It’s a war zone out there. Aphid forces broke out from their stronghold among the rose bushes this spring. By the end of May they had overrun territory stretching from the flower border to the furthest shores of the pond. After years of squirting bug sprays, sprinkling ant powder and scattering slug pellets, I have quit using chemical pesticides.
The tide turned at the beginning of June. Allied forces, gallantly spearheaded by seven-spot ladybirds and supported from the air by squadrons of hoverflies, won battle after battle. The aphids are now a spent force, their armies scattered to the winds. Only a few thousand blackfly remain, hanging on to their last bastions amid the fragrant valerian.
I’d like to say I foreswore chemical warfare against garden pests following an epiphany — that Mother Earth or organic gardening evangelist Bob Flowerdew came to me in a vision, asking, “What’s with the pesticides?â€
In reality, I got bored with them. Chemical pesticides are time-consuming, expensive and accidentally kill or harm animals we cherish.
“Once you start using them, it’s hard to stop,†says Andrew Whitehouse of Buglife, a charity. “You get stuck in a loop.†Wipe out the greenfly on the rose bush and you have also exterminated their predators. You have to keep on spraying.
You need to be as steely-nerved — or merely as lazy — as I am to suspend your hostilities. Aphids are the original fast-breeder reactors. When the sap starts rising, a female greenfly can pop out four duplicates a day. Baby greenflies already have their daughters and granddaughters growing inside them, says Helen Roy, president of the Royal Entomological Society.
Aphids reproduce fast because predation is so high. You can even order reinforcements online in the form of native ladybirds. Roy doubts the usefulness of this. The old rhyme “Ladybird, ladybird, fly away home†reflects how readily these insects take to the wing in unwelcome surroundings, whether the hot hands of children or the wrong garden. It is better, she says, to encourage resident insect predators with log piles and wild patches.
There are almost 50 species of ladybirds in the British Isles. The most familiar is the seven-spot, though it is facing competition from the harlequin, an Asian import.
Most gardeners appreciate ladybirds. The pretty red wing cases catch your eye when you’re weeding or deadheading. In children’s book illustrations, these typically become the red cape of a motherly insect. The archetype is The Ladybug in James and the Giant Peach. Francis, the grumpy, card-sharping ladybug in the Disney animation A Bug’s Life, was irked by strangers always assuming he was a girl.
He was not a bug either. Ladybirds are beetles. That makes them members of a very successful order of animals. Scientist JBS Haldane was supposedly once asked what characteristics of the Almighty his studies had revealed. “An inordinate fondness for beetles,†he replied. There are more than 300,000 species.
There are not, however, enough of the right sort in my London garden.
I need more of the ground beetles that feed on slugs and snails. I found
a big, tough northern ground beetle of a kind that doesn’t bother with a coat on a night out running around on the chilly summit of Helvellyn, in the Lake District, recently. Garden fences appear to restrict the spread of its soft southern cousins. Most ground beetles cannot fly.
Stag beetles can. Sort of. One of these heavyweights careered into our garden last year, wings whirring frantically, legs thrown out and braced for impact.
If you live within their range you can encourage stag beetles to breed with a “stumperyâ€: a vertical log pile part-buried in the ground. I once met a naturalist who reared the huge, white larvae in tubs of rotten wood in his cellar. They looked like props from an Alien movie.
Beetle mania does not get much more niche than this, except in an enthusiasm for carrion beetles.
FT Weekend Festival
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Roy braves the embarrassment of relatives by looking for these on family walks. “It’s amazing what you can find under a dead deer!†she enthuses. Sexton beetles, named after graveyard caretakers, are apparently wonderful parents. To me, they simply smell bad.
We all have our limits. I do not expect most readers will want to embrace laissez-faire gardening to the extent I have. But I would encourage you to experiment with low-impact pest control. You can flick lily beetle larvae off host plants with a paintbrush. Soap solution can be effective against aphids.
Where they are accessible, you can dig out and scatter the nests of black ants. These farm greenfly for their honeydew, repelling ladybirds in
the process. I am planning to dig out the city of thousands that has mushroomed on the rockery. But first I will let it spew forth its seasonal bounty of flying ants. They will help fatten up the swifts for their return trip to Africa. The eternal war of pests vs predators will have broken out again by the time the birds return next spring.
Jonathan Guthrie is the head of Lex
