Wasps are probably one of the most familiar and feared groups of insects because of their stings. They are beneficial in the garden as the workers collect insect larvae and thereby help control insect pests. However, generally they are regarded as nuisance pests particularly at the end of the summer when the worker wasps are attracted to sweet materials such as fruits and jams.
The fertilized queen wasp over winters in harbourages such as garden sheds, buildings, under loose bark and bird boxes. She emerges from hibernation around mid April and searches for a suitable site to build a nest. This could be in roof spaces, or cavities in walls or trees.
An initial cell is constructed from chewed bark dried timber and saliva. This is about the size of a golf ball. The queen lays between 10 and 20 eggs and this first brood of sterile workers start enlarging the nest and providing food for subsequent eggs. By the end of the summer a nest may contain 3000 to 5000 or more wasps.
With the onset of cooler weather the workers and drones (males) become tired and feeding on ripe fruit can produce a “tipsy” behaviour leading to aggression towards anyone interfering with them. With the onset of severe weather the workers and drones die out and the nests will not be used again.
Proprietary treatments can be bought to get rid of wasps nests. They should be treated early or late in the day when wasp activity is at its minimum. Firstly find the entrance to the nest by observing where the wasps are entering.
Nests are frequently located in loft spaces, cavity walls, flower beds, garden sheds, rockeries and roof eaves. When you have located the entrance puff the insect power in and around the entrance; returning workers will then carry the insecticide into the nest on their bodies contaminating the nest. Within several days all the wasps should be eradicated.
Stings can be treated with cold compresses and anti-histamine creams applied within twenty minutes of stinging. A suitable antiseptic cream should also be rubbed into the skin to prevent infection.
If you are stung in the mouth, around the throat, receive multiple stings or develop distressing symptoms please seek medical advice
If you feel that you cannot carry out this work yourself, the Pest Control Officer can do it for you. There may be a charge for this service.