PARK WATCH Article June 2025 |

Golden Sun Moth (Synemon plana)

When we take a walk in nature it’s easy to forget the whole other world bustling beneath the surface. For Golden Sun Moth larvae it’s all they know. They live underground for up to three years, tunnelling through the soil and feeding on the roots of tussock grasses.

Come mid-October through January, when conditions are just right, adults will emerge for the flying season to breed. They will know this life above ground for just a few days. With no functioning mouthparts they cannot eat or drink and live only to reproduce.

Males fly in a distinctive zigzag pattern, searching for the females who sit flashing their bright orange hind wings. Females lay their eggs in the base of a tussock grass, their most preferred host species being Wallaby Grass (Rytidosperma spp.) and Spear Grass (Austrostipa spp.).

As the name suggests, the Golden Sun Moth is most active on warm, sunny and still days. Open space where the moths can soak up some rays is an important habitat requirement.

They once graced an area stretching from central NSW, through the ACT and Victoria’s north and west, all the way to the SA border. They are now listed as Vulnerable in Victoria and nationally due to the widespread loss and degradation of their only habitat – grasslands. Given their short adult lifespan and females’ mostly sedentary nature, they cannot disperse very far. This makes populations particularly vulnerable to the effects of habitat fragmentation and leads to local extinctions.

Like many things that can be found in a grassland, the Golden Sun Moth is rather unassuming and easy to miss, but by taking a closer look you can see how fascinating they are. They’re yet another reason to continue the fight to save our grasslands.

Grassy Plains Network intern Ella Darling recently completed a Diploma of Conservation and Ecosystem Management at Melbourne Polytechnic