Invasive plant species targeted in B.C. have been introduced from other continents, primarily Europe and Asia, and have no natural enemies to attack them and keep them under control. Biocontrol research and thereafter management efforts reunites these invasive plants with their natural enemies by importing agents, mainly insects, that feed on the plants from the native habitat. Release of biological control agents into British Columbia began in 1951 with the introduction of Chrysolina quadrigemina (Suffrain) and C. hyperici (Forster) to control St. John's wort (Hypericum perforatum L.) [1]. As of February 2020, B.C. has records for 87 separate species, or 89 if strains of species are considered as separate biocontrol agents, having either been purposely introduced (72) or having found their way into the province (17) to target 38 invasive plants. Establishment of the purposely introduced species in B.C. is at 74%, which is higher than the average of about 60% reported for classical invasive plant biocontrol agents released elsewhere in the world [2], and even the average of 70% recorded for agents released in western Canada [1]. In few historic occasions, and in current rare circumstances, natural predators have been able to follow their hosts into new habitats. These adventive insects are described:
References
[1] De Clerck-Floate, R. and H. Cárcamo. 2011. Biocontrol Arthropods: New Denizens of Canada's Grassland Agroecosystems. In Arthropods of Canadian Grasslands (Volume 2): Inhabitants of a Changing Landscape. Edited by K. D. Floate. Biological Survey of Canada. pp. 291-321.
[2] McFadyen, R.E.C. 1998. Biological control of weeds. Annual Review of Entomology. 43:369-393.
The table below lists invasive plant species and their biological control agents.
Invasive Plant |
Biocontrol Agent |
Agent Type |
First Reported / Released in B.C. |
Released in BEC Zone |
Positive Monitoring / Dispersal BEC Zone * |
---|---|---|---|---|---|
Black knapweed |
Seed feeding beetle (weevil) |
Imported for other Centaurea species |
None |
CWH, CDF, IDF |
|
Bohemian knotweed (PDF, 67KB) Fallopia bohemica |
Aphalara itadori | Sap-sucking psyllid | 2014 | ICH | None |
Brown knapweed |
Seed feeding fly |
1986 |
None |
None |
|
Bull thistle |
Larinus carlinae (PDF, 737KB) |
Seed feeding beetle (weevil) |
Adventive: Approved for Canada thistle in 1988 |
None |
BG, CDF, CWH, IDF |
Bull thistle |
Seed feeding beetle (weevil) |
Imported for Nodding thistle |
IDF |
BG, CDF, CWH, IDF, PP |
|
Bull thistle |
Rosette/ root crown feeding beetle (weevil) |
1991 |
CWH |
None |
|
Bull thistle |
Seedhead gall-producing fly |
1973 |
BG, BWBS, CDF, CWH, ESSF, ICH, IDF, MS, PP, SBS |
CDF, CWH, ICH, IDF, MS, PP, SBS |
|
Burdock |
Seed feeding moth |
Adventive |
None |
BD, IDF, MS, PP |
|
Canada thistle |
Foliar feeding beetle |
1964 |
CDF, CWH, PP |
None |
|
Canada thistle |
Foliar feeding beetle |
Adventive |
None |
BG, CDF, CWH, ICH, IDF, MS, PP |
|
Canada thistle |
Hadroplontus litura (PDF, 798KB) |
Stem feeding beetle (weevil) |
1975 |
BG, CDF |
CDF |
Canada thistle |
Larinus carlinae (PDF, 737KB) |
Seed feeding beetle (weevil) |
Adventive; approved for release on Canada thistle in 1988 |
BG, BWBS, CDF, CWH, ESSF, ICH, IDF, MS, PP, SBS |
BG, CDF, CWH, ICH, IDF, MS, PP, SBS |
Canada thistle |
Leaf and stem rust (fungus) |
Adventive |
None |
BG, CDH, CWF, IDF, SBS |
|
Canada thistle |
Seed feeding beetle (weevil) |
Imported for Nodding thistle |
BG, CWH, IDF, MS, SBS |
CDF, CWH, IDF, MS |
|
Canada thistle |
Seed feeding fly |
Adventive: first report 1931 |
None |
None |
|
Canada thistle |
Stem gall-forming fly |
1974 |
BG, BWBS, CDF, CWH, ICH, IDF, MS, PP, SBS |
BG, BWBS, CDF, CWH, ICH, IDF, PP, SBS |
|
Canada thistle |
Seedhead gall-producing fly |
Imported for bull thistle |
None |
IDF, SBS |
|
Cypress spurge |
Root feeding beetle (flea beetle) |
Imported for leafy spurge |
IDF |
None |
|
Dalmatian toadflax |
Seed feeding beetle |
Adventive |
BWBS, PP |
BG, IDF, PP |
|
Dalmatian toadflax |
Foliar feeding moth |
1960s |
BG, CWH, ICH, IDF, PP |
ICH, IDF, MS, PP |
|
Dalmatian toadflax |
Root feeding moth |
1991 |
BG |
None |
|
Dalmatian toadflax |
Mecinus janthiniformis (PDF, 692KB) |
Stem mining beetle (weevil) |
1991 |
|
BG, CDF, CWH, ICH, IDF, MS, PP |
Dalmatian toadflax |
Rhinusa antirrhini (PDF, 883KB) |
Seed feeding beetle (weevil) |
1993 |
BG, IDF, MS, PP, SBS |
BG, IDF, MS, PP |
Dalmatian toadflax |
Rhinusa linariae (PDF, 769KB) |
Root feeding beetle (weevil) |
1996 |
BG |
None |
Dalmatian toadflax |
Rhinusa neta (PDF, 695KB) |
Seed feeding beetle (weevil) |
Adventive |
IDF |
BG, CWH, IDF, MS, PP |
Diffuse knapweed |
Root feeding moth |
1982 |
BG, ICH, IDF, PP |
BG, ICH, IDF, PP |
|
Diffuse knapweed |
Seed feeding fly |
Imported for spotted knapweed |
None |
BG, ICH, PP |
|
Diffuse knapweed |
Root feeding beetle (weevil) |
1987 |
BG, CDF, CWH, ICH, IDF, MS, PP |
BG, CWH, ESSF, ICH, IDF, PP |
|
Diffuse knapweed |
Seed feeding beetle (weevil) |
1991 |
BG, CDF, CWH, ICH, IDF, MS, PP |
BG, CDF, CWH, ESSF, ICH, IDF, MS, PP |
|
Diffuse knapweed |
Seed feeding beetle (weevil) |
1993 |
BG, CWH, ICH, IDF, MS, PP |
CDF, ICH, IDF |
|
Diffuse knapweed |
Seed feeding moth |
1981 |
None |
BG |
|
Diffuse knapweed |
Root feeding moth |
1982 |
BG, IDF, PP |
None |
|
Diffuse knapweed |
Root feeding moth |
1986 |
BG, IDF, PP |
BG, ICH, IDF, PP |
|
Diffuse knapweed |
Leaf and stem rust (fungus) |
Adventive 1988 |
None |
PP |
|
Diffuse knapweed Centaurea diffusa |
Sclerotinia sclerotiorum (PDF, 475KB) | Root, leaf, stem fungus | Naturally occurring | IDF | IDF |
Diffuse knapweed |
Root feeding beetle |
1976 |
BG, CDF, ICH, IDF, PP |
BG, CDF, ICH, IDF, PP |
|
Diffuse knapweed |
Gall forming nematode |
1985 |
IDF |
IDF |
|
Diffuse knapweed |
Seed feeding fly |
1970 |
ICH |
BG, ICH, IDF, PP |
|
Diffuse knapweed |
Seed feeding fly |
1972 |
ICH |
BG, CDF, PP |
|
Field bindweed |
Aceria malherbae (PDF, 674KB) |
Leaf and bud galling mite |
1992 |
BG, IDF, PP |
BG, PP |
Field bindweed |
Charidotella sexpunctata bicolor (PDF, 687KB) |
Foliar feeding beetle |
1969 (B.C. lab study) |
CWH |
None |
Field bindweed |
Deloyala guttata (PDF, 272KB) |
Foliar feeding beetle |
1969 (B.C. lab study) |
CWH |
None |
Gorse |
Foliar feeding moth |
Adventive |
None |
CDF |
|
Hedge false bindweed |
Charidotella sexpunctata bicolor (PDF, 687KB) |
Foliar feeding beetle |
1971 |
CWH |
CWH |
Hedge false bindweed |
Deloyala guttata (PDF, 272KB) |
Foliar feeding beetle |
1971 |
CWH |
None |
Hound's tongue |
Root feeding flea beetle |
1998 |
BG, IDF, PP |
BG, IDF, PP |
|
Hound's tongue |
Mogulones crucifer (PDF, 659KB) |
Root feeding beetle (weevil) |
1997 |
BG, ICH, IDF, MS, PP |
BG, ICH, IDF, MS, PP |
Japanese knotweed Fallopia japonica |
Aphalara itadori | Sap-sucking psyllid | 2014 | ICH | None |
Kingdevil hawkweed |
Aulacidea subterminalis (PDF, 704KB) | Gall-forming wasp | 2011 | IDF | IDF |
Leafy spurge |
Aphthona cyparissiae (PDF, 654KB) |
Root feeding flea beetles |
1989 |
BG, IDF, PP, SBS |
BG, IDF, PP |
Leafy spurge |
Aphthona czwalinae (PDF, 598KB) |
Root feeding flea beetles |
1995 |
BG, IDF, PP |
IDF, PP |
Leafy spurge |
Root feeding flea beetle |
1990 |
BG, IDF, MS, PP |
BG, IDF, PP |
|
Leafy spurge Euphorbia esula |
Aphtona lacertosa (PDF, 520KB)
(mix with A. czwalinae) |
Root feeding flea beetle | 1995 | BG, IDF, PP | IDF, PP |
Leafy spurge |
Root feeding flea beetle |
1986 |
BG, IDF, PP, SBS |
BG, IDF, PP, SBS |
|
Leafy spurge |
Foliar feeding moth |
1966 |
IDF |
IDF, PP |
|
Leafy spurge |
Leaf tying moth |
1987 |
BG, IDF, PP |
BG, IDF, PP |
|
Leafy spurge |
Foliar feeding moth |
1994 |
PP |
None |
|
Leafy spurge |
Bud gall forming midge |
1990 |
BG, IDF |
None |
|
Marsh plume thistle |
Seed feeding beetle (weevil) |
Imported for nodding thistle |
ICH, SBS |
ICH, SBS |
|
Marsh plume thistle |
Seed feeding fly |
Adventive |
None |
ICH |
|
Marsh plume thistle |
Rosette/root crown feeding beetle (weevil) |
Imported for nodding thistle |
ICH, SBS |
None |
|
Meadow hawkweed Pilosella caespitosa |
Cheilosia urbana (PDF, 491KB) | Root feeding hover fly | 2018 | ICH | None |
Meadow knapweed |
Root feeding moth |
Imported for other Centaurea species |
CDF, CWH |
IDF |
|
Meadow knapweed |
Root feeding beetle (weevil) |
Imported for other Centaurea species |
CDF, CWH |
None |
|
Meadow knapweed |
Seed feeding beetle (weevil) |
Imported for other Centaurea species |
CDF, CWH, ICH |
CDF, CWH, ICH, IDF |
|
Meadow knapweed |
Seed feeding moth |
Imported for other Centaurea species |
None |
ICH, IDF |
|
Meadow knapweed |
Seed feeding fly |
Imported for other Centaurea species |
None |
CWH |
|
Meadow knapweed |
Seed feeding fly |
Imported for other Centaurea species |
None |
ICH, IDF |
|
Mouse-ear hawkweed (PDF, 675KB) |
Aulacidea subterminalis (PDF, 704KB) | Gall forming wasp | 2011 | IDF | IDF |
Mullein |
Rhinusa tetra (PDF, 586KB) |
Seed and foliar feeding weevil |
Adventive |
None |
BD, ICH, IDF, PP |
Nodding thistle |
Foliar feeding beetle |
Adventive |
None |
IDF |
|
Nodding thistle |
Larinus carlinae (PDF, 737KB) (previously L. planus) |
Seed feeding beetle (weevil) |
Adventive: approved for Canada thistle (1988) |
None |
IDF, PP |
Nodding thistle |
Leaf and stem rust (fungus) |
Adventive |
None |
BG, IDF |
|
Nodding thistle |
Seed feeding beetle (weevil) |
1979 |
BG, ESSF, ICH, IDF, PP |
IDF, PP |
|
Nodding thistle |
Rosette/root crown feeding beetle (weevil) |
1979 |
BG, IDF, PP |
BG, IDF, PP |
|
Nodding thistle |
Seed feeding fly |
1991 |
None |
None |
|
Orange hawkweed |
Gall forming wasp |
2011 |
IDF |
IDF |
|
Orange hawkweed |
Root feeding hover fly |
2017 |
ICH |
None |
|
Perennial sow thistle |
Leaf gall forming fly |
1984 |
SBS |
None |
|
Plumeless thistle |
Foliar feeding beetle |
Adventive |
None |
BG, PP |
|
Plumeless thistle |
(previously L. planus)
|
Seed feeding beetle (weevil) |
Adventive: approved on Canada thistle (1988) |
None |
ICH, IDF, PP |
Plumeless thistle |
Seed feeding beetle (weevil) |
Imported for nodding thistle |
ICH, IDF |
BG, ICH, IDF, PP |
|
Plumeless thistle |
Rosette/ root crown feeding beetle (weevil) |
1975 |
BG, IDF, PP |
BG, ICH, IDF, PP |
|
Plumeless thistle |
Seed feeding fly |
1991 |
ICH |
None |
|
Puncturevine |
Microlarinus lareynii (PDF, 529KB) |
Seed feeding beetles (weevils) |
1986 |
BG |
None |
Purple loosestrife |
Foliar feeding beetle |
1993 |
BG, CDF, CWH, ICH, IDF, PP, SBPS, SBS |
BG, CDF, CWH, ICH, PP, SBS |
|
Purple loosestrife |
Foliar feeding beetle |
1994 |
BG, CWH, PP |
BG, CWH, PP |
|
Purple loosestrife |
Galerucella calmariensis (PDF, 798KB) |
Foliar feeding beetle |
1995 |
CDF |
CDF |
Purple loosestrife |
Root feeding beetle (weevil) |
1994 |
CDF |
CDF |
|
Rush skeletonweed Chondrilla juncea |
Aceria chondrillae (PDF, 606KB) (previously Eriophyes chondrillae) |
Gall forming mite | 1993 | ICH, IDF | ICH, IDF |
Rush skeletonweed |
Root feeding moth |
2007 |
IDF |
None |
|
Rush skeletonweed |
Leaf and stem rust (fungus) |
Adventive |
IDF |
ICH, IDF |
|
Russian knapweed |
Leaf and stem rust (fungus) |
Adventive |
BG, PP |
BG, PP |
|
Russian knapweed Acroptilon repens |
Aulacidea acroptilonica (PDF, 575KB) | Gall forming wasp | 2015 | BG, PP | PP |
Russian knapweed |
Gall forming nematode |
1985 |
BG, PP |
None |
|
Scentless chamomile |
Stem mining beetle (weevil) |
1997 |
BWBS, IDF |
BWBS |
|
Scentless chamomile |
Omphalapion hookeri (PDF, 797KB) |
Seedhead feeding beetle (weevil) |
1992 |
BWBS, ICH, IDF, MS, SBPS, SBS |
BWBS, ICH, IDF, MS, SBS |
Scentless chamomile |
Gall forming midge |
1999 |
BWBS, ICH, IDF, MS, SBS |
BWBS, ICH, IDF, MS, SBS |
|
Scotch broom |
Gall mite |
Adventive |
None |
CDF, CWH |
|
Scotch broom |
Foliar feeding moth |
Adventive |
None |
CDF |
|
Scotch broom |
Seed feeding beetle (weevil) |
Adventive |
ICH |
CDF, CWH, ICH |
|
Scotch broom |
Seed feeding weevil |
Adventive |
ICH |
CDF, CWH, ICH |
|
Short-fringed knapweed |
Seed feeding beetle (weevil) |
Imported for other Centaurea species |
None |
IDF |
|
Short-fringed knapweed |
Seed feeding fly |
Imported for other Centaurea species |
None |
IDF |
|
Spotted knapweed |
Root feeding moth |
1982 |
BG, CDF, CMA, CWH, ESSF, ICH, IDF, IMH, MS, PP, SBS |
BG, CDF, CMA, CWH, ESSF, ICH, IDF, MS, PP, SBS |
|
Spotted knapweed |
Seed feeding fly |
1991 |
BG, CWH, ICH, IDF, SBS |
BG, ICH, IDF, MS, PP |
|
Spotted knapweed |
Root feeding beetle (weevil) |
1987 |
BG, BWBS, CDF, CWH, ESSF, ICH, IDF, MS, PP, SBS |
BG, CDF, CMA, CWH, ESSF, ICH, IDF, MS, PP, SBS |
|
Spotted knapweed |
Seed feeding beetle (weevil) |
1991 |
BG, CDF, CWH, ESSF, ICH, IDF, MS, PP, SBS |
BG, CDF, CWH, ICH, IDF, MS, PP, SBS |
|
Spotted knapweed |
Seed feeding beetle (weevil) |
1993 |
BG, CDF, CWH, ESSF, ICH, IDF, MS, PP, SBS |
BG, CDF, CWH, ESSF, ICH, IDF, MS, PP, SBS |
|
Spotted knapweed |
Seed feeding moth |
1973 |
CDF, CWH, ICH, IDF, MS, SBS |
BG, CDF, CWH, ICH, IDF, PP |
|
Spotted knapweed |
Root feeding moth |
1982 |
None |
None |
|
Spotted knapweed |
Root feeding moth |
1987 |
ICH |
ICH |
|
Spotted knapweed |
Leaf and stem rust (fungus) |
Adventive |
None |
None |
|
Spotted knapweed Centaurea biebersteinii |
Sclerotinia sclerotiorum (PDF, 475KB) | Root, leaf and stem fungus | Naturally occurring | IDF | IDF |
Spotted knapweed |
Root feeding beetle |
1987 |
CDF, ICH, IDF |
BG, CWH, ESSF, ICH, IDF, PP |
|
Spotted knapweed |
Seed feeding fly |
1991 |
BG, ICH, IDF, PP |
ICH |
|
Spotted knapweed |
Seed feeding fly |
1970 |
CDF |
BG, CDF, CWH, ICH, IDF, PP |
|
Spotted knapweed |
Seed feeding fly |
1972 |
None |
BG, CDF, CWH, ICH, IDF, PP |
|
St. John's wort |
Root feeding beetle |
1955 |
CDF, ESSF, ICH, IDF |
ESSF, ICH, IDF, PP |
|
St. John's wort |
Sap sucking aphid |
1979 |
CWH, ESSF, ICH, IDF, PP |
ESSF, ICH, IDF, PP |
|
St. John's wort |
Aplocera plagiata (PDF, 876KB) |
Foliar feeding moth |
1967 |
CDF, CWH, ESSF, ICH, IDF, MS, SBS |
CDF, CWH, ICH, IDF, MS, PP |
St. John's wort |
Foliar feeding beetle |
1951 |
CWH, ICH, IDF, MS, PP |
ESSF, IDF, MS |
|
St. John's wort |
Chrysolina quadrigemina (PDF, 732KB) |
Foliar feeding beetle |
1952 |
CWH, ICH, IDF, MS |
CDF, CWH, ESSF, IDF, MS |
St. John's wort |
Foliar feeding beetle |
1957 |
ICH, PP |
None |
|
St. John's wort |
Gall forming midge |
1955 |
ICH |
None |
|
Tansy ragwort |
Botanophila seneciella (PDF, 721KB) |
Seed feeding fly |
1968 |
CWH |
CDF, CWH, IDF |
Tansy ragwort |
Root crown feeding moth |
1990 |
CDF, CWH, IDF |
CDF, CWH |
|
Tansy ragwort |
Root feeding flea beetle |
1971 |
None |
None |
|
Tansy ragwort |
Longitarsus gracilis |
Root feeding flea beetle |
Adventive, 2005 |
IDF |
IDF |
Tansy ragwort |
Longitarsus jacobaeae (PDF, 809KB) |
Root feeding flea beetle |
1971 |
CDF, CWH, IDF |
CDF, CWH |
Tansy ragwort |
Longitarsus jacobaeae (PDF, 916KB) |
Root feeding flea beetle |
2011 |
IDF |
None |
Tansy ragwort |
Foliar feeding moth |
1962 |
CDF, CWH, IDF |
CDF, CWH, IDF |
|
Whiplash hawkweed |
Gall forming wasp |
2011 |
ICH, IDF, SBS |
ICH |
|
Yellow/ Common toadflax |
Seed feeding beetle |
Adventive |
None |
CWH, ICH, IDF, MS, PP, SBS |
|
Yellow/ Common toadflax |
Foliar feeding moth |
1960s (on dalmatian) |
BG, ICH, IDF, SBS |
BG, ICH, IDF, PP |
|
Yellow/ Common toadflax |
Root feeding moth |
1992 |
BG |
None |
|
Yellow/ Common toadflax |
Root feeding moth |
1992 |
BG, IDF |
None |
|
Yellow/ Common toadflax |
Stem mining beetle (weevil) |
Moved from Dalmatian to yellow toadflax |
|
IDF |
|
Yellow/ Common toadflax |
Rhinusa antirrhini (PDF, 883KB) |
Seed feeding beetle (weevil) |
Adventive |
None |
CWH, ICH, IDF, MS, PP, SBS |
Yellow/ Common toadflax |
Rhinusa linariae (PDF, 769KB) |
Root feeding beetle (weevil) |
1997 |
BG, ICH, IDF, MS |
IDF |
Yellow/ Common toadflax |
Rhinusa neta (PDF, 695KB) |
Seed feeding beetle (weevil) |
Adventive |
None |
IDF, PP |
Yellow/ Common toadflax |
Stem galling weevil |
2014 |
ICH, MS, PP, SBS |
MS, PP, SBS |
* The monitoring/dispersal Biogeoclimatic Ecosystem Classification (BEC) zones listed as positive for biocontrol agent survival include those where monitoring has been performed and the agent has been found. This information does not necessarily preclude the possibility of the biocontrol agents establishing in additional BEC zones.
**The categories and their definitions for the 'collectability' of biocontrol agents in B.C. are as follows: