Beneficial Insects in the Garden

Which Insects Are Useful to Gardeners?

January 29, 2019
Beneficial Insects in the Garden

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Here’s a short list of great beneficial insects with pictures—and with tips on attracting these good bugs to your garden.

The average backyard is home to thousands of insects. Only about a tenth of these are destructive. Most are either beneficial or harmless. Beneficials fall into three categories:

  • Pollinators: we depend on these insects to pollinate our fruits and vegetables.
  • Predators: they eliminate pests by eating them.
  • Parasitizers: they lay their eggs on or in the bad bugs. When the eggs hatch the larvae feed on the host insects, eventually killing them.

You may have seen these good guys in your garden but were not formally introduced. Here are a few you might want to meet:


Ladybugs start out life looking like this. Did you know that a ladybug larva can eat up to 40 aphids an hour?


Adult green lacewings feed on pollen and nectar but their larvae, which look like little alligators, suck the juice from many soft-bodies insects, including caterpillars.


A praying mantis will make short work of any grasshoppers that are troubling you; these fierce predators will aso hunt many insect pests that terrorize gardens, including moths, beetles, and flies. Note too many praying mantids will turn to eating other beneficials, such as butterflies, bees, and hummingbirds—and even each other! . 


Wolf spiders—though technically not 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.


Ground beetles are predatory as adults and as larvae. They will eat a wide range of insects including nematodes, caterpillars, thrips, weevils, slugs, and silverfish.


Soldier beetles are an important predator of Mexican bean beetles and Colorado potato beetles. Like many beneficials, they are attracted to plants that have compound blossoms.

There is another soldier beetle called the spined soldier beetle that looks like a stink bug. I fear I may have killed more than my share of them thinking they were bad guys!


Hoverflies look like yellowjackets but don’t sting. They feed on pollen and nectar and are important pollinators. Their larvae are voracious predators, killing aphids, caterpillars, beetles, and thrips by sucking the juice from their victims.


Parasitic wasps are very tiny so you will probably not see them at work but they are very effective.

  • Brachonid wasps lay their eggs on the backs of tomato hornworms, forming those white cocoons you see on the worm’s back. Leave the parasitized worms alone - the wasp larvae will take care of them for you by eating the worms from the inside out. The larvae will hatch into more wasps who will continue to do their good work in your tomato patch.
  • Trichogramma wasps lay their eggs in the eggs of over 200 different insect pests preventing them from hatching. 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.

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 be 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 like 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 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 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.”

About This Blog

Get inspired by Robin Sweetser’s backyard gardening tips and tricks. Robin has been a contributor to The Old Farmer’s Almanac and the All-Seasons Garden Guide for many years. She and her partner Tom have a small greenhouse business and also sell plants, cut flowers, and vegetables at their local Farmer’s Market.

Reader Comments

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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 are actually arachnids. They have 8 legs instead of 6 like insects.


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!

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.


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