Caterpillar Alert

With Andy at home this week coinciding with me working at the same site for two consecutive days, I was able to run to work minus a backpack full of work clothes! It was bliss and a beautiful morning with loads of wanderer butterflies flitting about. I was enjoying the moment when I literally was stopped in my tracks by this humongous caterpillar. After taking a photo, I continued on with my run contemplating it's size and if it was in fact a caterpillar? If so how big would the butterfly be???

Luckily the internet has the answer...

White-stemmed Gum Moth

The White-stemmed Gum Moth is one of the largest common moths found in Sydney. With females reaching a size of 16 cm, they have sometimes been mistaken for bats.

Alternative Name/s

Prickly Gum Moth

Identification

The wings of the female White-stemmed Gum Moth are attractively patterned with soft grays and browns. The male is slightly smaller and is darker, with more strongly contrasted markings. Both sexes are active at night. They sometimes fly to lights where the large females have been compared to bats as they move around the light source. As in many moth species, the males have large bipinnate (feathery) antennae, while the females have narrow, simple antennae.

The large, thick caterpillars are grey-black with yellow bands and are covered with tufts of reddish-brown spiky bristles. The bristles can penetrate human skin and cause painful skin irritations, even after the larvae have been preserved in alcohol.

Size range

Adults: 16 cm wingspan; larvae: 12 cm length

Life cycle

The White-stemmed Gum Moth has an annual life cycle. The pupal stage lasts over late summer and most of autumn before the adult moths emerge in May.

The females lay eggs that hatch into small caterpillars. The caterpillars feed on eucalypt leaves and grow throughout the rest of the year until they reach their maximum size before pupation.

In summer, when the caterpillars are fully grown and are ready to pupate, they spin cocoons. As the caterpillar changes into a pupa, the bristles from its skin are pushed through the walls of the cocoon from the inside. The projecting bristles protect the pupa inside the cocoon in the same way that they protect the caterpillar. Pupation usually takes place under the loose bark of trees.

Adults are short-lived (two to three days) and mate soon after emerging. They do not feed because none of the anthelids have functional mouthparts as adults.