Wasps - What You Need to Know
Here's the buzz. Wasps are not all pests. Many native wasp species are solitary beneficial insects, controlling garden pests and posing no threat to people or animals. It is the introduced colonial social species such as the common, German and paper wasps that are regarded as pests. There are no native social species in New Zealand.
Common and German Wasps
- Common and German wasps build nests that when in the open have a ball-shaped outer covering of ‘paper’.
- Common wasp nests are brown. German wasp nests are grey.
- Common and German wasps tuck their legs up in flight.
- In New Zealand, nests are commonly built in hollows in the ground.
- The German wasp (Vespula germanica) is from Europe and northern Africa.
- The common wasp (Vespula vulgaris) is from Europe and parts of Asia.
- Nests begin when a fertilised queen that has overwintered builds a small golf ball size nest and lays eggs in a few ‘paper’ cells within. The first few workers she rears take on the care of the young and finding food and the queen spends her time laying more eggs.
- Normal, single season, wasp nests are about the size of a soccer ball, however, beach ball-sized nests are not uncommon.
- At their peak, a normal nest may contain up to 10,000 wasps.
- The world's largest wasp nest was discovered near Auckland. It was 3.75 metres tall and 1.7 metres wide. It is likely it had been built over several years.
- Colonies usually die out in winter and only the queen survives to start a new nest next spring. But in New Zealand, a significant proportion of nests and workers survive through to spring to continue the colony.
- New Zealand has one of the highest densities of wasps in the world because they have no natural predators and they find the honeydew produced by sap-sucking insects in beech forests a plentiful supply of food.
- Common wasps are more efficient at feeding on honeydew in New Zealand beech forests and have largely displaced the German wasp.
- German and common wasps are enemies of honey bees, they attack the beehives, kill bees and steal the honey.
- In America, the common and German wasps are called yellow jackets.
- Paper wasps can be distinguished from the common and German wasps by their legs dangling down in flight and that they are longer and more slender.
- Asian (Polistes chinensis), Australian (Polistes humilis) and European (Polistes dominula) paper wasps build small open-celled nests without an outer covering.
- Nests are usually built under leaves of shrubs and trees or under eaves of buildings.
- At their peak paper wasp nests may contain only hundreds of wasps.
- The European paper wasp was only recently found in New Zealand but may have been here for several years.
- Paper wasps can sting but are less aggressive than the common and German wasps and pose a lower risk because of their much smaller colony size.
- The paper wasps are enemies of monarch butterflies and other butterflies. They attack all the stages of the life-cycle; eggs, caterpillars, pupae and adults.
- A wasp sting is a minor but painful irritation for most people. However, some people are sensitive to stings and may develop a severe allergic reaction called anaphylaxis.
- Wasps can sting more than once because, unlike honey bees, their stinger is not barbed and is not left in the skin.
- The wasp sting venom contains a pheromone (smell) that induces other wasps to become aggressive and sting too. So if you get one sting calmly and quickly, walk away from the wasps.
- Aluminium-containing deodorants can help reduce the pain of a wasp sting.
- Unlike honeybees, wasps do not swarm, it is the queens alone that set off to found a new colony.
- Wasps chew wood to make the 'paper' they use to build their nests.
- Wasps are members of the Hymenoptera which includes bees, ants and sawflies.
- There are no wasps in Antarctica*. They live in all other continents.
- The pest wasps are not all bad, they predate on flies and other insect pests like aphids.
*Unless they hitched a ride in an aircraft or on a boat, but they wouldn't last long.