Beneficial Insect — Ladybugs (Lady Beetles)
Common Name: Ladybugs
Ladybugs share a characteristic shape – a dome-shaped back and a flat underside. Ladybug
elytra display bold colors and markings, usually red, orange, or yellow with black spots.
Ladybugs walk on short legs, which tuck away under the body. Their short antennae form a
slight club at the end. The ladybug's head is almost hidden beneath a large pronotum,
a prominent plate-like structure that covers the top of the thorax. Ladybug mouthparts are modified
Male ladybugs have more hair-like structures called setae on the last segment of their abdomen.
The have large prominent bands on the underside between the segments with a notch on the posterior
Female ladybugs are usually slightly larger than males. Female ladybugs do not have lots of setae, just a few on the last segment on the underside of their
abdomen. They do not have large prominent bands between the segments or a notch on the rounded
Test your knowledge:
Most ladybugs are predators with ravenous appetites for aphids and other soft-bodied
insects. Adult ladybugs will eat several hundred aphids before mating and laying eggs on the
infested plants. Ladybug larvae feed on aphids as well.
Ladybugs lay eggs in clusters, mainly on the underside of leaves, and usually on or near plants with a
sufficient population of aphids, scales or mealybugs.
Ladybug eggs look similar to small jelly beans and are arranged in clusters. See image opposite of an
adult female ladybug laying a cluster of eggs.
After 3 – 12 days, larvae of ladybugs hatch from the eggs. Larvae are elongated and look similar to a
tiny alligator. Their bodies are covered with bristles. Some larvae have black spots or bands of bright
color which will eventually form to create their adult spots. Image below is a typical example of a
These tiny larvae have an insatiable appetite during this stage - single larvae devour hundreds of
aphids. They not only dine on aphids, but they also eat other soft-bodied insects including scale
insects, mites, adelgids, and insect eggs. They cannot fly at this stage so will seek out food locally.
They may also eat eggs of other species too.
After hatching out, the larva is in its first instar (a phase between two periods of molting). It eats and
eats until it grows in size, breaks out of its shell (cuticle) and molts. Usually, a larva molts four times in
total before it becomes a pupa. Now, this larva will attach itself to leaf when it is ready to pupate.
After the larval stage, comes the pupa stage. Pupae are usually yellow or orange with dark markings.
In this stage pupa is still, attached to a leaf, its body experiences striking change. Pupal stage may last
for 3 to 12 days, depending upon the species, temperature and environment also play a factor. The
image shows a ladybug in mid pupa progress.
As soon as the metamorphosis is complete, a beautiful soft bodied adult ladybug emerges. This
recently emerged ladybug does not look like the one we see in our gardens. It appears pale, golden or
even pinkish when only a couple of hours old.
Ladybugs reproduce sexually. The exact ladybug courting ritual is not precisely known. They all emit
pheromones to help attract a suitable mate and begin the process of mating. As soon as male finds a
suitable mating partner he mounts on top of her from behind and grips tightly with his front four legs.
This process of copulating can last for up to two hours. Female ladybugs can have more than one
partner while mating. She can store sperm for up to 3 months before she’s ready to lay eggs.
A female ladybug lays her eggs where there’s an abundant supply of food, often near to colonies of
aphids. If food availability is insufficient, she’ll lay both fertilized and unfertilized eggs alongside each
other, so that larvae, when hatched, can feed on unfertilized eggs to satisfy their body’s immediate
Their gestation period lasts for 4 – 7 weeks. The number of offspring depends upon the type of
species but eggs are laid usually in clusters of 10-15 eggs, usually 1 – 2 weeks.
When purchasing lady beetles, inspect the container and make sure almost all beetles are alive. Lady
beetles purchased from primary suppliers (those who obtain beetles directly from collectors) may
be healthier than those held in stores for several weeks.
Lady beetles need to be kept refrigerated until they are released. Live lady beetles on display in stores
are attractive for customers, but beetles left out at room temperature rapidly deteriorate. Also, lady
beetles are often dehydrated and need water, especially if they have been held at room temperature,
even for a few hours. Stores or gardeners are advised to mist lady beetles with water in a squirt bottle
before placing them in the refrigerator for storage, making sure not to let water puddle in containers.
High numbers of lady beetles are required to control aphids. One large, heavily infested rose bush in
the landscape required two applications of about 1,500 lady beetles each, spaced a week apart. Most
packages sold in stores contain only enough lady beetles to treat one aphid-infested shrub or a few
There is no point in releasing them on plants with few aphids. Lady beetles are voracious aphid feeders
and an adult beetle will eat 50 or more aphids a day. The convergent lady beetle, which is the species
sold for release, feeds almost entirely on aphids and will not remain on plants with low aphid populations
and will not control other garden pests.
Lady beetles will fly away almost immediately if released during the heat of the day or where the sun is
shining, so wait until evening to release them. Spray a fine mist of water on the plants before the release.
Giving beetles a drink may keep them around longer. Place beetles at the base of plants or in the crotches
of low branches. Lady beetles will crawl higher into the plant in search of aphids. Once lady beetles begin
to fly, they are likely to fly a substantial distance, often outside the boundaries of your garden.
Even when released with care, lady beetles will fly away within a few days. About 95% of released beetles
fly away within 48 hours. The remainder were gone within 4 or 5 days. Lady beetles are unlikely to lay eggs
on the plants they are released on. If aphids return a week or two later, gardeners will need to release more
lady beetles, hose aphids off with water, use insecticidal soap sprays, or wait for other native aphid natural enemies to fly in.
Almost all ladybugs sold in the US are wild harvested typically in California's Eastern Sierras. Ladybug
harvesters collect them in the fall during hibernation and sell them during the spring gardening season.
It's a lucrative business but it's technically illegal and the reason is complicated.
Wild caught ladybugs that you purchased could possibly carry parasites or diseases and releasing them
into your garden could result in you introducing them into your area.