Why are so many ladybugs trying to get into your home right now?

If you think there are a lot more ladybugs in Toronto than usual, you’re right — and also wrong.

While they’re making their presence felt inside homes and garages right now, the sudden increase in ladybug sightings is not an indication of increased numbers.

“It’s called the Halloween Beetle, but it’s also called the Asian multicoloured Ladybird Beetle, and its scientific name is Harmonia Axyridis,” explains Antonia Guidotti, entomology technician at the Royal Ontario Museum.

They’re looking to get inside at this time of year for the same reason everyone else is — it’s cold.

“These ladybird beetles really need a warmer place [to overwinter]. So they’re coming into our homes or garages and they’re looking for the south side of the building because that’s a little bit warmer and they congregate when they come indoors to hibernate,” she explains.

That’s partially because they are not native to Canada but were deliberately introduced in the 1970s.

“In the late seventies there were a lot of soybean aphids that were on crops and so they introduced these ladybird beetles to eat the aphids,” says Guidotti.

“They were first introduced as an agricultural biocontrol agent,” adds David Dutkiewicz, entomology technician at the Invasive Species Centre in Sault Ste. Marie.

“So they have actually helped play a role in prevention of [the use of] pesticides.”

There are more than 80 recorded species of ladybird beetles in Ontario. While the Halloween variety is competing with native species and by some accounts, outnumbering them, they are not considered invasive.

“Invasive is a term that’s used for something that’s really detrimental to our environment. And these beetles, while being non-native and being very much everywhere, they’re still beneficial,” says Guidotti.

They’re mostly harmless

Halloween beetles are fairly harmless and will not cause any damage to your home or house plants.

However, they’re not as well-tempered as the local variety of ladybugs.

“Our native species, they don’t tend to bite. Usually, you can have them on your hand. But if you were actually playing with the Asian ladybug species, it’s just a small pinch — it’s not a very harmful bite,” says Dutkiewicz.

“They may bite and there are reports of them biting, but they don’t bite all the time. You don’t want to handle them, just let them be, let them do their job,” adds Guidotti.

In addition, they tend to release a yellow liquid when startled or squished that stains fabrics and smells somewhat foul — a few other reasons why they’re not the best house guests and most people would rather not board them for the winter.

How to identify Halloween beetles

Halloween beetles have a few distinct features compared to other ladybird beetles:

• They come in a variety of colours ranging from pale yellow to orange and red
• They do not have a fixed amount of spots and the number can be anything from two to 20
• They have a distinctive black M or W pattern just above the head that’s not present in native species
• They may bite when handled

What to do if you find Halloween beetles in your home

There are only two things to do if you find these bugs in your home and want to get rid of them — relocate or eliminate.

Guidotti suggests gently sweeping them into a dustpan and placing them back outside so they can find a cozy spot elsewhere.

Dutkiewicz says if you’re looking to dispose of them entirely, it’s best not to squish or vacuum them as they will release that stinky, staining liquid mentioned above.

Like with many other insects that may be considered pests, he suggests mixing up some soap and water in a bottle or jar and scraping or flicking the unwanted bugs into the container.

If you don’t mind having them in your home, Dutkiewicz says it’s useful to note that they might keep coming back.

“If they found a place that they really like they can actually release a pheromone … just to sort of alert them that, ‘oh, this is a safe place. I can come back here again,'” he says.

“It will sort of tell other ladybugs that this is a good spot [too].”

If you’d prefer not to extend your hospitality that far, Dutkiewicz suggests wiping down any surfaces the bugs may have been on to get rid of the pheromone.