European wasp

Introduction

The European wasp, Vespula germanica, is an established pest in Australia. This non-native wasp was first found in Australia in 1959 in Tasmania. By 1978 they were also known in Victoria, South Australia, New South Wales and Western Australia, and are now firmly established in the Sydney area.

Identification

• European wasps are a stout wasp with a bright yellow and black banded abdomen, and a pair of black spots on each yellow band.
• They have two pairs of clear wings with the first pair larger.
• They have black antennae and fly with their legs held close to the body.

Habitat

• European wasps are found in large communal nests, normally only visible as a small entrance hole.
• They are normally built either underground or in cavities in walls, ceilings, logs or trees.
• The nests are made from chewed wood fibre and can be found in ceilings, wall cavities, logs, tree trunks and soil.

Distribution

• The European wasp is a native of Europe, North Africa and Asia Minor.
• They are now firmly established in metropolitan Sydney, and are also found in Bowral/Moss Vale, the Blue Mountains, Narrandera, Deniliquin, Albury, Wagga, Coleambally, Griffith, Dareton, Junee, Forbes, Coonabarabran, Orange, Bathurst and West Wyalong.
• European wasps are also present in New Zealand.

Feeding and diet

Workers of the European wasp leave the nest in search of food, and are attracted to meats, sweet food and drink.

Life history cycle

• European wasp colonies are started in spring by a single fertilised queen, which lays an egg in a number of cells in the nest.
• These hatch into grub-like larvae and are tended by the queen for a number of weeks.
• They become the first batch of workers that take over nest construction and rearing of the larvae while the queen concentrates on laying eggs.
• The nest grows throughout the summer until a batch of males and new queens are hatched in the autumn.
• These mate and fly off to start new nests.

Breeding behaviours

Towards the end of summer, several larger cells are constructed, in which a new generation of queens develop. Males also develop, and mate with the queens outside the nest before they die.

In late autumn the original queen dies, and the new queens disperse to find suitable over-wintering sites before forming a new nest in spring.

In Europe the old nest then disintegrates and the dispersed queens hibernate in sheltered spots beneath loose tree bark or in roofs. A hibernating queen holds on to the substrate with her jaws, and tucks her legs, wings and antennae beneath her, remaining immobile for up to six months.

It is significant that in the warmer climate of Australia, one of the new queens may stay in the nest and begin laying eggs, without the usual over-wintering period being observed. Over several seasons, this can result in giant and potentially dangerous nests of over 100,000 wasps.

Management

You can report all European wasp nests to the European wasp Hotline. By reporting, they are able to monitor the distribution of this introduced pest species through urban and bush land areas and how they are affecting the native species of both prey and predator. For the research to be successful, they rely heavily on the public reporting all European wasps nests to the hotline.

European wasp Hotline: 02 6258 5551, or website: http://ewasp.com.au/contact/

Danger to humans

• European wasps are more aggressive than bees and will attack when their nests are disturbed.
• Unlike bees, wasps can sting more than once, and do not die after stinging.
• The sting causes a burning pain and swelling. If stings are multiple, a more severe systemic reaction may occur.
• In some individuals, wasp, bee and ant stings can cause an allergic reaction (anaphylaxis), but this is relatively uncommon.
• Effective treatment is available, which involves known bee/ant/wasp sting allergy sufferers carrying a special kit when outdoors. Immunotherapy or desensitisation is also available, and can reduce the severity of the allergy.
• Seven deaths over a twenty-year period attributed to wasp stings have been recorded in Australia, mainly amongst known allergy sufferers who were not carrying their preventative medicine with them.
• A cold pack may be used to relieve the pain of the sting.
• If there is evidence of a more severe reaction or the sting victim is known to be allergic to wasp and bee venom, medical attention should be sought immediately.

References

• AGFACTS Information Leaflet AE31. 1994. European and Papernest Wasps. NSW Department of Agriculture.
• CSIRO. 1991. The Insects of Australia. CSIRO Publishing.
• Hadlington, P. & Johnston, J. 1998. An Introduction to Australian Insects. UNSW Press: Sydney.
• Zbrowski, P. & Storey, R.1995. A Field Guide to Insects in Australia. Reed Books: Sydney.