Venomous joro spider not likely to fly to Quebec, but brilliant invasive lanternfly is coming

Recent concern about a flying, yellow, invasive spider the size of a human hand entering Quebec is unfounded, according to experts in the field -- while a pretty, spotted moth is much greater concern.

Joro spiders (Trichonephila clavata) are not native to North America and are spreading in the southern United States. However, the species native to Asia is not likely to arrive in Canada anytime soon.

The same can not be said for the invasive spotted lanternfly.

"It's pretty much all over the United States now," said Andre Philippe Drapeau Picard, an entomological information officer at the Montreal Insectarium. "The federal authorities are looking at this particular species because it's a question of time because it gets before it gets here."

The lanternflies, Drapeau Picard said, suck the sap from different plants, including grapevines, causing massive distress for wine growers.

Recent distress about the large brilliant joro spiders, however, is misplaced, said Drapeau Picard.

He explained that a 2023 Royal Entomological Society study showed that suitable joro spider habitats exist in most parts of the eastern United States and some southern regions of Ontario and Quebec.

• Meet the joro, a flying spider scientists say could someday spread to Canada

However, the spiders are unlikely to show up north of the border in the near future.

"They looked at the range in Asia, and they applied that to North America and they said, 'Well, in that area, that spider could survive,' but it's not because it could survive there that it will end up there," he said.

The joro spider showed up in Georgia about a decade ago and has been spreading in the southern United States since.

According to the site jorowatch.org, the most northern spider sightings were in Maryland and Michigan.

Part of the concern about their spread is due to their ability to travel vast distances when young.

Though they're not able to fly, very young Joro spiders can "balloon" by climbing onto high structures, secreting a thin line of silk, and jump.

"They wait for the wind... And they can travel several kilometres to well over 100 kilometres in some cases," said Drapeau Picard.

He said a joro spider could wind up here in the summer by ballooning or hitching a ride with a human, but it would not last long.

"Even though it could end up here for a summer by ballooning, our winters are cold enough to kill those who would have settled here," said Drapeau Picard. "We are not expecting that species to become established in Canada in the short term.

"Of course, in the context of climate change, the winters are getting warmer, so more species or more exotic species will be able to settle here to become established, but we are talking decades."

Joro spiders also don't bite humans or animals.

What should I do?

The spotted lanternfly (Lycorma delicatula), however, is a potential threat to the grape, fruit tree and forestry industries in Canada, according to the government of Canada.

It is native to Asia and was first detected in 2014 in Pennsylvania.

Drapeau Picard said that once a species arrives, the best thing the public can do is monitor it, so scientists know where they are and when they arrived.

"So we can act at a very precise scale to destroy them and try to mitigate the impacts they have," he said. "Really, there is not much we can do in the long run because they will arrive here, so prevention is the best thing. People can keep an eye open and share their findings if they see a bug.

The site and app iNaturalist is a useful site for amateurs to document what they see, and is very useful for experts in the field to track the spread of invasive species.

If spotted, you should also contact the Canadian Food Inspection Agency (CFIA).

Also, spider hate is unhelpful, Drapeau Picard said.

"Most people don't like them," he said. "Unfortunately, because they're highly important for ecosystem health and for our crops, too. It's been documented that they are very badly represented in the media."