Ladybugs 101: What Are Ladybugs?
by Alex Schnee | March 19, 2025 | Blog
If you’ve noticed small, round, colorful beetles in your garden or home, you’re likely encountering ladybugs. While these insects are often welcomed in gardens for their pest-controlling abilities, they can sometimes become a nuisance when they enter homes in large numbers. Understanding these beneficial insects can help you determine whether to encourage their presence or control their numbers.
What are ladybugs?
Ladybugs, also known as lady beetles or ladybird beetles, belong to the family Coccinellidae. These beneficial insects are known for their voracious appetite for garden pests, particularly aphids. A single ladybug can consume up to 5,000 aphids in its lifetime, making them valuable allies for gardeners and farmers.
While most species are predatory, feeding on plant-damaging insects, some feed on plant material or fungi. There are over 5,000 ladybug species worldwide, with approximately 500 species in North America.
What do ladybugs look like?
Ladybugs are small, dome-shaped beetles typically measuring 1/16 to 3/8 inch long. While the classic red ladybug with black spots is most familiar, they actually come in various colors including orange, yellow, brown, and black. Spot patterns vary widely by species—some have many spots, others have few or none, and some have stripes instead.
The Asian lady beetle, a common household invader, typically has an “M” or “W” marking on its pronotum (the area behind its head). All ladybugs have short legs and antennae, and a compact, rounded body shape.
Lifecycle of a ladybug
Ladybugs undergo complete metamorphosis with four distinct life stages. The cycle begins when females lay clusters of 10-50 small, yellow, oval eggs near aphid colonies or other food sources. These eggs typically hatch within 3-5 days, depending on temperature.
The larvae that emerge look nothing like adult ladybugs—they’re elongated, somewhat alligator-shaped, and often black with orange or yellow markings. These predatory larvae are voracious feeders, consuming more pests than adults in some cases. They grow rapidly, molting several times over a 2-3 week period.
After reaching full size, larvae attach themselves to a leaf or other surface and enter the pupal stage. Within the pupal case, the transformation to adult form occurs over approximately 7-10 days. When adults emerge, they’re pale and soft but soon develop their characteristic coloration and hardened wing covers.
The entire lifecycle from egg to adult typically takes 3-4 weeks under favorable conditions. Adult ladybugs can live for up to a year, with many species producing multiple generations annually in warmer climates.
Are ladybugs dangerous?
Ladybugs pose minimal risk to humans or pets. They don’t sting, transmit diseases, or cause structural damage. Some species can release a yellowish defensive fluid that may stain surfaces, and in rare cases, cause minor skin irritation.
A small percentage of people may develop allergic reactions to ladybugs, typically resulting in respiratory symptoms or eye irritation. However, these reactions are uncommon, and for most people, ladybugs are completely harmless.
Can ladybugs survive winter?
Ladybugs have developed effective survival strategies for winter. Many species enter a dormant state called diapause, similar to hibernation. They often gather in large groups under leaves, rocks, or bark for protection and warmth.
Some species, particularly the Asian lady beetle, seek shelter in buildings, clustering in wall voids, attics, and around windows. During this period, they live off stored fat reserves, becoming active again when temperatures rise in spring.
What type of plants do ladybugs like to eat?
Contrary to what many believe, most adult ladybugs don’t actually eat plants. They’re primarily predatory, feeding on soft-bodied insects like aphids, scale insects, mites, and insect eggs. Some species supplement their diet with pollen and nectar, particularly when prey is scarce. Plants that attract ladybugs include members of the composite family (daisies, yarrow, cosmos) and umbellifers (dill, fennel, angelica).
Only a few ladybug species are herbivorous, with the Mexican bean beetle and squash beetle being exceptions that feed on leaves as both larvae and adults. Gardeners often intentionally plant specific flowers to attract ladybugs, though it’s primarily the presence of prey insects that draws them to plants.
Are ladybugs harmful to cats?
Ladybugs generally pose no significant threat to cats. If a cat eats a ladybug, the defensive chemicals might cause temporary discomfort, resulting in excessive drooling or mouth irritation, but serious harm is unlikely. The primary risk comes from Asian lady beetles, which can cause more pronounced irritation due to their stronger defensive secretions. In very rare cases, a cat might develop an allergic reaction after consuming multiple ladybugs.
Ladybugs are not toxic to cats, and any discomfort usually resolves quickly without treatment. However, if your cat shows signs of distress after encountering ladybugs, such as persistent drooling, difficulty eating, or swelling around the mouth, consulting a veterinarian is advisable.
How to know if you have a ladybug infestation
While individual ladybugs in your garden are beneficial, large indoor aggregations can constitute an infestation. The most obvious sign is seeing clusters of ladybugs gathering on windows, ceilings, and walls, particularly on sunny days during fall and winter. These clusters typically form on the south or southwest sides of buildings where it’s warmest.
You might notice ladybugs emerging from wall voids, light fixtures, or ceiling corners. Their presence is most noticeable during temperature fluctuations, especially when heating systems activate in fall or during warm winter days. A faint, musty odor might be detectable in areas with large aggregations due to their defensive secretions. Look for staining on walls or surfaces where ladybugs have released their defensive fluids.
How to prevent a ladybug infestation
Preventing ladybugs from entering your home starts with sealing potential entry points. Inspect your home’s exterior for cracks and crevices around windows, doors, utility entries, vents, and siding. Seal these openings with caulk, weather stripping, or appropriate repair materials. Pay particular attention to the south and southwest sides of your home, where ladybugs most commonly gather before entering.
Install or repair screens on windows, vents, and other openings and consider using finer mesh screens, as the Asian lady beetle can squeeze through standard screening. Replace damaged door sweeps and ensure that doors and windows close tightly. Consider treating exterior walls, especially on sunny sides of buildings, with appropriate residual insecticides in late summer or early fall, before ladybugs begin seeking winter shelter.
How to get rid of a ladybug infestation
Addressing a ladybug infestation requires a combination of physical removal and prevention methods. For immediate relief, vacuum up ladybugs using a vacuum cleaner with a hose attachment. Empty the vacuum bag or canister into a sealed plastic bag and dispose of it outside to prevent escapees. Avoid crushing ladybugs, as this can release their defensive fluids, potentially causing stains and odors.
Light traps can be effective for drawing ladybugs away from living spaces. Simply place a light source over a bowl of soapy water—ladybugs attracted to the light fall into the water. Various commercial traps are also available specifically designed for ladybugs. Insecticidal dust can be applied in wall voids and attic spaces where ladybugs gather, though this should be done cautiously to avoid contaminating living areas.
For severe infestations, professional pest control services offer the most effective solutions. These experts can identify entry points you might have missed and implement targeted treatment strategies that address both current populations and prevent future invasions. They have access to professional-grade products and specialized equipment for treating wall voids and other hiding spots that are difficult to reach with DIY methods.
Professional pest control technicians can also help develop a prevention plan tailored to your specific situation, addressing the unique characteristics of your home and property. If you’re experiencing recurring ladybug invasions each year, a professional consultation is particularly valuable for breaking this cycle.
When to Call a Professional
If you’re dealing with persistent ladybug problems, you’ll want to contact our featured providers – like Terminix – today for a free inspection and customized treatment plan! Our experts will help you manage ladybug invasions while preserving these beneficial insects in your garden where they belong.
