Wasps
European Wasps
European wasps, Vespula germanica, are accidental introductions to Australia from Europe and were first found in Tasmania in 1959 and on the mainland near Melbourne, Victoria, in 1977.
They are now found in Tasmania, Victoria, the Australian Capital Territory, south-eastern New South Wales, and the wetter parts of South Australia.
They can be serious pests. Wasps aggressively defend their nest, swarming out to attack if disturbed.
Their sting is painful and multiple stings, or a sting in the throat, can be dangerous. Unlike bees, they can sting multiple times.
European wasps are also an environmental pest. In large numbers, they are a threat to native insects and spiders. They may however, have some beneficial value as predator of other pest insects.
European wasps are social insects and form large colonies. The queen hibernates through winter and emerges in spring to establish a new nest.
Her first offspring are workers which take over nest chores. They build a 'paper' nest from saliva mixed with wood fibres which grows over summer to football size.
The nest is nearly always concealed, often underground or in a roof or wall cavity, and by the end of summer may house several thousand wasps.
Newly mated queens are produced in autumn and the nest usually dies out in winter.
Workers are 12-15 mm long (about honeybee size) and are bright yellow (not orange). They have black markings (including arrow-shaped marks down the middle of the abdomen and paired black spots on the sides), long and transparent wings, black antennae and mostly yellow legs.
Queens are similar but larger, growing to about 20 mm in length.
The wasps feed on sweet substances such as secretions from sucking insects and fermenting fruit. The grubs in the nest are fed on insects and spiders or bits of meat from carrion or pet food bowls.
European Wasps and People
Where wasps are abundant, people dining alfresco should be wary of them and avoid drinking from opened bottles and cans.
Destruction of nests should be done by someone qualified.
For multiple stings or a sting in the throat, seek urgent medical aid. Otherwise apply an ice pack or anaesthetic spray.
Common Paper Wasps
Common paper wasps are social insects, who build nests of grey papery material around the home often under eaves, pergolas or in vegetation.
Polistes humilis or common paper wasps are generally slender with long thin wings.
They are 10-15 millimetres long, tan in colour with darker bands and some yellow on the face.
Other species of paper wasps are larger or smaller and differently coloured.
Paper wasps make nests of grey papery wood fibre material.
The nests are cone-shaped, becoming round as more cells are added.
Nests are a maximum diameter of 10-12 centimetres, with numerous hexagonal cells underneath, some with white caps.
Nests are exposed and suspended by a short stalk under an overhang, often on a pergola, the eaves of a roof or in a shrub or tree.
Wasps cluster on the nest or forage in the garden and around buildings.
Paper wasps are found across mainland southern Australia.
Life History
Adult wasps feed on nectar and make 'paper' nests by mixing saliva and wood fibres.
Nests are a nursery where larvae are kept one to each cell.
The larvae are fed on chewed-up caterpillars caught by the adults.
The cells are then capped and the larvae pupate. Most paper wasps die in autumn or winter, while some hibernate to start new nests next season.
Pest Status and Management
Paper wasps have some beneficial value as predators of pest caterpillars, however they have a painful sting and will attack any person approaching or disturbing their nest.
Nests likely to be disturbed represent a hazard and should be avoided during the day.
Nests in high traffic areas such as doorways, pergolas or carports can be sprayed with a registered aerosol wasp insecticide.
In the event of a sting apply a cold pack.
Seek medical attention if the victim is known to be allergic or if symptoms become more severe.