Garden pests are a fact of life for gardeners. There’s no escaping it — lots of creatures want to feed on your hard-won harvest. They’ll chomp away happily if given the chance. That’s why many gardeners have come to love bugs. Not all bugs, of course, but a subset called beneficial insects.
You’re already familiar with the beneficial insects that pollinate the flowers and food crops, like bees and butterflies. Other beneficial insects help gardeners by consuming pests that go after our flowers and vegetable gardens.
Read on to find out which insects will manage the pesty ones, how to attract beneficial insects, and how to reframe the way you think about garden pests.
The Risks With Pesticides
Some gardeners might think that dousing their gardens with pesticides is the answer to nibbling insects. But there are serious downsides to using chemical pesticides. Pesticides have negative impacts on human health and can persist in the environment, harming soil health, polluting waterways, and endangering wildlife.
In addition, by applying chemical pesticides, gardeners destroy some of their best weapons against pests — beneficial insects.
Beneficial Insects to the Rescue
Many gardeners know the sinking feeling of discovering their beloved plants destroyed by unwanted guests. Slugs, aphids, and other garden pests have little regard for the hard work we put into our gardens. But, what nature destroys, nature can replenish. Sometimes, if we step aside, nature will give us just what we need — in this case, hard-working beneficials that keep garden pests in check.
Meet Insect Predators
One way that beneficial insects help in the garden is by preying on the bugs we don’t want. Insect predators can consume thousands of harmful pests.
Most of us think of ladybugs as being red with black spots, but there are hundreds of species of ladybugs. Also known as ladybird beetles, almost all ladybugs are voracious eaters of aphids as well as spider mites and scale insects.
You can find them on the underside of leaves, working for you. Even their larvae eat aphids. Ladybugs feed on nectar and pollen as well as garden pests, so that makes them good pollinators, too. Be sure to feature hearty flowering plants to keep them happy.
Praying mantids are one of the larger insects you’ll see in your garden. Depending on the species, adults can reach 2 to 12 inches long, although in North America, you’ll generally find them within the 2- to 5-inch range. They may look like they are praying, but they spend their time preying on a variety of insects and animals. Some species are large enough to eat mice. Others eat bugs such as aphids and spiders.
Praying mantids aren’t picky eaters. They’ll munch down any grasshoppers eating your plants, but they’ll also eat helpful insects — including other mantids. They’ll even eat hummingbirds. As long as you don’t introduce an outsized species, you should be able to reap their rewards without losing what you value.
Preying mantids prefer hiding in tall grasses, shrubs, and heavy foliage. A healthy garden with plenty of places to hide should attract enough to help you out.
Not all flies are pests. Some, like the hoverfly, pollinate plants and hunt pests for our benefit. Hoverflies resemble a dainty wasp, but a closer look reveals no stinger. Hoverfly larvae feast on thrips, aphids, mealybugs, and caterpillars.
Attract hoverflies by offering a variety of flowering plants in your garden.
Dragonflies won’t save your cucumbers, but their diet can make sitting in your yard a lot more enjoyable. Dragonflies eat other flying insects — gnats, flies, and mosquitos. They can pack away hundreds of mosquitos in a day. They do take down an occasional butterfly, but as mosquitos can spread disease, that’s probably an okay trade-off.
Dragonflies spend part of their lives in water, but they travel pretty far when they leave it. If you have a pond or wetlands nearby, you should see plenty. If not, adding a small pond can attract them.
Meet the Parasitoid
Parasitoids are creatures that set up house in another animal and kill it from the inside out. The most common parasitoid you’re likely to see is the parasitic, or braconid, wasp.
Stumbling across one of these babies (literally, they’re larvae) on your tomato plant is equal parts unnerving and fascinating. In a pretty amazing feat, the adult wasp lays its eggs inside a tomato hornworm. Sometime later, the larvae eat their way out, leaving a heavy worm carcass with dozens of eerie-looking white cocoons on the outside.
You may jump out of your skin when you see one, but those weird little buggers will save your tomato plant. Parasitic wasps also lay their eggs in grubs that feed on the roots of your plants. If you find any parasitic wasp cocoons, leave them alone. When they hatch, these beneficial insects will lay their own eggs and keep garden pests in check.
You Don’t Have to Kill All the Pests
Gardeners used to bring out the heavy artillery against the first sign of pests, but that’s changing. The effects of human behavior on the environment grow clearer every day. People are looking for ways to live in harmony with nature, not fight against or conquer it.
That just may mean changing our perspective about what we deem as pests. The fact is that if you have a garden, you’re going to have bugs. But beneficial insects — including those mentioned above and a wide variety of pollinators — can be our allies if we recognize how to work with them. Even the ones we consider pests can be tolerated in a well-managed garden. If you have an otherwise healthy garden, they shouldn’t result in an all-out infestation.
Feature image: mature hoverfly, Adobe Stock
Mary McDonald May 2, 2022 at 04:41PM