Iolaus collinsi, 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 : 55-60

Iolaus collinsi sp. nov. Sáfián, Bayliss & Congdon

FIGS.: 2C, F; 3C, F; 4C; 5C; 6C, F; 7C; 10

Holotype: ♂ MOZAMBIQUE, Mount Namuli , NE Mozambique 1900 m, 20-30.XI.2008 Bred. Leg.: Bayliss, J., Bampton, I. Congdon, T. C.E., Hassan, M. Gen. prep.: SAFI00359 . ABRI unique number: ABRI-2019-3061. Deposited in ABRI.

Paratype: 1♀ MOZAMBIQUE, Mount Namuli 28 th November 2008. Leg.: Bayliss, J., Congdon, T . C.E. Gen. prep.: SAFI00360 . ABRI unique number: ABRI-2019-3062. Deposited in ABRI.

Description of male. Forewing length: 21.5 mm. Wingspan: 39.5 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 and 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 almost to base, leaving a broad, 1.5 mm black costal margin. Black outer margin very broad, 2 mm at tornus. The outer edge of blue area evenly rounded, except in space 3 where edge of blue patch slightly lobed. Majority of hindwing covered with blue, except dark grey-black space 1a, along dark grey-black costa and the broad black margin between apex and tornus. Black margin tapers down from 1.5 mm at apex to fine black marginal line at the end of vein 3. Androconia cover most of cell and upper part of wing to black costa, dark greasy grey-black with black, well-defined oval heart. Prominent black tornal spot present at the end of space 2, while the tip of space 1b entirely black. Tornal lobe dark claret-red, with black margin. Underside dirty white, with creamy tinge along forewing costa and very faint grey dusting along forewing and hindwing margin. Forewing with obsolete, slightly curving blackish submarginal line between veins 2 and 7. Forewing androconial hair tuft beige. On hindwing, narrow, pale orange inner submarginal line keeps strongly away from outer margin, reaching costa 4 mm from apex. Outer submarginal line absent. Tornal spot at the end of space 1a claret-red, that in space 2 bright red, 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, 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. Antennae black, speckled with tiny white dots underneath, only slightly thickened towards apex, their length shorter than half of forewing.

Male genitalia. General morphology is like those of other species in the group as described above. Valvae very narrow, ending in long acute tip, which are evenly serrated. Cingulum short, triangular, the terminal cornutus on aedeagus broad, curving gently upwards. Cornutus on lower tip very strong and acute.

Description of female. Forewing length: 23.5 mm. Wingspan: 43 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 dull sky-blue tone, slightly darker towards the bases and with a whitish area in the apical corner of the blue patch on forewing. Less than half of forewing covered with blue basally, except along costa, where wing broadly black to base. Outer edge of blue area evenly rounded, with small, black, cell-closing tooth present. Basal half of hindwing covered with blue, between vein 1 and 6, dark grey between vein 6 and costa. Black submarginal streaks-spots inconspicuous, seen as darker black band in spaces 1b, 2, 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.

Female genitalia. Papillae analis medium (nearly 1 mm), weakly sclerotized, flat and somewhat squat, with short hairs. Apophyses gently bent downwards, 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, half of ductus sclerotized, narrows down strongly before the mouth of bursa. Bursa copulatrix completely membranous, ovoid.

Differential diagnosis. On the upperside of the male I. collinsi (as well as in I. njombe ), the outer edge of the blue patch is rather evenly rounded. In males of I. maritimus usambara and I. uluguru the outer edge of the forewing blue patch is more lobed, particularly in space 1b. Their forewing outer edge is also almost straight, while slightly convex in I. njombe and I. collinsi . I. njombe males have similar wingshape, but the hindwing black margin is evenly broad with only little blue scaling in spaces 2 and 3, and the margin tapers down towards the tornus in I. collinsi ( Figs. 2A, B, C, G ). The forewing underside submarginal line on the male is blackish and very faint in I. collinsi , the hindwing one is pale orange. In the female, the submarginal lines on both wings are pale orange, while in other species in the group the lines are bright orange, bright brick red or claret ( Figs. 2D, E, F, J ; 6D, E, F, J ). The tip of valvae in male genitalia of I. collinsi are as long as in I. maritimus , however, the valvae of I. collinsi are significantly narrower ( Figs. 3A, C ). The upperside of the females do not differ much, except their blue colour and the whitish area at the apical corner of the blue patch on the forewing, which is completely blue in I. uluguru . The upperside blue colour in I. collinsi is sky blue, slightly darker towards the bases, similarly to I. maritimus usambara , where the base is scattered with turquoise scales. The blue area is darker and even in I. uluguru , while the blue is very light, almost whitish-blue in I. njombe , slightly darker towards the bases ( Figs. 6A, B, C, G ). In female genitalia, the ductus bursae narrows down to a bottleneck before the mouth of bursa copulatrix in I. collinsi and I. njombe , but the latter has the ductus sclerotized almost to the bottleneck, while only the basal half of it is sclerotized in I. collinsi . I. uluguru has an almost evenly broad ductus, while the ductus in I. maritimus usambara narrows down only moderately ( Figs 7A, B, C ; 8C ).

Biology and habitat. The two known specimens were found in montane forest on the high plateau of Mount Namuli. The larval foodplant is suspected to be Erianthemum schelei Tiegh. , the only Taxilloid Loranthaceae found on the mountain.

Etymology. This species is named after Steve Collins, director of the African Butterfly Research Institute (ABRI). The species is dedicated to Steve specifically for all of the support and guidance he has given for the butterfly work on the expeditions carried out on the mountains of northern Mozambique and southern Malawi.

Discussion. The species is currently known exclusively from Mount Namuli (15°21’37”S 37°03’31”E) in northern Mozambique, which is part of a collection of a range of mountains that straddle the border between northern Mozambique and southern Malawi, including well known sites such as Mount Mabu in Mozambique or Mount Zomba, and the Mulanje Massif in Malawi. These mountains are the southernmost representatives of the East African tropical montane forest habitat, which are patchily distributed alongside both branches of the East African Rift but are also present on the higher slopes of the large volcanoes of Tanzania, Kenya and Uganda.

In recent years, there has been a concerted effort to survey the biodiversity of these mountain sites, especially of the mountains in northern Mozambique. A series of scientific expeditions have been undertaken to them, and members of ABRI involved to collect and study the butterflies ( Congdon et al. 2010, Congdon & Bayliss 2012). As a result, several new species have already been described ( Bayliss et al. 2016, van Velzen et al. 2016, Bayliss et al. 2018, Bayliss et al. 2019), although more are expected with further study effort and scientific expeditions to these mountains. It is therefore possible that I. collinsi occurs on other mountains in northern Mozambique besides Mount Namuli. However, the forest habitat on Mount Namuli is under severe threat through local agricultural practices, and much has been removed since I. collinsi was first collected in 2008. Further forest loss needs to be prevented at Mount Namuli to ensure the survival of this species.

Figures

FIGURE 2. Males: I. maritimus usambara (Tanzania, Usambara) upperside—A, underside—D; I. uluguru (holotype) upperside—B, underside—E; I. collinsi (holotype) upperside—C, underside—F; I. njombe (holotype) upperside—G, underside—J; I. stewarti (Malawi, Nyika Plateau) upperside—H, underside—K; I. bundali (holotype) upperside—I, underside—L.

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 6. Females: I. maritimus usambara (Tanzania, Usambara) upperside—A, underside—D; I. uluguru (paratype, Tanzania, Uluguru Mountains) upperside—B, underside—E; I. collinsi (paratype, Mozambique, Mount Namuli) upperside—C, underside—F; I. njombe (paratype, Tanzania, Njombe) upperside—G, underside—J; I. stewarti (Malawi, Nyika Plateau) upperside—H, underside—K; I. bundali (paratype, Tanzania, Bundali Hills) upperside—I, underside—L.

FIGURE 7. Female genitalia (lateral view): I. maritimus usambara (Tanzania, Usambara, Gen. prep.: SAFI00376)—A; I. uluguru (paratype, Tanzania, Uluguru Mountains, Gen. prep.: SAFI00370)—B, I. collinsi (paratype, Mozambique, Mount Namuli, Gen. prep.: SAFI00360)—C.

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.