Orange Flash

Hoare described the larvae of this species as follows:

Head dark brown, marked darker longitudinally. Thorax and abdomen dorsally and laterally grey, ventrally whitish grey; broad irregular broken dorsal and subdorsal lines whitish yellow; dorsal pinacula black and shiny; A10 darker grey, mottled black. Hudson described the species as follows:

The expanse of the wings is 7⁄8 inch. The forewings are very rich dark brown, thinly speckled with elongate bluish-white scales; there are usually cloudy discal marks before and beyond the middle, and a darker curved terminal band. The hindwings are rich velvety-black, with two unequal elongate-triangular bright orange-yellow marks, and a cloud of minute yellow dots near the tornus. The cilia of the hindwings are bright orange-yellow. The wingspan is 20–30 mm with the forewings being blackish, variably overlain with reddish and whitish scales. The hindwings of the common form are blackish with orange streaks. This species is variable in appearance with some specimens having a rich reddish brown forewings without markings. There is a form with hindwing markings that are whitish in thin stripes from the base of the hindwing. It is possible to confuse H. illita with H. atychioides where specimens of the former species have very dark hindwings. This species can be distinguished from H. bilineata as it has a larger wingspan. …

This species is endemic to New Zealand and is found throughout the North and South Islands. This species has not been recorded at Stewart Island / Rakiura.

Adults of this species are on the wing from November until February. This species is known to fly during the day and have been observed flying over tall bushes and trees, including Coriaria ruscifolia and Kunzea ericoides, during hot, sunny days.