Where have all the wasps gone?

Despite their bad reputation and tendency to disrupt picnics, wasps are an important part of our ecosystem.

During this time of year, it can seem like most outdoor activities are plagued by the flying insects… but they appear to have lacked their usual numbers in 2024.

Colder and wetter weather and climate change have had a global impact on the invertebrates.

The change has been monitored by gardeners, experts and pest controllers, but what do wasps do, why do we need them and will they return?

“The numbers are so low it’s unbelievable,” said EraserPest owner James Tennent, who was called out to treat between 60 and 80 wasp nests this time last year.

In comparison, his company – which covers Essex, Suffolk and Cambridgeshire – was called out to deal with eight nests during June 2024 and only about 10 in July.

“We had done a lot by this time last year and couldn’t cope with the amount of calls,” Mr Tennent said.

“This year there’s been some days where we’re waiting for the phone.”

He believed the weather had an impact on the number of wasps and nests being found.

“People haven’t been outside as much to spot them building up,” he said.

“Some of the ones we have been to this year are as big as basketballs, or bigger.”

Hitchin Lavender Farm in Hertfordshire said it had noticed an “unusually low” number of wasps around the time they typically begin to build up.

It is the same for Norfolk Lavender, in Heacham, near King’s Lynn. A spokesperson said there would usually be lots of wasps flying around the restaurant tables, “but there has been a noticeable absence”.

Typically, the farm expects to find a couple of nests in the lavender fields each year but, so far, it has not found any.

Although pesky for visitors, wasps are accidental pollinators and play a valuable part in the pollination process.

And without wasps, the world could be overrun with spiders and insects, according to the Natural History Museum.

Each summer, wasps in the UK capture about 14 million kilogrammes of insects such as caterpillars and greenfly, making them important friends to gardeners.

Peterborough-based insect conservation charity Buglife said it was not just the East of England that had seen a fall in wasp numbers but the whole of the UK.

It said this was “almost certainly a direct consequence of the wet weather”, winter flooding and general dampness leading to mould growth, impacting the winter survival rate.

“Many wasp nests are created in the ground and will also have been severely impacted by the further flooding across the country in spring and early summer,” said a spokesperson for the charity.

“A loss of wasps will impact us in a number of ways.

“It leads to reduced pollination, and without wasps our plants are more likely to be eaten by insect larvae otherwise controlled by wasps.”

Thomas Ings, an associate professor in zoology specialising in entomology at the Anglia Ruskin University in Cambridge, has a long-standing interest in wasps.

He said the population tended to fluctuate from year to year.

There has been a decline in insect numbers around the globe, and in the UK there is evidence of severe declines in some flying insects.

But with wasps it is difficult to say if there is a long-term decline, said Mr Ings.

“There is evidence what happens in the year before influences what we get the following year,” he said.

“When there are a lot more wasps in one year, you do tend to have slightly fewer wasps in the next.

“It’s probably better to say you can have a bumper year following a bad year, so it could be next year is a better year for wasps, depending on the weather conditions.”