Beneficial Insects in the Garden (2024)

Which are the most beneficial insects? We’re talking about bugs that are good for plants in the garden and eatpests that would otherwise eat your plants. Find out and start thinking about which plants and flowers attract beneficialinsects!

What Are BeneficialInsects?

The average backyard is home to thousands of insects, but you may be surprised to learn that only about a tenth of these are destructive. In fact, most are either beneficial or harmless. Beneficial insectsfall into three maincategories:

1. Pollinators:We depend on these insects—including bees, butterflies, flies, and moths—to pollinate our garden’sflowers.
2. Predators:These insects eliminate pests by eating them. Things like ladybugs, praying mantids, and green lacewing larvaefall into thiscategory.
3. Parasitizers:Likepredators, parasitizersalso 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 thiscategory.

Meet the Beneficial Bugsin YourBackyard

Everyone knows their bees from theirbutterflies, but what about the many other beneficial bugs? It’s likely that you’vealreadyseen these good guys in your garden, but maybe you weren’t formally introduced. Here are a few you might want to become acquaintedwith:

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 anhour?

GreenLacewings

Adult green lacewings feed on pollen and nectar, but their larvae, which look like a mix between a slug and analligator, prey uponsoft-bodied garden pests, including caterpillars andaphids.

PrayingMantids

A praying mantis will make short work of any grasshoppers troubling you; these fierce predators will also hunt many otherinsect pests that terrorize gardens, including moths, beetles, and flies. Note, however, thatpraying mantids are ruthless and will also eat other beneficial creatures, like butterflies, bees, and hummingbirds—and even eachother!

Spiders

Spiders—though technically arachnids rather thaninsects—are often overlooked asbeneficial,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 undercontrol.

GroundBeetles

“Ground beetles” is the name ofa large group of predatory beetles that are beneficial as both adults andlarvae. 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, don’t crush every beetle yousee!

SoldierBeetles

Soldier beetles are an important predator of Mexican bean beetles, Colorado potato beetles, caterpillars, and aphids. Like many beneficial bugs, they are attracted to plants that have compound blossoms, such as Queen Anne’s lace andyarrow.

AssassinBugs

Assassin bugs look like a strange mix between a praying mantis and a squash bug.They use their sharp mouthparts toprey upon many different types of insect pests in the garden. They can be mistaken for squash bugs in their adult form, so look carefully before you squishsomething!

RobberFlies

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 can bite when threatened). Instead, they go after a number of common garden pests. Try not to shoo thisfly!

Hoverflies

Another good fly in your garden, the hoverfly looks like a tiny yellowjacketwithout a stinger. They feed on pollen and nectar and are crucial pollinators. Their larvae are voracious predators, killing aphids, caterpillars, beetles, and thrips by sucking the juice from theirvictims.

ParasiticWasps

Parasitic wasps are very tiny, so you probably won’t see them at work. However,they are a very effective pestcontrol.

• Brachonid wasps lay their eggs on the backs of tomato hornwormsand other caterpillars, forming those white cocoons you see on the caterpillar’s back (pictured below). If you see aparasitizedcaterpillar, 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 tomatopatch.
• Trichogramma waspsare minuscule wasps (several of them can fit on the head of a pin) that lay their eggs inside the eggs of over 200 different insect pests, preventing the pests’ eggs from ever hatching in the firstplace.
• The tachinid fly looks like just a small housefly but is an active parasitizer of corn borers, gypsy moth caterpillars, grasshoppers, Japanese beetles, Mexican bean beetles, squash bugs, and greenstinkbugs.

Attracting BeneficialInsects

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 forthem.

A diversity of plants will attract a wide range of insects. Many beneficials appear in the garden before the pests do, and they need alternative food sources such as pollen and nectar if they are to stickaround.

• 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 thespring.
• 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 lemonbalm.

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 beneficialinsects.

In her book Green Thoughts, Eleanor Perenyi writes, “Every insect has a mortal enemy. Cultivate that enemy, and he will do your work foryou.”