Some bugs are good for the garden! Here’s a list of some of the best beneficial insects to have in your gardening space, with pictures and tips for attracting them.
What Are Beneficial Insects?
The average backyard is home to thousands of insects, and you may be surprised to learn that only about a tenth of these are destructive. Most are either beneficial or harmless. Beneficial insects fall into three main categories:
- Pollinators: We depend on these insects—including bees, butterflies, flies, and moths—to pollinate our garden’s flowers.
- Predators: These insects eliminate pests by eating them. Things like ladybugs, praying mantises, and green lacewing larvae fall into this category.
- Parasitizers: Like predators, parasitizers also prey upon other insects, but in a slightly different way. They lay their eggs on or in the bad bugs, and when the eggs hatch, the larvae feed on the host insects. Parasitic wasps are the main member of this category.
Meet the Beneficial Bugs in Your Backyard
Everyone knows their bees from their butterflies, but what about the many other beneficial bugs? It’s likely that you’ve already seen these good guys in your garden, but were not formally introduced. Here are a few you might want to become acquainted with:
Ladybugs
Despite their delightful name and appearance, ladybugs are ferocious predators! Before they get their bright red colors, they start out life as larvae (pictured below), cruising around on plants and feasting on aphids. Did you know that a ladybug larva can eat up to 40 aphids an hour?
Ladybug larva
Green Lacewings
Adult green lacewings feed on pollen and nectar, but their larvae, which look like a mix between a slug and an alligator, prey upon soft-bodies garden pests, including caterpillars and aphids.
Adult green lacewing
Praying Mantises
A praying mantis will make short work of any grasshoppers that are troubling you; these fierce predators will also hunt many other insect pests that terrorize gardens, including moths, beetles, and flies. Note, however, that praying mantises are ruthless and will turn to eating other beneficials, such as butterflies, bees, and hummingbirds—and even each other!
Praying mantis
Spiders
Spiders—though technically arachnids rather than insects—are often overlooked as beneficial, but they are very effective pest controllers. Since they are attracted to their prey by movement, they eat many live insects. Jumping spiders and wolf spiders (pictured) are especially good at keeping pests under control.
Wolf spider
Ground Beetles
“Ground beetles” is the name of a large group of predatory beetles that are beneficial as both adults and larvae. They will eat a wide range of insects, including nematodes, caterpillars, thrips, weevils, slugs, and silverfish. While insects like Japanese beetles should be controlled in the garden, be careful not to crush every beetle you see!
Ground beetle
Soldier Beetles
Soldier beetles are an important predator of Mexican bean beetles, Colorado potato beetles, caterpillars, and aphids. Like many beneficials, they are attracted to plants that have compound blossoms.
Red soldier beetles
Assassin Bugs
Assassin bugs look like a strange mix between a praying mantis and a squash bug. They use their sharp mouthparts to prey upon many different types of insect pests in the garden. In their adult form, they can be mistaken for squash bugs, so look carefully!
Assassin bug nymph feasting on prey.
Robber Flies
With their extra-long legs, robber flies are bug-eating machines that we’re thankful to have on our side. They may look intimidating, but unlike horseflies, they do not attack humans (although they are capable of biting when threatened). Instead, they go after a number of common garden pests. Try not to shoo this fly!
Robber fly with prey.
Hoverflies
Another good fly to have in your garden, the hoverfly looks like a tiny yellowjacket without a stinger. They feed on pollen and nectar and are extremely important pollinators. Their larvae are voracious predators, killing aphids, caterpillars, beetles, and thrips by sucking the juice from their victims.
Hoverfly
Parasitic Wasps
Parasitic wasps are very tiny, so you will probably not see them at work. However, they are very effective.
- Brachonid wasps lay their eggs on the backs of tomato hornworms and other caterpillars, forming those white cocoons you see on the caterpillar’s back (pictured below). If you see a parasitized caterpillar, don’t kill it. Instead, move it to elsewhere in your garden. The wasp larvae will take care of them for you and turn into more wasps, who will continue to do their good work in your tomato patch.
- Trichogramma wasps lay their eggs inside the eggs of over 200 different insect pests. The tachinid fly looks like a small housefly but it is an active parasitizer of corn borers, gypsy moth caterpillars, grasshoppers, Japanese beetles, Mexican bean beetles, squash bugs, and green stinkbugs.
Parasitic wasp eggs on a hornworm.
Attracting Beneficial Insects
Like all living creatures, beneficial insects have a basic need for water, food, and shelter. By providing these things, your garden will become an inviting home for them.
A diversity of plants will attract a wide range of insects. Many beneficials appear in the garden before the pests do and need alternative food sources such as pollen and nectar if they are to stick around.
- Early blooming plants, especially ones with tiny blossoms like alyssum, or biennials such as carrots or parsley that have been left to bloom will help draw beneficials to your yard in the spring.
- Later, they will be especially attracted to plants with compound blossoms such as yarrow, goldenrod, and Queen Anne’s lace and flowering herbs like lavender, mint, sage, dill, fennel, and lemon balm.
Remember that if you resort to using chemical pesticides to control insects, you will often kill good and bad bugs alike. Even the so-called “natural” pesticides like pyrethrum and rotenone will kill many beneficial insects.
In her book Green Thoughts Eleanor Perenyi writes, “Every insect has a mortal enemy. Cultivate that enemy and he will do your work for you.”
Reader Comments
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BENEFICIAL INSECTS IN THE GARDEN WHY BENEFICIAL BUGS SHOULD BE W
The Picture of Soldier Beatles is highly amusing since what they are engaged-in, is a Herculean-Caligula like embrace-amour---now that's how you march in a parade....
Well done Soldier....Otherwise, the info provided is Stellar.
Sow Bugs
I hope I'm calling this right but, the little gray crawling bugs under flower pots and boards:
Are they beneficial (can't imagine it) or destructive. They're under every pot on my patio.
Thanks in advance.
Marie
It sounds like pill bugs or
It sounds like pill bugs or sow bugs. If they roll into a ball when touched they are pill bugs. They usually don’t harm garden plants. Since they mostly dine on organic debris, it is a sign that your soil is high in organic matter.
Parasitic Wasps
As a person who cares for Mason bees, having a house and habitat, I can't say I see parasitic wasps as beneficial because they will lay their eggs in bee cocoons and the larvae will eat the bees.
Thank you for bringing this
Thank you for bringing this to our attention. Here is a website that explains this problem better than I can. It also has a few ideas for discouraging the leucospid wasp. http://bugoftheweek.com/blog/2016/6/9/mason-bee-peril-parasitic-wasps-il…
Garden
Good to see someone writing about gardening. Recently I found a article and i got to know that spider is a good one. Now I get some elaborate information . Thank you.
Attracting beneficials in the garden
I've found planting a small patch (or a few rows) of buckwheat, even in a flower garden, attracts a heap of beneficials. Most are very small bees/wasps that love-love-love the teeny tiny blossoms of buckwheat.
Japanese Stilt Grass
Watch out for this very invasive "grass". Destroys a good lawn almost instantly. Badly need controls for this weed. Any suggestions will be appreciated. Using a weed& grass killer by the gallons and killing my good grass along with the bad.
Spiders
Spiders are actually arachnids. They have 8 legs instead of 6 like insects.
Spiders
Of course! Thanks for catching that.
Beneficial Insects in the Garden
Thank you for your candid "short list" commentary & pictures -- but I can't help but wish you had included pics of both the adult AND larval forms of these useful critters, instead of only one or the other (as in, the lacewing -- the larval form eats caterpillars but you show a pic of the adult).
Maybe I'm crazy (pretty
Maybe I'm crazy (pretty certain of that), but I mow around my yellow-jackets nests in the ground, leave them a few feet of tall grass around their entrances, and I enjoy a lot less bugs because these guys are out foraging for them all day long.
remove deep rooting weeds
Some weeds like horse radish and dandelion can have roots as deep as 4 ft. If you attempt to pull them out some rootlets will snap off and regrow. My solution is to cut the weed at the soil line and invert an empty tin can over it and then stamp it flush with the ground, wait a season and all will be dead. In the case of horse radish it may take longer, that depends on the size of the tuber which can be 2 inches in diameter and several feet long. I have not yet tried this on blackberries. Will someone please try it and let me know. TA
Monarch butterflies
While there is a lot of truth in what you say, there are aspects, such as the wasps that deal to many butterfly species. In southern New Zealand it is not easy to attract beneficials to an urban garden. The aphids of asclepiads ignore pyrethrum daisies, nasturtiums and other 'attractants'.
Breeding beneficials is as big a task as the object of conserving butterflies!
Bad bugs
You listed the beneficial bugs but left out the bad bugs. I would like to see that list also!
Bad Bugs
Your wish is our command. We have an entire library on Pests and Problems here: http://www.almanac.com/topics/gardening/pests-and-problems You’ll see a lot of pests from aphids to slugs.
Tomato plants are being eaten
Can one horn cattapiller crawl from plant to plant
Tomato plants being eaten.
Yes. The tomato hornworm, or as you identify as a horned caterpillar, will eat its way tomato plant to tomato plant. But where there is one you can bet you'll have no less than a second one equally as hungry.
Nice Post
Thanks for the great share and keep up with this great work! Best of luck