Often called the atlas moth in error, the Hercules (Cosinocera hercules) is the largest moth species in the world. With a wingspan of roughly 30cm, it is a special treat to find one in their rainforest home. The handsome brown wings of both males and females have triangular transparent 'windows' and a white triangle edge looks as if it was dusted onto the wings. The males wings have long tapered tails while the females wings lack the tails but they are larger in overall area. The adult female emerges from the chrysalis without mouthparts as her brief life does not include feeding. After she emerges and her wings unfold and dry, she will emit pheromones to attract a male. After mating, she will fly away, lay her eggs and die shortly after.
The caterpillar is equally impressive at 12cm long and bearing long yellow spikes from each segment of its pudgy, pale green body. A common tree species, the bleeding heart (Homalanthus novoguineensis) is the food plant of the Hercules moth.
The zodiac moth (Alcides zodiaca) is readily confused as a butterfly because of its lovely strong bands of tan and mauve that diagonally cross its black wings. This colour is necessary because the zodiac moth is a day-flying moth. Commonly seen around Cairns and the Atherton Tableland, the zodiac moth's food plants are the toywood tree (Endospermum medullosum) and the day moth vine (Omphalea queenslandiae).
Like the Hercules the emperor gum moth (Opidiptera spp) is another large species, with a wing span of 15cm. It has vivid eye spots on the pale brown wings which help to scare away potential predators. The body is hairy and the antennae are feathery. Although the caterpillars are easy to raise, the pupa stage can last quite a while before the adult emerges. The emperor gum moth emerges from its cocoon in an unusual way - its cocoon is very hard so the newly formed adult secretes a fluid which softens the bottom end of the cocoon. The adult then cuts its way through the softened part with a 'thorn' at the base of the forewing.
The giant ghost moth (Anetus spp) is an unusual species in more ways than one. Like the male and female eclectus parrots, which are completely different colours, the male ghost moth has blue wings while the female's are green. The caterpillars of the moths in this family burrow into soil but more often into tree trunks to feed and pupate. A preferred tree for the giant ghost moth is the alphitonia, occurring as a pioneer tree and on the edges of rainforest. Just before entering the pupa stage, the caterpillar weaves a silken plug to seal up its food tunnel. When it is ready to emerge, it chews around the edge of the plug which drops out, allowing the metamorphosed adult to emerge from the tunnel and expand its wings.