Species: Cressida cressida
Common names: Clearwing Swallowtail, Greasy Swallowtail, Big Greasy
Both male and female Clearwing Swallowtail butterflies can often be seen in the reserve, particularly around the infestation of Dutchman’s Pipe vines, and also in the cleared areas in the north-west. However so far I haven’t found any butterfly eggs or larvae on the Dutchman’s Pipe vines. The photo is of a male Clearwing Swallowtail butterfly. The male butterflies usually fly slowly a few metres above the ground patrolling the area looking for a mate. The females fly slowly and purposefully very close to the ground searching for a suitable host plant on which to lay their eggs.
Their host plants are native species of Aristolochia and Pararistolochia praevenosa. The only one of these species that I have found in the reserve is Aristolochia meridionalis. This species seems to be appearing in increasing numbers as natural regeneration occurs in the weeded areas. Finding these plants can be quite difficult as they are normally quite small with only about 6 or 8 leaves. However it doesn’t seem to pose too much of a problem for the Clearwing Swallowtail butterflies because all but one of the plants I found had already been visited by a butterfly that had laid an egg or two on the leaves.
Aristolochia meridionalis continues to come up in small numbers at the bottom of the bank below the picnic area. However the plants don’t seem to be there very long before they are discovered by a Clearwing Swallowtail butterfly which lays an egg or two on them. The developing caterpillars then proceed to defoliate the plants. It is quite amazing that the butterfly can find such small and uncommon plants in the middle of the forest!