Clearwing Swallowtails, Cressida cressida, lay their eggs on five different species of Aristolochia, according to Don Herbison-Evans and Stella Crossley’s great Butterflies of Australia site. Peter Valentine (Butterflies of the Townsville Area) agrees, adding that they especially patronise “the low small species scattered through the grasslands.”
The caterpillars change colour and pattern as they grow. The three below are all Clearwing caterpillars, at early, middle and late stages of development.
Cairns Birdwing caterpillars (Troides euphorion) also depend on Aristolochia – four native species of it, in fact. However, there is only one species that both kinds of caterpillars like: Aristolochia tagala.
Here for comparison are Birdwing caterpillars, showing young and old since they also change considerably as they grow:
Recently we have had both species of butterfly laying eggs on our vines and we can’t grow enough of them to feed all the caterpillars that hatch. It’s a continuation, really, of the situation we had back in May. Part of the problem is that a single caterpillar can consume a whole vine seedling within a day so we have difficulty rearing a vine past its infancy; we may have to begin growing them under wire mesh until they are well established.