Pest wasps are the introduced social wasps; the German, common wasps and Australia and asian paper wasps. Wasp nests can contain several thousand wasps each with a sting.
Identify the problem
Pest wasps; German, common and the paper wasps, can be distinguished from bees by their shiny hairless bodies and distinct black and yellow stripes. Honey bees have much less distinct stripes of browns. Bumble bees are much larger, are rounded and have furry bodies.
The size of the nest will increase through the summer as more wasps are added to the colony. Nests reach their peak size in autumn and can be as large as a beach ball containing 3 to 5 thousand individuals. In New Zealand, conditions can be such that colonies do not die back during winter allowing more than the queen to survive. In this case the nests can grow over several seasons and become much larger.
The Asian and Australian Paper wasps form much smaller colonies than the common or German and the nest will have only a few tens of cells in an open type nest. The Paper Wasps are consequently less of a direct threat to people. However, they are a threat to native insect species such as Monarch Butterflies on which it feeds. Many people will wish to control the paper wasps to protect their Monarchs.
- Wasps and bees have a painful sting, to which some individuals are more susceptible than others; on rare occasions a sting can cause anaphylactic shock. For those not allergic to wasp or bee stings a sting on the throat or mouth can still be dangerous if the swelling blocks airways. On such occasions seek immediate medical advice immediately.
- Wasps or bees should not be tackled without a sound knowledge of the risks.
- Bees are generally beneficial insects producing honey and pollinating our crops and flowers. However, occasionally a swarm will set up home in an inappropriate place such as the eaves of your house. In this case we strongly recommend that you contact a local beekeeper (see the Apiculture NZ swarm collection list) who may try and collect the colony to use for honey production. Only if this is not possible should the colony be destroyed.
- If bees have been present for months or years at the nest site, there likely to be a honey store in the nest. Once the colony has been destroyed this honey must be removed or it will attract new swarms of bees or wasps.
To get rid of wasp nests:
- The nests of wasps and bees generally have only one entrance/exit. If this can be identified the colony can be destroyed by sprinkling or puffing the wasp killer NO Wasps Eliminator powder into the entrance. The workers will then pick up the dust as they enter the nest and take it inside where it will kill larvae and queens.
- The problems caused by honey bee colonies that have had time to build a nest are not likely to be solved using insecticide alone because the honey store in the nest will continue to attract bees and wasps. The honey store must be removed or sealed up following destruction of the colony.
- Wasps, particularly Asian Paper Wasps, chew wood such as dead trees, decks, fences and stumps to make the 'paper' that they use to build their nests. Spraying such decaying wood with NO Wasps or NO Bugs Super can effectively control paper wasps and help to control German and Common wasps.
Honey bee swarms
- If you find a large 'clump' of bees, hanging from a branch or the side of your house, this is likely to be a bee swarm. This is a queen with her new colony looking for a place to build a nest. Contact you local bee-keeper (see the National Beekeepers Association swarm collection contact list) and he/she will try and collect the swarm without harming it for use in honey production. The swarm may move on of its own accord within a day or two.
- Honey bees are generally not aggressive while swarming. Great care should be taken in treating the entrance to a nest as there is a risk of being stung. It may be advisable to do this operation at night when there is no wasp or bee activity.
- If the nest site cannot be found it is possible to reduce wasp numbers (and maybe kill a whole colony) using NO Wasp Bait Concentrate mixed with a suitable bait such as sugar* or canned fish.
- NO Wasps sprays are useful to treat around rubbish bins and other areas where wasps are attracted.
*Caution: Where there is a risk of attracting bees to the bait, sugar and syrup baits should not be used. In such risk areas use canned fish, raw meat, carrion or fish skeletons as an attractant and spray with water based mix described above. Fix the bait inside an inverted can and suspend from a suitable tree. Respray every 2-3 days.
Did You Know
The common species of wasp in New Zealand include:
- The common vespulid wasp - Vespula vulgaris
- The German vespulid wasp - Vespula germanica
- The Asian paper wasp - Polistes chinensis
- The Australian paper wasp - Polistes humilis
- The solitary wasps - Ichneumon Wasps and Ancistrocerus gazella
- Recently the European paper wasp (Polistes dominula) has been found in the north of the South Island. It is not clear how widespread this new wasp to New Zealand is.