Land of plenty for unwelcome wasp

The cold, wet start to summer should have one big advantage for holidaymakers - fewer wasps.

No one likes wasp stings. At best they're painful. For about one person in 30, they spark stomach pains, diarrhoea, vomiting, severe swelling and, at worst, death. Wasps and bees kill about two people every three years in New Zealand. Auckland University ecologist Dr Jacqueline Beggs says this country is wasp heaven because there are no natural enemies to disturb them.

In Europe, where the wasps come from, blackbirds, magpies, starlings, dragonflies and spiders eat them. Stoats, weasels and mice disrupt their colonies and badgers destroy them. None of these creatures existed here before humans arrived.

Wasps particularly love the beech forests in the top half of the South Island, where a tiny insect lives in the bark of the trees and sucks a sugary sap from the tree stems. It excretes a sweet honeydew that is like wasp chocolate.

In most of the North Island, where the honeydew insect is rarer, there are three or four wasp nests in an average hectare of bush. But around Nelson there is an average of 12, and sometimes up to 60, nests in a hectare.

In most places, wasp colonies are founded in spring, flourish over summer and die in autumn, when the next summer's queens hibernate until the weather improves.

But in New Zealand, lush conditions allow some colonies to keep going through the winter and a second summer, building nests as big as a person.

There are fewer nests in New Zealand in years that start with a cold, wet spring, as this year has.

The solitary queen is twice as big as anyone else and does nothing except produce babies.

In a typical season, she may have 10,000 offspring. About 95 per cent will be female - about 400 potential queens, and the rest biologically programmed never to reproduce but to serve their brief one-month lives as "workers" gathering food, tending the young and defending the nest.

The queen will also have a few hundred male babies condemned to be "drones".

"The males are only around for a few weeks in late autumn.

"Their sole purpose in life is to reproduce," Dr Beggs says.

Although 400 queens from each nest may take part in this autumn orgy, fewer than 1 per cent survive to found their own nests. Some will die during hibernation. Others are pushed out by rival queens in spring.

But the winning queens themselves live only a few months longer. Impregnated in autumn, "reborn" in spring, they have just one summer in the sun before they die alongside their loyal workers as the next winter begins.

Avoiding wasps

* Wear light-coloured, long-sleeved clothes.
* Watch where wasps fly and keep away from their nests.
* Check that there are no wasp nests nearby before opening food or canned drinks.
* If a single wasp lands on you, ignore it - it will go away. If you push it, it may sting.
* If a swarm of wasps attacks you, run through thick vegetation to brush them off.