Dixeia spilleri (Spiller, 1884)

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 : 1572-1573

Dixeia spilleri (Spiller, 1884)

Larsen 1996: pl. 10, fig. 93 i. d’ Abrera 1997: 105 (2 figs). SI: Figure 34a–f.

Forewing length: male 20.5–25 mm (mean (n = 7) 22.56 mm, SD = 1.112); female 19– 24 mm (mean (n = 12) 21.32 mm, SD = 0.853).

Records. This distinctive monotypic species occurs in riverine and dry forests from South Africa northwards to eastern Tanzania and northern Kenya ( Ackery et al. 1995, p.213). For Tanzania Kielland (1990, p.64) records D. spilleri as a rather local bushland and forest roadside species found in coastal areas inland to Ifakara, Mikumi and the Usambaras, flying at altitudes up to 1700 m. Cordeiro (1995) noted an old specimen in BMNH from Moshi – but we failed to re-locate this material in the museum’ s main or Rothschild collections (perhaps the specimen was found among accession or supplementary material). However, given the details noted by Cordeiro, we think it unlikely he was mistaken. On this basis, and the evidence of three males from Taveta and a female from “Terta” in the BMNH, we include this butterfly as a member of the lower slopes fauna.

Males of D. spilleri are always a bright, clear yellow, while the females vary from white to cream or yellow ( Larsen 1996, p.144, as “ spilleri spilleri ”). Probably there is an underlying polymorphism in the females, which are generally yellow (male-like), piebald (forewing whitish, hindwing yellow or orangey-yellow), or whitish, with only the anal area of the hindwing with some orange scales. Worn specimens are difficult to assess.