Life

The truth about wasps

A warm summer has led to a rise in wasp numbers, according to pest controllers
A warm summer has led to a rise in wasp numbers, according to pest controllers A warm summer has led to a rise in wasp numbers, according to pest controllers

THE warm summer has led to a rise in wasp numbers, according to pest controllers, while the heat has caused fruit – the wasp's favourite sugary meal – to ripen much faster than usual.

We are all painfully aware of how much of a nuisance these critters are when we're in the garden, however don't 'diss' the wasp too much because:

:: Wasps are good for the garden

Wasps are hugely beneficial to the garden, says RHS principal entomologist Dr Andrew Salisbury. "The social wasps are hugely important beneficial predators – the grubs in the nest need to be fed a protein diet and that is other insects. Caterpillars are a favourite.

"I have watched them remove every single cabbage white caterpillar from a patch of nasturtiums. They come in, sting the caterpillar, remove the head and fly off with the body to feed the grubs."

:: They are eco-friendly

They control the numbers of potential pests like greenfly and many caterpillars, and are also valuable pollinators.

:: Traps can make things worse

The signals wasps give off when trapped can attract even more wasps to the same site.

:: Swatting won't help

"Wasps can release alarm pheromones when they think they are being attacked, so flapping about or swatting will cause this. It will induce defensive behaviour and makes them likely to sting."

:: There are good wasps and bad wasps

There are seven species of social wasps common to Britain and the north.

The hornet (Vespa crabro), Britain's largest social wasp, is much less aggressive than other species of wasp. It is a useful garden predator and will predate on other species of wasp. It nests in rot holes in trees and other dark cavities.

The Asian hornet (Vespa velutina), however, is an invasive non-native species which arrived in France in 2004 where it spread rapidly. It's a highly effective predator of insects, including honey bees and other beneficial species, and can cause significant losses to bee colonies.

It has only one yellow stripe on its abdomen whereas the native hornet has several yellow stripes.

:: Non-chemical control

If wasps are damaging your fruit, reduce the risk by enclosing some of the fruit trusses in bags made from muslin or nylon tights.

Fix wasp-proof screen over greenhouse doors to protect grapes and if you're going down the trap route, half fill a jam jar with water and jam, put a sheet of paper over the top of the jar, secured with an elastic band and punch a hole in it with a pencil to allow the wasps to enter - but not escape.