How to Tell the Difference Between Good Ladybugs and Bad Ladybugs
They may look similar, but one helps control unwanted insects in the garden while the other is part of the problem. Here's how to tell these look-alike bugs apart.
If you see a hard red shell with black spots, you probably automatically assume it's a friendly ladybug. But those little bugs in your garden could actually be a type of beetle that infiltrates your home, bites, and produce a foul-smelling odor similar to stink bugs. While Asian lady beetles share some similarities with ladybugs, they're becoming a problem for many homeowners and gardeners, and are overtaking the native ladybug population. If you can tell the difference between the two beetles, you might be able to stop an annoying problem before it starts.
These beetles are beneficial to your garden and harmless to humans. They don't bite and consume garden pests like aphids and scale insects. When the weather cools down, ladybugs seek shelter outside and they don't congregate in large numbers.
You can identify a ladybug by its markings and size. They have bright, cherry-red shells with black spots, and their heads are black with small white "cheeks." Ladybugs are typically rounder and smaller than Asian lady beetles if you look at them side-by-side.
Telling Asian Lady Beetles from Ladybugs
To tell the difference between an Asian lady beetle and a ladybug, look at the spot where the head meets the wings. If the bug has a small white 'M' marking in that spot, that's a telltale sign you're dealing with an invasive species. They also have larger white "cheek" markings and have more white on their heads overall. Their shell color can range from light orange to bright red, so most will have a similar color to a ladybug.
Asian lady beetles are known to sneak into your home through cracks or holes when it gets cold outside and congregate on siding, doors, and windows. They're more aggressive than ladybugs and bite by scraping the skin they land on. If they feel threatened, they'll excrete a foul-smelling yellow liquid from their legs that can stain surfaces and trigger allergic reactions.
While it isn't common, Asian lady beetles can infest dogs' mouths. Since they look for a warm shelter in winter, they attach to the roof of the mouths of dogs. While this won't always mean a trip to the emergency vet, it will still be very uncomfortable and unpleasant for them. If they swallow the beetles, the yellow liquid can burn the dog's mouth or gastrointestinal tract.
How to Control Asian Lady Beetles
The best way to keep Asian lady beetles out of your home is by sealing and patching potential entrance points. Close up any gaps around windows, doors, and siding to minimize risk. If they do get into your home, try not to squash them, or they'll release their smelly yellow liquid. The best way to avoid odor and stains is to vacuum them and empty the vacuum when you're done. Contain them in a sealed bag before tossing into the trash so they can't crawl out.
Outdoors, you can clear them off the areas the beetles usually congregate and scrub down the area with soapy water; they most likely won't return because the soap smell overpowers the pheromones that attract more beetles to the location. They especially don't like the scent of citrus, cloves, or bay leaves.