Golden Sun Moth

Synemon plana Walker, 1854 is a castniid moth. Unlike many moths, adults have clubbed antennae and are active during daylight. [1][2]

Males span approximately 34 mm and have grey-patterned dark forewings and bronze-brown hindwings. Females span approximately 31 mm, with dark-grey forewings and orange hindwings bearing dark submarginal spots. Both sexes have green eyes. [1]

Extant populations inhabit native temperate grassland and open grassy woodland in New South Wales, the Australian Capital Territory and Victoria. [2]

Larvae develop underground, with a generation estimated to last two to three years. Pupation takes place below ground; the empty pupal casing remains protruding at emergence. Adults live approximately one to four days. [1][2]

Larvae use roots of wallaby grasses, Rytidosperma, and speargrasses, Austrostipa. Breeding has also been recorded in Chilean needlegrass-dominated sites. Adults lack functional mouthparts. [2][1]

On warm, sunny days males patrol low over grassland. Semi-flightless females flash orange hindwings to attract them. [1]

Habitat fragmentation restricts dispersal. In New South Wales, patches separated by over 200 m of unsuitable habitat are considered likely to be isolated. [2]

Walker’s 1854 description was based on a female. Its diagnosis recorded yellow hindwings with small brown spots and a slender brown border. [2]

The 2026 recovery plan records the species as Vulnerable under Australia’s EPBC Act. Habitat loss, fragmentation and degradation from agriculture, urban development and invasive vegetation remain major threats. [1][2]

Keep the enclosure closed and display it in indirect light, away from heat and damp conditions. Handle the frame by its edges and clean only its exterior according to the maker’s instructions.