6)Management c)Control iii)Biological methods = “biologically” damaging plants

6) Managementc) Control

iii) Biological methods= “biologically” damaging plants

iii) Biological methods= “biologically” damaging plantsBiotic constraints/enemy release hypothesis

6) Managementc) Control

iii) Biological methods= “biologically” damaging plantsBiotic constraints/enemy release hypothesis

If plants are invasive because they have escaped natural enemies, introducing the natural enemies should help control the invasive!

6) Managementc) Control

iii) Biological methods• Least public opposition

6) Managementc) Control

iii) Biological methods• Least public opposition• Recall Nevada noxious weed legislation:

• Weed control analyst researches biological control options

6) Managementc) Control

iii) Biological methods• Least public opposition• Recall Federal Plant Protection Act :

Biological control is often desirable

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories

Prickly pear (Opuntia spp.) in Australia

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories

Prickly pear (Opuntia spp.) in Australia Chronology (source: http://www.northwestweeds.nsw.gov.au )• Introduced in 1788 with the First Fleet – dye industry• Additional introductions for forage and hedges though 1800s• Numerous species• Problem acknowledged 1870

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories

Prickly pear (Opuntia spp.) in Australia Chronology (source: http://www.northwestweeds.nsw.gov.au )• Introduced in 1788 with the First Fleet – dye industry• Additional introductions for forage and hedges though 1800s• Numerous species• Problem acknowledged 1870• 1886: prickly pear destruction act• 1910: ‘Roberts Improved Pear Poison’ created – 80% sulfuric

acid, 20% arsenic – considered best weapon

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories

Prickly pear (Opuntia spp.) in Australia Chronology (source: http://www.northwestweeds.nsw.gov.au )• Early chemical control: fumes from boiling arsenic

Photo: © L. R. Tanner

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories

Prickly pear (Opuntia spp.) in Australia Chronology (source: http://www.northwestweeds.nsw.gov.au )• Early chemical control: boiling arsenic• 1912 problem rampant: begin looking for biological control

Photo: © L. R. Tanner

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories

Prickly pear (Opuntia spp.) in Australia Chronology (source: http://www.northwestweeds.nsw.gov.au )• Early chemical control: boiling arsenic• 1912 problem rampant: begin looking for biological control• 1925, infested twenty-five million hectares in New South Wales

and Queensland. It was spreading at the rate of half a million hectares a year.

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories

Prickly pear (Opuntia spp.) in Australia Chronology (source: http://www.northwestweeds.nsw.gov.au )• 1926 introduction of Cactoblastis moth

Photo: © L. R. Tanner

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories

Prickly pear (Opuntia spp.) in Australia Chronology (source: http://www.northwestweeds.nsw.gov.au )• 1926 introduction of Cactoblastis moth• By 1932, most of the prickly pear stands had been decimated.

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories

Prickly pear (Opuntia spp.) in Australia • Summary: spectacularly successful BUT

• Took 14 years to find biocontrol agent (1912-1926)• Some cool-climate stands remained; insect less effective

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Klamath weed (Hypericum perforatum) in California

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Klamath weed (Hypericum perforatum) in California

• Broad-leaved, perennial herb• Introduced from Europe in 1793; reached California late 1800’s• Extremely invasive; toxic• By early 1940’s: 5 million acres of infested rangeland• Biological control in California: 1945-1950 @ $750,000 total

cost• By early 1960’s insects had reduced acreage to <1% of peak

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Tamarix in western US:

Photos: Bob Conrad, NAES

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Tamarix in western US:

• Source: Swedhin et al. 2006 (Tamarisk Research Conference, Fort Collins CO)

• Large scale dispersal and population expansion of Diorhabda elongata in CO, NV, and UT after initial releases

• Near Moab: two release sites in 2004. In 2005, less than 2 acres of tamarisk defoliated. In 2006, 109 acres defoliated, 4.1 miles upstream from release sites and area was expanding

• Expansion of beetles from UT release sites on Colorado River into CO expected by summer 2007

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations:

• Finding an enemy• ID promising species in native range• Test for host specificity• USDA has facilities in other countries for this purpose• http://www.ars-ebcl.org/

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations:

• Finding an enemy• ID promising species in native range• Test for host specificity• USDA has facilities in other countries for this purpose• http://www.ars-ebcl.org/• e.g. Montpelier, France

Photo © USDA ARS-EBCL

Current projects:Canada Thistle, Field Bindweed  Giant reed, Knapweeds, Leafy Spurge, Lepidium draba, Rush Skeletonweed, Saltcedar, Swallow-worts, Yellow Starthistle

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations:

• Finding an enemy• ID promising species in native range• Test for host specificity• USDA has facilities in other countries for this purpose• http://www.ars-ebcl.org/• e.g. Montpelier, France• Also Rome, Italy and Thessaloniki, Greece

Photos © USDA ARS-EBCL

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations:

• Finding an enemy• Host specificity: specialists not generalists

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations:

• Finding an enemy• Host specificity• Mode of action (plant part affected)

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations:

• Finding an enemy• Host specificity• Mode of action (plant part affected)• Type of organism (disease, insect)

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations:

• Finding an enemy• Host specificity• Mode of action (plant part affected)• Type of organism (disease, insect)• Climate requirements of organism (climate matching

for source populations and introduction sites)• e.g. some releases of Diorhabda from Texas

populations not successful at higher latitudes – couldn’t overwinter

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations:

• Finding an enemy• Host specificity• Mode of action (plant part affected)• Type of organism (disease, insect)• Climate requirements of organism (climate matching for

source populations and introduction sites)• Estimated that about ½ of introduced weed bio-control

insect species establish in new location

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations:

• Finding an enemy• Non-target effects

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations:

• Finding an enemy• Non-target effects

• Relatedness of flora

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations:

• Non-target effects – Pemberton (2000)

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations:

• Non-target effects

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations

• Non-target effects

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations

• Non-target effects

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations

• Non-target effects

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations

• Non-target effects

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations

• Non-target effects

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations

• Non-target effects

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations

• Non-target effects

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Difficulty locating enemy• Non-target effects – From Pemberton (2000)

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Difficulty locating enemy• Non-target effects – From Pemberton (2000)

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations

• Non-target effects

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Considerations

• Non-target effects

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Difficulty locating enemy• Non-target effects

Most likely a problem when the invasive species has closely related plants in the invaded area

6) Managementc) Control

iii) Biological methods• Least public opposition• Number of success stories• Difficulty locating enemy• Non-target effects

Most likely a problem when the invasive species has closely related plants in the invaded area

Monitor non-targets

6) Managementc) Control

iii) Biological methods: How to implement?Van Klinken RD, Raghu S (2006) Aust J Entomol 45:253-258

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds

• Agricultural impact• Impact to natural areas• Toxicity• Beneficial characteristics• Relatedness to native species• Origin• Extent of invasion

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds

• McClay (1989) and Peschken & McClay (1995) use a scoring system to rate weeds for biocontrol priority.

• economic losses (light to very severe) 0-30 pts• Additional points:

• Size of the infested area • expected spread• Toxicity• Available means of control• Economic justification.

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds

• McClay (1989) and Peschken & McClay (1995) use a scoring system to rate weeds for biocontrol priority.

• economic losses• Biological elements

• Geographic origin: more points for non-US weeds

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds

• McClay (1989) and Peschken & McClay (1995) use a scoring system to rate weeds for biocontrol priority.

• economic losses• Biological elements

• Geographic origin: more points for non-N. Am. weeds• Habitat stability: more points for stable habitats

(rangelands VS croplands)

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds

• McClay (1989) and Peschken & McClay (1995) use a scoring system to rate weeds for biocontrol priority.

• economic losses• Biological elements

• Geographic origin: more points for non-N. Am. weeds• Habitat stability: more points for stable habitats

(rangelands VS croplands)• Points added for absence of close native relatives

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Example: USDA ARS project: South American Biological

Control Agents to Suppress Invasive Pests in the U.S. began Nov 8 2005. Project Number: 0211-22000-006-00

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Example: USDA ARS project: South American Biological

Control Agents to Suppress Invasive Pests in the U.S. began Nov 8 2005

• Targets include: Tropical Soda Apple (Solanum viarum), Water-hyacinth (Eichhornia crassipes), Brazilian Peppertree (Schinus terebenthifolius)

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Example: USDA ARS project: South American Biological

Control Agents to Suppress Invasive Pests in the U.S. began Nov 8 2005

• Targets include: Tropical Soda Apple (Solanum viarum), Water-hyacinth (Eichhornia crassipes), Brazilian Peppertree (Schinus terebenthifolius)i) Literature review to identify promising species

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Example: USDA ARS project: South American Biological

Control Agents to Suppress Invasive Pests in the U.S. began Nov 8 2005

• Targets include: Tropical Soda Apple (Solanum viarum), Water-hyacinth (Eichhornia crassipes), Brazilian Peppertree (Schinus terebenthifolius)i) Literature review to identify promising speciesii) Field surveys in South America

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Example: USDA ARS project: South American Biological

Control Agents to Suppress Invasive Pests in the U.S. began Nov 8 2005

• Targets include: Tropical Soda Apple (Solanum viarum), Water-hyacinth (Eichhornia crassipes), Brazilian Peppertree (Schinus terebenthifolius)i) Literature review to identify promising speciesii) Field surveys in South America iii) Safety and effectiveness of control agent:

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Example: USDA ARS project: South American Biological

Control Agents to Suppress Invasive Pests in the U.S. began Nov 8 2005

• Targets include: Tropical Soda Apple (Solanum viarum), Water-hyacinth (Eichhornia crassipes), Brazilian Peppertree (Schinus terebenthifolius)i) Literature review to identify promising speciesii) Field surveys in South America iii) Safety and effectiveness of control agent:

• presence and abundance related to climate

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Example: USDA ARS project: South American Biological

Control Agents to Suppress Invasive Pests in the U.S. began Nov 8 2005

• Targets include: Tropical Soda Apple (Solanum viarum), Water-hyacinth (Eichhornia crassipes), Brazilian Peppertree (Schinus terebenthifolius)i) Literature review to identify promising speciesii) Field surveys in South America iii) Safety and effectiveness of control agent:

• presence and abundance related to climate• phenology of control agents and hosts

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Example: USDA ARS project: South American Biological

Control Agents to Suppress Invasive Pests in the U.S. began Nov 8 2005

• Targets include: Tropical Soda Apple (Solanum viarum), Water-hyacinth (Eichhornia crassipes), Brazilian Peppertree (Schinus terebenthifolius)i) Literature review to identify promising speciesii) Field surveys in South America iii) Safety and effectiveness of control agent:

• presence and abundance related to climate• phenology of control agents and hosts• type and level of damage on targets

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Example: USDA ARS project: South American Biological

Control Agents to Suppress Invasive Pests in the U.S. began Nov 8 2005

• Targets include: Tropical Soda Apple (Solanum viarum), Water-hyacinth (Eichhornia crassipes), Brazilian Peppertree (Schinus terebenthifolius)i) Literature review to identify promising speciesii) Field surveys in South America iii) Safety and effectiveness of control agent:

• presence and abundance related to climate• phenology of control agents and hosts• type and level of damage on targets • Oviposition and feeding substrates

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Example: USDA ARS project: South American Biological

Control Agents to Suppress Invasive Pests in the U.S. began Nov 8 2005

• Targets include: Tropical Soda Apple (Solanum viarum), Water-hyacinth (Eichhornia crassipes), Brazilian Peppertree (Schinus terebenthifolius)i) Literature review to identify promising speciesii) Field surveys in South America iii) Safety and effectiveness of control agent:

• presence and abundance related to climate• phenology of control agents and hosts• type and level of damage on targets • Oviposition and feeding substrates• overwintering sites

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Example: USDA ARS project: South American Biological

Control Agents to Suppress Invasive Pests in the U.S. began Nov 8 2005

• Targets include: Tropical Soda Apple (Solanum viarum), Water-hyacinth (Eichhornia crassipes), Brazilian Peppertree (Schinus terebenthifolius)i) Literature review to identify promising speciesii) Field surveys in South America iii) Safety and effectiveness of control agent:

• presence and abundance related to climate• phenology of control agents and hosts• type and level of damage on targets • Oviposition and feeding substrates• overwintering sites• Host range tests: primary and closely related

hosts, critical hosts

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Example: USDA ARS project: South American Biological

Control Agents to Suppress Invasive Pests in the U.S. began Nov 8 2005

• Targets include: Tropical Soda Apple (Solanum viarum), Water-hyacinth (Eichhornia crassipes), Brazilian Peppertree (Schinus terebenthifolius)i) Literature review to identify promising speciesii) Field surveys in South America iii) Safety and effectiveness of control agentiv) Climate modeling to match sources to target

populations

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Example: USDA ARS project: South American Biological

Control Agents to Suppress Invasive Pests in the U.S. began Nov 8 2005

• Targets include: Tropical Soda Apple (Solanum viarum), Water-hyacinth (Eichhornia crassipes), Brazilian Peppertree (Schinus terebenthifolius)i) Literature review to identify promising speciesii) Field surveys in South America iii) Safety and effectiveness of control agentiv) Climate modeling to match sources to target populations v) Introduction of bio-control agents to quarantine sites

in US for further testing

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Example: USDA ARS project: South American Biological

Control Agents to Suppress Invasive Pests in the U.S. began Nov 8 2005

• Targets include: Tropical Soda Apple (Solanum viarum), Water-hyacinth (Eichhornia crassipes), Brazilian Peppertree (Schinus terebenthifolius)i) Literature review to identify promising speciesii) Field surveys in South America iii) Safety and effectiveness of control agentiv) Climate modeling to match sources to target populations v) Introduction of bio-control agents to quarantine sites in US

for further testingvi) Progress: have ID’d several agents and host species

lists for each invasive plant. Prioritization of agents next priority. Import and testing in US projected for 2007-2008.

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Rear the bio-control agent

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Rear the bio-control agent

• Laboratory rearing:• Easier, more cost effective, less mortality, more

insects?• Not ‘hardened’ to environmental conditions, lower

success in releases

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Rear the bio-control agent

• Laboratory rearing:• Easier, more cost effective, less mortality, more

insects?• Not ‘hardened’ to environmental conditions, lower

success in releases• Field rearing:

• More difficult, more expensive, fewer insects• Site selection is important (high quality stand of target

plant)

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Rear the bio-control agent

• Laboratory rearing:• Easier, more cost effective, less mortality, more

insects?• Not ‘hardened’ to environmental conditions, lower

success in releases• Field rearing:

• More difficult, more expensive, fewer insects• Site selection is important (high quality stand of target

plant)• ‘quality’ probably outweighs ‘quantity’ in bio-control

releases

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Rear the bio-control agent• Release the biocontrol agent

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Rear the bio-control agent• Release the biocontrol agent

• Only about 60% of released agents become established (Crawley 1989).

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Rear the bio-control agent• Release the biocontrol agent

• Only about 60% of released agents become established (Crawley 1989)

• Success affected by climate, size of release, number and timing of releases, predators, weather conditions

• Improve success by releasing field-reared agents, matching climate, selecting release site carefully (high density of target plants, few predators)

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Rear the bio-control agent• Release the biocontrol agent

• Only about 60% of released agents become established (Crawley 1989)

• Success affected by climate, size of release, number and timing of releases, predators, weather conditions

• Improve success by releasing field-reared agents, matching climate, selecting release site carefully (high density of target plants, few predators)

• Caged releases VS open field releases

6) Managementc) Control

iii) Biological methods: How to implement?• Identify appropriate target weeds• Identify possible bio-control agents• Rear the bio-control agent• Release the biocontrol agent

• Only about 60% of released agents become established (Crawley 1989)

• Success affected by climate, size of release, number and timing of releases, predators, weather conditions

• Improve success by releasing field-reared agents, matching climate, selecting release site carefully (high density of target plants, few predators)

• Caged releases VS open field releases• e.g. Kirby et al 2000: released 80 beetles in 1989, 1000

beetles in 1990. Open release, colonization was successful.

6) Managementc) Control

Biological control in CA: success rates and references

Biological control in CA: cont’d

iv) Underlying socioeconomic issues• Introductions = $$$

• Many (most) invasive species introduced intentionally

6) Managementc) Control

iv) Underlying socioeconomic issues• Introductions = $$$

• Many (most) invasive species introduced intentionally• Concern about control (including biological control)• Other economic benefits of invasives – e.g. Purple

Loosestrife makes good honey!

6) Managementc) Control

iv) Underlying socioeconomic issues• Introductions = $$$• Public sentiment

Southwest Willow flycatcherEndangered species; Nests in Tamarisk

(nest success lower in Tamariskthan in native vegetation but still a concern)

6) Managementc) Control