You may be wondering “what do ladybugs eat?” Ladybugs feed one a wide variety of small insects and insect eggs. Their favorite food is aphids, but they also eat small spiders, mealy bugs, and other insects and mites they can attack and subdue. Ladybugs eat the eggs of the Colorado Potato Beetle and European Corn Borer, which are big agricultural pests. They eat other eggs they find, too.
Adult ladybugs don’t just eat bugs. Some adults feed on nectar and pollen and some eat mildew that forms on the plants and pollen, but the larvae are strictly carnivorous. All ladybugs will eat other ladybug eggs, larvae, and pupae, especially if prey is scarce.
Ladybugs in the genus Stethorus are very tiny insects and feed mostly on spider mites. Ladybugs in the genera Exochomus, Coccidophilus, and Chilocorus prefer scale insects.
Description of Ladybugs
Ladybugs, also called ladybird beetles in Europe, are not bugs at all, but beetles. They belong to the Coccinellidae family. There are nearly 6,000 species of ladybugs in the world. There are about 450 species in North America.
When most people think of ladybugs, they picture a small oval insect that is red with black spots on the body, and black on the head and the pronotum, the part just behind the head. The ladybugs can pull their head beneath the pronotum, in full or in part, to protect it. Many of the ladybugs have markings that look like a head for this purpose. Ladybugs are about 1/16 to 3/8 inches long. They have two wings under the colorful wing covers. Ladybugs have six legs.
Some species are orange and black, some are solid black or brown (these usually feed on spider mites or scale insects). Others have stripes instead of spots.
The larvae have a body like an alligator tail and are also black with orange spots. Most species have large sickle-shaped mandibles to grab their prey with. They eat more than the adults do.
The red and black color of the adults tells potential predators that they taste bad, so is a defense for the ladybug. The black and orange body of the larvae gives the same message.
Common Ladybug Species
Ladybugs live all across North America. Here are some common ladybug species.
When most people think of a ladybug, they think of the ten-spotted ladybug (Bothrocalvia pupillata). The body is red with ten black spots and the head and pronotum black. These ladybugs are distributed widely across North America.
Two-spotted ladybugs (Adalia bipunctata) have black heads and pronotum with yellow markings. They have red bodies with one spot on each wing cover. The larvae are black with yellow markings.
The Seven-Spotted Ladybug (Coccinella septempunctata) is the most common ladybug in Europe. It was introduced into the United States in the 1960s through the 1990s to eat aphids on crops. It has spread and now lives anywhere there is enough food for it. Native ladybugs are having trouble competing with it. It is a relatively large ladybug at 1/4 inch long.
Asian Lady Beetle
Asian lady beetles (Harmonia axyridis) were introduced by the government from the 1960s to the 1990s to eat agricultural pests. They are now naturalized. These ladybugs can be anything from red to orange to tan colored. The female Asian lady beetle tends to have more spots, while the males have fewer or can even be a solid color.
In North America, you find one of three color schemes predominate: red or orange with black spots, black with four red spots, and black with two red spots. Most species of Asian lady beetles have an “M” or “W” marking in white or cream on the pronotum, but not each individual beetle. There is some concern that as these ladybugs spread across the country they are displacing native ladybugs.
Asian lady beetles are considered pests in vineyards and wineries. They are accidently harvested with the grapes. They affect the taste of the wine to such an extent that it is called “ladybug taint.”
Convergent Lady Beetle
The convergent lady beetle (Hippodamia convergens) is the state insect of Ohio. These ladybugs have black heads. The pronotum is black with some cream markings. The body is red with black spots. Convergent lady beetles migrate for the winter. This is the most common species sold by nurseries and online dealers for placement in gardens or greenhouses.
Lifecycle of Ladybugs
The lifecycle of a ladybug takes three to four weeks in warm months. In the cooler spring, it can take up to six weeks. Ladybugs lay eggs on a leaf close to a supply of aphids and other prey. The eggs are yellow and football-shaped. Most ladybugs lay their eggs in clusters of 10-15 eggs on the underside of a leaf. Ladybugs that eat primarily scale insects or spider mites lay single eggs close to prey.
Ladybug larvae hatch in three to five days and immediately start eating. Newly hatched larvae will eat each other, ladybug eggs, and pupae, especially if food is scarce. Baby ladybugs undergo four molts, or instars, over two to three weeks before pupating. The adults emerge in seven to ten days. As the adults age, their spots may begin to fade. Some species of ladybugs are thought to live as long as one to two years and can have several generations a year, mostly in the warm months.
Ladybugs overwinter at the base of trees, in leaf litter, along fence rows, and under rock or bark. Some of them congregate in large numbers to overwinter, while some do not. Since they are beneficial insects, do not disturb them while they are overwintering outside.
How Much Do Ladybugs Eat?
Ladybugs are very effective predators. Ladybug larvae will eat about 400 medium-sized aphids before pupating. An adult ladybug feeds on about 300 medium-sized aphids before laying eggs. It eats three to four aphids for each egg it lays. That comes out to about 5,000 aphids during the adult’s lifetime. They eat other insects as well, but prefer aphids.
There are always a few bad apples in any group and ladybugs are no exception. Most ladybugs eat aphids and other small insects and mites. A few are important plant pests. The Mexican bean beetle (Epilachna varivestis) feeds on bean plants and seeds. A ladybug infestation is a problem for bean growers. Squash beetles are also a type of ladybug that causes problems for farmers.
Ladybugs, especially Asian lady beetles, are attracted to houses with light color exteriors. The lady beetles tend to congregate in places that get afternoon sun. While they do not do structural damage, ladybugs do emit an unpleasant odor and will stain if crushed. Ladybugs are not poisonous to people or animals, but Asian lady beetles may in rare cases bite if handled roughly. In addition, there is some evidence that people may develop and allergy to Asian lady beetles if there are lots of them in the house overwintering.
Nurseries and online sites selling ladybugs are selling field-gathered convergent lady beetles. These ladybugs are gathered at meadows at high altitudes where they go in great numbers when prey is scarce. When released in your garden, they will probably just fly away. They do not start laying eggs for two to three weeks after release, so won’t even leave these behind.
Ladybugs are used successfully in greenhouses, where they cannot fly away. They are also used in large monocrop fields where aphid damage is just unacceptable. Farmers love ladybugs.
What Is The Best Way to Feed Ladybugs?
The best way to feed ladybugs is to provide nectar plants for them to eat in your garden and water sources for them to get a drink. If you have pet ladybugs, you will need to find a plant infected with aphids and put it in their enclosure for them to eat. You can also try mealy bugs or small spiders. You can put a wet paper towel in the enclosure for them to drink from. Some people use a damp cotton ball instead. Others use moist raisins to provide fluid for the ladybugs.
Attracting Ladybugs to Your Garden
If releasing adult ladybugs in the garden doesn’t work well, what does? Attract wild ladybugs to your garden by providing everything they need. Lady bugs need the same things other creatures need: food, shelter, water, and protection from preditors.
If you want to have ladybugs around, you will need to stop using pesticides that kill them. Horticultural oils such as neem oil and insecticidal soaps are less harmful to ladybugs, but you should spot treat plants that need help instead of spraying all the plants. That way, the ladybugs can retreat to safe plants that do not have pesticides on them.
Provide rocks, an area of leaf litter, or some mulch at the base of a tree (don’t let it touch the bark) for ladybugs to live in over the winter. You will be rewarded by hungry ladybugs in the spring, when most aphids become active, too. After they eat aphids for two to three weeks, they will start laying eggs ensuring a continuing supply of ladybugs.
Ladybugs drink water even though they get a lot of liquid from their prey. Fill a shallow saucer with pebbles and put water in it until the tops of the pebbles are just sticking up out of the water. Ladybugs can land on the pebbles and reach the water. You will need to refill the water often so the water level does not get too low for the ladybugs to reach it.
Nectar and Pollen Crops
Most adult ladybugs eat nectar and pollen in addition to aphids. They favor shallow flowers like dill, coriander, or alyssum which they can reach into. Deeper flowers are inaccessible to them. Plant nectar and pollen crops in your garden to attract the ladybugs and they will hunt the aphids on your other plants, too. Try to plant a mixture of early blooming, summer blooming, and late blooming plants so the nectar and pollen are available from early spring until it gets cold enough in the fall for the ladybugs to go to their overwintering sites.
Trap crops are sacrificial plants that are planted to attract pests and keep them from finding your good plants. Nasturtiums can be planted in a band around the perimeter of your garden to attract aphids. Most aphids will stay on the nasturtiums and never reach the plants inside your garden. Ladybugs will be attracted to the aphids. If some aphids do reach your garden, the ladybugs will find them and eat them, too. Never spray your trap crops because you will kill the ladybugs there, too.
Ants like the honeydew aphids produce. The ants will “farm” the aphids and protect them against the ladybugs. Controlling the ants keeps the aphids vulnerable to the ladybugs.
Fun Ladybug Facts
Ladybugs are able to bleed body fluid out of their leg joints. This yellowish liquid is used as a repellent when the ladybug is in danger. In some species, the liquid has various alkaloid toxins such as adaline, coccinelline, exochomine, hippodamine. These poisons are present in the eggs, larvae, pupae, and adults. They are not hazardous to people or pets but may cause skin irritation for some people.
In 1999, NASA sent ladybugs into space on the space shuttle Columbia to see if they could eat aphids in zero gravity. The experiment was designed by girls at a Chilean school. Ladybugs commonly climb stems to reach aphids. In turn, the aphids drop off the leaves onto the ground to escape. How did this work with no gravity? The ladybugs got the aphids. NASA may send ladybugs with astronauts to eat pests in onboard greenhouses so the astronauts can grow their own food.
Europeans call ladybugs “ladybirds”. The lady in the term refers to the Virgin Mary. In other languages, the association between Mary and ladybugs is clearer. In Germany, the name means “Mary’s beetle”. When aphids were eating the crops, farmers prayed to the Virgin Mary for relief. When the ladybugs showed up, they were seen as being sent in answer to the farmer’s prayers. The ladybug is still often seen as a symbol of good luck.
In the 1880s, the California citrus industry was decimanted by the imported cottony cushion scale. Desperate to save the citrus industry, the vedalia beetle (Rodolia cardinalis) was imported from Australia in the early 1890s to eat the cottony cushion scale. This ladybug ate the cottony cushion scale and saved the citrus industry.
Ladybugs have special organs on their feet that smell what they touch. This helps the ladybug track the aphids they want to eat.
The part we see, the elytra, is actually a wing cover to protect the delicate wings. According to Saito, Kazuya, et al., (link won’t load, says it is broken, but it isn’t, https://doi.org/10.1073/pnas.1620612114) when the cover is lifted, the wings unfurl and beat 85 times a second. The wings are larger than the ladybug, so they are stored folded beneath the elytra so they don’t get in the way. It only takes 0.1 second for the wings to unfurl.
Native ladybugs are disappearing. No one is sure why, but scientists at Cornell University have come up with a project to find out. The lost ladybug program asks everyone to take pictures of any ladybugs they find and upload them to the lost ladybug submission page. Even if you don’t find any ladybugs, they need to know that, too, so report the results of all your ladybug hunts.
Ladybugs lay both fertile and infertile eggs. Scientists think the infertile eggs are laid as a food source for the newly hatched larva. The less prey present, the more infertile eggs are laid.
Why Do Ladybugs Invade My House in the Fall?
Ladybugs tend to cause the most problems in the fall when they invade houses looking for a warm place to overwinter. These are generally Asian lady beetles, not native ladybugs. The problem is not that a stray ladybug comes inside. Ladybugs usually come in droves.
Gently sweep or vacuum the ladybugs up and then empty them outside. If you vacuum them, empty the vacuum bag immediately or they will crawl out of it into the house again. Ladybugs do not eat, drink, or lay eggs inside. If you do not put them outside they will hibernate in the house then crawl around in the spring looking for a way out.
Keeping Ladybugs Outside
The best way to keep ladybugs outside is to seal your house. Use caulk to seal around windows, seal cracks in the foundation and walls, and seal around where pipes, electrical wires, and cables come into the house. Make sure that your door sweeps are in good shape and that the screens over your windows and door do not have any holes in them. The screens should fit tightly in their frames, too. Prune trees and shrubs so they do not touch your house or hang over the roof. Move firewood away from your house. Put small stainless steel mesh over vents, chimneys, and other ways to enter the house that can’t be blocked off. Put copper mesh in weepholes in the brick or stone.
Despite the red or orange color that warns ladybugs taste bad, they have lots of predators. Larger spiders, wasps, dragonflies, frogs, toads, assassian bugs, stink bugs, very hungry birds, and even mammals such as bears all eat ladybugs. According to the Missouri Department of Conservation, researchers in Wyoming found bear scat with nothing but thousands of ladybug wing covers in it.
Beneficial Outside, Pests Inside
Ladybugs are overwhelmingly beneficial to have in the garden. They control aphids and other pests that would otherwise eat your plants. Attracting ladybugs to your garden is as simple as planting sources of nectar and pollen they can use. Putting out water for them will attract them, too, but make sure it is something they will not drown in.
Asian lady beetles can be pests because they congregate in large numbers on white or light colored walls to sun. When it starts to get cold, large numbers of the Asian lady beetles can enter your house to overwinter. The best way to prevent this is to seal the cracks and crevices that let them in.
Frequently Asked Questions
We have rounded up the questions we get asked most frequently about ladybugs and answered them below.
Does the number of spots on a ladybug tell its age?
No, different species of ladybugs have different numbers of spots. The number and placement of the spots is used to not only tell the species of ladybug you have, but whether it is male or female. Females are often bigger and have more spots than the males.
Do ladybugs eat spiders?
Ladybugs eat spiders small enough for them to attack and subdue. They are especially prone to eat spiders and insects when aphids are in short supply.
What can I feed a ladybug in my home?
It s best to put the ladybug outside in warm weather or leave it alone in the winter. Ladybugs do not feed or lay eggs in the house and will soon die unless they are overwintering. If you have a pet ladybug, you can feed it aphids from infected plants. Put out a wet paper towel so the ladybug can get a drink. Ladybugs will also eat small mealyworms, which you can purchase at pet shops.
Do ladybugs eat grass?
No, ladybugs eat small soft bodied insects and spiders. They do not eat grass.
Do ladybugs eat lettuce?
No, ladybugs do not eat lettuce.
What do ladybugs drink?
Ladybugs get a lot of liquid from their prey. However, they still have to drink water.
Do ladybugs eat fruit?
No, ladybugs do not eat fruit.
Do ladybugs eat each other?
Yes, ladybugs will eat other ladybugs’ eggs, larva, and pupa, especially if other prey is scarce.