9/29/2020
Biological Control: The Basics
Kristen Bowers University of Florida IFAS Indian River Research and Education Center Fort Pierce, FL
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Natural Biological Control
Alton Sparks Jr., University of Georgia
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Biological Control Agents
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What is Biological Control?
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Types of Biological Control: Augmentative
Photo: Jannine Raizz, University of Florida 5
Types of Biological Control: Conservation
Photo: Lyle Buss, University of Florida
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Types of Biological Control: Classical
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Origin of US non-native plant introductions
28% Deliberate
Accidental 61% 11% Unknown
* Lehan, N.E., Murphy, J.R., Thorburn, L.P., and B.A. Bradley. 2013. ACCIDENTAL INTRODUCTIONS ARE AN IMPORTANT SOURCE OF INVASIVE PLANTS IN THE CONTINENTAL UNITED STATES. Am. J. of Botany. 100:1287-1293. 8
Invasive aquatic plants in Florida
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Invasive Aquatic Plants in Florida
Common Name Scientific Name Aquatic soda apple Solanum tampicense Crested floating heart Nymphoides aquatica Cuban club-rush Cyperus blepharoleptos Feathered mosquitofern Azolla pinnata Giant salvinia Salvinia molesta Hydrilla Hydrilla verticillata Hygrophila Hygrophila polysperma Lyngbya Microseira wollei Napier grass Pennisetum purpureum Para grass Urochloa mutica Torpedograss Panicum repens Tropical American water grass Luziola subintegra Uruguayan waterprimrose Ludwigia uraguayensis Water hyacinth Eichhornia crassipes Water lettuce Pistia stratiotes Water spinach Ipomoea aquatica West Indian marsh grass Hymenachne amplexicaulis Wild taro Colocasia esculenta
https://plants-archive.ifas.ufl.edu/manage/why-manage-plants/floridas-most-invasive-plants/
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Impacts of Non-Native Plants
• Crowd out/out compete native vegetation • Reduce forage and habitat for native fauna • Threaten commercial, agricultural, and recreational activities • Harm to human/animal health • Alter fire regimes • Alter water flow
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Biological Control Theory
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Biological Control
• Natural enemies • Does not eradicate pest • Reduces density
Slide from C. Minteer 13
Biological Control WEED
TIME Adapted from Gettys, Haller &Petty eds., 2014 14
Biological Control
Advantages • Safe (Host specific)
• Self-perpetuating
• Spreads to new areas
• Environmentally friendly
• High return on investment in the long run
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Biological Control
Disadvantages
• High up-front cost
• Slow acting
• Will not eradicate pest
• Doesn’t always “stick”
• Cannot be recalled
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Invasion Stages
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The Biological Control Pipeline
Adapted from Gettys, Haller &Petty eds., 2014
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Classical Biological Control Step 1: Feasibility
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Classical Biological Control Step 2: Foreign Host Range
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Classical Biological Control Step 3: Quarantine
• Quarantine (importation)
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Classical Biological Control Step 3: Fundamental Host Range
Family Tribe Sub-tribe Genus
Photo:Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
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Classical Biological Control Step 3: Fundamental Host Range
• No choice test
• Choice test
• Multi-generation test
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Classical Biological Control Step 3: Biology
• Basic biology studies • Development time • # eggs laid/female • Where/when eggs laid
• Impact studies
Slide from C. Minteer
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Classical Biological Control Step 4: The Permit
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Classical Biological Control Step 4: The Permit
• Taxonomy plant
• Plant impacts
• Alternative plant management • Insect background
• Host range testing
• Impact studies
• Basic biology information
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Classical Biological Control Step 4: The Permit
• TAG RECOMMENDATION: • NO • NOT YET • YES – • US Fish and Wildlife evaluation • Letter of Concurrence issued • Environmental Assessment • Public Comment
• Process take 8-10 years
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The Biological Control Pipeline
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Step 5: Release and Establishment
• Releases! • Evaluation • Establishment • Effectiveness • Spread
• Field host specificity
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Integrated Weed Management
• Biological control is not a silver bullet
• Is it possible to combine biological control with other tactics?
Lake & Minteer 2017
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Integrated Weed Management: Biocontrol + Herbicide
??
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Integrated Weed Management: Biocontrol + Herbicide
+ =
Haag & Habeck 1991, Lake & Minteer 2017
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Biological control in a management plan
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Aquatic & Wetland Project Talks:
• Hydrilla
• Alligator weed
• Waterhyacinth
Dave Moorehead, U. of Georgia
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Questions?
Kristen Bowers [email protected]
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