Ladybugs are among the most effective natural predators of aphids, with a single adult eating around 50 aphids per day and up to 5,000 over its lifetime. Both adult ladybugs and their larvae feed on aphids, making them one of the most reliable forms of biological pest control available to home gardeners.
How Many Aphids Ladybugs Actually Eat
The numbers vary by species, but they’re impressive across the board. The convergent lady beetle, the most common species in North America, eats about 50 aphids a day as an adult. UC Statewide Integrated Pest Management puts the figure even higher for well-fed populations, noting that each adult can consume around 100 aphids per day before dispersing to find more prey. The seven-spotted lady beetle, common in gardens across the U.S. and Europe, can eat several hundred aphids per day as an adult.
Over a full lifespan, which ranges from a few weeks to a few months depending on conditions, a single ladybug can consume up to 5,000 aphids. That number includes both larval and adult feeding, and it’s why ladybugs have earned a reputation as one of the most useful insects in any garden.
Larvae Are Even Hungrier
Most people picture the familiar red-and-black adult when they think of ladybugs eating aphids, but the larval stage is just as important. Ladybug larvae look nothing like the adults. They’re small, dark, and spiny, often mistaken for pests themselves. If you spot one on your plants, leave it alone.
Convergent lady beetle larvae eat their own body weight in aphids every day. Seven-spotted lady beetle larvae consume 200 to 300 aphids over the course of their development before they pupate into adults. Young larvae pierce their prey and suck out the contents, while older larvae and adults chew and consume the entire insect. This means that from the moment a ladybug hatches, it’s already working as pest control in your garden.
What Else Ladybugs Eat
Aphids are the primary diet, but ladybugs aren’t limited to them. They also feed on other soft-bodied insects, insect eggs, mites, and small caterpillars. When aphid populations are low, adult ladybugs supplement with pollen and nectar, which is why you’ll sometimes see them on flowers even when no aphids are visible. This flexibility helps them survive between aphid outbreaks, but aphids remain their preferred and most frequently consumed prey.
Buying and Releasing Ladybugs
You can purchase live ladybugs (usually convergent lady beetles) from garden centers and online suppliers. The biggest challenge isn’t getting them; it’s keeping them from flying away immediately. Most purchased ladybugs will disperse within a day or two if conditions aren’t right.
A few steps improve your odds. Release them in the evening, after sunset. Ladybugs released during the day are far more likely to fly off immediately. Mist the plants with water before you set the beetles down, since they’re attracted to moisture after being stored dry. Make sure there’s actually a healthy population of aphids for them to eat. If your garden doesn’t have enough food, they’ll leave to find it elsewhere.
Store purchased ladybugs in the refrigerator (not the freezer) until you’re ready to release them, and mist them lightly with water to keep them hydrated. For heavy aphid infestations, the recommendation from UC Agriculture and Natural Resources is about 1,500 lady beetles per affected plant, released at one to two week intervals. That sounds like a lot, and it is. This is partly why many gardeners find it more effective to attract native ladybugs rather than buying them.
Attracting Native Ladybugs to Your Garden
Native ladybugs that find your garden on their own are far more likely to stay than purchased ones. The key is giving them reasons to show up and places to stick around. Planting a variety of pollen and nectar-producing flowers at different heights and bloom times draws in the widest range of beneficial insects, ladybugs included.
Herbs are especially effective. Dill, parsley, fennel, and cilantro all attract ladybugs once they bolt and flower. Rather than pulling these herbs when they go to seed, let them bloom. Mix these insectary plants throughout your vegetable garden or landscape rather than grouping them in one spot. Passionflower and elderberry have nectar glands along their stems that attract beneficial insects even without blooming, and clumping grasses provide ground cover where beetles can shelter.
One counterintuitive strategy: tolerate small aphid populations early in the season. If you spray every aphid the moment you see one, ladybugs have no reason to visit. A modest number of aphids acts as bait, drawing in predators that will then reproduce in your garden and handle larger outbreaks later. Milkweed, for example, attracts oleander aphids, which in turn attract aphid-eating insects like ladybugs. It functions as a banker plant, maintaining a small pest population that sustains your garden’s predator community.
Why Ladybugs Beat Pesticides for Aphid Control
A single ladybug eating 50 to 100 aphids a day doesn’t sound like much when you’re staring at a colony of thousands on your rose bushes. But ladybugs reproduce in the same environment where they feed. One female lays hundreds of eggs near aphid colonies, and each larva that hatches immediately starts consuming aphids. The effect compounds quickly. Broad-spectrum insecticides, by contrast, kill ladybugs and aphids alike, which means aphid populations often rebound faster after spraying because their predators are gone. Keeping ladybugs in your garden creates a self-sustaining cycle where predator populations rise to match prey populations, keeping aphids below damaging levels without repeated intervention.