What you need to know and how to report them
While hemlock woolly adelgid and spotted lanternfly haven’t been found in the Credit River Watershed yet, there is still a risk of invasion. Hemlock woolly adelgid have been found in neighbouring watersheds in the Golden Horseshoe and spotted lanternfly have been recorded in Essex County, Ontario.
These invasive insects can cause significant ecological and economic damage. They threaten native forests and wildlife habitat, reduce the enjoyment of outdoor spaces and impact industries that rely on healthy trees and plants.
As you spend time on your property this summer, keep an eye out for signs of these harmful critters. Here’s what to look for and what to do if you find them:
Invasive Species Spotting: What to Look For
Hemlock Woolly Adelgid
Hemlock woolly adelgid is easiest to identify during its egg stage. This insect lays their eggs on the base of hemlock needles and protects them with white, woolly egg sacs resembling the small cotton bud of a cotton swab, like those photographed above.
Egg masses begin to appear in late fall and throughout the winter, although snow can make it challenging to spot them. The easiest time to find them is spring after the snow is gone, but before they hatch.
An adult hemlock woolly adelgid by Kelly Oten, North Carolina State University, bugwood.org.
An aphid-like insect, hemlock woolly adelgid and its eggs are tiny and difficult to spot with the naked eye. Their presence may be identified from damage to your hemlock trees including needle loss, thinning tree crowns and greying foliage.
Spotted Lanternfly
Spotted lanternflies are showier than hemlock woolly adelgid. It’s easiest to identify adults with their distinctive pinkish-grey, black-spotted wings and bright red underwings.
In spring, nymphs hatch from grey mud-like egg masses that can be found on almost any hard surface, including tree trunks, buildings and shipping pallets. Young nymphs are small, wingless and black with white spots, while older nymphs are bright red with black and white spots. The four stages of nymph development are active from May to July, before they develop into winged adults.
Nymphs and adults feed on more than 100 plant species. Although they prefer the invasive tree-of-heaven, spotted lanternflies will also feed on black walnut, native and cultivated grapevines, willows, maples and many other plants.
An adult spotted lanternfly.
As they feed, spotted lanternfly nymphs and adults produce a sticky sugary substance called honeydew, which can leave behind a sooty mould and attract insects such as bees and wasps. Severe infestations can cause damage or kill grapevines and fruit trees.
What to Do If You Spot These Invasive Insects
Use iNaturalist to identify the spotted lanternfly or hemlock woolly adelgid, then report evidence or sightings of either species to the Canadian Food Inspection Agency (CFIA). For hemlock woolly adelgid, take photos of the egg masses and pass along the location to the CFIA.
For spotted lanternfly capture the insect, if possible, and place it in a plastic container and store it in the freezer. If the insect cannot be captured or a sample cannot be taken, take as many photos from multiple angles to support accurate identification. After you report it to the CFIA, they will contact you with the next steps to take with the captured insect or sample.
Do Your Part
Although these invasive species have not yet been detected in our watershed, you can help prevent their spread:
- Monitor for hemlock woolly adelgid while enjoying the outdoors with the Hemlock Woolly Adelgid Monitoring Network.
- Brush off footwear, wash clothing, gear and even car tires, after each hike or outdoor activity.
- Avoid moving firewood and purchase it locally wherever you plan to have a fire.
- Learn more about invasive species through the Invasive Species Centre.
- Take action on invasive species by controlling them on your property. Funding is available through our Landowner Action Fund.
Together, we can help protect the health and resilience of our watershed.