A new species of Paralucia Waterhouse & Turner, 1905 (Lepidoptera: Lycaenidae) from the highlands of south‐eastern Australia

A new species of lycaenid butterfly, Paralucia crosbyi sp. nov. (Theclinae: Luciini), is described, diagnosed and illustrated from Namadgi National Park, ACT, and adjacent areas in New South Wales in the highlands of south‐eastern Australia. It is most similar to Paralucia spinifera E.D. Edwards & Common, 1978, but comparative morphology of the adult and immature stages indicates fundamental differences between the two species. Maximum Likelihood phylogenetic analysis of mitochondrial cytochrome oxidase subunit I ( COI ) of all Paralucia species recovered P. crosbyi sp. nov. and P. spinifera as reciprocally monophyletic, with a mean uncorrected ‘ p ’ pairwise divergence of 0.93%. Paralucia crosbyi sp. nov. appears to be a narrow‐range endemic, restricted to dry montane eucalypt open woodland or woodland between 920 and 1130 m asl, in which the mean annual rainfall varies from 700 to 800 mm and where an abundance of the larval food plant Bursaria spinosa Cav. subsp. lasiophylla (E.M.Benn.) L. Cayzer, Crisp & I. Telford (Pittosporaceae) and colonies of the attendant ant Anonychomyrma sp. ( itinerans species group) (Dolichoderinae) are established. The immature stages are described, illustrated and compared with those of P. spinifera and P. aurifera (Blanchard, [1848]). Despite being limited to high altitudes, adults fly in late winter–early spring (late July to early October). The species is univoltine, with much of the year (~9 months) passed in the pupal stage. The ecology, biology and life cycle are discussed, and a likely mode of speciation is hypothesised.