Bogong moth fact sheet | Field of Mars EEC

What are bogong moths?

The bogong moth (Agrotis infusa) is a brown Australian moth in the family Noctuidae. Its caterpillar is sometimes called a black cutworm. Adult bogong moths have patterned forewings and a wingspan of up to about five centimetres.

Bogong moths are known for their seasonal migration. In spring, many adults fly from inland breeding areas towards cool, high places in the Australian alpine areas. They shelter there through summer, then become active again in autumn.

The journey connects inland and alpine environments across south-eastern Australia. Moths can also appear in towns and cities when winds carry them towards the coast or artificial lights attract them.

A bogong moth

Bogong moths migrate towards the Australian alpine areas in spring.

Where do bogong moths live?

Bogong moths breed in inland areas of south-eastern Australia, including parts of Queensland, New South Wales, Victoria and South Australia. Their caterpillars develop where young plants are available for food. In spring, many adult moths migrate towards the Australian alps, travelling as far as about 1,000 kilometres.

During summer, moths shelter in cool caves and deep cracks in alpine rocks. They become inactive in this period of summer dormancy, called aestivation. They usually become active again in autumn and migrate towards breeding areas. Migration and breeding patterns vary across the species’ range.

Granite outcrops are part of the alpine landscape where bogong moths shelter in summer.

What do bogong moths eat?

Bogong moth caterpillars feed on seedlings and other young broad-leaved plants growing close to the ground. These plants grow after rain in inland breeding areas, so dry conditions can reduce the food available to young caterpillars.

Adult bogong moths feed on nectar. They shelter in alpine areas during summer and are often inactive, but researchers have also recorded them visiting flowers during summer activity periods.

Bogong moths feed on nectar from flowers such as the common heath.

What is the life cycle of a bogong moth?

Bogong moths develop through four stages: egg, caterpillar, pupa and adult. In the usual seasonal pattern, adults return to inland breeding areas in autumn and lay eggs. The eggs hatch into caterpillars, which feed on young plants through the cooler months.

The caterpillars pupate in the soil. Adult moths emerge in spring, and many migrate to alpine shelters for summer. The timing depends partly on local conditions, including rainfall and the growth of food plants. Researchers have found that bogong moth breeding and migration patterns can be more varied than this broad seasonal pattern.

Bogong moths develop through egg, caterpillar, pupa and adult stages.

What adaptations do bogong moths have to help them survive?

Bogong moths are nocturnal, so they migrate at night. Researchers have found that they can use patterns in the night sky and Earth’s magnetic field as compass cues. These navigation abilities help them travel long distances to alpine shelters, even though individual moths have not made the journey before.

During summer, moths rest close together in cool caves and rocky crevices. This seasonal inactivity, called aestivation, helps them avoid the heat of inland breeding areas.

Bogong moths cluster together in deep crevices during summer.

Why are bogong moths important?

Bogong moths are an important food source for alpine animals, including the critically endangered mountain pygmy-possum. The large numbers that gather in alpine shelters also carry nutrients from inland breeding areas into mountain environments.

Adult bogong moths can feed on nectar and act as pollinators. Their numbers fell sharply in recent years, and the IUCN Red List classifies the species as Endangered. Researchers continue to study the moth’s population and the factors affecting it.

A bogong moth feeds on nectar from an azalea flower.

How can you help bogong moths?

Turn off outdoor lights when they are not needed, particularly during migration periods. Artificial lights can attract migrating moths and interfere with their movement. Avoid unnecessary insecticide use, which can harm moths and other insects.

If you see a bogong moth, leave it undisturbed. You can upload a photo of your sighting to Moth Tracker⁠ to help researchers learn where the moths are travelling.

Bogong moths gather on a building in Sydney.

Related fact sheets

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• Invertebrate fact sheets⁠ – Browse fact sheets about insects, spiders, crustaceans, molluscs, worms and other invertebrates.
• Moth fact sheet⁠ – Compare bogong moths with other moths, including their feeding, life cycles and adaptations.
• Butterfly fact sheet⁠ – Compare another member of the insect order Lepidoptera.
• Insects fact sheet⁠ – Explore insect features, life cycles, adaptations and ecological roles.

Habitats and ecosystems

• Alpine and subalpine environments fact sheet⁠ – Explore the mountain environments where migrating bogong moths shelter during summer.
• Ecosystems and environments fact sheet⁠ – Learn how living and non-living features connect through food webs and ecosystem processes.

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