The Gossamer Winged Butterfly-Ant connection

By Kathryn Lambert
Science Writer

Lycaenid-ant Association

The larval stage of a variety of butterflies has an association with a particular species of ant also known as myrmecophily and is commonly formed by pupae in the butterfly family Lycaenidae (Eastwood & Fraser 1999). Of the world’s 4400 Lycaenidae species, approximately 50 per cent have a relationship in some way with ants, which can range from a highly mutualistic or parasitic interaction to an unstructured coexistence with a diversity of ant taxa. In Australia there are approximately 150 species of Lycaenids and 70 per cent are recorded as myrmecophilous (Eastwood & Fraser 1999). According to Eastwood & Fraser (1999), P. spinifera has a mutualistic relationship with A. itinerans and is rarely found without the attendant ants. The larvae have also been constantly found vigorously attended by high ant numbers, usually five or more per larvae (Eastwood & Fraser 1999). Anonychomyma, according to Fiedler (2001), is the dominant ant in its habitat and intra- and inter-specifically defends its territories and resources; which coincide with the findings of Eastwood and Fraser (1999) who state that the relationship favours survival and reproduction.

Eastwood and Fraser (1999) suggest that obligately myrmecophilous species such as P. spinifera produce more nutrient rich secretions than those less dependent on A. itinerans. Increased predation and parasitism pressures affects may favour more nutritionally rich secretions as they may attract a larger number of protective ants (Eastwood & Fraser 1999). The secretions are produced by the dorsal nectary gland and are identified by the dominant ant species, A. itinerans (Pierce et al. 2002). The adult female, after mating, oviposits on B. spinosa subspecies lasiophylla, suggested by Dexter and Kitching (1993) to be detected by olfactory cues, laying up to four white eggs which turn green in colour with maturity. Eggs are positioned on the lower half of the bush on either the underside of leaves on the main trunk or on debris at the bottom of the plant. While the eggs are maturing, the ants are constantly searching B. spinosa subspecies lasiophylla, possibly to locate newly hatched larvae (Dexter & Kitching 1993).

Once hatched, the first instar larvae are immediately attended to by one ant which is intriguing as newly hatched larvae do not posses ant-attracting organs. While the larvae are in stages one to three, they along with the ants remain diurnal, feeding in the morning and afternoons and returning to the nest in the middle of the day and at dusk (Dexter & Kitching 1993). The larvae and ants become nocturnal after the third instar, only feeding in the safety of dark. Without ants in laboratory conditions, larvae of P. spinifera take between 60 and 70 days to pupate, have up to eight larval stages and remain on the bush permanently (Dexter & Kitching 1993).

Bathurst Copper Butterfly Paralucia spinifera
Source: http://www.abc.net.au/science/scribblygum/june2003/bath.htm

References
Dexter, E.M. & Kitching, R.L. 1993, ‘The Bathurst Copper, Paralucia spinifera Edwards and Common’, in Conservation Biology of Lycaenidae, eds. T.R. New, International Union for Conservation of Nature and Natural Resources Species Survival Commission, pp.168-170.
Eastwood, R. & Fraser, A.M. 1999, ‘Associations between lycaenid butterflies and ants in Australia’, Australian Journal of Ecology, vol.24, pp. 503-537.
Fiedler, K. 2001, ‘Ants that associate with Lycaenidae butterfly larvae: diversity, ecology and biogeography’, Diversity and Distributions, vol.7, no.1, pp. 45-60.
Pierce, N.E. Braby, M.F. Heath, A. Lohman, D.J. Mathew, J. Rand, D.B. & Travassos, M.A. 2002, ‘The ecology evolution of ant association in the Lycaenidae (Lepidoptera)’, Annual Review of Entomology, vol.47, pp. 733-771.