Wasps

Wasp (Dolichovespula).

Facts about Wasps

Wasps can be regarded as beneficial insects during the spring and early summer as workers collect insect larvae, which helps control garden insect pests. However, towards the end of the summer they often become a nuisance when worker wasps start to indulge in their passion for sweet materials.

It is the ability of wasps to cause painful stings that concerns most people and unlike bees, wasps can sting several times. Adult worker wasps have the characteristic black and yellow patterning on the abdomen and are between 15 - 20 mm long. They have a black head and thorax. The fore and hind wings are held together by a row of minute hooks giving the appearance of only one wing per side of the wasp.

Biology

The queen spends the winter hibernating then initiates the nest in early spring. She feeds on captured prey & nectar before laying her first eggs in cells constructed out of plant debris and chewed wood. The queen feeds the larvae until the first brood of workers hatch, then the workers take on the responsibility of looking after the future larvae, they gather food and carry on constructing the nest while the queen continues to lay eggs. The colony grows throughout the summer with the maximum number of workers occurring about 3 months after commencement of the nest. Reproductive males and the new queens are the last to hatch and leave the nest to mate, while the queens look for a sheltered site to hibernate over winter. At this time the workers change their foraging habits from looking for food & materials for the nest to nuisance scavengers, finding sweet substances to replace a similar sweet liquid which was secreted from the larvae. This is when most people come into contact with wasps. With the onset of colder weather the workers die off and the nest decomposes never to be reused again

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.

Call your doctor if the symptoms will not go away or if you are stung in the mouth, around the throat or receive multiple stings.

Significance

It is often forgotten that wasps are beneficial insects and eat harmful insects, Wasps do not sting unless they have reason, avoid swatting or squashing as a chemical is released which signals other wasps to attack this can cause alarm if there are large numbers and can sometimes cause painful dangerous stings.

 

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