Invasive insect and crayfish detected in the Hamilton-Niagara area — here's what you can do

Canada is coming out of a "summer of invasives," Ontario's Invasive Species Centre (ISC) says, pointing to a number of concerning critters moving through southern Ontario that residents can help curb this fall. 

In October, the centre warned an insect that targets hemlock trees and disrupts forest ecosystems was newly present in Haldimand County, Ont. and Lincoln, Ont.

In Burlington, Ont., the provincial government is investigating the first-ever Canadian detection of a self-replicating crayfish.

And, in the Halton and Niagara regions, there have been recent reports of a fly that could devastate grape crops.

"It's definitely [been] the summer of invasives," the ISC's Liana Hryniewicz  told CBC Hamilton.

The centre, headquartered in Sault Ste. Marie, Ont., works with organizations throughout Canada on invasive species education and management. In a post on its website, the centre notes that "climate change can exacerbate and be exacerbated by" the spread of invasive species, in part due to warmer winters making it easier for insects and their eggs to survive. 

Hryniewicz says education is key to pushing back. "At the end of the day, just learning how to identify and report them, knowing what they are and being knowledgeable is always the first step."

Here's what the experts say you need to know.

Hemlock woolly adelgid

In October, the Canadian Food Inspection Agency (CFIA) said it detected an aphid-like insect known to harm hemlock trees and their ecosystems in Haldimand County and Lincoln. Officials detected it in Hamilton this spring. The hemlock woolly adelgid, which can kill trees when it feeds on the nutrient and water storage cells at the base of their needles, was first reported in British Columbia in the 1920s. 

It was detected and eradicated in Ontario locations in the mid-2010s, according to the ISC. But it's come back since, being detected in Niagara Falls and Wainfleet in 2019, Fort Erie in 2021, and Pelham and Grafton in 2022.

The CFIA restricts the movement of hemlock in Niagara Falls, Wainfleet and Fort Erie, and told CBC Hamilton via email that it might expand restrictions to other affected areas as part of its response to new detections. 

Vincent La Tassa at the ISC said the detection in Haldimand County is particularly concerning because Hemlock is popular in nurseries due to its many uses and there are a lot of horticulture businesses in the region that potentially use it. "This would be especially problematic for that [industry]."

La Tassa said people can detect an infestation by spotting small fuzzy-looking egg sacs on the base of needles on the most recent twigs. He adds individuals can report detections to the CFIA. 

The ISC recommends:

• Monitoring one's hemlock trees and keeping them healthy.
• Not to hang bird feeders on hemlock trees since birds can spread the insect.
• Only buy locally sourced firewood.

Marbled crayfish

In July, a spokesperson for the Ministry of Natural Resources and Forestry (MNRF) said marbled crayfish were found in a Burlington pond, marking the first time the freshwater creature has been found in the wild in Canada. 

"The full range and extent of the population is not currently known and is under active investigation," a ministry spokesperson told CBC Hamilton in an email. "Since its discovery in July, only a small number of individuals have been found."

Hryniewicz said the crayfish, also called marmokrebs, is thought to have originated in the German pet trade in the '90s before arriving in North America in the early 2000s. All known crayfish have been female, and they reproduce by cloning themselves, meaning one individual can establish an entire population. 

"At the end of the day, invasive species always have some type of ecologic, economic or social impact," Hryniewicz said. In this case, the crayfish can out-compete native species, alter the food chain, spread diseases and affect biodiversity.

Hryniewicz said there have been bans on owning and importing the crayfish, which can grow to about 13 centimetres long and has a marble pattern on its back and claws, in Ontario since 2015. 

The MNRF spokesperson said surveillance in Burlington will continue late into the fall. Those efforts include taking water samples to test for the crayfish's DNA, and setting traps. 

The ISC recommends:

• Refusing to buy or sell marbled crayfish.
• Not releasing them into bodies of water (the ISC points to a source on "humane" ways to kill the creature).

Spotted lanternfly

CFIA and ISA both said in recent months, individuals have reported seeing the spotted lanternfly in Oakville, Ont., and in Niagara.

The brightly coloured insect, which feeds on over 70 species of trees and plants, has established populations in the United States (including across the border from Ontario in New York State), where its destructive feeding has cost the economy tens of millions, according to local researchers. 

To date, despite those reports, the CFIA says it has not detected the lanternfly on this side of the border.

However, the reports "indicate the threat of introduction is real and reinforces the need to be vigilant as spotted lanternfly can be detected anywhere in Canada." When a sighting is reported, "CFIA follows up and increases surveillance efforts in the area."

If the lanternfly were to establish itself in Ontario, "that would be bad," Emily Posteraro, an ISC program development coordinator, says.

The insects can destroy the plants they feed on, and they excrete a sticky substance that causes mould growth. The lanternfly's taste for grapes has Niagara growers particularly worried. 

Posteraro said she's been in touch with municipalities around the recent sighting areas. The goal is to get ahead of the insect with education and early detection. At this point, "the focus is mainly on prevention," she said.

While adult lanternflies are distinctive, the egg masses they lay on hard surfaces are not. They look like dried mud and can survive through the winter, so officials warn people to keep an eye out for those on structures, tools and vehicles, especially if traveling to Canada from regions where the insect lives.

"If people understand the risk, care about the impact and know where to look and what to do, we have a better chance of keeping this pest out of Canada," CFIA said.

The ISC recommends:

• Scraping any egg masses one detects into a bag, saving them and contacing the CFIA.
• If one spots an adult insect, report it, take a photo or video and catch it if possible.
• Do not plant Tree of Heaven, the fly's favourite host tree.