The gregarious larvae of J. evagoras consume at least 26 different species of Acacia. Eggs are laid in clusters, most often in crevices or holes in the bark, but occasionally on the leaves, stems, and in the hollow formed by the attachment of the leaf pedicel to the stem. The larvae pupate directly on the host plant, and pupae are also tended by ants. At locations in Queensland, ovipositing females often prefer the shorter, younger trees of Acacia (Elgar and Pierce 1988). However, juveniles are frequently found on considerably taller and older host plants in other locations (e.g. Braby 1988, 1998). It seems likely that the foraging behaviour of the attendant ant species influences the size of host plants chosen by females when they are laying eggs. In all cases, the foraging larvae feed preferentially on the terminal foliage of their host plants. Egg laying females use ants as cues and are more likely to lay eggs on plants that contain the attendant ants than on plants without the ants.

Information sourced from:

Pierce, N. E. and Nash, D. R. (1999) The Imperial Blue, Jalmenus evagoras (Lycaenidae). In: Monographs on Australian Lepidoptera Volume 6. Biology of Australian Butterflies (eds. R. L. Kitching, E. Scheermeyer, R. E. Jones and N. E. Pierce) pp. 279-315. CSIRO, Melbourne.

References cited:

Braby, M.F. 1988. New food plants for Jalmenus evagoras evagoras (Donovan) (Lepidoptera: Lycaenidae). Australian Entomological Magazine 15: 33-34.

Braby, M.F. 1998. Notes on the biology of some Hesperiidae and Lycaenidae (Lepdoptera) in South-eastern Australia. Victorian Naturalist 115: 4-8.

Elgar, M. A. and Pierce, N. E. 1988.  Mating success and fecundity in an ant-tended lycaenid butterfly.  Pages 59-75 in Reproductive Success: Studies of Selection and Adaptation in Contrasting Breeding Systems (T. H. CluttonBrock, ed.).  University of Chicago Press, Chicago.

Mimosaceae: Acacia binervata DC.; A. dealbata Link; A. decurrens (H.L.Wendl.) Willd.; A. disparrima M.W. McDonald & Maslin; A. falcata Willd.; A. filicifolia Cheel & Welch ex Welch; A. fimbriata Cunn. ex G. Don; A. floribunda (Vent.) Willd.; A. genistifolia Link; A. implexa Benth.; A. ingramii Tind.; A. irrorata Sieber ex Spreng.; A. leiocalyx (Domin) Pendley; A. leucoclada argentifolia Tind.; A. longifolia (Andrews) Willd.; A. macradenia Benth.; A. mearnsii De Wild.; A. melanoxylon R. Br.; A. neriifolia Cunn. ex Benth.; A. parramattensis Tind.; A. penninervis Sieber ex DC.; A. polybotrya Benth.; A. pycnantha Benth.; A. rubida Cunn.; A. spectabilis Cunn. ex Benth.; A. terminalis (Salisb.) Macbr.; and has been recorded on Amyema pendula (Loranthaceae) (from Braby 2000). The conspecific J. eubulus previously considered a subspecies of J. evagoras feeds exclusively on A. harpophylla (also known as brigalow).

Information sourced from:

Braby, M. F. (2000)  Butterflies of Australia: Their Identification, Biology and Distribution.  CSIRO Publishing, Melbourne.