The Worst Way to Bring Ladybugs to Your Garden—and What an Expert Says to Do Instead

Cute and colorful, ladybugs (more correctly termed lady beetles) are iconic symbols of a healthy garden. They help pollinate numerous species of flowers and are beloved by gardeners for their voracious appetite for multiple insect pests, notably aphids. 

Faced with an aphid infestation on their roses or tomato plants, many gardeners run to their local nursery to buy live lady beetles. But will purchased lady beetles actually solve the problem? Here's what to know about buying ladybugs for pest control, according to a garden expert, along with tips for naturally attracting them to your yard.

About Lady Beetles

There are about 400 lady beetle species in the United States, including natives and introduced species. The most prevalent one, and the one most sold for pest control, is the native convergent lady beetle (Hippodamia convergens). “They are predators of our vegetarian insects—the plant pests that are eating our plants," says Laura Matter, the Natural Yard Care Program Director for Tilth Alliance. “It’s one of our first lines of defense to make sure you have lady beetles in the garden.” 

A single adult lady beetle can consume up to 5,000 aphids in its short lifetime, which is usually about a year for the native convergent lady beetle. They also eat other notable pests like mites, whitefly, and scale insects.

These lady beetles grow from eggs laid in clusters on the underside of leaves near a food source, hatching in about ten days. After hatching, “They have an alligator-shaped body with ridges, in black and orange usually, and they run pretty fast which can be a little scary to people,” says Matter. Yet those larvae start eating aphids right away to prepare for pupating in three to four weeks. Then the larvae metamorphosize into the familiar hard-shelled beetles in approximately two weeks.

Why Buying Ladybugs Doesn't Work

Lady beetles are programmed to fly and search for food upon waking from hibernation. When purchased, ideally frozen, their instinct is to flee unless there are massive populations of aphids and other prey nearby. Some sources say only 5% of purchased ladybugs remain in the same place after 48 hours. For that reason, you may need to release ladybugs again the next week or two.

Plus you'd need massive numbers of lady beetles to make a dent in your aphid population. According to University of California Division of Agriculture and Natural Resources, one study showed a large rose required two applications of 1500 ladybugs a week apart. To entice them to stay, you also need a large supply of aphids. The convergent lady beetle, for whom aphids are its main food source, eats up to 50 a day.

There are environmental and ethical considerations, too. Most ladybugs sold are harvested by vacuum from wild populations, usually many states away, depleting their numbers. By introducing them to a new ecosystem, you are adding any mites, parasites, or disease they may carry to your environment. These new populations may outcompete and crowd out existing local species. 

They should ideally be frozen, but are often sold live, where they weaken in packaging. The longer they travel, the weaker they become, and less likely to thrive or do much pest control in your garden.

Attract Ladybugs Naturally

You can foster and encourage ladybugs to set up house in your garden by planting foods they and their food love. Other than the convergent beetle, many lady beetle species dine on numerous pests, like mites and whiteflies. By cultivating a rich environment with varied flowers and nectar sources, ladybugs will find a nurturing home. In other words, plant it and they will come.

You want to make sure you have lots of diverse flowers in the yard. Matter says lady beetles like flat flowers, particularly the daisy family like sunflowers, asters, and zinnias, as well as the umbrella-shaped flowers of the carrot families like dill, fennel, and carrot. She also notes they like plants with lush leaf surface for shelter, including mint family plants (mint, sage, bee balm, and rosemary).

Recognizing the eggs and larvae is key to maintaining ladybug populations you already have in your garden. You don’t want to remove them while dispatching aphids on your plants, for instance. “Ladybug adults are so distinctive and cheerful they are instantly recognizable,” Matter says, but the larvae look completely different and might be mistaken for foe rather than friend.

When should you look for the various stages of lady beetles in your yard? “All the time,” says Matter. Lady beetles proliferate in multiple generations throughout the warm seasons. They typically hibernate during winter in lower mountain elevations huddled in massive clusters. Spring is usually when you’ll see the first adults, she says.

Other Ways to Deal with Aphids

If you are facing a current aphid invasion, the best offense is closely observing your plants and creatures living in your garden, according to Matter. For example, unusual ant populations on your plant can be an indicator of aphids, she says, because ants love to eat the sugary secretions left by aphids and actually protect and “farm” them. 

Aphids can be green, white, peach or black and line the stems of plants starting with new growth from top to bottom. They rarely fly. Note that if you see a swollen, tan aphid body, it’s the sign that beneficial parasitic wasps are on the case, so you may not need to do anything. Check the plant for ladybug or other beneficial eggs before acting.

The most direct answer is to squish the aphids with your fingers. A more passive option is to use a strong water spray to dislodge them, such as the jet function of a spray bottle or if the plant is sturdy, a hose nozzle. “Once an aphid is knocked off, they usually aren’t going anywhere,” says Matter.

For a heavy infestation, consider this next option carefully, because it can kill beneficial insects including bees and lady beetles. Take a toothbrush covered in soapy water to the aphids or spray with a soap/water solution, Matter says. Spraying when most pollinators are inactive, like late evening, is safest because it should be dry before they return.