Aphnaeus nimbaensis Sáfián & Libert, 2013

Sáfián, Szabolcs, Libert, Michel & Collins, Steve C., 2013, Two new Aphnaeus (Lepidoptera: Lycaenidae: Theclinae) species from Liberia, Zootaxa 3718 (2), pp. 193-199 : 195-197

Aphnaeus nimbaensis Sáfián & Libert sp. n.

( Figs. 3 A , B, 4)

Holotype: ♂ Liberia, Mt. Gangra, Nimba Mountains, Western Range, Nimba County, 16.02.2012. Leg.: Sáfián, Sz. & Strausz, M. (type depository: ABRI, Nairobi, Kenya). Coordinates: 7°32'44.44"N, 8°38'9.27"W Paratype: ♂ Liberia, Libercell Telecommunication Tower, East Nimba Nature Reserve, Nimba County, 28.08.2013. Leg.: Sáfián, Sz. & Kőrösi, Á. (depository: reference collection of Szabolcs Sáfián, Sopron, Hungary). Coordinates: 7°32'6.05"N, 8°31'37.95"W

Description. Forewing approximately 15 mm, the tip of the apex is missing on both forewings by natural damage. The underside is very similar to that of A. liberti with its dark yellow ground-colour and blood-red rings with silvery-white centre ( Fig. 3 B, D) and a sub-marginal line and margin on both wings. The spots within the red rings are silvery-white. The upperside is black with turquoise-blue scaling on the forewing in spaces between the dorsum, and veins 2A, Cu2 and Cu1 and three blue spots in the cell (regular pattern in many Aphnaeus ). Half of the hindwing is covered with blue scales, especially in the centre and along vein 3A, which is separated from the larger blue area by a dark brown stripe. There is also a brick-red area or patch at the tornus, at the usual base of the hairtails, which are missing from natural damage. The body is black on the top, yellow-black ringed below. The antennae are black with pale yellow tip.

Genitalia. The valvae of male A. nimbaensis are short, triangular and bifurcate, with a projection almost as prominent as the tip of the valva itself. The length of the saccus is two-thirds of the valva, rather broad and evenly rounded at the tip. The tegumen is rather compact with completely reduced uncus, but the subunci are well developed, slender and long ( Fig 4 a).

Diagnosis. From the underside colour and pattern A. nimbaensis is closest to the Central African A. liberti , with minor differences in pattern: the silvery-white centre or the red rings is smaller in A. nimbaensis , in some cases the centre completely missing, the red-ringed whitish spots are replaced by red spotting, especially in the forewing apical area and along the hindwing costa. The same spots have well visible silvery-white centre in A. liberti . The spaces 1a and b on the forewing underside of both species are whitish, with two rather well defined redringed, silvery-white stripes along vein 2 in A. liberti . A. nimbaensis has only a single, rather short stripe in the submarginal area along vein 2, which is not well defined, at least on the holotype.

The upperside blue area on the male holotype of A. nimbaensis is very different from that of A. liberti being the most important diagnostic key. While A. nimbaensis is pure iridescent blue, the male of A. liberti is of strong greenish tone, which is consistent in the examined material and also in other greenish-coloured species (e.g. A. marci Collins & Larsen, 2008 ) (Collins & Larsen 2008). Although the male genitalia do not differ much within the “ A. adamsi -group”, A. nimbaensis and A. liberti differ with the latter having a “vinculum spur” below the tegumen, missing completely in A. nimbaensis . There are also differences on the bifurcated valva and the saccus: the forkedtip of the valva is shorter, while the saccus is longer and more robust in A. nimbaensis compared to those of A. liberti ( Fig 4 a, b).

Both the holotype and the paratype of A. nimbaensis are smaller (forewing length of A. liberti is 17 to 19 mm) and their body slightly less robust than the specimen of A. liberti illustrated and the only other existing male examined in the ABRI collection.

Discussion. The male holotype of A. nimbaensis was caught on the top of Mt. Gangra (1000 m), which is an assembly point for a rich hill-topping butterfly community. Quite a few rare species were observed there, including Iridana hypocala Eltringham, 1929 , which was formerly known only from the Togo Mountains ( Ghana, Volta Region) in West Africa and the magnificent Papilio antimachus Drury, 1782 . The paratype was found hill-topping under similar conditions in the East Nimba Nature Reserve at 1111 m along an undescribed Egumbia ( Lycaenidae : Miletinae ) species. As the summit of Mt. Gangra and those in the East Nimba Nature Reserve reach over a thousand metres above sea level, with upland forest as the original habitat, there is a chance that A. nimbaensis has upland or sub-montane affinities, and could be restricted to the higher mountains of western West Africa (e.g. Nimba , Loma, Tingi), or could even prove unique to the Nimba Mountains on the Liberian-Guinean and Ivorian border. The Nimba Mountains are known to have served as a refuge area during the drier periods in West Africa, hosting an extremely high diversity of animals, including various Liberian sub-region endemics e.g. Liberian Nimba Toad ( Nimbaphrynoides occidentalis liberiensis ), Nimba Otter Shrew ( Micropotamogale lamottei ), also other narrowly endemic butterflies such as Nimba Sprite ( Celaenorrhinus nimba ) (Coe & Curry-Lindahl 1965, Colston & Curry - Lindahl 1986, Larsen 2005, Hillers et al. 2008, Granier & Martinez 2011).

Etymology. As A. nimbaensis might prove unique to the sub-mountains of the Nimba area, we are glad to add another reference to the conservation value of this biologically extremely rich and still not very well known area.

Figures

FIGURE 4. Male genitalia of A. liberti (Mbalmayo, Central Cameroon) (a) and the holotype of A. nimbaensis (b) (dorsal view) both in coll. ABRI.

FIGURE 3. A. nimbaensis male holotype dorsal (A) and ventral (B) view, A. liberti male dorsal (C) and ventral (D) view (ABRI collection).