Environmental Impacts – invasive species can reduce biodiversity and threaten native species by outcompeting native species for resources such as space, light, water and food. Invasive species can also prey on native species or carry diseases and parasites.

Economic Impacts – invasive species affect agricultural productivity, forestry, public utility operations, native fisheries, and can damage buildings and infrastructure. Additionally, there are direct costs associated with invasive species control efforts.

Social Impacts – invasive species threaten recreational and outdoor activities such as hiking, swimming, fishing, boating, and visiting local parks.

Unraveling the Pathways: How Invasive Species Spread Across Regions

Discover the pathways through which invasive species spread from one area to another. Learn about human-mediated channels like trail use, boating, fishing, pet release, accidental escapees, firewood movement, horticulture, shipping, and canals. Understand the significance of these pathways in the rapid expansion of invasive species to minimize their impact on our ecosystems.

The European fire ant is a non-native, invasive species that is a nuisance pest for people and animals. These insects defend their territory by stinging anything they see as a threat. The sting feels similar to that of a bee or wasp. In rare cases, a sting may cause anaphylactic shock, requiring immediate medical attention.

The European fire ant prefers a warm, moist outdoor habitat for nesting and foraging. Reported infestations in Whitby are limited to natural areas and properties that back onto them.

Town response

Currently there are no effective, long-term methods for controlling the European fire ant in parks and natural areas.

Staying safe

When travelling through parks and natural areas, follow these tips to protect yourself from European fire ants:

• Stay on designated pathways and trails
• Wear covered footwear and long pants
• Keep dogs leashed and on designated trails

On private property, follow these steps to control European fire ants:

• Remove potential nest sites, such as leaves, logs and other debris, from your property
• Reduce moist conditions by decreasing irrigation and increasing exposure to the sun (e.g., mow tall grass, prune overhanging tree and shrub branches)
• Carefully inspect all plant and nursery materials, including plants, trees, soil, compost, wood chips and logs, before bringing them onto your property
• Call a professional if European fire ants become a nuisance on your property

The spongy moth is an invasive insect from Europe that was introduced in Ontario in 1969. Spongy moth caterpillars are 5 to 60 millimetres in length, dark and hairy, with five pairs of blue dots and six pairs of red dots on the back. Spongy moth was identified in your area in 2020 and may continue for two to five years in any one location. Natural control factors such as disease, parasites and predators eventually combine to cause a collapse of these outbreaks.

The spongy moth caterpillar is known to feed on most species of hardwood trees. Healthy trees can withstand one to several years of severe defoliation by spongy moth. Under normal circumstances, defoliated trees should regrow their leaves in two to three weeks or by early July depending on the year.

Town response

The Town of Whitby will continue to monitor the spongy moth infestation to determine if any control action is required.

Actions you can take

If you are concerned, you can help reduce spongy moth populations by following these techniques:

May to July: Hand Pick Caterpillars

Handpicking caterpillars is most effective on small newly planted trees, shrubs, and plants infested with spongy moth. If possible, gently shake the tree so caterpillars fall from leaves. Thoroughly inspect the remaining foliage, branches, and trunk for caterpillars and using gloves, pick them off your tree. Fallen and collected caterpillars should be placed and left to soak in soapy water to destroy them.

May to September: Burlap Banding

Once spongy moth caterpillars grow to about an inch (2.5 cm) in length by mid-June, they will move down the trunk to seek shelter from predators and heat. Reduce the number of larvae on the trees in your yard by trapping them.

Recommended Supplies

• Burlap cloth
• Twine or rope
• Bucket of soapy water. Dish soap works well.

Step-by-Step Instructions

1. Wrap and secure a piece of burlap cloth around the stem/trunk of your tree
2. Tie twine or rope around the center or slightly below the center of the burlap
3. Drape the burlap cloth over the twine or rope so there is an overhang where the caterpillars can crawl underneath to seek shelter during the day
4. Check the trap by lifting the overhanging burlap cloth every afternoon and collect any hiding caterpillars
5. Put them into a bucket of soapy water for a few days to destroy them

August to May: Egg Mass Removal

Look for egg masses on tree bark and scrape them off. Place eggs into soapy water to destroy them.

Required Supplies

• A flat object such as a butter knife or plastic paint scraper
• Catchment container or bag to collect the egg masses
• Bucket of soapy water. Dish soap works well.

Step-by-Step Instructions

1. Place your catchment container below the egg mass
2. Use your scraper tool to remove the egg mass from the bark surface. Ensure that all eggs are scraped. Try not to leave any residual eggs in bark ridges or crevices
3. Empty the contents of your catchment container or bag into a bucket of soapy water
4. Leave the eggs sitting in the bucket for a day or two, then dispose of the contents

Egg masses can be located high up in trees. Care needs to be taken if trying to access anything aloft, especially if using ladders. 

Giant hogweed and wild parsnip are both invasive perennial plants belonging to the carrot family, native to Europe and Asia. They grow in many areas throughout southern Ontario and are now widespread in Whitby's naturalized areas, particularly along stream banks, roadsides and open areas. The sap from these plants can make skin extremely sensitive to sunlight and cause a burn-like rash.

If you suspect you have giant hogweed or wild parsnip on your property, we recommend hiring a licensed professional to identify and safely remove the plant(s).

Town response

To protect trail users, trained Town staff have installed warning signs and are applying herbicides to plants located within a three-metre buffer area along trails. Due to the number of plants and size of the affected area, total removal of the plant is not an option.

If you see or suspect giant hogweed or wild parsnip on Town property, contact us at 905.668.3437 or email us.

Staying safe

Follow these tips to protect yourself from giant hogweed and wild parsnip:

• Learn to identify the plants
• Avoid all contact with them
• Keep children and pets away
• Stay on established trails at all times

If you come into contact with the sap, do the following:

• Immediately wash the affected skin thoroughly with soap and water
• Avoid further exposure of the affected skin to sunlight and UV
• Seek medical attention if a burn-like rash appears
• If eyes have been exposed to sap, immediately flush with water and seek urgent medical treatment