What should I do if I find an invasive species?
Report the sighting! Make sure to record where you saw the species and, if possible, take photos of the species and the host tree. This will help experts identify the species and evaluate the risk. Follow the information below to find out who to contact:
Where do invasive species come from?
Invasive species are species that exist in an area outside of their native or historic range. Therefore, in Canada, an invasive species can come from any other part of the world. Many invasive species in North America are native to our common trade partners, such as Europe and Asia, introduced accidentally through human activity. Europe and Asia also have similar climates to North America, increasing the potential for an introduced pest to become established.
How do invasive species arrive in Canada?
Invasive forest pests can enter Canada through a number of pathways, both natural and human-influenced. Urbanization increases the potential for spread of invasive species, as hitch-hiking insects can follow the movement of people and products from one area to another. Invasive species can also spread through vectors (eg. carried by birds), or natural dispersal outside of their native range.
Are all destructive forest pests considered ‘invasive’?
No. In addition to invasive species, Canada has a number of native forest pests that can be damaging to trees and forests. Some examples of native pests are the forest tent caterpillar and the spruce budworm. Outbreaks of these pests occur regularly across Canada within their historical ranges, and are considered natural disturbances within the ecosystem.
How can I help to stop the spread of invasive species?
- Report all new sightings
- Don’t move firewood
- Be sure to clean your shoes, bikes, ATVs, and other outdoor equipment thoroughly after a hike or ride through a natural area
- Stay on trails and pathways
- Avoid known infested sites
- Plant native plants and trees
- Properly dispose of garden waste and compost
- Do not move plants, seeds, fruits, woody materials, or other plant parts across borders.
- Do not place bird feeders near hemlock trees
Why can’t I move firewood?
Transporting firewood can very easily move invasive species to a new area. Many wood-boring invasive species spend the majority of their life underneath the bark of a tree in a larval or pupal form. When a tree is turned into firewood, these individuals can remain alive in the wood. When this material is transported to a new area, the invasive species hidden within the relocated firewood can emerge as adults ready to infest the surrounding forest.
Are invasive species destructive in their home range?
Invasive species are sometimes destructive in their home range, but in general are more destructive in introduced environments. In an introduced environment, successful invasive species can spread uncontrollably, free of natural predators or competitors. For example, emerald ash borer is inconsistently present in forest stands in Asia. Through coevolutionary processes, the native Asian ash trees (Manchurian) have developed resistance to beetle infestations, and are only lightly impacted. North American ash trees are lacking this resistance trait, and are therefore highly impacted by emerald ash borer.
What is the annual economic cost of invasive forest pests in Canada?
The economic costs are widespread and hard to predict. Costs are incurred as loss of forest products and timber, control and management costs, and the costs associated with the loss of environmental services (e.g. water and air filtration through forests). The City of Toronto estimates that it will cost $37 million over 5 years to manage the emerald ash borer infestation in Toronto alone. In Alberta, 40 million is budgeted for control of mountain pine beetle for 2014/2015 to include rehabilitation and operations costs. In the United States, roughly $2.1 billion worth of forest products and timber is lost every year to invasive forest insects, and this cost doubles when pathogens and plants are considered (Pimentel et al., 2005).
Are invasive species harmful to humans?
Most invasive forest pests are not directly harmful to humans. However, the sap of giant hogweed, an invasive forest plant, can cause serious burns to the skin and should be avoided. Also, if threatened, the Asian longhorned beetle can deliver a painful bite. Many indirect impacts on human health are also possible, both mental and physical. A healthy forest can be appreciated spiritually, culturally, or aesthetically, and the social benefits are almost impossible to measure. Forests and wetlands are essential for purifying the air we breathe and water we drink, regulating micro-climates in urban areas where we live, and breaking down waste that could be damaging to our health. Results from a recent study support the notion that the natural forest provides health benefits to humans, and reports increased mortality related to cardiovascular and lower-respiratory-tract illness in areas infested with the emerald ash borer (Donovan et al., 2013).
How many invasive species are there in North America?
Estimates vary widely. In the United States, there are roughly 50,000 non-native species present (Pimentel, 2005); however, most of these pose no serious risk to the environment or the economy. Some, such as agricultural plants and animals, are beneficial to society. Within Canada, the number of invasive species varies by province. For example, Ontario has the highest number of invasive plant species in Canada with 441, Quebec has 395, British Columbia has 368, and Nunavut has 16 (CFIA, 2008). The variation across the country is due to many factors, such as climate suitability, amount of international trade, and prevention efforts.