A single wasp flying around may be ignored, but if you have a wasp nest on your property, it’s definitely time to act! Wasps can be aggressive, particularly when protecting their nest. We all know they can sting, but unlike bees that can sting only once (and then die), wasps can deliver multiple stings without dying. A wasp attack can be very painful and can result in anaphylactic shock. Getting rid of wasp nests can be carried out by the confident homeowner, but it is important to use the correct products and appropriate safety equipment.
There are three types of wasps that homeowners commonly come across;
- Mud-dauber wasps
- Paper wasps
- European wasps
Each requires a different control strategy…
These are large, solitary wasps that live near water sources (where they can access mud). They use the mud to make cells, into which they place a paralysed insect or spider on which they lay an egg. The larva hatches from the egg, feeds on the insect and transforms into an adult before emerging from the mud cell. These mud cells are often seen on walls / ceilings in sheltered areas.
CONTROLLING MUD DAUBER WASPS:
Spray individual adults with an aerosol labelled for wasps. The mud nests and surrounding surfaces can be sprayed with any residual insecticide labelled for wasps. However, it is important to ensure the mud nest is thoroughly soaked to ensure the insecticide penetrates the mud cell to the larva inside. Alternatively, the nest can be physically destroyed (although make sure the adult is not around when you do!).
There are a number of solitary native paper wasp species found across New Zealand. However, the Australia and Asian paper wasp are introduced, social paper wasps that have become a nuisance. The adults feed on nectar, although they catch caterpillars to feed the larvae. Paper wasp nests consist of a series of hexagonal cones, joined together, hanging from a stalk. Typically they will hang from leaves and branches or from the eaves or buildings and from ceilings in sheds / garages. Nests tend to relatively small normally from 10-20 up to 200 or so.
CONTROLLING PAPER WASPS:
Control is best achieved by spraying the nest directly, quickly soaking all the wasps and nest with insecticide. Typically as paper wasp nests tend to be out of reach, a standard aerosol cannot deliver enough insecticide as it gets quickly dispersed, especially outside. The best options for control involve using product that can deliver a jet of insecticide over a range of several metres. PestXpert Wasp Jet Long Reach, a high output aerosol with an ability to spray up to 6m aerosol is a great option.
The European or German wasp arrived in New Zealand after World War II. The similar common wasp, although recorded as early as 1921, wasn’t really establish until the 1980s but is now abundant. European wasps are also “paper” wasps but are much more aggressive than the Australian and Asian paper wasps and can develop into huge nests….. up to 100,000 individuals. About 80% of nests are found in hollows or holes in the ground (especially on raised banks). The remaining 20% of nests can be found in buildings (eaves, roof and wall voids).
CONTROLLING EUROPEAN WASPS:
Extreme care needs to be taken when attempting to control European and common wasp nests (see safety tips below). The control technique is very much dependent on the location and size of the nest. A confident homeowner, wearing the correct safety equipment (see safety tips) can tackle small, exposed wasp nests. Generally such nests are only around in spring when the nests are young. Coating the nest rapidly with insecticide, from a distance using PestXpert Wasp Jet Long Reach aerosol (which can spray up to 6 meters!), is a good option.
However, when the nests get bigger (as summer approaches), they become enclosed in an outer layer of “paper” with only a single entrance. In such cases it is difficult and risky to try and treat with aerosol products. For such nests and for wasp nests in the ground or other enclosed areas, it is recommended that you contact the local council or professional pest controller as specialised equipment will be required, to safely remove the nest.
Safety is key when dealing with wasps. Follow all instructions on the product label. To minimize the chances of being stung, any treatment should be carried out at dusk or night when all the wasps are in the nest and they are generally calm. Use a red light to aid visibility (insects cannot see red light). In addition to any safety clothing recommended on the product label, thick long sleeved shirts and trousers, sealed shoes and thick gloves should be worn. For native paper wasps, ideally a bee net should be worn over the head, but if one is not available, a hat and goggles should be worn. For European wasps, fully safety equipment (bee net, thick overalls with sealed joins and thick gloves and boots) should be worn. Do not stand on a ladder when spraying a nest and ensure you have a safe escape route to allow quick evacuation from the area if required!
With the right products, correct technique and complete safety equipment, DIY wasp control can be achieved by the confident homeowner. If you have any doubts or concerns, phone your local council or pest control company for assistance. To prevent wasps building nests on the outside of your home in the first place, a residual surface spray in Spring will help you avoid the challenge of dealing with an active nest. (PestXpert Outdoor Perimeter spray is a great option to prevent wasp nest building).
For more information on wasps, prevention tips, control techniques and wasp products, click here