Wasps - the wings of autumn

Wasps have become one of the features of a New Zealand autumn, cleaning up ripe fruit and also feeding on meat and other insects.

Many a late summer afternoon with a cup of tea and a jam sandwich has been marred by wasps attempting to share the jam. They especially like sweet foods, and compete with birds for nectar, fruit and honeydew.

Their nests are started by a queen wasp, usually underground, and their numbers increase as the summer goes on. Winter usually kills the whole nest, leaving the queen to take shelter and start a new colony the following spring.

In northern New Zealand, where some colonies are not killed by rain or winter chill, they can grow as large as 3m across, according to Andrew Crowe's excellent book, Which New Zealand Insect?

Nests are grey and made by the wasps out of chewed-up wood fibre, softened with saliva. The larvae inside are kept at a constant temperature by the insulating paper-like material and by the movement of adult wasps, called "shivering".

As well as targeting sweet foods, wasps eat meat and will hunt and kill insects such as flies, mosquitoes, spiders, honeybees and caterpillars. They use these to feed their larvae.

German wasps and common wasps look similar, with the main distinguishing feature being a different pattern of yellow and black on their backs. Both are native to Europe and parts of Asia. They were introduced to New Zealand by mistake and their numbers have increased hugely, to the point where they are a serious threat to native insects, as well as competing with native birds for food.

They can become aggressive when disturbed and adult wasps can inflict several painful stings.

Nature Watch

Nature Watch is a Wednesday feature for the Wanganui Chronicle's outdoor section. It aims to note the sights, sounds, smells and tastes of the region, through its plants and animals.

Do you have a favourite sight, sound or smell of autumn? Ring 06 349 0710 ext 50833, email laurel.stowell@wanganuichronicle.co.nz or write to Laurel Stowell, PO Box 433, Wanganui.