There are more than 5,000 described species of ladybugs in the insect family Coccinellidae. New species are still being discovered, with a few being described for the first time as recently as 2020. The name ladybug is often misleading since these insects are beetles, in the order Coleoptera, not true bugs which are in the order Hemiptera. While ladybug is the most common name used in North America, these little critters are also known as ladybirds, lady beetles, or ladybird beetles.
Ladybugs are considered to be beneficial insects in gardens because they are predators of many of the most common insect pests. However, a few species of ladybirds are considered pests because they will eat plants or overwinter in man-made structures. In this article we will cover everything you need to know about ladybugs including their lifecycle, what they eat, and how to repel the pest species. Let’s start with how they got the name ladybug.
Ladybug meaning
The origin of the common name ladybug is quite interesting. Initially, the British common name started out as ladybird in the late 1600s. Back then, farmers suffering crop damage from insect pests would pray for help. Ladybugs would show up and feast on the pests helping the farmers save their crops.
While it is not uncommon for ladybugs to show up when pest insect populations increase, farmers saw this as a gift from the Virgin Mary answering their prayers. The Virgin Mary was referred to as ‘Our Lady’, and the ladybug became known as ladybirds in her honor. The common name ladybird is still used in Europe today. However, it has changed to ladybug in North America.
More recently, the word beetle has been added to the common name. This includes the common name ladybird beetle and lady beetle. Whichever name is used, they all refer to beetles that are members of the family Coccinellidae.
Ladybug Lifecycle
The lifecycle of a ladybug has four stages (egg, larva, pupa, adult) known as complete metamorphosis. Most live for 1 to 2 years, with females producing up to 300 eggs during the mating season. There can be multiple, overlapping generations of ladybugs produced each year since their life cycle from egg to adult can be completed in as little as 2 to 3 weeks.
Ladybird eggs are yellow to orange in color, oval in shape, and approximately 1 millimeter in size. Females lay their eggs in clusters, typically on plants where prey insects such as aphids are present. Depending on temperatures, eggs can take 5 to 7 days to hatch.
Ladybug larvae are typically black with orange or yellow markings, and many have a series of fleshy projections on their backs. They are widest at their head and become more narrow down to their rear end. Larvae go through 4 instars or growth stages, shedding their skin between each one as they grow larger. The larval stage is typically completed in 10 to 14 days.
Once they’re fully grown, larvae will attach themselves to a solid surface to pupate. The pupae are round in shape and usually red to orange in color with several black spots. Pupation takes around 5 to 8 days.
Adult ladybugs emerge, and their exoskeleton will darken and harden in 1 to 2 days. They begin feeding and mating to start the next generation of ladybugs. Most adults will overwinter under leaf litter or other woody debris.
During winter, ladybug adults go into diapause which is a form of hibernation. The Asian lady beetle prefers to overwinter inside man-made structures. They will emerge the following spring and continue the life cycle.
Ladybug Benefits
Ladybugs are extremely beneficial to plants. They feed on many plant pests and can keep populations from growing to a size that would significantly impact plant health. Several species can be purchased online for release in gardens to help control pest populations. However, since they can fly they may simply leave the area they are released if there isn’t enough food available.
Ladybug Diet
Ladybugs feed during both the larvae and adult stages of their life cycle, and both have the same diet. They prefer feeding on aphids and can eat as many as 5,000 aphids in their life cycle. Ladybirds will feed on any small soft-bodied insect they can catch, including scale insects, mites, and whiteflies.
Some species feed on pollen, mushrooms, and mildew[1]. They can even be cannibals and eat other ladybugs. Ladybirds will also drink water, nectar, and the honeydew that aphids and scales leave behind.
While most ladybugs are good, there are a few ladybugs that eat plants instead of other insects. These include the Mexican bean beetle (Epilachna varivestis) and Squash beetles (Epilachna borealis). Mexican bean beetles will feed on lima beans, snap beans, cowpeas, black-eyed peas, and soybean, while squash beetles will feed on plants in the Cucurbitaceae family.
Types Of Ladybugs
There are more than 5,000 types of ladybugs so it’s no surprise that they come in all kinds of sizes and colors. They can be anywhere from 0.03 to 0.7 inches long and come in a wide variety of colors and patterns. Some species have only been found in a single state, while others are found on every continent except Antarctica.
Lady beetles can be red, orange, yellow, blue, pink, white, tan, or black. Some species have no spots, while others have intricate designs with zig-zags or even smiley faces on them. There are even some species, like the Asian lady beetle, which can be a variety of colors, which can make species identification tricky.
What Repels Ladybugs?
If you’re dealing with one of the few ladybugs that eat plants, there are a few things you can do to repel them. Potatoes, garlic, nasturtiums, rosemary, petunias, and marigolds have all been shown to repel the Mexican bean beetle. You can plant these repellants alongside plants you’re trying to protect to help reduce the chances of pest ladybugs eating your plants.
Native Ladybug vs Asian Lady Beetle
The most common native ladybug in North America is the nine-spotted lady beetle. Since its introduction in the 1950s, the non-native Asian lady beetle has taken over and is now the most common ladybug you’ll see.
While both are beneficial predators in your garden, the Asian lady beetle can be a pest since it likes to overwinter in homes. Some people will have hundreds or thousands of Asian lady beetles enter their homes in late fall. Below are a few other differences between these two species of ladybug.
| Native Ladybug | Asian Lady Beetle | |
| Common Name | Coccinella novemnotata | Harmonia axyridis |
| Adult Appearance | Red with nine black spots | Can be red, yellow, orange, or black with or without spots |
| Overwintering location | Under leaf litter or woody debris | Man-made structures |
Frequently Asked Questions
Since ladybugs have mandibles, they are capable of biting. However, the only know species to bite humans are the Asian lady beetle. Their bite is more of a pinch but they can break the skin if it is thin and delicate. Thankfully, ladybug bites don’t cause any long-term damage or transmit any diseases.
Ladybugs do have alkaloids in their hemolymph (blood) that are toxic when ingested. Different ladybug species produce different alkaloids in different concentrations. Luckily, there are no known deaths of humans or pets due to ingesting ladybugs. This is likely due to how terribly the alkaloids they produce taste and the large number you’d have to consume to cause death.
Since ladybug eyes don’t have a tapetum lucidum, they are unable to see in the dark. Even in the daytime, they see the world in black and white and can’t detect colors. They primarily use scents to move around the environment which they detect using their antennae.
There are many cultures that do consider ladybugs to be lucky. This could be linked to humans noticing that their presence tends to correlate with years of fewer insect pests on crops. In some cultures, the number of spots you count on a ladybug can predict how many years of good luck it will bring.
References:
[1] Sarwar, M. (2016). Food habits or preferences and protecting or encouraging of native ladybugs (Coleoptera: Coccinellidae). International Journal of Zoology Studies, 1(3), 13-18.