Invasive Plant Integrated Pest Management: Where, When and Why Classical Weed

Biological Control is Critical

Carol Randall USDA Forest Service, State & Private

ForestryUMISC/NAISMA Meeting

10/2018

Since the beginning of agriculture man has engaged in a never-ending struggle to rid his land of weeds.

In this age of chemistry, there are yet millions of acres of land on which weeds flourish and where they either do not yield to chemicals used against them, or else this solution has proved impractical for other reasons.

With some of the worst weeds known where chemical, mechanical, or precautionary measures have failed, biological control, or the employment of natural enemies, has proved eminently successful.

C. B. Huffaker, 1957

Cohesive Narratives Promote Basic Literacy

• Conceptual models like the invasion curve and the enemy release hypothesis facilitate conversations about where, when and why weed biocontrol makes sense

• Explaining the invasion curve in the context of integrated pest management helps land managers recognize where biological control tactics are appropriate

• The enemy release hypothesis is useful for managing land manager expectations of weed biocontrol impacts

The Invasion Curve• An organizing concept for U.S. Early Detection

Rapid Response (EDRR) Framework

• Provides a simple yet effective way to quickly and responsibly evaluate the best course of action to minimize the impact from invasive species

• First described in Australian document “Protecting Victoria from Pest Animals and Weeds: Invasive Plants and Animals Framework”

• http://agriculture.vic.gov.au/agriculture/pests-diseases-and-weeds/protecting-victoria-from-pest-animals-and-weeds/invasive-plants-and-animals/invasive-plants-and-animals-policy-framework

Integrated Pest Management (IPM)

• A strategy to prevent and suppress pests with minimum impact on human health, the environment, and non-target organisms - Steve Dreistadt- University of California

• Focuses first on preventing problems

• Involves monitoring pest populations, identifying pests, and choosing individual or combinations of treatment tactics to keep pest populations at acceptable levels

• A recursive process- evaluate management strategy and adjust treatment tactics as needed to reach goals

Monitoring, Evaluation, and Reporting (MER)• One element of integrated pest management (IPM).

• Programs are continually reviewed and analyzed to ensure their approach is consistent with and supportive of any changes in environmental response, community expectation or scientific knowledge.

Research and Development (R&D)• The knowledge that comes from research and development is critical to

implement evidence-based management approaches and IPM. • Substantial advances in invasive species detection and management will

require development of new techniques and acquisition of greater knowledge.

• The investment in research needs to be sufficient to ensure future management is not seriously constrained by insufficient research and development support.

MER/R&D*Cultural

MER/R&D*IPM: Cultural Mechanical Herbicide CBC**To Treat or Not

MER/R&D*IPM: Cultural Mechanical Pesticide CBC**

MER/R&D*CulturalMechanicalPesticide

*MER/ R&D – Monitoring, Evaluation, Reporting; Research andDevelopment

IPM- Integrated Pest Management**CBC- Classical Biological Control

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If cannot eradicate, manage them at low levels

Classical Biological Control (CBC)

Components of Integrated Pest Management (IPM) for Invasive Species• Monitoring, Evaluation, and Reporting (MER)

• Research and Development (R&D)

•Determining Injury Levels and Thresholds- is Treatment Necessary?

• Type/ Scope/ Timing of Treatments• Cultural• Mechanical• Pesticide• Biological

• Evaluating Treatment Effectiveness- Revisiting Treatment Strategy

Management Response by Stage of Invasion

• Containment: • Where a invasive species cannot be eradicated, there can be substantial net benefit

gained from preventing its further spread by combining EDRR and IPM strategies

• Containment involves measures to eradicate outlying (satellite) infestations and prevent spread beyond the boundaries of core infestations (those that are too large and well established to eradicate)

• Obtaining a high degree of community support is a prerequisite for any long-term containment program

• Asset-based protection: • Appropriate once a weed has become so widespread that it would be inefficient to

control the species everywhere it occurs and containment would provide a low return on investment; focus becomes IPM

• The asset-based approach is to manage the species only where reducing its adverse effects provides the greatest benefits by achieving protection and restoration outcomes for specific highly valued assets

Managing at the Far End of the Invasion Curve

Van Driesche et al., 2010

• Invaders- once established- often persist indefinitely and spread to their ecological limits

• Reducing damage in small areas with chemical or physical/ mechanical control is possible for some species if funds and staff are available; but at the landscape level these tools work only if the infested area is small or sufficiently isolated to prevent re-infestation

• For landscape-level suppression or prevention of emerging damage from an expanding invasion; classical biological control should be considered because if successful it brings about desired ecological change over large areas without repeated costs or treatment of the entire infested area

• Classical biological control can be integrated with other weed management practices at the landscape scale such as grazing, fire management, land use change, etc.

Managing at the Far End of the Invasion Curve

Invasive Species Action Committee, 2016

• Among the various control options for invasive species, effective biological control may be the only option for achieving affordable and sustained management, particularly for widely dispersed pest species

Spatial Considerations of Stage of Invasion

• A particular weed may be widespread in one county (Asset-Based Protection); but a target for Prevention or Eradication a couple of counties away

• A western example: Rush Skeletonweed (RSW)

• Considered widespread in many parts of Idaho

• Montana conducting detection surveys and eradicating RSW populations when encountered

• Idaho focusing on RSW biological control

Weed density

Biocontrolagentdensity

Desirable vegetation density

Release ofcontrol agent

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Damage threshold

Managing Expectations: Enemy Release Hypothesis and Weed Biocontrol

Successful control

Keane & Crawley, 2002

Safety First• The International Code of Best Practices for Biological Control of

Weeds (Balciunas & Coombs, 2004) addresses concerns raised by biocontrol skeptics

• Following the Code helps ensure that biological control activities are most likely to be successful and least likely to have negative impacts

Outreach and Education

• Weed biocontrol information is becoming more readily available in technical manuals and on credible websites

• The important role classical biocontrol can play in landscape invasive plant management is being discussed in academic journals

iBiocontrol.org

Local and Regional Coordination

• In the Western United States many states have identified weed biocontrol coordinators to increase implementation of weed biocontrol in large weed infestations

• State biocontrol coordinators communicate intrastate with clients (CWMAs, land managers, etc.) and interstate with each other to share information and facilitate the collection and redistribution of weed biocontrol agents

• Interstate coordination facilitates technology transfer, increases the availability of needed biocontrol agents, and enables regional planning and national advocacy

Leading the Biological Control Charge

• In spite of constraints at the highest levels, state and local efforts continue to highlight the demand for existing weed biocontrol agents and the need for continued classical biocontrol research and development

• In the Western United States, state and local entities are weed biocontrol’s best proponents

Thank you

References

Balciunas, J.K., Coombs, E., 2004. International code of best practices for classical biological control of weeds. In: Biological Control of Invasive Plants in the US. 1st edition. Corvallis, OR: Oregon State University Press. p.130-136.

Corn, M.L., Buck, E.H., Rawson, J., Segarra, A., Fischer, E. (2002). Invasive non-native species: Background and issues for Congress. Congressional Research Service Report RL30123. US Government Printing Office, Washington D.C.

Corn, M.L, and Johnson, R. (2013). Invasive species: Major laws and the role of selected federal agencies. Congressional Research Service Report R43258. US Government Printing Office, Washington D.C.

Hoodle, M. (2003). The strength of biological control in the battle against invasive pests: A reply. Conservation Biology 18(1); 61-64.

Huffaker, C.B. (1957). Fundamentals of biological control of weeds. Hilgardia 27(3):101-157

Ielmini, M.R., Hopkins, T.E., Mayer, K.E., Goodwin, K., Boyd, C., Mealor, B., Pellant, M., Christiansen, T. (2015). Invasive plant management and greater sage-grouse conservation: A review and status report with strategic recommendations for improvement. Western Association of Fish and Wildlife Agencies. Cheyenne, Wyoming. 47 pp.

Keane, R. M. and Crawley, M. J. 2002. Exotic plant invasions and the enemy release hypothesis. TRENDS in Ecology & Evolution, 17 (4), pp. 164-170.

Pulling Together Initiative. Accessed 10/18/2017. http://www.nfwf.org/pti/Pages/home.aspx

The U.S. Department of the Interior. 2016. Safeguarding America’s lands and waters from invasive species: A national framework for early detection and rapid response, Washington D.C., 55p.

Van Driesche, R.G., Carruthers, R.I., Center, T., Hoodle, M.S., Hough-Goldstein, J., Morin, L. Smith, L., Wagner, D.L., et al. (2010). Classical biological control for the protection of natural ecosystems. Biological Control 54, S2-S33

Warner, K.D., McNeil, J.N., Getz, C. (2007). What every biocontrol researcher should know about the public. In Proceedings of the XII International Symposium on Biological Control of Weeds (eds Julien, M.H., Sforza, R., Bon, M.C., Evans, H.C., Hatcher, P.E., Hinz, H.L., Rector, B.G.) pp 390-394 CAB International Wallingford, U.K.

Invasive Plant Integrated Pest Management: Where, When and Why Classical Weed Biological Control is Critical

The invasive plant (weed) management community has developed best management practices to prevent or eradicate new weed invaders, but remains confounded by landscape weed infestations. Integrated pest management with its emphasis on a broad based approach that integrates practices for economic control of pests makes sense when managing weeds across landscapes. The invasion curve can be used to facilitate conversations about where, when and why land managers should take an integrated pest management approach to address weeds and identify classical weed biological control opportunities.

Classical weed biological control is particularly appropriate for landscape scale weed infestations because, if successful, it brings about desired ecological change over large areas without repeated costs or treatment of the entire infested area, and classical weed biological control can be integrated with other weed management practices. The United States has a history of successful weed biocontrol programs and a process in place to evaluate and regulate weed biocontrol agents. Weed biocontrol information is readily available in technical manuals and on credible websites, and the important role classical biocontrol can play in landscape invasive plant management is being discussed in academic journals.

In spite of a number of constraints, state and local efforts continue to highlight the demand for existing weed biocontrol agents and the need for continued classical biocontrol research and development. In the western U.S., state and local entities are weed biocontrol’s best proponents.