The Pale Sun-moth (Synemon selene), a species last recorded in South Australia in 1948 and considered locally extinct, was rediscovered in 2018 by SA Museum staff near Peterborough, in the state's mid-north. This significant rediscovery occurred in an uncropped native grassland, home to a resident population of endangered Pygmy Bluetongue lizards (Tiliqua adelaidensis).

Pale Sun-moths are listed as endangered in Victoria but have no conservation status in South Australia, likely due to a lack of data. Subject matter experts widely regard them as critically endangered in South Australia. This year, the Department for Environment and Water (DEW) has been undertaking widespread surveys in collaboration with expert entomologists to identify new colonies of Pale Sun-Moths and better understand the species' distribution and abundance.

In early March there were two sightings of Pale Sun-moth at Nature Foundation's heritage-listed 85-hectare Tiliqua Nature Reserve in South Australia’s mid north, during management and research activities on the site. Northern and York Landscape Board staff observed around 50 individuals in one location on the reserve, with smaller groups of 2-5 individuals across the reserve. Grassland experts saw a group of around 24 moths in a different location on the reserve around a week later.

The Pale Sun-moth is typically found in uncropped native grasslands in the northern Mount Lofty Ranges and southern Flinders Ranges that have not been sprayed with herbicides or pesticides. It prefers areas dominated by Wallaby grass (Rytidosperma spp.) and Spear grass (Austrostipa spp.). Threats to this habitat include land clearance, agricultural processes, overgrazing, and bushfires. Pale Sun-moths have been recorded on multiple properties with resident Pygmy Bluetongue lizard populations, likely due to their similar habitat preferences.

There is limited data on the lifecycle of the Pale Sun-moth in South Australia, with current life history observations based on Victorian populations. Female Pale Sun-moths are known to lay their eggs in the base of Wallaby grass or Spear grass tussocks, or small cracks nearby to these species. The eggs can take up to 3 months to hatch, with larvae then moving down into the root zone of grasses, where they remain for 2-3 years. Adults emerge from mid-February to mid-March, living for approximately 5-7 days, during which time they do not eat. The males fly about looking for females to mate with, and the females then lay their fertilised eggs, with each female laying up to 120 eggs, and the cycle repeats.

The species potentially represents a valuable food resource for the grassland ecosystem during what is typically a hot and dry time of the year and may be preyed upon by bird species and small reptiles such as Pygmy Bluetongues.

Nature Foundation will monitor this critically endangered species on an ongoing basis as part of our conservation management activities at Tiliqua Nature Reserve.

Photo by Nick Modra.