‘Dangerous’ invasive species, the Gypsy moth, discovered in Caledon

Written By JULIA LLOYD

When people first hear the word “gypsy,” many imagine a woman or man from the dark streets of Paris making a living by stealing and fortune telling. 

But — the Gypsy moths identified in some parts of Caledon earlier this summer are far from that depiction. 

In early summer of 2019, Gypsy moths were found infesting Heather Clark's backyard trees. 

“One day, we kind of looked at our trees and thought ‘oh my god, that is disgusting, what are we going to do?' So we looked up some pesticides and so on,” explained Clark. “But then, I was speaking with my brother-in-law, who is a naturalist with Ontario Parks, and he informed me that they are considered an invasive species and if they are as bad as I say, I should report them.” 

Gypsy moth caterpillars defoliate host trees. Their larvae feed voraciously, mostly on the leaves of leafy trees, but also evergreen levels. 

“During the larval stage a single Gypsy moth caterpillar can eat an average of one square metre of leaves,” reports the Government or Canada website. 

Clark still wanted to try and find a solution. She spoke with members of the Town of Caledon, who they appeared to have no clue what to do. Clark was informed that, if the trees are on her property, then the Town wasn't responsible. However, the Town told her to get an operation temperature to treat the issue on her property. 

“I have a feeling that the caterpillar doesn't know where my property line ends. There is no way my property is the only one in the area with this infestation,” said Clark. 

After calling the Town, Clark spoke with the Region of Peel, but they too didn't know what to do. Clark eventually found a hotline for people to report any sightings of Gypsy moths to the Ontario Invasive Species (OIS) hotline, found on the Invasive Species Awareness Program website. 

“I called them and they said that this is a high-pressure invasive species because they spread so fast,” explained Clark. 

The hotline told her to spray some-sort of pesticide on the infested trees, but when she did, less than half died. 

The OIS said they could not do anything until receiving more sightings of Gypsy moths from residents in Caledon. However, Clark said she has neighbours and friends who told her they have this problem and don't know what to do.

“We do not have an actual role in the management of the Gypsy moths. Local governments have historically undertaken management of Gypsy moths, i.e. The City of Toronto and Hamilton just completed their aerial sprays,” explained Kate Powell, terrestrial specialist with the invading species awareness program. 

Clark found information about a Gypsy moth infestation in Mississauga two years ago, and as a result, the City destroyed Gypsy moth's habitats by spraying pesticide treatment via helicopters. So, why can't that happen in Caledon? Clark questioned. 

“You know I just want to make people aware that if they do have these moths flying around in their backyard and there are millions of little caterpillar poops at the bottom of the tree, your backyard is infested,” said Clark.  “If they procreate, at this rate next year I'd lose half my trees.” 

While waiting for more people to report to the hotline, Clark put up posters, erecting them on all the mailboxes in her area to inform the public. 

“And, as I was doing that I discovered that a neighbour across the street a few houses down has them as well,” 

The Citizen asked for comment from the Mayor and he had this to say about the issue: 

“There is valuable information residents can access on how to identify and address Gypsy moth infestations through the Ontario Invading Species website and Credit Valley Conservation website,” said Mayor Allan Thompson. “The Town will continue to monitor the health of trees in our parks and public lands.” 

Gypsy moths are not native to Canada and are originally from Europe and Asia. They are mainly found in Ontario, Quebec and the Maritime provinces. The moths were accidently introduced in 1869 and have been in the country ever since. 

Since leaves play a huge role in food production for trees, by eliminating a tree's source of food, trees may die or become so weakened they get infested again. 

The Gypsy moths appear in July or August, the moth starts as a caterpillar (larvae) and change looks as they grow. Young caterpillars are black and brown about 6 cm in length. 

As they grow, bumps develop and long black hairs grow on their back. But, until this point, the caterpillar is not as recognizable to the human eye. The caterpillar changes colours to charcoal grey with a double row of blue and six red dots on its back. Feeding ends by early July, and mature caterpillars can be as long as 35 cm. Once they transform they mate and die - males in between 7 and 10 days and females after laying her eggs. 

If you are concerned that you may have these invasive species on your property, please contact the OIS hotline 1 800-563-7711 or email info@invadingspecies.com.