Small colourful beetle identified
FOR the past two months there have been a number of enquiries about a tiny longhorn beetle resembling the illustration.
Bright shining pink, with a conspicuous yellow spot on each wing case, the beetle is only 5mm long. The colour renders it highly visible. These exquisite creatures belong to the genus
Zorion, whose 10 species have been called ‘‘New Zealand’s prettiest longhorn beetles’’. The various species range from 37mm long.
The species currently common around Dunedin is Zorion australe, meaning ‘‘southern Zorion’’. It is a brilliant pinkish orangebrown, with a purplishblue band across each wing case containing an oval yellow spot.
Called ‘‘flower longhorns’’, these beetles are currently conspicuous throughout lowland East Otago on native blossoms, where they feed on nectar and pollen, especially of New Zealand native plants such as Veronica.
The individuals brought to the museum have been found in people’s sections, where the brilliant coloration had caused people to wonder whether it was poisonous, which it is not.
The larvae are harmless, for they eat only dead wood, feeding internally on the bark or woody material of trees and shrubs, tunnelling in twigs or under the bark of dead branches. They also breed in clippings pruned from trees, including shelterbelts.
In the North Island, adults have been found to lay their eggs in freshly broken or cut branches of the karaka tree (Corynocarpus laevigatus), suggesting that the beetles seek out dead wood in which to lay their eggs.
Flower longhorn beetles of the genus Zorion are native to New Zealand, where they are widely distributed on the mainland and occur on some offshore islands as well.