VAL BOURNE’S GARDEN WILDLIFE
Val explains why we should all want harlequin ladybirds to fly away home
Why we need to discourage foreign ladybirds
AFEW years ago the Best Beloved and I were enjoying a wellearned rest and a cup of tea after some strenuous hours in the garden. It was late October 2008, but the weather was warm and the sky was blue with ne’er a cloud in view. As we looked up we saw a black haze coming towards us and then veering off towards our cottage. It was a swarm of harlequin ladybirds – hundreds of them – many of which landed on the warm stone of our cottage and headed for two old metal sheds on either side.
These harlequins (Harmonia axyridis) are well-named because they come in all sorts of mixtures of red and black and a hundred different colour patterns have been recorded. Although they’re similar in size to our native 7- spot( Cocci ne ll a sept em punc ta ta) they’ re slightly larger and rounder, with two distinctive white footballs on either side of their heads.
They are natives of eastern Asia and, because they can devour up to a 100 aphids a day, started to be used as a biological control in greenhouses in America in 1988. By the mid-1990s however they were causing huge problems in central states like Ohio; invading houses biting people and squirting a strong-smelling yellow liquid on soft furnishings.
Closer to home the harlequin was also being used in French, Dutch and Belgian glasshouses. Then on September 19 2004 one, thought to have been carried on the wind from Holland, was spotted in the garden of the White Lion pub at Sible Hedingham in Essex. The first British sighting, verified by the late Dr Michael Majerus of Cambridge University, caused alarm but Majerus wasn’t worried about his curtains. We now know that the harlequin will eat adult ladybirds, their larvae and pupae, lacewing and hoverfly larvae and moth and butterfly eggs, posing a threat to our native ladybirds.
A lot of ladybirds are attacked by parasitic wasps, most commonly Dinocampus coccinellae, but the harlequin is predated less often. Let’s hope the predators, or the chilly English weather, finally take their toll. I see the odd one every so often, but I haven’t seen anything like that first swarm again.
To find out more see the map at
harlequin-survey.org showing its progress up to 2015.
“The harlequin will eat adult ladybirds”