Beneficial Insects: All About Lacewings

Garden Guardians: How Lacewings Keep Pests at Bay

Picture this scene: A vampire-like creature is poised to strike and suck the lifeforce out of a hapless victim… Suddenly, a hero swoops in to save the day and thwart the diabolical attack.

Scenes like this are surprisingly common in gardens. The attackers—aphids—don’t necessarily wear capes or speak with a Transylvanian accent, but they have earned a reputation for being vampires of the plant world. These insects, also called greenflies or plant lice, pierce plants’ tissues with a sharp proboscis and suck out their sap. A few attacks here and there aren’t necessarily a problem, but on a large scale, aphid sap-sucking can cause stunted growth, distorted leaves, vulnerability to disease, and even plant death.

That’s why it’s helpful to have a vampire hunter—or in this case, a beneficial insect known as a lacewing—on your side. What you really want are juvenile lacewings, or larvae, because munching on aphids (along with mites, thrips, and other harmful insects) is one of the ways they satisfy their voracious appetites.

A garden hero

While lacewings aren’t as famous in the insect world as ladybugs or the common housefly, they make up a significant portion of the insect population with more than 4,000 species worldwide.

As adults, lacewings enjoy eating pollen and drinking nectar (though not to the harmful levels that aphids do). They have delicate, transparent wings, and their greenish-brown bodies are about one-half to 1-inch long. Adult lacewings are beneficial garden visitors because they’re pollinators.

But again, for gardeners interested in lacewings’ superpower, natural pest control, it’s the juvenile lacewings that do the heavy-lifting. Lacewings spend a month in the larval, feeding-frenzy stage. During that period, one lacewing larva will scarf down more than 500 aphids, excellent news for gardeners.

Because of their larvae’s feeding habits, lacewings tend to lay their eggs near aphid colonies. In fact, lacewings are pros at homing in on the scent of “honeydew,” a sweet, sticky substance that aphids excrete when they feed.

But if you want lacewings to start laying eggs in your garden, you don’t have to rely on fragrant aphids to draw them in. 

Extending an invitation

There are measures you can take make your garden attractive to lacewings.

Plant a variety of flowers

Since adult lacewings love nectar and pollen, planting flowering plants is a highly effective lure. Lacewings are particularly attracted to alyssum, angelica, asters, calendula, cosmos, coreopsis, coriander, daisies, dill, fennel, golden marguerite, Queen Anne's lace, tansy, verbena, and yarrow.

Provide shelter

Lacewings need places to lay their eggs and for their larvae to develop. So, offer them a habitat with dense foliage. You can even make (or buy) an insect motel made out of dry leaves, twigs, dead grass, and pieces of cardboard or bark.

Use attractants

Some garden centers sell lacewing attractants, substances designed to lure lacewings into your garden.

Buying and implementing lacewings

You also have the option of buying lacewings from suppliers and garden centers. Here are a few tips to keep in mind:

Choose the right life stage

Lacewings are typically sold as eggs, larvae, or adults. Eggs or larvae are your best choices because they can be strategically placed in areas with high pest populations. Larvae are especially effective since they immediately start feasting on pests.

Prepare your garden

Before releasing lacewings, make sure your garden is ready. Keep your garden pesticide free and provide plenty of nectar sources by planting flowers.

Release method

Distribute lacewing eggs or larvae evenly throughout your garden, focusing on areas with high pest activity. For eggs, place them on plant leaves near pest populations. For larvae, gently sprinkle them around affected plants.

Evaluate effectiveness

Regularly check your garden’s pest levels and lacewing activity to evaluate the effectiveness of your release. If necessary, you can follow with more releases or complementary pest control methods.