Bogong moth

[5] Adult bogong moths breed and larvae hatch during this period, consuming winter pasture plants during their growth.

[4] During the spring, the moths migrate south or east and reside in mountains such as Mount Bogong, where they gregariously aestivate over the summer until their return towards breeding grounds again in the autumn.

[6] It is an icon of Australian wildlife due to its historical role as an important food source and because Aboriginal peoples would come to where the moths spend the summer to feast on them and hold intertribal gatherings.

[4] In recent years, it has invaded major cities like Canberra, Melbourne, and Sydney due to strong winds during its spring migration.

[10] In the Australian state of New South Wales, a series of mountains in the Kosciuszko National Park are named the Bogong Peaks.

[4] The adult bogong moth lays eggs across New South Wales, southern Queensland, and northern parts of Victoria, where larvae hatch and grow until adulthood.

[3] During the spring and summer seasons, when grasses overtake these pastures, conditions are unfavourable for larval survival since larvae do not consume these plants.

[3] Instead, adult bogong moths migrate in a southerly direction during the summer and aestivate (remain dormant), until conditions are favourable again.

[4] During the spring migration, adult bogong moths can be found in their ideal aestivation sites, which generally consist of cool, dark caves and crevices but can include spaces underneath tors and even fallen tree trunks.

[3][12] Attacks on a wide variety of cultivated crops have been seen, with plants such as Medicago species, wheat, cabbages, cauliflowers, silver beet, peas, and potatoes all recorded being consumed by bogong moth caterpillars.

[17] The spring migration begins in early September and occurs from the lowlands of Southern Australia south towards the Australian Alps for purposes of reaching aestivation sites.

[3] During the summer, the moths remain in their aestivation sites until autumn, when they migrate back towards the breeding grounds of the lowlands as early as February, but primarily in April.

[18] A study published in 2018 concluded that the Bogong moth uses a combination of the Earth's magnetic field and recognisable landmarks to calibrate their route.

[17][3] Facultative diapause, an optional period of delayed development in response to environmental conditions, accompanies the biannual migration of the bogong moths.

[4] Bogong moths avoid this harsh environment by delaying development during the summer so that their eggs do not hatch in a poorly-suited environment; instead, they migrate to cooler, more suitable areas and delay their development during aestivation until the winter season, when they return to the breeding grounds and winter pasture crops begin to grow again.

[3] During aestivation, the bogong moths remain dormant for several months, possibly delaying development due to the lower temperatures.

[4] Little raven, currawong and Australian pipit congregations form to feast on bogong moths as they travel from aestivation sites during migration.

[4] Concerns have been raised over the potential role of agriculture in turning the bogong moth into a biovector of arsenic in the Australian Alps.

[20] Aggregations of bogong moths in aestivation sites has led to the bioaccumulation of the pollutant in both the surrounding local environment and within predators, particularly in the endangered mountain pygmy possum.

Investigation into the causes of the grass mortality showed that the concentration of arsenic in the surrounding areas was much higher than normal, and the source was determined to be the bogong moths.

While no source has been determined, concerns have been raised over the possible role of agriculture in the bioaccumulation of arsenic due to its presence in historically and presently-used insecticides.

[23] Other biologists and ecologists have pointed to the dramatic effect on animals which feed on the moths, which are an important source of protein for wildlife, including the threatened mountain pygmy possum as well as other insectivorous mammals and birds.

"The vulnerability of the Australian Alps to climate change is the worst in the world because we've got these short little mountains so when it gets warmer, there is nowhere for these cold-adapted species to go", according to Euan Ritchie, a wildlife ecologist at Deakin University.

[12] The bogong moth is an icon of Australian wildlife due to this historical role as an important food source and as an inter-tribal gathering point in Southeastern Australia.

[4] An excavation of Cloggs Cave, near Buchan in Victoria, revealed microscopic remains of moth on a small grinding stone, estimated to be about 2,000 years old.

The excavation was done by researchers from Monash University in collaboration with the traditional owners, represented by the Gunaikurnai Land and Waters Corporation (GLaWAC).

Bogong moths have had a role in damaging crop plants since winter pastures serve as breeding grounds and larval food sources.

[3] Medicago species, wheat, cabbages, cauliflowers, silver beet, peas, and potatoes have been recorded as being attacked by bogong moth larvae.

[4] Efforts have been made to try and drive the moths out by turning off lights, covering attractive corners and pathways indoors, and using insecticides.

[5] In December 2021 the bogong moth was added to the IUCN Red List as an Endangered Species,[7] based on a February 2021 assessment.

Side profile of an adult
Capeweed, one of the larval host plants of the bogong moth
Gregarious aggregation of bogong moths during aestivation. Hundreds of moths can be seen densely huddled together so that only their wings are visible.
Gregarious aggregation of bogong moths during aestivation
Parasites on the antennae of an adult moth
Bogong moths within Sydney, aggregating in crevices of a building. In the dark corners hidden from the sun, thousands of bogong moths are crowded togegher.
Bogong moths in Sydney, aggregating in the crevices of a building.