Information

Agent

Cyphocleonus achates (Fåhraeus)

Class: Insecta
Order: Coleoptera
Family: Curculionidae

Agent Name References:
- Stinson, C.S.A., D. Schroeder, and K. Marquardt. 1994. Investigations on Cyphocleonus achates (Fahr.) (Col., Curculionidae), a potential biological control agent of spotted knapweed (Centaurea maculosa Lam.) and diffuse knapweed (C. diffusa Lam.) (Compositae) in North America. Journal of Applied Entomology 117: 35-50.
- Story, J.M., G.L. Piper, and E.M. Coombs. 2004. Knapweeds. In E.M. Coombs, J.K. Clark, G.L. Piper, and A.F. Cofrancesco, Eds. Biological Control of Invasive Plants in the United States. Oregon State University Press, Corvallis, Oregon. pp. 196-232.

Weed

Centaurea diffusa Lam.

Family: Asteraceae
Common Name: diffuse knapweed

Origin: Eurasia

Weed Name References:
- Seastedt, T.R., D.G. Knochel, M. Garmoe, and S.A. Shosky. 2007. Interactions and effects of multiple biological control insects on diffuse and spotted knapweed in the Front Range of Colorado. Biological Control 42: 345-354.
- Story, J.M., G.L. Piper, and E.M. Coombs. 2004. Knapweeds. In E.M. Coombs, J.K. Clark, G.L. Piper, and A.F. Cofrancesco, Eds. Biological Control of Invasive Plants in the United States. Oregon State University Press, Corvallis, Oregon. pp. 196-232.

Weed Common Name References:
- Seastedt, T.R., D.G. Knochel, M. Garmoe, and S.A. Shosky. 2007. Interactions and effects of multiple biological control insects on diffuse and spotted knapweed in the Front Range of Colorado. Biological Control 42: 345-354.
- Story, J.M., G.L. Piper, and E.M. Coombs. 2004. Knapweeds. In E.M. Coombs, J.K. Clark, G.L. Piper, and A.F. Cofrancesco, Eds. Biological Control of Invasive Plants in the United States. Oregon State University Press, Corvallis, Oregon. pp. 196-232.

Weed Origin References:
- Seastedt, T.R., D.G. Knochel, M. Garmoe, and S.A. Shosky. 2007. Interactions and effects of multiple biological control insects on diffuse and spotted knapweed in the Front Range of Colorado. Biological Control 42: 345-354.
- Story, J.M., G.L. Piper, and E.M. Coombs. 2004. Knapweeds. In E.M. Coombs, J.K. Clark, G.L. Piper, and A.F. Cofrancesco, Eds. Biological Control of Invasive Plants in the United States. Oregon State University Press, Corvallis, Oregon. pp. 196-232.

Release and Source Information

List: 1 - Exotic Organisms Intentionally Introduced

Source: Ex. Austria & Hungary & Romania
Year: 1988
Region: North America
Country: United States of America
Subregion of Country: CO, ID, MT, OR, WA
Subregion specific:

Release History: MT WA 1988; Redistributed OR 1995, CO 1996-1997, OR to ID 2008 2009 2011

Release Notes: Initially introduced onto Centaurea stoebe subsp. micranthos (primary host) and C. diffusa in 1988. Redistributions attempted on C. ×moncktonii in 1998 and C. virgata subsp. squarrosa in 1995.

Source Information References:
- Coombs, E.M. 1997. Biological control of weeds in Oregon. Annual Report. Project summaries 1996. Oregon Department of Agriculture, Noxious Weed Control Program, Salem, Oregon, USA. 33 pp.
- Coombs, E.M. 2013. (personal communication) Oregon Department of Agriculture, Noxious Weed Control Program, 635 Capitol St NE Salem, OR 97301 USA.
- Hansen, R. 1997. (personal communication) United States Department of Agriculture, Animal and Plant Health Inspection Service, Bozeman, Montana 59717, United States of America.
- Littlefield, J.L. 1997. (personal communication) Dept. Land Resources & Environmental Sciences Montana State University PO Box 173120 Bozeman, Montana 59717-3120, USA.
- Piper, G.L. and S.S. Rosenthal. 1995. Diffuse knapweed. In J.R. Nechols, L.A. Andres, J.W. Beardsley, R.D. Goeden, and C.G. Jackson, Eds. Biological Control in the Western United States: Accomplishments and Benefits of Regional Research Project W-84, 1964-1989. Publication 3361. University of California, Division of Agriculture and Natural Resources, Oakland, California. pp. 237-241.
- Seastedt, T.R., D.G. Knochel, M. Garmoe, and S.A. Shosky. 2007. Interactions and effects of multiple biological control insects on diffuse and spotted knapweed in the Front Range of Colorado. Biological Control 42: 345-354.
- Stinson, C.S.A., D. Schroeder, and K. Marquardt. 1994. Investigations on Cyphocleonus achates (Fahr.) (Col., Curculionidae), a potential biological control agent of spotted knapweed (Centaurea maculosa Lam.) and diffuse knapweed (C. diffusa Lam.) (Compositae) in North America. Journal of Applied Entomology 117: 35-50.

Original Host Species

Centaurea diffusa Lam., Centaurea maculosa Lam. (more recently referred to as the tetraploid cytotype of Centaurea stoebe L. sens. lat. but whose appropriate nomenclature remains to be resolved)

Original Host Species References:
- Stinson, C.S.A., D. Schroeder, and K. Marquardt. 1994. Investigations on Cyphocleonus achates (Fahr.) (Col., Curculionidae), a potential biological control agent of spotted knapweed (Centaurea maculosa Lam.) and diffuse knapweed (C. diffusa Lam.) (Compositae) in North America. Journal of Applied Entomology 117: 35-50.

Establishment

Established: Yes
Established in Subregion of Country: CO, ID, MT, OR, UT, WA, WY
Established in Subregion specific:

Establishment References:
- Coombs, E.M. 2013. (personal communication) Oregon Department of Agriculture, Noxious Weed Control Program, 635 Capitol St NE Salem, OR 97301 USA.
- Seastedt, T.R., D.G. Knochel, M. Garmoe, and S.A. Shosky. 2007. Interactions and effects of multiple biological control insects on diffuse and spotted knapweed in the Front Range of Colorado. Biological Control 42: 345-354.
- Story, J.M., G.L. Piper, and E.M. Coombs. 2004. Knapweeds. In E.M. Coombs, J.K. Clark, G.L. Piper, and A.F. Cofrancesco, Eds. Biological Control of Invasive Plants in the United States. Oregon State University Press, Corvallis, Oregon. pp. 196-232.
- Andreas, J.E., J. Milan, C. Randall, and J. Price. 2020. Biological Control. In E. Peachey, Ed. Pacific Northwest Weed Management Handbook. Oregon State University, Corvallis, Oregon. pp. A1-A7.

Abundance

Variable

Abundance References:
- Coombs, E.M. 2013. (personal communication) Oregon Department of Agriculture, Noxious Weed Control Program, 635 Capitol St NE Salem, OR 97301 USA.
- Story, J.M., G.L. Piper, and E.M. Coombs. 2004. Knapweeds. In E.M. Coombs, J.K. Clark, G.L. Piper, and A.F. Cofrancesco, Eds. Biological Control of Invasive Plants in the United States. Oregon State University Press, Corvallis, Oregon. pp. 196-232.
- Andreas, J.E., J. Milan, C. Randall, and J. Price. 2020. Biological Control. In E. Peachey, Ed. Pacific Northwest Weed Management Handbook. Oregon State University, Corvallis, Oregon. pp. A1-A7.

Agent Impact

Impact: Variable
Geographic Scale of impact: Variable
Impact Notes: In some states, principal host is Centaurea stoebe subsp. micranthos, but also damages C. diffusa to a lesser extent. In WA, C. diffusa is primary host; numbers also increasing on C. diffusa in ID. Impacts to C. diffusa not studied extensively, but moderate to high in CA, ID and WA, likely less important than Larinus spp. elsewhere. Impacts to C. diffusa overall likely greater under drought conditions when plants less capable of compensation.

Impact References:
- Andreas, J.E. 2013. (personal communication) Washington State University Extension, Integrated Weed Control Project, Puyallup Research Center, 2606 W Pioneer, Puyallup, WA 98371 USA.
- Coombs, E.M. 2012. Biological control of weeds in Oregon. Annual Report 2012. Oregon Department of Agriculture, Noxious Weed Control Program, Salem, Oregon, USA. 35 pp.
- Seastedt, T.R., D.G. Knochel, M. Garmoe, and S.A. Shosky. 2007. Interactions and effects of multiple biological control insects on diffuse and spotted knapweed in the Front Range of Colorado. Biological Control 42: 345-354.
- Story, J.M., G.L. Piper, and E.M. Coombs. 2004. Knapweeds. In E.M. Coombs, J.K. Clark, G.L. Piper, and A.F. Cofrancesco, Eds. Biological Control of Invasive Plants in the United States. Oregon State University Press, Corvallis, Oregon. pp. 196-232.
- Andreas, J.E., J. Milan, C. Randall, and J. Price. 2020. Biological Control. In E. Peachey, Ed. Pacific Northwest Weed Management Handbook. Oregon State University, Corvallis, Oregon. pp. A1-A7.
- Pitcairn, M.J. 2018. Weed biological control in California, USA: review of the past and prospects for the future. BioControl 63: 349–359.

Limiting Factors

None

Other Attack

Were other species attacked?: No
Other Species Attacked Notes:

Research Organizations

Oregon State Department of Agriculture, Salem (State (15))
Montana State University (State (7))
Bozeman, Montana (USDA (10))

Notes