The driest spring on record has made this a great year for insects, which thrive in warm weather. But this is especially the case for wasps: feeding on flies, caterpillars and aphids, the apex predators of the insect world will certainly have had their numbers boosted over the past 12 months.
Professor Seirian Sumner, Professor of Behavioural Ecology at University College, London, and author of Endless Forms: The Secret World Of Wasps, says: ‘That double combination of the spring weather being perfect for wasps and the summer being good for insects in general with lots of prey around for the wasps means it’s a really good wasp year.’
While this is good news for those who study wasps, it might be less welcome to anyone afraid of getting stung. If you see a steady stream of these yellow and black striped insects flying back and forth, there is probably a nest somewhere nearby.
But don’t panic. Despite their bad reputation, wasps are very useful – particularly in the garden where they are a natural form of pest control. They are also pollinators, and help to decompose dead carrion, which they feed to their young.
If you still aren’t convinced, though, there are several simple measures you can take to wasp proof your home and garden this summer.
The most common wasps in the UK are the native yellow jackets: Vespula vulgaris and V. germanica. These are the kind that nest in the ground or in sheds and roofs, and the most likely to cause problems. This year, there have also been more reports of Dolichovespula wasps, which nest in trees and bushes and have an earlier life cycle. These are less likely to cause problems unless you disturb their nests.
Queen wasps hibernate over winter and emerge in the spring. To begin with, they work by themselves, making a nest around the size of a golf ball in which to lay eggs. These become larvae, which in turn pupate into worker wasps who continue the work of building the nest until it becomes bigger than a football.
The wasps use their mandibles to scrape exposed wood from sources such as fence panels and sheds, then make this into a paste to build the inner hexagonal cells and the outer covering of the nest.
Professor Seirian Sumner, Professor of Behavioural Ecology at University College, London, and author of Endless Forms: The Secret World Of Wasps
Despite their bad reputation, wasps are very useful – particularly in the garden where they are a natural form of pest control. They are also pollinators, and help to decompose dead carrion, which they feed to their young
They also hunt for insects and carrion, chewing up the meat and regurgitating it to feed the larvae, which reward the vegetarian adults with a sugary substance. At the end of summer, the larvae pupate into young queens and males and leave the nest to mate. Males die soon after mating, along with the workers and old queens, leaving only the young queens to seek shelter for the colder months before beginning the cycle all over again.
Prevention is better than cure
Mark Moseley, founder of London-based pest control business PestGone Environmental, believes that when it comes to avoiding wasps in your house and garden, prevention is better than cure.
‘If you’ve got a big loft space, don’t have loads of clutter that nests can hide behind,’ he advises. He also suggests putting wasp traps containing sweet liquid in each corner of your roof space. When young queens come inside at the end of the summer, they will go straight into these pots and die before they can build a nest. Where possible, seal up any cavities in sheds and roof spaces where wasps could get in and build a nest.
Moseley also suggests checking your roof space and sheds in late March or early April, when the young queens are waking up. At that time of year, the nests will be small and can be removed before they become a problem. Once a nest has reached the size of a volleyball, if it is somewhere that is going to cause a problem in the house, you need to call in the professionals.
Leave nests alone where possible
Professor Dave Goulson, Professor of Biology at the University of Sussex, and author of The Garden Jungle, believes we need to learn to live alongside wasps. ‘People should remember that wasps are pollinators, they visit flowers, and they are pest controllers. A single wasps’ nest hoovers up tens of thousands of small insect pests, so they are beneficial insects.’
Professor Sumner points out that wasps will only sting if we accidentally touch them or threaten their nest. If you find a nest in your garden, she suggests putting a barrier around it to keep children and pets away and observing the wasps’ flight path.
If possible, avoid walking through this, or you can also put an obstacle in front of the nest to divert wasps away from footpaths or well-used areas, as they are highly visual insects. By late summer or early autumn, the wasps will leave the nest to die, and it will no longer be a problem.
Mark Moseley, founder of London-based pest control business PestGone Environmental, believes that when it comes to avoiding wasps in your house and garden, prevention is better than cure
Professor Dave Goulson, Professor of Biology at the University of Sussex, and author of The Garden Jungle, believes we need to learn to live alongside wasps
Wasp traps don’t always work
You can make a homemade wasp trap using a jar half filled with a mixture of water and jam and covered in paper secured with an elastic band with holes punched into the top so they can crawl inside, where they will become trapped and drown. However, it is not clear whether these are effective, or simply attract more wasps.
If you want to have a go at making a trap, Professor Sumner and her team are inviting members of the public to register to take part in the Big Wasp Survey from August 2-10, now in its ninth year, to help find out more about these under-researched insects (bigwaspsurvey.org).
‘We ask members of the public to make a simple beer trap, hang it in their garden, and at the end of seven days they collect the wasps that have been attracted into the beer and we have tools online for people to identify them,’ she says.
Leave a wasp offering
At this time of year, if a wasp visits your barbecue or picnic, they are probably looking for protein such as meat, rather than the sugary food and drink that attracts them later in the summer.
This is because they are still feeding their carnivorous young. Professor Sumner suggests diverting wasps from your plate by leaving a small offering – such as a piece of sausage or smelly fish – a short distance away.
‘Giving a wasp offering is not new. In other parts of the world, they do it all the time,’ she says.
Whatever you do, don’t start flapping your arms about and shouting, as this will make wasps think you are a badger, one of their main predators, and they will attack you fearing you are about to dig up their nest and eat them.
Cover fruit
If you have fruit trees growing in your garden, wasps will be attracted to the ripe fruit at the end of the summer. With hard-skinned fruit such as apples and pears, they only cause holes where there are already blemishes, burrowing inside to make bigger openings.
The Royal Horticultural Society advises wrapping trusses in a fine mesh such as muslin or nylon tights to protect them. If you are growing grapes in a greenhouse, you can fix a wasp-proof screen over the door and air vents.
Watch out for Asian hornets
In recent years, there has been an increasing number of reports of the invasive Yellow-legged hornet (Vespa velutina), which attack honeybees as well as other wasps.
These should not be confused with the native European hornet (V. crabro) which is an important species that makes its nest in holes in trees and walls and rarely stings. If you think you have spotted the invasive kind, don’t go near it, but report it here (risc.brc.ac.uk/alert.php?species=asian_hornet).
