Leonore McLay of Balclutha asks :-
I have never before seen this butterfly/moth. What is it?
Brian Patrick, an entomologist at Otago Museum, responded.
Actually the insect is an endemic New Zealand geometrid moth called Pseudocoremia leucelaea. Although first described from Invercargill, the attractive species is widely distributed in the forests of all three islands of New Zealand. The adult moth is variable in colour pattern with males and females also differing a little. The caterpillar, like the adult, is very well camouflaged on its host-plants, which include various podocarp trees such as rimu and kahikatea. Some introduced podocarps are also eaten.
Geometrid moths are characterised by triangular shaped wings in the adult and looper caterpillars. In New Zealand there are about 280 geometrid species out of a total moth fauna of about 2000 species, with more being discovered every year. The genus Pseudocoremia contains about 30 medium sized nocturnal moths that are found from coastal saltmarshes to the alpine tops of mountains. Some of these species are still undescribed.
All the species are very selective as to the larval host-plant with some laying eggs only on one single host. Others will feed on a group of closely related hosts. Some of the host-plants of the genus are Carmichaelia (native brooms), Urtica ferox (tree nettle), Celmisia (mountain daisies), Olearia (tree and shrub daisies), Plagianthus (ribbonwood),Phyllocladus (celery pine), Hebe, Kunzea(kanuka), Nothofagus (beech), Ozothamnus (cassinia) and various Muehlenbeckia climbers. Because Olearia and Hebe are the most popular hosts for this group of moths it is no surprise that the genus is most diverse and common in the montane and low alpine shrubland zone of southern New Zealand, where no doubt many new species await detection by some keen entomologist.