What does it look like?
German wasps are 12–17 mm long, with queens growing up to 20 mm. They look and behave like common wasps. In both species, colony members work together to care for their young and to build and defend the nest.
German and common wasps have distinctive yellow and black striped bodies, hold their legs close to their bodies when flying, and can sting repeatedly. They build large paper nests, often around the size of a soccer ball. German wasp nests are typically grey and, in some cases, can survive through winter, allowing colonies to grow very large in the following season.
Why is it a problem?
New Zealand has some of the highest densities of common and German wasps in the world. This is because their natural predators are not present here, there is an abundance of food sources, and our winters are mild.
Wasps eat huge numbers of native insects and have even been seen killing newly hatched birds. By eating so much, they upset the natural food chain of the forest. Large densities have been observed in beech forests containing honey dew (a substance produced by a native scale insect) which serves as an important food for native birds, bats, insects, and lizards. They also pose a danger to people working outdoors or who are allergic to their sting
German wasps are a successful invader of disturbed environments and natural ecosystems. They establish large nests, and the workers efficiently exploit food resources such as nectar and insects, which native fauna depend on. This species is difficult to control as new colonies are established each spring from mated females that hibernate over winter.
Control methods
The best way to reduce a local wasp population is to find and destroy all the nests in the area. If a nest is small and you are not allergic to stings, then you can do it yourself. If the nest is large, contact a professional pest controller.
If you suspect or find that you have multiple wasp nests, contact a specialist pest management firm. It’s important to be aware that accidental contact or proximity with the nest will signal a threat to these wasps, and they are capable of stinging many times.
To find and destroy German wasps, start by tracking the insects to their nest. These are usually within 200 metres of where the wasps are foraging, and can be on a building, tree, or a hole in the ground.
If you buy an insecticide from a local garden or hardware store, follow the instructions and place the insecticide at all entrances to the nest. It's safer to do this when the weather is fine and at night when there are fewer wasps around. Worker wasps will spread the powder into the nest, and the colony usually dies within a day. If the nest is still active after a few days, then repeat the procedure the next fine evening.
If you can't find the wasps' nest then build a trap to catch them. All you need is a plastic bottle, water, sugar, and vinegar. There are many options for making your own wasp traps, but the NoPests' Wasp Dome Trap is an effective commercial product.
As most wasp queens start constructing a new nest each year after their winter hibernation, early spring is the time to trap queens and stop them building new nests.
More information
The best way to reduce a local wasp population is to find and destroy all the nests in the area. If a nest is small and you are not allergic to stings, then you can do it yourself. If the nest is large, contact a professional pest controller.
If you suspect or find that you have multiple wasp nests, contact a specialist pest management firm. It’s important to be aware that accidental contact or proximity with the nest will signal a threat to these wasps, and they are capable of stinging many times.
To find and destroy German wasps, start by tracking the insects to their nest. These are usually within 200 metres of where the wasps are foraging, and can be on a building, tree, or a hole in the ground.
If you buy an insecticide from a local garden or hardware store, follow the instructions and place the insecticide at all entrances to the nest. It's safer to do this when the weather is fine and at night when there are fewer wasps around. Worker wasps will spread the powder into the nest, and the colony usually dies within a day. If the nest is still active after a few days, then repeat the procedure the next fine evening.
If you can't find the wasps' nest then build a trap to catch them. All you need is a plastic bottle, water, sugar, and vinegar. There are many options for making your own wasp traps, but the NoPests' Wasp Dome Trap is an effective commercial product. As most wasp queens start constructing a new nest each year after their winter hibernation, early spring is the time to trap queens and stop them building new nests.
Related links
Management Programme
Unwanted Organism
An unwanted organism is any organism that's capable of causing harm to natural or physical resources (like forests and waterways) or human health. A number of introduced pests in New Zealand are classed as unwanted.
More information
