Watch out for the following invasive species which have been found in BC but are not yet established in our province. Familiarize yourself with these invasive species, be on the lookout and report any suspected sightings!
Watch out for the following invasive species which have been found in BC but are not yet established in our province. Familiarize yourself with these invasive species, be on the lookout and report any suspected sightings!
The American bullfrog is the largest frog found in BC. Adults can be up to 18-20 cm long, not including the legs. Bullfrogs were imported to BC for farming by frog leg farms. They have since become established throughout the Lower Mainland and on Vancouver Island from Victoria to Campbell River, and west to Port Alberni. They have also been found on several Gulf Islands and in the Kootenays.
Apple maggot fly is native to Eastern North America and was introduced to BC in 2006. Apple maggot fly feeds on apples and various stone fruits including cherries, plums, and apricots. Maggot damage makes fruit unsellable. The importance of apple and stone fruit crops to BC makes this a pest of serious concern.
Argentine ants are one of the most prolific invasive insects in the world. Though these ants are not dangerous to humans, they pose a serious threat to other ant species, and can become a serious nuisance pest in human buildings and public spaces.
Also known as Golden clam or Good luck clam, this freshwater clam is native to Southeast Asia, Asia Minor, Australia, and Africa. It has been found on southern Vancouver Island near Sooke, and in the Fraser River, Pitt River, and Coquitlam River systems of the Lower Mainland. They may pose a risk to water treatment facilities, irrigation canals, and dams.
Asian giant hornets are the largest hornet in the world. Asian giant hornets were first seen in BC in 2019 in Nanaimo. If they establish in BC, they may pose a serious threat to our beekeeping and commercial pollination industries, creating serious consequences for BC agriculture.
Asian long-horned beetle is a highly destructive wood-boring insect native to Asia.In Canada, Asian long-horned beetle has not been found outside of Ontario, but could spread long-distances to other provinces or territories through transport of infested wood products like firewood and logs.
Baby’s breath is very invasive in BC. When Baby’s breath invades grazing land, it reduces native grasses and forage for grazing animals and wildlife. When it develops seeds and matures, the plant breaks off at the ground and rolls long distances across the landscape with the ability to spread the over 10,000 seeds per plant!
Also known as cornflower, Bachelor’s button is common in “wildflower” mixes. This invasive plant produces large amounts of seed and can easily invade dry meadows, fields, and grasslands.
The Balsam wooly adelgid is a small, sap-sucking insects that feeds on true firs. It is an established invasive species throughout northwestern North America, including BC.
Black slugs, also known as red or chocolate slugs, are native to Europe and have been introduced to many countries through human activity. This slug has been well established in British Columbia since the 1940s and is common throughout Southern BC and Haida Gwaii.
Blueweed is a noxious weed throughout BC. It is toxic to horses and cattle and thereby reduces forage quality in rangelands and pastures, resulting in economic losses.
Bohemian knotweed is a hybrid between Japanese and Giant knotweed, and resembles both species. Knotweeds were introduced to British Columbia for use in gardens and landscaping due to their rapid growth and attractive appearance. There are now four species established in BC: Bohemian, Giant, Himalayan, and Japanese knotweed.
Brown marmorated stink bugs were first seen in BC in 2016, and have spread throughout the Lower Mainland, to the Okanagan Valley, and Brentwood Bay on Vancouver Island. They have become a serious pest in many crops and are considered nuisance pests in human homes.
Bur chervil is considered a noxious weed throughout BC. It can be found in most growing conditions, particularly in moist areas such as ditches and fields. Bur chervil easily out-grows native vegetation.
Burdock is known for its clinging burrs that attach to the manes and tails of horses, cows, and sheep’s wool. This causes the animal to be unhealthy and can lowers the market value of the animal. It is considered a noxious weed in many regions of the province.
Butterfly bush is a semi-evergreen shrub that grows up to 5 m tall. This attractive, fast growing plant has escaped gardens and now rapidly spreads into disturbed, open areas and along coastal forest edges, roadsides, and especially on sunny stream edges and riverbanks where it replaces native plants.
Canada thistle, despite its common name, is native to Europe and N. Asia. It spreads by its creeping roots. Plants form thick infestations that crowd out forage grasses in pastures and rangelands, reducing crop yields and production.
Chinese mystery snail is a freshwater aquatic snail. They were introduced to California in the late 1800s and have since spread to water bodies around North America. In BC, these snails have been reported in various lakes in Southern Vancouver Island, including the Victoria region, and around Mission.
Common bugloss invades disturbed areas such as pastures and hay fields, which reduces the yield of these crops. It is considered regionally noxious in the Kootenay-Boundary region.
Common comfrey is a popular perennial for herb and permaculture gardens, but it is a weedy pest that is extremely difficult to eradicate! It has large, pointed oval leaves and purple or white flowers that hang like bluebells.
Common periwinkle was an ornamental groundcover popular for its fast growth, dense coverage, shiny evergreen leaves, and showy purple flowers. However, it has since escaped captivity and become a pest in forests, choking out native plant species.
Common snapping turtles are invasive to BC. They are much larger than any other turtle species found in BC, and may displace native turtles from their habitat or outcompete them for food.
Common tansy is often found growing in sunny, disturbed areas such as roadsides or pastures. It is considered a noxious weed in the may regions of BC.
Cypress spurge was grown as an ornamental but has since escaped into the wild. It prefers sun but tolerates shade as well. It can be found growing in open, disturbed sites like meadows, pastures, and roadsides.
Daphne was a popular ornamental in gardens at one time due to its glossy, rhododendron-like leaves and fragrant flowers. It is tolerant of both sun and shade and rapidly takes over native vegetation by forming dense thickets in a range of ecosystems.
Diffuse knapweed plants can produce up to 18,000 seeds per year that can remain dormant in the soil for a long time. Seeds can be spread by wind, livestock, and people.
Eastern cottontail rabbits were introduced to BC in Sooke in 1964 and have since spread throughout Eastern Vancouver Island from Victoria to Campbell River. They are considered a serious threat to sensitive Garry Oak habitats on Vancouver Island and are also known to feed on several at-risk plant species.
Eastern grey squirrels compete with native squirrel species and birds for habitat, and feed on bird eggs and nestlings. They have established in the deciduous woodlands of the Lower Mainland, Vancouver Island, and the Southern Interior, primarily in the South Okanagan.
English holly is known for its shiny berries and dark green, spiny evergreen leaves. English holly has become a serious invasive because of its adaptability to grow in shade or sun, and how easy its seeds are spread by birds.
English ivy is commonly planted to provide quick cover for walls and buildings, and as ground cover in commercial landscapes. Unfortunately, it quickly forms a dense mat that suppresses native plants.
Eurasian collared doves are an invasive species throughout the United States and Western Canada, including BC. Eurasian collared doves nest in areas where people live and food is readily available.
Eurasian watermilfoil is an aquatic plant which has been let loose from aquariums. It can quickly take over waterways, causing sluggish water that attracts mosquitos and reduces the recreational potential of the waterway such as swimming and boating.
European brown garden snail is present in Southern BC and Vancouver Island. This snail eats a wide variety of ornamental and agricultural crops and will compete with native snail and slug species for food and habitat.
European chafer beetle was first introduced to BC. in 2001, likely through infested turf. They are a nuisance pest to homeowners, as they infest lawns and attract predators such as crows, skunks, and raccoons that damage lawns as they dig for larvae.
This is a stinging insect. When their nest is disturbed, ants may emerge, swarm and deliver irritating stings. If you encounter a European fire ant nest DO NOT attempt to remove it yourself. In rare cases, European fire ant bites have led to allergic reactions.
European green crabs are a highly invasive species in many parts of the world, including along the BC coast. They are known to outcompete native crabs for food and habitat and could pose a serious threat to many other marine species.
European rabbits have been introduced to every continent except Antarctica. In BC, they are established on Southern Vancouver Island, Triangle Island, and in isolated patches around the Lower Mainland. European rabbits are herbivores and compete with native species for food and habitat.
European starlings were introduced to North America in the late 1800s and are found throughout BC. They compete with native birds for food and space and cause agricultural damage.
European wall lizards were introduced to Southern Vancouver Island in 1967 and have slowly been spreading. The lizards are thought to spread by hitchhiking on vehicles, shipments of produce and plants or released by people who keep them as pets.
Feral pigs are the descendants of domestic pigs that have escaped to the wild and may or may not have mated with wild pigs. Feral pigs are large omnivores, and are known to threaten various species of amphibians, ground-nesting birds, crustaceans, small mammals, mollusks, and reptiles in the regions here they have become established.
Field scabious crowds out forage and pasture plants, reducing food availability for grazing animals. It grows along disturbed roadsides throughout the province.
Flowering rush is an aquatic perennial with green, grass-like foliage and pink almond-scented flowers. It can be difficult to identify as it resembles several native species, but quickly crowds out other plants. It is considered a noxious weed throughout the province.
Foxglove is an extremely abundant exotic species that has naturalized throughout the province, leading many to believe this plant is a BC native! Found growing along roadsides, waste areas, and forests, a single foxglove specimen can produce 5,000 seeds each season. Every part of this plant (including the seeds) is extremely poisonous.
This popular, fragrant aquatic perennial is still sold in garden and pond centers throughout the province despite its potential to invade and destroy our sensitive aquatic ecosystems.
Garlic mustard is a biennial – in the first year, plants appear as a rosette of green leaves close to the ground; these rosettes remain green through the winter and develop into mature flowering plants the following spring. It is considered a noxious weed throughout the province.
Giant hogweed is an invasive plant listed as noxious throughout the province of BC according to the BC Weed Control Act Regulation. Currently it’s found in the Lower Mainland, Fraser Valley, Gulf Islands, and central to southern Vancouver Island.
Knotweeds grow aggressively and are very hard to kill. Giant knotweed is the largest of the species, with leaves about twice the size as those found on the other species.
Goldfish are one of the most widespread invasive fish in North America and are found in southern BC. Goldfish contribute to habitat loss for native aquatic species.
This rapidly growing succulent was popular for rock and xeriscape gardens and is also occasionally used as a green roof species for its ability to withstand extreme temperatures and drought. However, this species is quite aggressively growing and overtakes other plants, rapidly spreading by both seed and vegetatively. A single leaf can root and turn into a whole new plant.
Gorse is a spiny, perennial evergreen shrub. A mature plant can disperse up to 18,000 seeds per plant, and their seeds are easily distributed by human, environmental, and animal transport. Gorse poses a fire hazard due to its volatile oils. It is considered a noxious weed throughout the province.
Green frogs are invasive to BC and may outcompete native frogs for nesting habitat and food.
Originally from the Mediterranean, Hairy cat’s-ear is a perennial that invades pastures, meadows, roadsides, riverbanks, lawns, and disturbed sites.
Himalayan balsam is also known as Policeman’s helmet. Originally from the Himalayan region of South Asia, this plant can take over areas with moist soils, including stream and riverbanks
Himalayan blackberry is valued by humans for its delicious berries; however, it easily invades disturbed sites, pastures, roadsides, streambanks, and forest edges.
Knotweeds were introduced to British Columbia for use in gardens and landscaping due to their rapid growth and attractive appearance There are now four species established in BC: Bohemian, Giant, Himalayan, and Japanese knotweed. Knotweeds grow aggressively and are very hard to kill.
Hoary alyssum spreads quickly through a long season of seed production. Seeds are dispersed by vehicles, equipment, footwear, wildlife, and birds. It can also contaminate hay and is considered a noxious weed in the Kootenay-Boundary region.
Also known as “white-top”, Hoary cress is a perennial plant that invades open, sunny areas such as hayfields, meadows, and roadsides. It spreads by roots and seeds and crowds out native vegetation. It is considered a noxious weed in parts of BC.
Hound’s tongue grows on dry, well-drained sites. Each plant can produce 2,000 -4,000 barbed seeds a year that cling to clothing, livestock, and wildlife. It is considered a noxious weed throughout the province.
Italian wall lizards are invasive to BC. In 2019, a single adult female was caught in Vancouver BC.
Japanese beetles were first found in BC in July 2017 in downtown Vancouver. Adult Japanese beetles can feed on over 300 species of plants, including many species of agricultural and horticultural importance.
Knotweeds were introduced to British Columbia for use in gardens and landscaping due to their rapid growth and attractive appearance There are now four species established in BC: Bohemian, Giant, Himalayan, and Japanese knotweed.
Largemouth bass was introduced as a stock fish in BC and can now be found throughout the Columbia River system. This species has a serious potential to disrupt food webs when introduced to new habitats, and has been identified as a potential threat to multiple aquatic species at risk in BC.
Introduced to BC as a garden plant, Leafy spurge is a perennial that has escaped into natural areas. It can now be found on dry roadsides, fields, grasslands, open forests, and disturbed sites.
Native to Europe, Marsh plume thistle is a biennial that prefers moist to wet, naturally open or disturbed areas. Seeds spread by wind, water, birds, vehicles, and equipment.
Mountain bluet is a popular garden perennial, however, it easily escapes gardens and invades natural areas. This plant can self-seed, which makes it difficult to control.
Mute swans are native to Europe and Asia and became invasive throughout North America after being intentionally introduced by settlers in the 1870s. In BC, they are found in Southern Vancouver Island and in the Fraser River delta. They compete for food and habitat with native waterfowl and other wildlife and can drastically alter aquatic ecosystems.
It is thought that the New Zealand mudsnail was transported to North America in the ballast water of ships arriving from Europe and Asia. The New Zealand mudsnail can live in a variety of habitats and can disrupt the natural ecology by out-competing native aquatic snails and insects.
Northern pike are native to northeast BC and are common throughout Quebec, Ontario, the Prairie provinces and northern territories. They have been introduced in many regions as stock for sport fishing and are spreading into southern BC.
Nutria are native to South America, and have become invasive throughout North America, including Washington, Oregon, and BC. Nutria can turn lush wetlands into open ponds, destroying important habitat for native species of wetland animals.
Originally from Europe, Orange hawkweed can create dense mats that crowd out native plants. Hawkweeds spread quickly through above ground runners, horizontal roots, and seeds.
Oriental weatherfish, also known as Weather loach, Pond loach, or Dojo, is an eel-like freshwater fish. They are a widespread invasive species in North American freshwater systems, and are found in the Alouette River system in BC.
Originally from Eurasia, Oxeye daisy was first introduced to North America in seed mixes. It is still commonly sold in many store-bought wildflower mixes and remains popular among gardeners despite its negative impacts.
Purple deadnettle is native to Europe and a common weed throughout BC. It survives as an annual or biennial. A single plant can produce thousands of seeds which remain viable in the soil for several years. It can also spread via stem and root fragments.
Purple loosestrife is a pretty perennial plant that spreads rapidly by seed and root fragments. The tiny seeds are dispersed by wind, mud, moving water, wildlife and humans
Queen Annes’ lace, also known as wild carrot, is common to roadsides and other disturbed areas. This biennial plant persists in clay soils and can be a threat to recovering grasslands.
Red swamp crayfish are native to the Mississippi river drainage and the Gulf of Mexico. It is not yet present in BC, but would damage local ecosystems by feeding on aquatic plants and invertebrates, competing with native species for habitat, and could spread diseases to native crustaceans.
Red-eared sliders are popular pets in many parts of the world, especially when they are young and small. Unfortunately, many pet owners have released these turtles into natural ecosystems.
Rosy red minnow is an invasive that appears occasionally in waterways around BC, likely after having been intentionally dumped by pet owners. These fish can readily breed in BC waterways and would likely compete with other small fish for food and habitat if they spread.
Rush skeletonweed is a perennial plant native to Eurasia that invades rangelands, roadsides and disturbed areas. It competes with other plants for soil moisture and nutrients.
Russian olive is a short invasive tree that can survive in dry conditions and cold temperatures. It drinks more water than most plants in dry soil settings, therefore it can outgrow and compete with native species.
Rusty crayfish are are not yet present in BC, but have become invasive in Eastern Canada and Oregon. They are frequently transported to new areas by fishermen in bait buckets. They have a diverse diet and may easily outcompete native species for food and habitat.
Scentless chamomile prefers moist soil conditions. It can produce up to 1,000,000 seeds every year, and the seeds can survive in the soil for up to 15 years. This plant can aggressively take over pastures, grasslands, and other agricultural areas.
Scotch broom was introduced from the Mediterranean and is an escaped garden plant in Canada. It easily invades sunny, disturbed sites such as rangelands, roadsides, and areas of recent logging.
Scotch thistle is a biennial or perennial that reproduces through thousands of seeds that can survive in the soil for over 30 years. Seeds can spread with the wind, but also in hay and water, and by attaching to clothing or animal fur.
Smallflower touch-me-not is a twiggy, branching, fine-textured annual species is often found growing in moist soils such as those around rivers, streams, and wetlands mainly in the Fraser Valley region. It is native to Asia. Although this species prefers moist soils, it is tolerant to a range of sun exposures, soil types, and climates, making it difficult to eradicate.
Smallmouth bass have been introduced into BC waterways as sport fish. They have been known to deplete waterways of smaller fish and are considered a serious threat to native animals, including juvenile salmon.
Gypsy moth have not established in BC but are widely spreading the Eastern United States and Canada. In their invasive range, Gypsy moths are known to defoliate entire trees by feeding in large numbers. If they were to establish in BC they would likely cause significant economic damage to our forestry and tree nursery industries, as well as on residential properties.
Spotted knapweed is a prolific seed producer, with individual plants producing up to 140,000 seeds per square metre. Seeds and plant fragments make their way into hay and the undercarriages of vehicles, allowing for new infestations over great distances.
Spotted lanternfly is NOT present in BC. In areas where it has become invasive, it has caused widespread damage and is considered an extremely harmful pest. Adults fly between host plants and may land on vehicles which carry them to new areas.
This plant is a perennial that grows in dense patches which can crowd out natural plants and reduce the grasses that animals feed on. St. John’s-Wort is found in most of southern BC.
Strawberry blossom weevil is native to Europe, where it is a pest of strawberries and cane-fruits. This weevil is a recent arrival in BC and has a serious potential to disrupt the BC berry growing industry.
Sulphur cinquefoil is a long-lived perennial native to Eurasia. It invades grasslands, dry open forests, and disturbed sites such as roadsides and rangelands.
Tamarisk is a shrub-like tree, also known as ‘salt cedar’. The term ‘salt cedar’ comes from its ability to release salt from its leaves, which prevents the growth of any native vegetation within its range.
Tansy ragwort is a biennial to short-lived perennial that grows in pasturelands and disturbed areas. Seeds are easily transported by wind, soils, human activity, and livestock.
Teasel is a biennial plant that prefers sunny locations and can grow in a range of wet to dry soils. Spreading through seed dispersal, it typically invades meadows, pastures, roadsides, and disturbed areas.
Tench have spread to British Columbia from Washington through the Columbia River. They pose a threat to many native aquatic species, competing for food and habitat.
Native to China, Tree of Heaven is a deciduous tree that became popular in BC with gardeners for its rapid growth and interesting foliage. It produces by seed and by division and can sprout nearly anywhere, making it very difficult to eradicate!
The Virginia opossum is the only species of marsupial found North of Mexico and has been present in Southern BC since 1949. The priority for this species is to prevent its spread to new areas in the province, where it could potentially have unforeseen effects on native ecosystems.
Wild caraway was introduced to Canada as a spice crop but has escaped cultivation. It is a biennial plant that can quickly outgrow native plants. It can grow in light shade, survive light frost and extra moisture in the soil.
Wild chervil is a biennial to short-lived perennial in the Parsley family. It is typically found along roadsides, fencelines, streambanks, in ditches and competing with pasture and hay crops
Winter moths were introduced to Canada during the 1930s in the Maritimes, and were first reported on Vancouver Island in 1970. They are considered a threat to sensitive Gary Oak ecosystems on Southern Vancouver Island, and are occasional pests in cranberry bogs.
Yellow archangel is a perennial garden plant usually seen in hanging baskets and as a ground cover. This plant prefers shady sites such as forested areas and grows in a dense mat that smothers other native plants. It spreads by seed and plant fragments, and by animals and humans passing through the vegetation.
Yellow flag iris invades ditches, wetlands, streams, lake shorelines, and shallow ponds. This plant reproduces through seed dispersal, horizontal roots, and when pieces of the roots break off, which can form new plants.
Yellow floating heart is an aquatic perennial native to Eurasia that forms thick mats of vegetation in our sensitive aquatic ecosystem. It resembles a water lily with its round, glossy leaves that float on the water’s surface with yellow flowers attached to sturdy, upright stems. If you see this plant in BC, be sure to report it!
Yellow loosestrife is a fast-spreading perennial plant native to central Europe and Turkey. It can form dense clumps that spread out over large areas, crowding out native plants.
Yellow perch have been intentionally released in BC as stock fish and from aquariums and private ponds, and accidentally spread by boats and in bait buckets. Yellow perch reproduce quickly and may overwhelm and outcompete native predatory fish for food and habitat.
Native to Europe, Yellow toadflax, also known as Common toadflax, spreads by a creeping root system. It is typically found in cultivated fields, pastures, along roadsides and other disturbed areas.
Zebra and Quagga mussels are freshwater mussels native to the Black Sea in Europe. They have become invasive in Ontario, Quebec, and Manitoba, but have not yet been detected in BC, Alberta, Washington, Oregon, or Idaho. They are primarily spread in North America by recreational boaters.