Iolaus bundali, Sáfián & Bayliss & Congdon, 2022

Sáfián, Szabolcs, Bayliss, Julian & Congdon, T. Colin E., 2022, Description of four IolausHübner, 1819 species in the subgenus PhiliolausStempffer & Bennett, 1958 from East Africa, assigned to the proposed I. maritimus species group (Lepidoptera, Lycaenidae, Theclinae), Zootaxa 5099 (1), pp. 46-64 : 61-62

Iolaus bundali sp. nov. Sáfián & Congdon

FIGS.: 2I, L; 3I, L; 4F; 5F; 6I, L; 8A; 9A;10

Holotype: ♂ TANZANIA, Bundali Hills 2.I.2004. Leg.: IB/ TCEC / MH. Bred. Gen. prep.: SAFI00212 . Deposited in ABRI.

Paratype: ♀ TANZANIA, Bundali Hills 3.I.2004. Leg.: IB/ TCEC / MH . Bred. Gen. prep.: SAFI00213 . Deposited in ABRI.

Description of male. Forewing length: 21 mm. Wingspan: 37.5 mm. General appearance as males of other species in the subgenera Argiolaus and Philiolaus with black ground colour overlaid by extensive iridescent blue on upperside, and dirty white underside with black and orange submarginal lines, two tails at the tip of veins 1 and 2 and a small kick at the tip of vein 3 on the hindwing. Upperside blue colour of royal blue tone with no greenish or silverish tinge. Slightly less than basal half of forewing covered with blue, except along costa, where black extends to base, leaving a moderately broad, 1.5 mm black costal margin. Black outer margin very broad, over 2 mm at tornus. The outer edge of blue slightly lobed in spaces 1b, 2 and 3, also with small blue dusting also beyond cell in space 4.

Majority of hindwing covered with blue, except dark grey-black space 1a, along black costa and the broad black margin between apex and tornus. Black margin narrows down to 1 mm at tip of vein 2, with a black spot in the blue area further inwards. Androconia cover most of cell and upper part of wing to black costa, dark, greasy grey-black with brownish-black, well-defined circular heart. Tornal lobe dark claret-red, speckled with few blue scales, with black margin. Underside dirty white, with very faint creamy tinge along forewing costa and almost invisible grey dusting along forewing and hindwing margin. Forewing with bright, slightly curving orange-red submarginal line between veins 1 and 8. Black, faint, 1 mm-long cell-closing streak also present. Forewing androconial hair tuft beige. On hindwing, prominent, orange-red inner submarginal line keeps strongly away from outer margin, reaching costa 5 mm from apex. Outer submarginal line absent. Tornal spot at the end of space 1a largely black, edged with claret-red and silvery-blue ring inwardly. That in space 2 circular, claret red, with faint silvery-blue dusting, loosely connected to tornal end of orange submarginal line. Tails black with white edge. Fringes short along outer margin of forewing, black on upperside, longer, grey along inner margin. Fringes black on hindwing outer margin around apex, black and white double layered towards tails, with longer white hairs around tornus. Fringes replaced by longer whitish hairs along inner margin. Fringes grey on forewing underside, white on hindwing. Head, thorax and abdomen black with greyish hairs on upperside, covered by white hairs on thorax underneath, abdomen with yellowish overlay. Palpi black on top, white below, twice as long as diameter of eyes. Eyes bald, black and brown. Antennae black, speckled with tiny white dots underneath, only slightly thickened towards apex, their length shorter than half of forewing.

Male genitalia. General morphology like other species in the group, but anterior half of valvae, process on vinculum completely reduced. Valvae oblong, ending in long inwardly curving acute tip, with two, almost equally large spines and almost no serration on between spines. The terminal cornutus on aedeagus strong, straight, the inner one narrow, shorter. Spike on aedeagus short, rather blunt, protruding upwards.

Description of female. Forewing length: 20.8 mm. Wingspan: 38 mm. General appearance as females of other species in the subgenera Argiolaus and Philiolaus with black ground colour overlaid by blue and orange spotting along outer margin on hindwing in spaces 1a, 2 and 3. Underside dirty white with black and/or orange-red submarginal lines and two tails at the tip of veins 1 and 2 and a small kick at the tip of vein 3 on hindwing. Blue colour of darker sky-blue tone. Less than half of forewing covered with blue basally, costa broadly black to base. Outer edge of blue area evenly rounded, with a small black indentation at the end of discal cell. Basal half of hindwing covered with blue, between veins 1 and 6, with blue dusting in space 6. Black between vein 7 and costa, except light blue basal spot. Black submarginal line fused to black margin, appears as black indentation in the blue area in spaces 1b, 2, and 3. Tornal lobe claret red, with black margin, not conjoint with fused bright orange spotting in spaces 1b, 2 and 3. Tails black, edged with white. Underside colour and pattern and body identical to those of male with more prominent orangish submarginal lines and visible grey dusting along hindwing margin.

Female genitalia. Papillae analis small (0.6 mm), moderately sclerotized, strongly rounded. with dense hair, apophyses straight, shorter than 1 mm. Lamella antevaginalis strongly sclerotized, its terminal end slightly bilobed, anteriorly, ending in strongly sclerotized mouth of ductus. Mouth of ductus broad, two thirds of ductus also sclerotized, narrows down moderately before the mouth of bursa. Bursa copulatrix completely membranous, ovoid.

Differential diagnosis. Due to variation in facies and the limited number of specimens available for examination, no diagnosis is given based on wing morphology. The main differences between I. bundali and I. stewarti lie in male genitalia, particularly in the shape of the lobes of uncus, which is narrow and pointy in I. stewarti , broad in I. bundali ( Figs. 5E, F ). Also, the valva in I. bundali is much narrower with only the tip turning upwards. Valva is broad in both known populations of I. stewarti , also the two spines on the tip of valva are more developed in I. stewarti and the valva turns upwards gradually towards the tip (3H, I). In I. stewarti the narrow, anterior part of the aedeagus is much longer, twice the size of the squat posterior part (without the terminal cuneus), while the anterior part is only one and a half times the size of the posterior part in I. bundali ( Figs. 3K, L ). The main difference in female genitalia appears in the ductus bursae, which narrows down only moderately in I. bundali , while it is very narrow (bottleneck-like) in I. stewarti ( Figs. 8A, B ). The lower plate of the lamella antevaginalis has a single, gently curved tip in I. bundali , while it is also gently bilobed in I. stewarti ( Fig. 9A, B ).

Biology and habitat. I. bundali flies in the riverine montane forest—montane grassland mosaic of the Bundali Hills. The larval foodplant is Phragmanthera usuiensis usuiensis (Oliv.) M.G.Gilbert (Loranthaceae) , a hemiparasite growing on the shrub Tecomaria capensis (Thunb.) Lindl.

Etymology. The species is named after its type locality, the Bundali Hills in south-western Tanzania. The butterfly fauna of this undulating grassy plateau with submontane-montane forest in the deeper valleys is very poorly known.

Discussion. I. bundali is known only from its type locality and is replaced by I. stewarti only 60 km south in the Mafinga Hills in Zambia. This extreme speciation projects the existence of further similar taxa in mountainous areas along the western shores of Lake Malawi.

Taxonomic note. the genitalia of the “as yet undescribed” taxon mentioned in the original description of I. stewarti to occur on Nyika Plateau correspond with those of the holotype of I. stewarti illustrated by Heath (1985). It is not mentioned again by Heath et al. (2002). However, the blue colour on the upperside of females in the Nyika Plateau population is visibly lighter compared to one of the paratypes illustrated in colour by d’Abrera (2009). The cell-closing black tooth on the forewing upperside (illustrated on Fig. 10B, E ) is also rather inconspicuous. The matter could be best approached using molecular techniques.

Figures

FIGURE 3. Male genitalia: I. maritimus usambara (Tanzania, Usambara, Gen. prep.: SAFI00375) lateral view—A, aedeagus— D; I. uluguru (holotype, Gen. prep.: SAFI00369) lateral view—B, aedeagus—E; I. collinsi (holotype, Gen. prep.: SAFI00359) lateral view—C, aedeagus—F; I. njombe (Tanzania, Njombe, Gen.prep.: SAFI00366) laterial view—G, aedeagus—J; I. stewarti (Malawi, Nyika Plateau, Gen. prep.: SAFI00210) lateral view—H, aedeagus—K; I. bundali (holotype, Gen. prep.: SAFI00212) lateral view—I, aedeagus—L.

FIGURE 5. Male genitalia (dorsal view): I. maritimus usambara (Tanzania, Usambara, Gen. prep.: SAFI00375)—A; I. uluguru (holotype, Gen. prep.: SAFI00369)—B; I. collinsi (holotype, Gen. prep.: SAFI00359)—C; I. njombe (Tanzania, Njombe)—D; I. stewarti (Malawi, Nyika Plateau, Gen. prep.: SAFI00210)—E; I. bundali (holotype, Gen. prep.: SAFI00212)—F.

FIGURE 8. Female genitalia (lateral view): I. bundali (paratype, Tanzania, Bundali Hills, Gen. prep.: SAFI00213)—A; I. stewarti (Malawi, Nyika Plateau, Gen. prep.: SAFI00211)—B; I. njombe (paratype, Tanzania, Njombe, Gen. prep.: SAFI00367)— C.

FIGURE 9. Female genitalia (lamella antevaginalis and papillae analis ventral view): I. bundali (paratype, Tanzania, Bundali Hills, Gen. prep.: SAFI00213)—A; I. stewarti (Malawi, Nyika Plateau, Gen. prep.: SAFI00211)—B; I. stewarti (allotype, Zambia, Mafinga Hills)—C (redrawn from Heath’s (1985) original).

FIGURE 10. Known localities of species in the Iolaus maritimus species group. Only type localities and identifications confirmed via examination of genitalia are illustrated.