Butterflies and Moths
Butterflies and moths belong to a group of insects known as Lepidoptera (“scale wings”) They are well represented within the Wet Tropics, Cape York and Gulf Savannah regions of tropical north Queensland. More than 250 species, or around 70% of Australia’s butterflies, so far described, occur in diverse habitats from mangroves and rainforest to the savannah woodlands of the arid interior.
The most common species at Warrigal Rainforest Preserve (1,000 + metres) are Northern Sword-grass Brown, Macleay’s and Ambrax Swallowtails, Grey Albatross, Blue and Green-spotted Triangles, Cairns Birdwing, Ulysses, Red-banded, Yellow-spotted and Black Jezabels. Other species are recorded passing through on migration.
In tropical north Queensland butterflies are most active during the warmer months from about October through to late March/mid-April depending on the season. They are mainly active in the daytime. They become most active when temperatures reach between 27-38 degrees C.
Butterflies have two pairs of wings which, unlike moths, do not lock together in flight. The exception being the male Regent Skipper which has these moth-like characteristics.
Most butterflies feed on nectar from flowering plants. Some species also feed on the exudate from trees and the fluids from rotting wood and fruit. We have even seen butterflies feeding on the juices from rotting and very smelly fungi. These fluids are sucked up via a long, straw-like, tubular proboscis. For many rainforest species the favoured food appears to be nectar from an introduce flowering plant species, Lantana which grows in thickets along rainforest margins.
Wing surfaces of butterflies are covered with overlapping scales which produce the bright and often iridescent colours and patterns which identify the species. These colours are the result of either refracted light from the physical structure of the scales or pigments within the scales.
Populations of many species can be eruptive given favourable, seasonal conditions.
Because of their mostly bright colours and ease of visibility, butterflies are now used as environmental indicators for monitoring the health of the environment. Populations of many insects, including butterflies and moths have declined noticeably over the past few years.
Each butterfly species has a specific plant on which it lays its eggs. When the caterpillars emerge they feed on the leaves. The caterpillars of several species are attended by Green Tree Ants.
Butterflies and moths are also important pollinators for many plant species. There is also some evidence to indicate that butterflies and moths also aid in the distribution of fungi spores.
The Apollo Jewel lays its eggs on Ant Plants (Mymecodia beccari), an epiphytic species with large bulbous roots. The caterpillars live inside chambers within the plant and are attended by small ants.
About 95% of all Lepidoptera are moths. In contrast to butterflies most are nocturnal. Moths have fore and hind wings that are linked together by bristle-like structures in flight. Their antennae are variable in shape but rarely clubbed at the ends like those of butterflies.
Moths feed on sugary substances in the form of nectar, sap and exudate from trees and also fruit.
We have also seen a number of individuals of an unidentified moth species that appeared to be feeding on a decomposed carcass of a road-killed kangaroo, possibly to extract salts.
A few species of moth are diurnal and very easily seen in tropical north Queensland. Some even mimic butterflies.
The easiest way to observe nocturnal moths is with a mercury vapour lamp or light with similar output.