Wasps can be useful to gardeners, but also pose a risk in late summer, when wasp activity is at its peak, a national trade body has said.
British Pest Control Association (BPCA), is encouraging gardeners to be aware of the dangers posed by wasps, when to seek help from a professional pest controller and whether nests can be left alone.
Wasps will regularly nest in outbuildings such as sheds and garages, as well as wall cavities and attics, but different species will also nest in the ground, in trees or in masonry.
While they are generally considered a pest, wasps are also accidental pollinators and perform a role as garden pest controllers themselves.
BPCA recommends leaving wasp nests alone if they are in a low traffic area. Nests can be removed in early spring, before they become established, or in the autumn once they have been abandoned.
But a well-established nest that is becoming a hazard in the garden should be dealt with by a professional pest controller.
Dee Ward-Thompson is Head of Technical at BPCA. She said: “Wasps can be beneficial in gardens as they feed their grubs on caterpillars and other insects, thereby reducing these pest populations.
“Starting off around the size of a golf ball in early spring, a wasp nest will be home to a solitary queen and a few workers.
“But as the colony grows, hundreds of wasps build the nest, which can expand to the size of a beach ball to accommodate them all.
“Each one is a unique piece of architecture that is home to around 5,000 wasps during the peak activity of late summer.
“We always advise seeking help from a professional pest controller when dealing with nuisance wasp nests. If you scare a wasp, it might call for backup. While being stung by one wasp isn’t usually dangerous, multiple stings could kill you.”
Most stings cause pain, redness and swelling but a small percentage can cause anaphylaxis – an allergic reaction that can be potentially fatal to people of any age and to house pets.
Dr Andrew Whyte, a Consultant Allergist and Immunologist at Derriford Hospital, Plymouth, advises getting as much information as possible about the insect if you are stung, as the venom produced will vary between species.
He said: “The symptoms can occur very quickly (within minutes), and rarely longer than 30-45 minutes after the sting. Some of the symptoms include swelling of the tongue, swelling or tightening of the throat, difficult breathing, abdominal pain, vomiting, dizziness and loss of consciousness.
“Not all stings will be avoidable, but gardeners can minimise the risk by avoiding brightly coloured clothing, strongly scented materials, covering exposed skin and avoiding eating or drinking outdoors – particularly from cans or opaque containers.
“If they have been given adrenaline pens they should carry these with them at all times, and if they have anaphylaxis they should be assessed in a specialist allergy clinic.”
While many wasp nests can be left alone, gardeners who believe they may be allergic to wasp stings should never attempt to remove a nest themselves.
Dee added: “Wasps should only be treated if they pose a risk or become a nuisance.
“You’ll see all sorts of DIY nest removal guides online. They’re all very dangerous and not recommended by BPCA.
“The label warnings and instructions can alter on insecticides and other products, so it is also essential for gardeners to check the latest information and advice before using any product – even one they have used before.
“A professional pest controller has the technical knowledge and access to a range of professional use insecticides which are not available to the public.
They’ll also have the appropriate protective equipment to avoid getting a nasty sting.”
All BPCA members are trained, qualified and regularly assessed to the British Standard in Pest Management BS EN 16636.
To find a pest controller in your area visit: bpca.org.uk/find.
For more information visit bpca.org.uk/wasps