WASPS (Vespula Vulgaris)
 |
 |
What do they look like?
Small winged flying insect with a sting in its tail. It makes a distinct buzzing noise. There are several species of wasps and some of these are up to 30mm in length. Their eyes are kidney shaped, they have two pairs of wings, the hind wings smaller than the forewings. The wings are folded longitudinally at rest and the mouth parts are adapted for chewing and licking. They can easily be distinguished from mining bees because of their pointed body and waist.
How do I spot them?
Wasps are common throughout Britain. They are social insects forming colonies inside nests specially constructed in soil, barks, roof spaces and in cavities in trees and walls. They are frequently found in domestic housing. Wasps are social insects with a Queen, which is much larger than the workers, starting a new nest each year. Nests are constructed of wasp paper made by chewing wood and other plant debris mixed with saliva.
How do they affect me?
Wasps can be regarded as beneficial insects because they kill an enormous number of flies, caterpillars and other insects. This helps to prevent plagues of other insects occurring. However, in general they are regarded as a nuisance during the summer when workers go about the business of collecting food for young wasps and can indulge their passion for sweet foods e.g. jams and syrups. It is their ability to cause painful stings that concern us the most. The sting is caused by the injection of venom into the victim by means of the modified ovipositor (egg laying tube) of the females. A wasp can withdraw its sting from the victim, a bee cannot. Histamine in the body reacts with the venom causing redness, flare and weal in the skin.
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.
How do I control them?
Although wasps are troublesome to us it would be unwise to destroy nests without good reason. Wasps are controllers of far more injurious pests of forestry, agriculture and gardens. If the presence of a nest is causing no direct problems, then it is best left well alone. Wasp nests are abandoned at the end of the autumn.
Should it be necessary to carry out a treatment the nest can be treated by either:-
- Dusting an insecticidal powder around the entrance of the nest, preferably using injection tubes, which contaminates the workers as they return thereby carrying the dust inside; or
- Surface spraying an insecticide directly onto the nest. Do not use domestic aerosols.
- For health and safety reasons please do not attempt to remove the wasp nest yourself as specialist equipment is required.
Practical advice
- Destruction of a wasp's nest should NOT be undertaken by untrained persons. If wasps are causing a problem it is advisable to contact us immediately.
- Stings should be treated with antihistamine creams.
- Wasp stings around the throat can lead to respiratory obstruction which may cause faintness or vomiting. In these cases you should seek medical assistance.
- Repeated stings can cause anaphylactic shock. Symptoms include respiratory distress, swelling of the face and vomiting with abdominal pain. Medical assistance should be sought immediately where anaphylactic shock is suspected