp. nov.

( Figs 4–6, 8 , 40 )

Holotype ♂ ( ANHRT):

“ REPUBLIC OF CONGO 372m / Sangha Prov. , Nouabalé-Ndoki / National Park, Mbeli camp/( Gilbertiodendron forest) / 02°14’23.8”N, 16°23’52.1”E / 1–10.x.2022 General Coll. / Dérozier, V., Fouka, B., / Kirk-Spriggs, A., Takano, H. / ANHRT:2022.14 // ANHRTUK / 00260603”

Paratypes (5♂♂ 3♀♀):

REPUBLIC OF CONGO: same data as holotype (2♂♂ 1♀ ANHRT) ; same data but 14–20.ii.2023, leg. N. Bakala, V. Dérozier, A. Kirk-Spriggs & G. László (1♂ 1♀ ANHRT) ; Bomassa camp, Nouabalé-Ndoki National Park, 341m, 02°12’36.9”N, 16°11’30.2”E, 10–16.x.2022, leg. V. Dérozier, B. Fouka, A. Kirk-Spriggs & H. Takano (1♀ ANHRT) ; Mondika camp, Nouabalé-Ndoki National Park, 365m, 02°21’50.6”N, 16°16’25.8”E, 07–14.ii.2023, leg. N. Bakala, V. Dérozier, A. Kirk-Spriggs & G. László (1♂ ANHRT) ; same data but 27.iv–06.v.2023, leg. V. Dérozier, A. Kirk-Spriggs, G. László & S. Mvouende (1♂ ANHRT) .

Description.

Forewing length: holotype male: 12 mm; paratype males: 12–13 mm; paratype females: 15 mm.

Male. Upperside. Ground colour of head and thorax black, abdomen dark grey. Antennae black, with white scaling ventrally at the base of each segment. Frons with a narrow row of white scales running adjacent to the eye. Palps longer than diameter of eye, black, with creamy-white scaling at base. Thorax with long, ciliate, dark greyish-brown scales anteriorly, turning paler posteriorly. Ground colour of wings creamy-white, bordered with fuscous charcoal-brown. Forewing costa evenly arcuate, rounded at apex; outer margin convex. Dark border ca. 2 mm wide along costa, almost 5 mm at the base of vein 5, and 3 mm along vein 2. Inner edge of border clearly-defined, with incipient tooth at the end of cell and a slight protrusion in space 2. Discal spot small and indistinct, fused with border. Hindwing rounded, with 2–3 mm wide border terminating at tornus, suffused with paler, slightly-greyer scales. Discoidal spot of underside showing through faintly. Underside. Ground colour of head and thorax black, abdomen creamy-white. Legs black with yellow scaling at the base of each tarsal segment. Ground colour of wings the same as the upperside. Forewing border narrower along the outer margin, evenly rounded and tapering towards tornal angle. Elongate subapical marking, creamy-white, and very indistinct. Hindwing border the same width as the upperside, continuing along the length of the inner margin. Small discoidal spot the same colour as border, longitudinally ovoid, centred around the juncture of veins 6 and 7.

Male genitalia. Uncus triangular, with weakly-depressed, pointed apex. Tegumen broad, half the width of valve. Subuncal lobe, slender, with a pair of long, slightly curved arms on the outer margin; the free end drawn out into a long, gently excurved, pointed apex. Valve oblong, apex recurved towards dorsum, with a small digitate process on the dorsal margin. Aedeagus long, slightly longer than valve, sinuate, tapering gradually from base to apex.

Female. Similar to male but larger, the forewing outer margin is more convex and the creamy-white basal area is much more extensive on both wings.

Diagnosis. The new species is similar in appearance to F. lybia ( Staudinger, 1892) ( Figs 1–3 ), a peculiar member of the genus distinguished by a single discoidal spot on the hindwing underside, somewhat reminiscent of the white Liptena Westwood, [1851] in the L. opaca group of Libert (2021). The genitalia are also distinctive, the slender construction of the subuncal lobes being strongly excurved anterio-ventrally and lacking projections from the inner surface ( Stempffer & Bennett 1963). Falcuna nouabaleensis sp. nov. can most readily be separated from F. lybia based on the presence of subapical and apical white spots on the forewing and hindwing undersides respectively, the broader hindwing border, and the larger discoidal spot of the hindwing in the latter. The ground plan of the genital capsule is similar but in F. lybia ( Fig. 7 ), it is generally larger, the subuncal lobes are cranially shorter and more robust, and caudally more excurved, the valve is more elongate, its dorsal margin straighter and the recurved apex broader. Intraspecific barcode PWDs of the new species were 0.0% (n=3) and diverged from a F. lybia sample on GenBank (MCZ:RE08J104) by 1.6%. This is a greater divergence than that observed between GenBank sequences of F. margarita ( Suffert, 1904) and F. orientalis ( Bethune-Baker, 1906) which was 1.1%.

Derivatio nominis. The new species is named after its type locality, Parc National de Nouabalé-Ndoki in northern Republic of Congo.

Distribution. The new species is only known from the short series collected at the type locality. Its sister species, F. lybia was described by Staudinger (1892) from a small series of both sexes collected in Gabon by Albert Mocquerys (see Fig. 1 for paralectotype in MfN), and is known from Cameroon (a long series in ABRI), as well as from Etoumbi, Kellé and Ketta in ROC ( Bampton et al. 1991). These ROC records are based on specimens collected by T.H.E. Jackson in the National Museum of Kenya but since they have not been examined, it is not known to which species they belong. Despite the close proximity of Ketta to PNNN, it may be possible to speculate that all these specimens belong to F. lybia ; Lycaenidae and in particular the Liptenini were a speciality of Jackson’s ( Carcasson & Clench 1969) and had the underside lacked the white subapical and apical spots on his specimens, he most likely would have noticed such differences in these distinctive insects. Taking into consideration the evolutionary history and biogeography of this region (discussed further below), it is believed these two species are allopatric vicariants and F. nouabaleensis sp. nov. is likely endemic to this region.

Figures

FIGURES 1–8. Falcuna species. Adults (1–6), upperside (above) and underside (below); ♂ genitalia (7–8) in lateral view. 1. F. lybia (Staudinger), paralectotype ♂ of Larinopoda libya (MfN) with labels. 2. Id., ♂, Cameroon, Nkol Nlong (RCJS). 3. Id., ♀, Cameroon, Zoétélé (RCJS). 4. F. nouabaleensis sp. nov., holotype ♂. 5. Id., paratype ♂ (ANHRTUK 00260604). 6. Id., paratype ♀ (ANHRTUK 00321798). 7. F. lybia. 8. F. nouabaleensis.

FIGURES 38–40.Parc National de Nouabalé-Ndoki, Republic of Congo.38.Mbeli camp, typelocality of Falcuna nouabaleensis sp. nov. and Anthene sangha sp. nov. 39. Ndoki formation, type locality of Neurellipes smithi sp. nov. 40. F. nouabaleensis sp. nov., paratype ♂, taken in natura at Mondika camp. (All photographs V. Dérozier).