Pests please!
Creating a wildlife-rich garden means accepting that the creatures we once thought of as ‘pests’ can play a vital role in boosting biodiversity. Wildlife gardener, writer and broadcaster Kate Bradbury has been at the forefront of a shift in the way we manage our home patches
Above: a leafcutter bee; and the holes they leave in leaves; leaf miner scribbles in bramble leaves (‘nature’s graffiti’); and aphids on a juicy new shoot
What a good year the aphids are having. Everywhere I turn there are clusters of them – black, green and red jewels gathered on stem tips and other new growth. There are many different types: the black Aphis viburni (top right) are all over my guelder rose, while rose greenfly (Macrosiphum rosae) accumulate on my shrub and climbing roses. The species that eat them are having a good time, too: I’m enjoying watching house sparrows picking them off to feed their chicks. Wasps hunt them like sharks, grabbing them in their mandibles to take back to the grubs in the nest. Then there are the ladybirds, lacewings and hoverflies, which lay eggs close to aphid colonies so their larvae can feast on them – lacewing larvae are such voracious aphid eaters they’re called aphid lions. Roar!
Tolerating ‘pests’ in the garden is more about respecting natural cycles than suffering an assault on your plants. I don’t need to remove aphids from my plants because there are plenty of natural predators to keep numbers in check. Plus, it’s nice knowing the sparrows, wasps, ladybirds, hoverflies and lacewings have full bellies this year.
Aphids aren’t the only ‘pests’ crucial to the day-to-day workings of our gardens and wider environment. Did you know that one baby blue tit needs to eat 100 caterpillars a day for the first three weeks of its life (and that a nest can have up to 16 eggs in it?) Despite being known for eating slugs and snails, hedgehogs mainly eat caterpillars, too (along with beetles and earthworms) – as do amphibians. So, the more caterpillars we can welcome into our gardens, the more birds, hedgehogs and frogs there will be.
Above: two types of sawfly caterpillar, both specialists in particular plants: rose (left) and solomon’s seal. The host plants rarely suffer long-term harm.
Sawfly larvae, which look like caterpillars but are actually the larvae of flies, rather than moths or butterflies, are also excellent food for birds. And there are other leaf-munching invertebrates: leaf miner larvae, which burrow into leaves, creating ‘nature’s graffiti’, and leaf beetles and weevils, which nibble leaves.
I hope we are all beyond seeing leafcutter bees as pests. These beautiful solitary bees cut elliptical holes in leaves and roll them into a cigar shape, before flying with them – often clumsily – back to their nest. They favour roses, wisteria, birch and sometimes flowers, and use them to create snug chambers in which they lay eggs and leave food for their grubs to eat when they hatch. Why not erect a bee hotel near your roses and see if the leafcutters take residence? Watching them attempt to fly with a rolled up rose leaf is completely joyous.
In wetter years, slugs and snails can cause havoc, eating all the fresh new growth we tend to have plenty of in our gardens and allotments. The damage they cause can be devastating, but fostering a good ecosystem in your garden, where birds, reptiles, amphibians and other mollusc munchers can thrive, can help keep numbers down.
How do we do this? The first thing to do is to stop using all pesticides, and also stop removing them from our plants. The second is to grow plants that these species are attracted to. Many garden plants are attractive to aphids and other leaf munchers, but moths and butterflies tend to be more fussy with their egg-laying needs – you’ll find more information on caterpillar foodplants here.
The more predators you attract, the fewer problems you’ll have with ‘pests’ – and that includes slugs and snails. A good garden ecosystem takes care of itself, and the more nibbled your leaves are, the more alive your garden is.
Kate Bradbury’s most recent book is One Garden Against the World: In Search of Hope in a Changing Climate. It was the non-fiction winner of the People’s Book Prize earlier this year.
