Last summer was a bumper season for wasps and the Taranaki Regional Council expects a repeat soon with the reappearance of warmer weather.
The council's phones rang red-hot about infestations last summer, with many callers not realising that wasp control is up to individual landowners or occupiers, says Environment Services manager Steve Ellis.
The insects are not among the 23 declared pests in Taranaki's current Pest Animal Strategy, so control is voluntary. Options include:
- Poisoning: There are a range of insecticides at garden and hardware stores, farm outlets and the like. Strictly follow the instructions on the label.
- Engaging a contractor: Look under 'pest control' in the Yellow Pages.
To find a nest, watch the flight paths of wasps at dawn and dusk. They seldom venture further than 200 metres from their nests and generally fly in a straight line. Nests might be in cavities in or above the ground, or attached to branches or structures, and are often near water.
As well as inflicting nasty stings on people, wasps prey on native insects and compete with native species for food.
"New Zealand has some of the highest densities of wasps in the world," says Steve. "Their natural enemies are not present, winters are mild and there is a lot of food."
The council is trialing a promising new wasp bait called Vespex at one of its regional gardens, Pukeiti, this summer. It is also funding biocontrol research into other control options.
For more information on wasps, go to www.landcareresearch.co.nz/science/plants-animals-fungi/animals/invertebrates/invasive-invertebrates/wasps and www.doc.govt.nz/nature/pests-and-threats/animal-pests/animal-pests-a-z/wasps/