Beyond the beloved butterflies, bees, and ladybirds, a hidden world of less glamorous, even alarming-looking insects plays a crucial role in maintaining healthy gardens.
Anton Rosenfeld, research manager at the sustainable gardening charity Garden Organic, emphasizes the importance of biodiversity in your green space.
He said: “It’s unrealistic to think that one creature alone will help, and while our instinct might be to create a space that is simplistic and ordered, a diverse habitat will keep pest levels manageable and our gardens full of life.”
Here, he highlights six often-misunderstood garden critters that contribute significantly to a thriving ecosystem.
1. European hornet (Vespa crabro)
Despite their alarming appearance and armour-plated faces, these giant-sized wasps are quite docile and are only likely to sting you if their nest is under threat, says Rosenfeld.
Their nests are usually found in trees and are more common in the south of the UK and the Midlands, although they are moving further northwards. You will usually first see queens in April looking for a place to build a nest, and they will remain active until late autumn, when all the workers die off, he explains.
Why they are good for the garden: “Hornets definitely have their uses in an organic garden both for pollinating plants and hunting down ‘pests’ such as caterpillars which they feed to their young. The adults themselves like to feed off brightly coloured pollen and nectar-rich plants such as cosmos, fennel and ripe sugary fruits.”
Rosenfeld adds: “Contrary to confusing misinformation, European hornets pose no threats to UK bee populations. This threat comes from the Asian hornet that looks vastly different: it’s smaller with a high proportion of black on its body.”
2. Parasitic wasps
There are more than 9,000 different wasps in the UK, of which 6,500 are parasitic. When we think of wasps, we think of the black and yellow variety, but many are tiny black insects that we hardly notice and most are unlikely to be able to sting you, he explains.
They inject their eggs into aphids, which then eat the aphid from the inside.
Rosenfeld says: “To bring them into your garden, grow plenty of flowering plants (e.g. buckwheat, poached egg flower, phacelia, corn marigolds and fennel) to sustain the adult wasps with pollen and nectar.”
Why they are good for the garden: “Despite many of them not being very noticeable, they make a vital contribution to keeping key pests such as aphids and caterpillars under control. A common species is Diaeretiella rapae which preys on grey furry cabbage aphids and can be seen from early spring to mid-autumn, especially on the vegetable patch.”
3. Ladybird larvae (Coccinellidae)
Ladybird larvae are less photogenic than the brightly coloured adult ladybirds we see in our gardens. They’re an elongated oval shape, deep purple and grey with orange markings and can reach sizes larger than the adult ladybird.
Why they are good for the garden: A ladybird larva can help consume 100 aphids a day and eats thrips and spider mites – which can all damage crops. You’re very likely to find them on many aphid-infested plants such as beans and roses, Rosenfeld observes.
“To encourage more ladybirds into your garden, it’s important to have a place where the adults can overwinter, which includes long grass, hollow stems and vegetation. For this reason, we would advise not cutting all your perennial plants back in the autumn. The adult ladybirds emerge from winter hibernation and lay eggs from spring to summer, so you should see the larvae scavenging around during late spring and summer.”
4. Ground beetle (Carabidae)
Ground beetles are rounded, shiny black beetles approximately 1cm long. They don’t damage our plants and the worst you can expect is a gentle nip if picked up.
They are most active at night and tend to hide under stones, logs or tussocks of grass during the day. A few less tidy corners, with logs, long grass and dried leaves will provide a place for ground beetles to shelter. You can see them any time of year, although they will be more active during the spring and summer months.
Why they are good for the garden: “In the organic garden, they eat many common garden pests such as aphids, caterpillars, wireworms and are now thought to make a significant contribution to slug control.”
5. Hoverfly larvae (Syrphidae)
A few millimetres long and looking like maggots with pointed heads, hoverfly larvae frequently waggle their heads around, often in a frenzy looking for aphids. You will see them from late spring until early autumn.
Why they are good for the garden: It’s easy to mistake them for something that might harm your crops, but in fact they do an excellent job of hoovering up aphids and other sap-sucking ‘pests’. They can typically eat 50 aphids a day. Adult hoverflies often look like wasps but are harmless and feed on pollen and nectar. They like flowers with a shallow structure, especially those in the carrot family, so encourage them into your plot by providing a range of flowering herbs such as coriander, dill and fennel.
6. Lacewing larvae (Neuroptera)
The outward appearance of lacewing larvae is in stark contrast to the delicate structure of the adults. They look like grumpy, segmented slugs with pincer-like jaws. Lacewings overwinter as pupae or adults, but you are most likely to see the larvae from mid-spring into autumn.
Why they are good for the garden: “They use their jaws to grab hold of aphids, spider mites and whiteflies before they pierce them and suck out their juices. Perhaps that’s a bit scary, but it’s very useful for the organic gardener,” says Rosenfeld. “Like other predators, they can be encouraged by a range of nectar-rich plants such as cosmos, fennel, dill and overwintering vegetation for shelter.”
