The bogong moth (Agrotis infusa), once an abundant presence in the Australian skies, is now vanishing. Known for its extraordinary migratory patterns and revered in Aboriginal culture, this unassuming insect plays a vital role in both ecological balance and Indigenous heritage. But in recent decades, the bogong moth has faced a dramatic population collapse and is now listed as endangered—threatening not only biodiversity but also cultural traditions intimately tied to its life cycle.
The journey of the bogong Moth
Each Spring, the bogong moth embarks on one of the most astonishing migrations in the insect world. Born in the lowland breeding grounds of southern Queensland, western and north-western New South Wales, and western Victoria, these moths take to the skies under the cover of night. They travel more than 1,000 kilometres, navigating by a suite of sensory tools—visual landmarks, olfactory signals, magnetic fields, and mechanical cues. Their destination? The cool alpine crevices and granite caves high in the Australian Alps, above 1,800 metres. Here, they seek refuge from the summer heat in a state of dormancy known as aestivation.
From late September to March, these caves teem with bogong moths—densities can reach up to 17,000 individuals per square metre. This period of rest is critical for their survival and sets the stage for their return journey. As the heat wanes and the breeding season nears, the moths awaken and fly back to the lowlands to reproduce and, ultimately, die—completing their life cycle.
A deep cultural connection
Long before scientific interest in the bogong moth began, Aboriginal peoples of south-eastern Australia had forged deep relationships with these insects. Each summer, tribes from across the region converged on the Snowy Mountains, Brindabella Ranges, and Bogong Peaks to harvest the moths. Using smoke, sticks, nets, and coolamons, they gathered moths from the caves and roasted them in ashes, ground them into paste, or smoked them for preservation. High in fat (around 60%) and protein (27%), the moths provided a dense, nutritious food source.
These gatherings were more than seasonal feasts—they were vital cultural events. With hundreds of people—sometimes 500 to 700—coming together, the bogong moth harvests enabled trade, intertribal marriages, initiations, and the exchange of knowledge. The timing of these migrations helped synchronise cultural rhythms with the natural world, embedding the moth deeply into spiritual and communal life.
The cultural significance of the bogong moth is backed by archaeological finds. At Cloggs Cave in Victoria, evidence of cooking practices involving moths dates back 1,600–2,000 years. Ethnographic studies also reveal parallels with insect-based food traditions among Indigenous groups worldwide, such as the pine nut moth harvests of Great Basin tribes in the United States.
A species in crisis
For decades, the bogong moth’s migrations remained a reliable spectacle. But starting in the early 1980s, population numbers began to fluctuate. Then, from 2017 to 2020, a devastating collapse occurred. Key aestivation sites—once blackened by the sheer volume of moths—stood eerily empty. On Mt. Buffalo and the Bogong High Plains, near-total disappearance was recorded.
A plethora of factors have contributed to the decline of the bogong moths, such as global warming, droughts, agriculture, and light pollution. Warmer temperatures are melting snowpacks earlier and shortening the cool periods needed for aestivation. This disrupts the moths’ biological rhythms and their alignment with the needs of alpine species dependent on their arrival. Severe droughts, particularly between 2017 and 2019, dried out breeding grounds in the Murray-Darling Basin. Poor soil moisture and lack of vegetation reduced larval survival rates dramatically.
Agricultural practices, such as the expansion of rice and cotton farming has also degraded habitat quality. Pesticides like deltamethrin and neonicotinoids further harm moth populations, while monoculture farming reduces biodiversity and limits food availability for larvae. Additionally, with light pollution and urban expansion, artificial lighting has become a deadly trap. Iconic incidents—such as massive swarms disoriented by the lights of Parliament House in Canberra—illustrate how moths are drawn away from their migratory path and often die before reaching their destination.
The disappearance of bogong moths ripples through alpine ecosystems. Many species, including the endangered mountain pygmy possum, rely on the moths for a critical post-snowmelt energy boost. Without this influx of nutrients, food chains destabilise, and fragile mountain environments face intensified stress and disruption.
Planting hope: How you can help
While global solutions require systemic change, individuals and communities can play a powerful role—starting in their own backyards.
Bogong moths feed on nectar during their migration. By planting native species that bloom at night or produce abundant nectar, we can create a lifeline for these insects as they journey across vast distances. Bogong moths are known to feed on the following native Australian plants:
- Grevillea (spider flowers)
- Eucalyptus
- Epacris (common heath)
- Correa (dusky bells)
- Lecopogon (beard heath)
- Prostanthera (mint bush)
By integrating these plants into urban gardens, schoolyards, and our own backyards, we not only support bogong moths but also contribute to wider ecological restoration. These plants are drought-resistant, pollinator-friendly, and vital to countless native species.
The decline of the bogong moth is a warning, yes—but it’s also a call to action. Aboriginal communities are reviving traditional moth festivals, reconnecting with land and culture. Conservationists are working to protect breeding sites, reduce pesticide use, and monitor moth populations. Now, everyday Australians can join this movement. By planting nectar-rich natives and turning down outdoor lights during migration seasons, we can become caretakers of an ancient journey.
Article by Alice Owen
Image R. Jessop (C) Australian Museum