Biology

The wasps are colonial insects living in social groups. Each colony is established in the spring by an over wintering queen which makes a smaller starter nest from paper made by itself by mixing wood and saliva.

The colony grows throughout the summer and the nest with it. Many thousand individuals are often to be found associated with each nest, with the workers feeding on nectar, sweet materials and at certain times insect larvae and other animal pieces.

The colony develops males towards the end of the summer to mate with the presumptive queens which when mated over winter start a new colony the following year.

Significance

The wasps can cause alarm when present in large numbers and if the nest is in a place where the individuals from it interfere with humans they can inflict painful and sometimes dangerous stings.

How do they live?

The fertilised queen wasp emerges from hibernation around mid-April and searches for a suitable site for a nest. The Queen rears the first brood of worker wasps by herself and upon hatching these workers will carry on the building of the nest.

The Queen, the only wasp able to lay eggs, will remain in the nest laying more eggs for further broods. The more workers there are the quicker the nest will grow. By late summer the normal wasp nests will contain from 3,000 to 5,000 individuals and be up to 30cm across. With cooler weather, the workers and mates may become tired and aggressive towards anyone interfering with them.

The cold winter weather kills off all the workers and males - only the queen survives.

What to do if you are stung

The rash or individual 'spot' is usually itchy and may become inflamed and swell.

Some people are strongly allergic to stings and can become very ill. If there is any shortness of breath, dial 999. Scratching can infect bites.

Although itchy and sometimes painful stings are rarely dangerous and need only some antihistamine or local anaesthetic cream from your pharmacist. Ask your pharmacist for advice.

The redness and swelling are usually due to the allergy rather than an infection, a cold compress is usually effective to control redness.

Control

The most effective treatment for wasps is an insecticidal dust to the nest, around and into the entrance.