Invasive Species

Invasive species are plants, animals, and micro-organisms introduced by human action outside their natural past or present distribution whose introduction or spread threatens the environment, the economy, or society, including human health.

Species of Concern

Below are some invasive species to keep an eye out for in the future.

Spongy Moth (European Gypsy Moth)
Outbreaks of this pest are cyclical, typically occurring about every seven to ten years. The most recent outbreak peaked in 2021 and was the largest on record in Ontario. Stay vigilant and survey trees for egg masses in the fall.

The larvae (caterpillars) feed on crown foliage of a wide range of hardwood and some softwood trees, which makes it a defoliating forest pest of concern.

The spongy moth is formerly known as the European Gypsy Moth or LDD (Lymantria dispar dispar). In March of 2022, Entomological Societies of Canada and America adopted the name spongy moth as the new common name for the moth species Lymantria dispar.

Timing Life stage Characteristics Control options
August to mid-April Egg masses The eggs are tanned yellow and covered with fuzz. Remove egg masses and discard
Mid-April to mid-May Early-stage caterpillar (larvae) The eggs hatch and the larvae begin to feed on foliage. Apply biological pesticide
Mid-May to June Late-stage caterpillar (larvae) The mature larvae are long, dark and hairy with 5 pairs of blue dots and 6 pairs of red dots down its back. Attach burlap bands and discard larvae
June to mid-July Pupae The larvae seek shelter to transition to winged moths, the skin hardens and metamorphosis takes place. Remove by hand and discard
July to August Adult moth Males are brown with feathery antennae and females are white/beige and unable to fly. Short-lived; focus on other stages

Types of Invasive Species & Impacts

Invasive terrestrial plants include trees, shrubs, or herbaceous plants that have been moved from their native habitat to an introduced area where they are able to reproduce quickly and crowd out native species. To learn more about how the County is managing invasive terrestrial plants, read our Integrated Vegetation Management (IVM) Plan.

Invasive insects can cause damage and loss to forest and agricultural systems. These insects can defoliate and/or bore holes into the vascular systems of plants, shrubs, and trees. This can weaken plants, making them more susceptible to pathogens.

Invasive pathogens include diseases and disease-causing microorganisms that can have detrimental effects on forests. Their impacts degrade the quality of wood, eliminate wildlife habitat, and reduce the recreation/cultural value of habitats.

Invasive animals are able to spread disease, prey on or compete with native species, hybridize, and alter natural systems. They can impact both vegetation growth and soil create disturbances.

Invasive aquatic plants can impact recreational activities (e.g., boating, fishing, swimming), displace native vegetation, slow down water flow, and alter oxygen levels. These plants can be floating, floating and rooted in sediment, rooted and submergent (underwater), or emergent (partly under and partly above the water’s surface).

Invasive fish and invertebrates (e.g., crayfish, snails, mussels, clams, water fleas, or mysids) alter food webs by competing with native species for resources (food and habitat) and predating on fish eggs and larvae populations.

Pathways of Introduction

There are many ways that invasive species are introduced into the environment. These introductions are sometimes natural, deliberate, or accidental. These pathways include:

  • Horticulture and gardening
  • Movement of wood
  • Equipment and tools (e.g., lawn mowers)
  • Animals and pets
  • Internet sales and mail
  • Watercraft and boats
  • Shipping and ballast water
  • Outdoor recreational gear (e.g., boots, camping equipment, clothes, SCUBA gear)
  • Recreational vehicles (e.g., ATV’s)

Report a Sighting

Visit the Canada Food Inspection Agency Website or EDD Maps to report an invasive species sighting or call the Invading Species Hotline at 1-800-563-7711.

To Learn More Visit

 

For further information, email ivm@lanarkcounty.ca.