Chrysoritis stepheni (Dickson 1978), 2023

Heath, Alan, 2023, Chrysoritis Butler (Papilionoidea: Lycaenidae: Aphnaeinae) - Part III: An integrative taxonomic revision, Metamorphosis 34 (1), pp. 11-28 : 26

Chrysoritis stepheni (Dickson 1978) stat. rev.

Poecilmitis stepheni Dickson 1978: 294 .

Holotype: NHM, London. Type locality: Hantamsberg, Calvinia . See also Heath & Pringle (2007: 24).

MPT: montane slopes and prominences. Host ant: Crem. peringueyi . Larval host plants: Dimorphotheca cuneata Thunb. , at Calvinia and Osteospermum amplectens (Harvey) T.Norl. , at Garies; both Asteraceae and of very similar structure. In captivity late instar larvae readily transferred from one of these host plants to the other with no change observed in feeding behaviour (A. Heath).

Taxonomy: Chrysoritis stepheni has 100% bootstrap support in the COI tree and is sister to C. beaufortia . Thus far C. stepheni has been treated as a subspecies of C. beaufortia due to its morphological similarity with the subspecies C. b. beaufortia and its shared ecology with all of C. beaufortia (same MPT, elevation, and host ant species). Chrysoritis stepheni is separated from the similar looking C. b. beaufortia by 270 km, but from the darker C. b. charlesi, it is separated by only 17 km. The long subtending branches between C. beaufortia and C. stepheni in the COI tree indicate deep divergences and warranted a look at their pairwise fixation index (ΦST see Note S 2 in QEA22) from the AMOVA analyses. The ΦST value for C. beaufortia (n = 6) vs. C. stepheni (n = 4) is 0.725 (p <0.05; see Note S3 here). Thus, despite only a 17 km (minimum) separation, an overwhelming proportion (72%) of the total genetic variation among all individuals occurs between the two taxa (versus 28% within taxa). This is much higher than a typical range for subspecies (explained in Note S3). Thus, C. beaufortia stepheni is raised to C. stepheni stat. rev.

Chrysoritis stepheni itself consists of two discrete populations known to the authors, one on the Hamtamsberg, Calvinia (n = 2) and the other 195 km NW on the Kamiesberge (n = 2), Despite their geographic distance, they are ecologically comparable and morphologically identical – two populations yet to meet the requirements for subspecies ( Braby et al., 2012).

Conservation status: LC – Rare.