Insect Pest Control Articles - Wasps
Insect Pests: Wasps
(published February 2009)
Wasps are common throughout Britain and really it is unfair to call them a pest since they do more good than harm - though they can spoil a picnic or barbeque and can cause alarm in the home. If they enter your home and build a nest in the attic or eaves you may need to call in professional help to remove it. Prevention is better than cure - fit Mousemesh grills over your airbricks to minimise the entry of wasps into your home!
There are several species of wasps and some of these are up to 30mm in length - easily big enough to be exluded by Mousemsh! There are six species of wasp commonly found in the UK but only two enter buildings. The most common species in the UK are the German and European wasps. Wasps can be seen throughout the country but the wasp 'season' tends to be shorter in the cooler north.
They are social insects forming colonies inside nests specially constructed in soil, barks, roof spaces and in cavities in trees and walls. The nests are made from a papery substance which is produced when workers mix wood scraped from trees, fence posts or materials scraped from dried grasses with saliva. A wasp nest survives only for that season as the nest dies off in the late autumn, and although they will never re-inhabit an old nest, they may build a new one directly beside an old nest. At the height of the season, there may be as many as 25,000 wasps in a very large nest!
The fertilised queen wasp emerges from hibernation around mid-April and searches for a suitable site for the 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. A queen wasp can lay as many as 2,000 eggs each day. The more workers there are the quicker the nest will grow. The wasp larvae are fed on caterpillars, spiders and aphids, which the workers catch for them. Worker wasps also love to eat nectar or anything sugary, such as rotting fruit.
With cooler weather in the autumn the workers and males 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.
In late summer wasps can become a real nuisance if you are enjoying a picnic or barbeque. Worker wasps are at their highest numbers at this time of year and they adore eating anything sugary. They seem to be particularly attracted to jam and beer! When they start to pester, the worst thing you can do is to wave your arms about and try to scare them away. This seems to attract more wasps and makes it much more likely that they will sting you. The best thing to do is place a plate of jam or glass of beer a short distance away from you. The wasps will quickly discover this and should soon stop pestering you.
Wasps are also attracted by windfall apples or other soft fruit. You can often find scores of wasps in orchards enjoying the sugary leftovers on the ground. If you do go gathering windfall fruit, pick up the fruit very carefully or wear thick gloves, just in case a wasp has got there before you. Otherwise, there is a chance that you might startle the wasp and it will sting you.
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 the Environmental Health Department.
- 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
- Leave wasp nests well alone. Only move them on when it is unavoidable. Make sure you demand that the bees are relocated. Pest controllers destroy most wasp nests as they are difficult to relocate - be sure this destruction of up to 25,000 animals is really necessary.
- Don't swat a wasp. When having a picnic, put some beer or jam out for the wasps a short distance away. They will then leave you alone.
- Provide nectar and pollen rich flowers for bees. Plant wild flowers like foxgloves, knapweed or scabious and other plants which flower between early spring and late summer. Look out for the plants which attract bees and plant them.
- Leave areas of your garden undisturbed for bees to build a nest. They prefer rough ground, sheltered by trees and shrubs, which faces north-east. Old bird boxes or flower pots can even be used to give them something to build a nest in.
- Take care when dealing with wasps and hornets (a larger member of the wasp family) - they have a potent sting and can attack in large numbers if disturbed.
- A wasp trapped indoors can be dealt with using a Wasp & Fly Killer spray.
- If you are experiencing high numbers of wasps in your home or garden it is likely that there is a wasp nest nearby.
- A single nest may contain thousands of wasps which can swarm and attack if disturbed. If the location of a wasp nest is likely to put people at risk, then the nest should be destroyed.
- Fit Mousemesh grills over all your air bricks