Asian lady beetles resume crawl around Maritimes

While much of New Brunswick grapples with high water levels, a flood of a stinkier sort is also underway.

Asian lady beetles, known for their bite and smell, are returning to fields, cars and homes again this year.

"I think we're not going to be seeing any fewer of these invasive ladybird beetles," said Chandra Moffat, an entomologist based in Fredericton. 

"We'll only be seeing more and more of them."

The invasive species is native to Russia and Asia. And though present in North America since the early 1900s, the insect only crossed the border into Canada in the last 15 to 20 years.

The lady beetle's preferred food is the soybean aphid, and the little bug's expansion can be tracked alongside the spread of the plant and its pest.

"I don't think it would ever get really out of control,"  Moffat said of the beetle in the Maritimes. "Soy is a minor crop, but a growing crop."

M-shaped marker

To the untrained eye, Moffat said, it's hard to tell the difference between the biters and the peaceful ladybugs native to New Brunswick.

Native ladybugs are solitary creatures, while the invaders from the distant east stick together, she said.

"One of the more distinguishing features is on what's called the pronotum, the black part," the entomologist said. "There's a white, sort of M-shaped marking. It's not on every individual but most of them."

When threatened, the beetles bend their limbs and excrete a brown substance with a distinct, unpleasant odour.

Best to vacuum

Moffat said it's best to seal cracks in your home before the bugs get in, but if that's not possible, vacuum them up.

To avoid getting beetles into your vacuum bag, create a pantyhose attachment for the end of the vacuum hose. The toe end of the nylon stocking can be stuffed into the hose and the open end held in place on the outside of the hose with an elastic band. 

After vacuuming, put the sock of beetles into bags and stick them in the freezer for later disposal.

"If they get into your vacuum cleaner bag, they're not going to die from being vacuumed up, so they'll probably do this 'reflexive bleeding' and will be releasing this really smelly substance into your vacuum cleaner," Moffat told Information Morning Moncton.

Apart from the smell and a messy cleanup, the beetle isn't a danger to humans.

One group of New Brunswickers might even enjoy the aphid-eaters: gardeners.

"Pest management companies in the past in North America have sold them as beneficial insects," Moffat said.  

But native lady beetles won't join in with the same enthusiasm. According to Moffats, the Asian lady beetle can out compete local populations.

"They actually carry a parasite that they themselves are immune to but can affect native ladybird populations."