Andronymus magma, Sáfián & Belcastro & Tropek, 2019

Sáfián, Szabolcs, Belcastro, Claudio & Tropek, Robert, 2019, Two new species in the genus Andronymus Holland, 1896 (Lepidoptera, Hesperiidae), Zootaxa 4624 (1), pp. 108-120 : 109-112

Andronymus magma sp. nov. Sáfián & Tropek

FIGS.: 1E, F, G, H; 2A, C; 3

Holotype: ♀ CAMEROON, Drink Gari Camp , Southwestern slope of Mount Cameroon, 650 m asl., 16.IV.2015. Leg.: Sz. Sáfián, R. Tropek. Coordinates: 4°6’5.21”N, 9° 3’39.60”E. Altitude: 650 m asl. Type depository: MZUJ.

Paratypes: 8♀♀ CAMEROON, Drink Gari Camp , Southwestern slope of Mount Cameroon, 650 m asl., 07- 23.IV.2015. Leg.: Sz. Sáfián, R. Tropek . 2♀♀ Same data, 26.II.2017. Leg.: J. Mertens, R. Tropek, Sz. Sáfián. Depositories: MZUJ, ANHRT, ABRI . 1♀ CAMEROON, Ebogo on Nyong River IX.2011. Leg.: local collector, In coll.: C. Belcastro.

Description of holotype. Wingspan: 34.5 mm, Forewing length: 18.5 mm. General appearance like other Andronymus , but significantly larger than congeneric species, except A. marina and A. bjornstadi . Upperside very dark brown with creamy coloured opaque spotting on forewing, dark yellow central spot and margin on hindwing. Forewing sub-apex with three small quadrangular spots; oval upper spot and small streak present in discoidal cell; longer spot with straight inner edge and strongly toothed outer edge present below cell in space 2; rectangular postdiscal spot with concave outer edge present in space 3; darker cream basal streak and triangular spot present in space 1B; fringes creamy yellow. Hindwing with a prominent dark cream-coloured spot from inner margin to beyond the centre, outer margin bent inwards in space 2; margin broad, dark creamy yellow between tornus and vein 3, rest of margin dark brown with creamy yellow fringes. Underside forewing dark brown, slightly lighter than upperside, all upperside spots present, except streak and triangular spot in space 1B, where only one prominent large creamy spot with diffuse margin appears, extending into space 1A; creamy patch also present at base, spread along cell-edging veins. Much of hindwing creamy yellow, with brown margin along costa and broad brown marginal band from apex stretching just beyond vein 3. Four small, inconspicuous, opaque spots present in the centre, characteristic for the genus. Smaller sub-basal and a larger brown oval discal spot present in space 2. Body brown on upperside with dark creamy hairs and creamy band across abdomen on segments 4-5. Underside white on head (including palpi), thorax and segments 1 and 2 of abdomen, creamy yellow beyond with small brown lateral streaks. Legs brown and creamy white; eyes bald, black. Antennae long, black, weakly ringed with creamy yellow, club long, brown with acute tip.

Female genitalia. Papillae analis large (1 mm in lateral view), edge flat in the middle with curving edges, with densely scattered short hairs. Apophyses anterior and posterior missing. Von Siebold organ approximately half the size of lamellae. Lamellae antevaginalis large (1 mm), triangular in lateral view, oval, discoid dorsally. Seventh sternum rather strongly sclerotized, rather wide (dorsally). Ductus bursae long (3 mm), of even width (0.4-0.5 mm). Bursa oval, completely transparent, slightly shorter than ductus.

Differential diagnosis. The females of the new species can be separated from those of A. marina by a small ochre oblique streak present in the forewing cell, which is always missing in A. marina and is present in the holotype and nine paratypes of A. magma . Even in specimens, where the streak is not present (two further paratypes), the spot below the cell in space 2 is also more oblong, at least one-third longer in all known female specimens of A. magma than in A. marina , similarly to trapezoid post-discal spot in space 3 which are diagnostic to tell apart those specimens of A. magma without the oblique cell-streak.

The cell-streak is also missing in the females of the paler and much smaller A. evander , with which A. magma overlaps in distribution.

Small differences are found also between female genitalia of A. magma and A. marina . Lamellae antevaginalis of A. magma is oval in dorsal view and the seventh sternum is broad, more widely open, while lamellae are more triangular in A. marina and the seventh sternum is narrower ( Fig 2 ). The male of A. magma is unknown.

Etymology. The name of the species refers to its type locality, Mount Cameroon or Mount Fako, an active volcano, which regularly oozes magma from various cracks around the mountain. These lava flows are very characteristic to the mountain and larger ones could reshape entire slopes, allowing a dynamic forest regeneration over the centuries.

Discussion. A. magma was initially treated as unusually large specimens of A. evander , however, the differences between these two species became evident when all specimens were examined in MZUJ. Its larger size, deeper yellow colour and the broader creamy-yellow hindwing margin immediately sets it near A. marina , an East African species, restricted to the Lake Victoria outlier forests in Uganda and Tanzania, recorded also from riverine forests further south in Tanzania and closer to the Albertine Rift in Uganda. Larsen (unpublished manuscript), listed no records west of the Rift, however a female specimen was collected by ABRI collectors in the Kivu Region, Eastern DRC. These forests are all outliers of the Congolian forest zone with upland and in a few localities sub-montane affinities, as they are situated on higher altitude plateaus on both sides of the Albertine Rift, between 1100 m and 1800 m with unique butterfly fauna.

A. magma was collected almost exclusively at a single locality on the lower slopes of Mount Cameroon and was first believed to be one of the upland butterflies, which on Mount Cameroon uniquely descend into the lowland forest zone on the extremely wet and cool southwestern slope (e.g. Bettonula bettoni (Butler, 1902) , Uranothauma heritsia (Hewitson, 1876) , Amauris echeria occidentalis Schmidt, 1921 Sáfián, Tropek et al. unpublished records). Later, a single, identical female specimen was found in C. Belcastro’s collection, captured by a local collector in lowland forest around Ebogo, a famous butterfly locality near the Nyong River in Central Cameroon. The latter record indicates that A. magma could inhabit wet lowland rainforests west of the Congo Basin, possibly also extending further into the basin, but this could not be confirmed with specimen records. Still, the consistent external differences and the most probably genuine disjunction justify the validity of the Cameroonian population as a distinct species. A further undescribed taxon in the same species-group appears also in northern Zambia as illustrated in Larsen’s unpublished manuscript (leg.: Alan Gardiner), and another taxon is incorrectly illustrated on the supplementary CD-ROM in Heath et al. (2002) as A. marina , but the information available is not sufficient for description of these taxa in the present paper.

Figures

FIGURE 2. Female genitalia: A. magma (holotype)—A, C and A. marina (Tanzania)—B, D.