The following information refers to Nyctemera annulata and Nyctemera amica: They are closely related and are able to interbreed.
It is a medium sized moth, the adults have a wing span of 35 – 45 mm, and are black with white patches. They flutter away slowly when disturbed.
The moths can often be seen feeding at flowers; it is common around its preferred food plants of the daisy family, for example Groundsel (and other Senecio spp.), ragworts and cineraria. The colourful hairy larvae feed openly on the plants, often stripping off all the leaves. The mature larvae will sometimes wander from the plant to pupate. The loosely spun cocoon incorporates some of the larval hairs and may also be found amongst leaves.
In New Zealand its liking for the introduced ragwort causes its caterpillars to be sometimes mis-identified as those of the Cinnabar moth which was introduced as a biological control for ragwort. The magpie moth’s ‘woolly bear’ caterpillars are predominantly black with yellowish-orange stripes running along the length of their bodies and have long black bristles, whereas by contrast cinnabar caterpillars have smooth bodies and alternating yellow- and black-coloured rings around their bodies.