Belenois margaritacea plutonica (Joicey & Talbot, 1926)

Liseki, Steven D. & Vane-Wright, Richard I., 2014, Butterflies (Lepidoptera: Papilionoidea) of Mount Kilimanjaro: family Pieridae, subfamily Pierinae, Journal of Natural History 48 (25 - 26), pp. 1543-1583 : 1567-1568

Belenois margaritacea plutonica (Joicey & Talbot, 1926)

Kielland 1990: 267 (1 fig). d’ Abrera 1997: 89 (2 figs). SI: Figure 29a–d.

Forewing length: male 24–28 mm (mean (n = 8) 26.13 mm, SD = 0.873); female 24– 30 mm (mean (n = 7) 27.61 mm, SD = 1.627).

Records. Northern highlands ( Mt Kilimanjaro , Ngorongoro Crater ), Pare Mts , Usambaras and Rubeho Mts, montane forest glades and margins at 1500–2700 m ( Kielland 1990, p.61). Recorded on Kilimanjaro by Aurivillius (1910a, p.11) as “ Pieris raffrayi ” from the agricultural zone around Kibongoto upwards into the primary forest, as high as 2200 m, during March, April, September, October and December. This taxon shows geographical variation, with some populations intermediate to B. margaritacea kenyensis Joicey and Talbot , described from southeastern Kenya (Kielland loc. cit.) . The Kilimanjaro population (represented in BMNH by numerous male and a few female specimens collected by B. Cooper) appears to be typical plutonica (type locality: Ngorongoro Crater ). However, it was not encountered on Kilimanjaro by Liseki (2009). Belenois margaritacea is limited to highland forests in Tanzania and Kenya .

The butterflies are fairly constant in appearance, with very slight sexual dimorphism: the greyish-blue discal coloration of the male hindwing upperside is slightly more extensive than in females. Additionally, females lack preapical forewing streaks on the forewing upperside, whereas males usually have two, three or four such streaks. However, some males have only one streak – and occasionally, like the females, the apex is entirely black. In this regard the supposed near diagnostic difference between B. margaritacea and the essentially allopatric B. raffrayi is not entirely reliable (cf. Larsen 1996, p.138). See also Discussion.