Systematic revision of the Ogyris idmo (Hewitson, 1862) species group (Lepidoptera: Lycaenidae): implications for the conservation management of Australia's most threatened butterflies

Lycaenid butterflies of the Ogyris idmo species group are endemic to Australia and obligatorily associated with Camponotus ants. Several species are threatened with extinction, but there are considerable uncertainties with the present classification. Here, the taxonomy of the species group is revised based on molecular and morphological data. Mitochondrial sequence data were obtained from GenBank for Ogyris Angas, 1847, from cytochrome oxidase I (COI) and cytochrome b (cytb) (total of 1203 bp), and a phylogeny of the genus was reconstructed using Maximum Likelihood methods. Based on these molecular data, adult morphology and other evidence, the following eight taxa are recognised in this species group: Ogyris otanes (C. & R. Felder, 1865), Ogyris arcana M.R. Williams & Hay, 2001 stat. rev., Ogyris arcana arcana M.R. Williams & Hay, 2001 comb. nov., Ogyris arcana sublustris M.R. Williams & Hay, 2001 comb. nov., Ogyris halmaturia (Tepper, 1890), Ogyris halmaturia halmaturia (Tepper, 1890), Ogyris halmaturia waterhouseri (Bethune-Baker, 1905) stat. rev., Ogyris idmo (Hewitson, 1862), Ogyris subterrestris Field, 1999 and Ogyris petrina Field, 1999 stat. rev. The female of Ogyris halmaturia halmaturia is described for the first time. Phylogenetic relationships among the six species are as follows: (O. otanes + O. arcana) + (O. halmaturia + (O. idmo + (O. subterrestris + O. petrina))). The life history switch from phytophagy (O. otanes and O. arcana) to entomophagy (suspected myrmecophagy) within this species group has led to diversification of four species, a most unusual evolutionary pattern within the Lycaenidae globally. The taxonomic changes proposed herein affect some of the most threatened Australian butterflies and their conservation status is discussed.