Ladybugs, also known as ladybirds or lady beetles, can become a serious nuisance, especially when they pop up inside in large numbers.
When approaching a ladybug issue, it is important to keep in mind that lady beetles are considered largely beneficial. They eat a number of harmful insects (especially plant-damaging pests like aphids), they do not reproduce indoors, and they do not attack food, clothing, or wooden items. (Some gardeners even try to attract ladybugs.) It is not ideal to kill lady beetles, and this should be avoided whenever possible.
It is when certain types of lady beetles move inside that they can become a problem. Interior lady beetle infestations can cause stains to walls, fabrics, and paper products, as well as a smell issue. The lady beetles that infest the interior of homes are also more likely to bite. While their bites are rare and are not likely to cause harm, they can be irritating.
What should you do if ladybugs start showing up in large numbers in or around your home, and how can you safely get rid of ladybugs inside? Read on for everything you need to know about dealing with ladybugs indoors.
What Does a Ladybug Look Like?
Most people have a pretty good idea of what a standard ladybug looks like: small, red, and round with white markings on the head and black spots on its back. It is important to note, however, that with more than 5,000 species of ladybugs worldwide, you're likely not always dealing with the same type of ladybug.
In many areas throughout the world, beneficial native ladybirds are losing their food sources to the much more invasive and aggressive Asian lady beetle, also known as the Harlequin ladybird. Luckily, there are a number of ways to tell these pests apart. Start by determining which lady beetle you are dealing with, then formulate a plan of control.
Harlequin Ladybirds (Asian Lady Beetles)
These pests range widely in color and markings. Some Asian lady beetles are yellow or tan, others are orange, some are deep red. The number of spots on a Harlequin ladybird varies; some have several black spots on their backs while others have no spots at all.
The most distinguishing feature of these pests is the "M" or "W" marking they have on the white colored area behind their head. These insects are slightly larger than most native ladybird species with a more oblong shape. Their faces and mouths are more pointy than native ladybirds, and they can bite if provoked.
While these beetles also eat nuisance pests, they eat them so ravenously and in such large numbers that they compromise the food sources of beneficial native ladybugs. Harlequin ladybirds prefer to overwinter inside in large numbers, often seeking out spaces inside homes where they can hide during cold months. They will sometimes show up in the thousands, covering the walls and floors of certain houses.
Worth mentioning is that they also secrete a terrible-smelling, yellowish-brown liquid from their leg joints when threatened. This secretion can cause odor as well as staining when released inside. Some people may also have an allergic reaction when exposed to dead Asian lady beetles indoors.
Some studies suggest that infestations of Asian lady beetles inside can cause a number of allergic responses, including eye irritation, allergies, and asthma.
Native ladybirds are typically red or orange in color. They are small, round, and have a mostly black head with small white markings on their "cheeks," and their "snout" is far stubbier and less pointed than the Asian lady beetle. Native ladybirds often have a distinct number of spots with some varieties having exactly seven or nine spots depending on the species.
Native ladybugs are harmless and incredibly beneficial, given that they consume irritating and harmful garden pests. Native ladybirds shelter outdoors when the weather becomes cold and do not tend to congregate in excessively large numbers.
Slightly larger and oblong
Color ranges between brown, yellow, red, and orange
Varied spots and markings, sometimes none at all
'M' or 'W' shape on the head
Longer, pointier face and mouth
Overwinter inside in large numbers
Slightly smaller and round
Generally red or orange in color
Species have specific markings
Small white spots on their 'cheeks'
Shorter, rounder face and mouth
Overwinter outside in smaller numbers
3 Ways to Get Rid of Ladybugs
Remember that native ladybugs are incredibly beneficial and are not likely to overwinter inside in large numbers. Whenever possible, is is best to leave ladybugs outside, where they are an important part of the ecosystem and eat plant-damaging garden pests. If, however, you find large numbers of Harlequin ladybirds inside, especially just before winter, you may need to take steps to get rid of them.
Seal Them Out
An entry point is an access route that pests are using to enter your space. The most permanent way of dealing with overwintering ladybugs in your home is to seal them out, and the best time to do this is going to be late spring or early summer, before these pesky bugs begin looking for a place to overwinter.
- Seal up large holes, ideally with a metal mesh or concrete filler. Foam can be used in some instances but is easily damaged (especially by rodents), so use with caution.
- Small cracks around window frames, pipes, cables, and doors should be sealed with some sort of caulk sealant.
- Replace damaged window screens.
- Check the screens behind attic vents and replace if damaged.
- Place tight-fitting rubber sweeps and foam weather stripping on doors.
Vacuum Them Up
When you find large numbers of overwintering ladybugs inside, grab your vacuum and get to work! It may seem simple, but this is a great way to remove these pests from inside your home.
In any pest control program, chemical repellents and sprays should be used as a last resort and in tandem with other control methods. Chemical should never be a first resort, and it is never a primary defense.
Indoor treatments are not typically ideal for overwintering ladybugs, especially once the issue is already established inside. Vacuuming up the pests is more sanitary, it reduces your exposure to pesticides, and it reduces chemical residues left behind in your living space. Preventative measures such as sealing up entry points and vacuuming are much safer and effective.
If you live on a property that has recurring and severe overwintering ladybug issues, professional pest control companies can perform an "overwintering insect treatment" around your home to deter the pests from entering when the cold weather rolls around. This treatment is applied outside to the areas where pests are likely to enter, such as around the foundation, door frames and window frames.
Signs of a Ladybug Problem
During the autumn months, invasive Harlequin ladybirds (Asian lady beetles) are looking for places that offer protection from the winter weather. This can include homes and buildings, which are most commonly invaded in the months of September through November.
Lady beetle flights are typically noted on sunny days where temperatures are at least in the mid-sixties, just after a period of cold weather. They are especially drawn to light including the light reflected off of white paint. Ladybugs will congregate in large number on the outside of buildings, especially southwestern facing areas where the afternoon sun is strong and warm. When inside, they can also accumulate in window sills where they are drawn to the warmth and light of the sun.
What Causes Ladybugs?
Native ladybirds are common all over the world, but Harlequin ladybirds are, too. If you live in a home near fields or wooded areas, you are at a higher risk of having these pests invade your home when winter comes. You may also see them emerging in the spring when overwintering is finished.
Places you may find overwintering or emerging Harlequin ladybirds include:
- Crevices in wall voids or attics
- Illuminated surfaces, such as sunny, southwest facing sides of buildings
- Contrasting light and dark paint colors on the outside of the home, such as white paint with black trim
- Cracks around window frames, door frames and behind siding
- Gaps behind baseboards
When to Call a Pro
Most homeowners can handle an interior ladybug issue on their own with a vacuum and some caulking, but if you have noticed a consistent, seasonal overwintering ladybug issue in your home, it may be worth calling a local Integrated Pest Management specialist to assist you.
If you are interested in an overwintering insect treatment, be sure to schedule it for the late summer or early fall, before insects start their overwintering behaviors. If you wait too long, the treatment will not be effective.
Will ladybugs go away on their own?
Ladybugs should be left alone outside as they are incredibly beneficial, and issues that arise inside will go away on their own with the changing of the seasons. In severe overwintering ladybug situations, steps can be taken to reduce the severity of the issue, but the issue is seasonal and will resolve when the warmer weather comes and insects head back outside.
Do ladybugs bite?
Some species of ladybugs, particularly the Harlequin ladybird (or Asian ladybeetle) can bite if threatened, but they rarely do. Their bite feels like a pinch and can become slightly irritated, especially in sensitive individuals, but generally speaking, their bite is harmless.
Where do ladybugs come from?
There are various species of ladybugs world wide. Ladybugs typically live at peace with humans, minding their business outside and not causing many serious issues. The main problem is when large numbers of invasive Harlequin ladybirds overwinter inside homes and structures. Large numbers of these insects can be incredibly bothersome inside homes and businesses.