Dysphania numana (Cramer) (Geometridae: Geometrinae), the Four O'clock Moth
The seems an unusual geometrid moth and it is. It is a member of genus that has species in the Oriental Region as well as Australia. All are brightly coloured. D. numana is a large moth with some specimens measuring 8 cm across.
The caterpillars feed on a freshwater mangrove, Carallia brachiata (Rhizophoraceae) and on the leaves of Melicope elleryana (Rutaceae). The caterpillars are said to position themselves so that they resemble catkin flowers. Their bright yellow colours and the startling colours of the moth suggest that both caterpillar and moth are distasteful to vertebrates.
The Four O'clock moniker stems from the fact that the moths fly in late afternoon. However, on dark days they can fly earlier and well into the evening, hence the presence of this one at the light sheet.