Ipana atronivea
Ipana atronivea, commonly called the North Island lichen moth or North Island zebra moth, is a moth of the family Geometridae. It is endemic to New Zealand and found only in the North Island.
Taxonomy
Ipana atronivea was first described by Frances Walker in 1865 as Detunda atronivea. The male holotype specimen, collected by Captain Parry in Wellington, is held at the Natural History Museum, London. In 2023, the species was moved to the newly reinstated genus Ipana.Description
The larvae have a lumpy appearance and are brown and brownish-white in colour, growing to approximately. In the early stages of their life they look similar to a bird dropping when curled on a leaf. When an adult Ipana atronivea has a wingspan of between.This moth is white with dark brown or black markings. It is very similar in appearance to its close relation the South Island lichen moth, Ipana egregia, but it has fewer dark markings and does not have the dark edges on the forewing. This gives Ipana atronivea a more mottled appearance; it also has a black rectangular mark on the back of the thorax.
Hudson noted that Ipana atronivea "varies considerably in the size and shape of the black markings on the fore-wings, which are often slightly different on the opposite sides, in the same specimen." One authority has claimed that Ipana atronivea is the only one of 180,000 Lepidoptera species with asymmetrical patterning: its wings are not mirror images of each other.
Research has indicated that the forewing colouration of this species is much more likely to protect the moth against predation when the adult insect is at rest on lichen compared to when it is resting on bare tree trunks.