Wasps (Vespa)

The queen wasp emerges from winter hibernation around mid-April and searches for a suitable site to form her nest. This is made from bark and timber mixed with saliva. She makes the initial 'cell' which is around the size of a golf ball and lays between 10 and 20 eggs feeding the resultant larvae on insects. The emergent first brood of adult workers (sterile female wasps) takes over the task of enlarging the wasp's nest and providing food for the subsequent eggs laid by the queen.

By late summer, the average wasp's nest can contain up to 30,000 wasps and be up to 30 cm across.
During late summer males and young queens emerge (fertile female wasps), mating takes place, and the fertilised queens fly away to select suitable over-wintering sites.
In August the workers start feeding on over-ripe fruit which can produce a 'tipsy' behaviour which may lead to aggression towards humans.

The cold winter weather kills off all the worker and male wasps, with only fertilised queens surviving individually in hibernation, ready to start new colonies in the following spring.
Old wasp's nests are not re-used although a new nest may be built close to an old one.

The main hazard is the risk of 'anaphylactic shock', which can arise from even a single wasp sting, which may lead to the death of susceptible people.

Treatment for Wasps
This is carried out by a fully trained technician using an insecticide which is injected directly into the nest, usually through the entrance hole on the outside of the building. Protective clothing has to be worn as the wasps become very aggressive.