The bush is home to many of New Zealand’s insects. They can be found tunnelling in wood, feeding on leaves, flowers or seeds, or in the fungi, litter or soil below.
The green pūriri moth (Aenetus virescens), the country’s largest moth, is found only in the North Island. Its caterpillar spends a year on the ground among decaying logs, and then climbs a tree trunk to excavate a short tunnel, where it spends the next two or more years. From this tunnel, which is sealed with a silken cap, the caterpillar feeds on the cell layer just beneath the bark. Because these cells regenerate, the caterpillar can survive in the same tunnel until it emerges as a moth. Moths have a wingspan of 13–15 centimetres. Unable to feed, they live only about two days.
The huhu beetle (Prionoplus reticularis), a species of longhorn beetle, is a large bush insect. Its larvae chew into recently dead rimu wood, leaving it riddled with holes. The grubs, as long as your little finger, are a favourite food of the kākā bird, and formerly of Māori. Huhu beetles have adapted well to introduced pine forests and thrive on pine wood.
The giraffe weevil or tūwhaipapa (Lasiorhynchus barbicornis) can be found where karaka or ribbonwood trees grow. Their grubs bore into the recently dead timber of these trees. Adult weevils show marked sexual dimorphism. The male proboscis is up to 3 centimetres long and carries the jaws and antennae at its tip. The female uses her shorter, 1-centimetre proboscis to drill holes into wood for laying eggs. The antennae are some distance back from the tip, leaving the end free to dig the hole.