Bogong Moth

Victorian Conservation Status: Secure

Bogong Moths are often very abundant but this varies from year to year. Their migratory behaviour makes it difficult to monitor populations. There is some concern about the moths accumulating arsenic in their bodies while feeding in the lowlands, then carrying it into fragile alpine ecosystems. Furthermore, the caterpillars are crop pests and millions are destroyed by pesticides each year

Did you know?

Bogong Moths

• fly up to 1000 km during their annual migration
• shelter in alpine caves over summer
• are an important food source for many alpine animals
• are herbivores and adult Bogong Moths eat nectar and feed on plants as larvae
• wingspan is up to 5 cm

Where they live

Bogong Moths are found across much of south-eastern Australia. They breed in hot, dry areas then migrate to alpine caves.

Amazing Bogong Moths

The annual migration of Bogong Moths begins in their winter breeding grounds in the Darling Downs of Queensland and the dry inland regions of New South Wales and Victoria. Here the females deposit around 2000 eggs and the larvae (or caterpillars) feed and develop. The caterpillars are known as cutworms because they chew through plant stems at ground level. They eat a variety of plants, including introduced crops.

The larvae pupate in the ground and emerge in early spring to begin their migration. Adult Bogong Moths are grey-brown with dark mottles and eye spots. Their drab colouring provides good camouflage for hiding in crevices during the day. At dusk they become active, and fly through the night. They feed on nectar to build up fat reserves that sustain them over summer.

Arriving around November, Bogong Moths cover the walls of alpine caves over summer – up to 17 000 moths in one square metre. They create a massive influx of high-fat, high-protein food to alpine ecosystems and are feasted upon by marsupials. For thousands of years they were also harvested by Indigenous people, who roasted them whole.

Those that survive summer fly back to breeding grounds in autumn to start the cycle again. Bogong Moths are attracted to lights and are a common sight around buildings in Canberra, Sydney and Melbourne.