Stop Australian, Asian, common and German wasps from damaging high value biodiversity sites.
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Four species of wasps in the Waikato region are considered pests, the Australian paper wasp, Asian paper wasp, common wasp and German wasp.
German and common wasps pose the greatest risk to human health. They also attack beehives and prey on native insects. The common wasp and the German wasp inhabit agricultural areas, native forests, planted forests, scrub/shrublands and urban areas where they nest underground and in cavities in trees and buildings.
Asian and Australian paper wasps are far less aggressive than German and common wasps, but they also prey on insects and chew weatherboards. The Asian paper wasp is larger than the Australian paper wasp. It arrived in New Zealand in the late 1970s and by 1995 was widespread throughout the Upper North Island. It thrives in lowland open habitats such as shrublands, swamps and salt marshes but will often build nests on houses or other buildings as well as nesting in trees or bushes. Australian paper wasps have been in New Zealand for over a hundred years and also build nests in buildings and trees.
All of these wasps compete to some degree with birds and other insects for the same food sources (many of which native animals depend on). These include nectar and honeydew/ sugar resources, insect prey and fruit crops.
As well as inflicting a painful sting (which can cause an allergic reaction), wasps can frighten people, cause schools to close and forestry operations to stop. Their presence can force campers and tourists to leave some of New Zealand’s most visited conservation areas. Beekeepers class wasps as a serious threat to their industry and orchard and viticulture operations suffer the destruction of fruit damaged by these wasps.
On direction from an authorised person, landowners/occupiers in the Waikato will control wasps and/or their nests on their property.
On direction from an authorised person upon complaint, all landowners/ occupiers in the Waikato are responsible for controlling these wasps and/or their nests on their property. Problem wasp nests on district or city council reserves and accessways should be reported to the appropriate council, which will arrange for the nests to be destroyed. Nests on Department of Conservation (DOC) land should be reported to the nearest DOC office or visitor centre.
German and common wasps usually nest underground, although they sometimes use hollow trees, walls and roofs of buildings. Nests can be difficult to find, particularly in bush or scrub.
Paper wasps build elaborate ‘paper mache’ nests, which are generally bell shaped with hexagonal cells and suspended from branches of shrubs or hanging under eaves.
Wasps will most often search for food near their nest so if you can kill all the nests within 200m of a problem area, you should significantly reduce their numbers. If you are allergic to stings don’t attempt to destroy nests. Arrange for a local commercial pest control contractor to fumigate the nests (look under ‘pest control’ in the Yellow Pages).
Look for flight paths at dawn or dusk on warm, sunny days when large numbers of wasps will be leaving or returning to the nest. Attract them using a plate of meat pet food and as they land, sprinkle with flour so you can see them and follow them until you find the nest. Wasp control is best done at night or twilight on cool days when they are generally inactive.
Suitable insecticides available from hardware and garden shops include:
Follow the directions on the container.
Disclaimer: Any product names mentioned above are not an endorsement nor are they a criticism of similar products not mentioned.
The use of petrol or diesel to control nests is not recommended. Apart from the potential fire hazard, wasps may react violently to the fumes.
Spray the nest with household flyspray. The nest can then be removed by placing a bag under the nest, pulling it up over the nest and clipping the nest off into the bag. Seal and dispose of it in the rubbish or burn it.
If you come across wasps, stay calm. Put food down and quietly move away. Wasps are unlikely to chase you unless you have disturbed a nest. When you are walking through the bush in spring or summer, particularly in honeydew beech country, be wary of where you put your hands and feet and what you brush against. Wear light coloured clothing as wasps are attracted to dark colours, particularly blue.
A wasp sting will cause an itchy painful swelling. Cold pads and antihistamine cream will help. If stung on the neck, face or in the mouth, tell somebody, take an antihistamine and see a doctor immediately. Stings can cause swelling in the throat, making it difficult to breathe. If there are multiple stings, or the victim shows symptoms of nausea or shock, call 111.
In the bush or at the beach, make sure that your first aid kit includes antihistamine cream and tablets. Ensure people with known allergies carry medication.
Common and German wasps are slightly larger than honey bees, with distinctive black and yellow stripes. Paper wasps are generally smaller with less yellow in their markings.
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