BioControl of Invasive Plants: A Florida Perspective

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BioControl of Invasive PlantsA Florida
Perspective
J.P. Cuda, Ph.D. Associate Professor
Entomology Nematology Department Gainesville,
FL 32611-0620
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Acknowledgements

• R. Charu Charudattan, Univ. of Florida
• Mike Grodowitz- ERDC, Vicksburg, MS
• Bill Overholt, University of Florida
• Greg MacDonald, University of Florida
• Yasser Shabana, University of Florida
• Judy Shearer, ERDC, Vicksburg, MS
• Phil Tipping, USDA, ARS, IPRL
• Greg Wheeler, USDA, ARS, IPRL
• FLDEP, SFWMD, FLEPPC, Osceola Co.

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Outline

• Introduction
• State of the Science
• Research Extension Priorities
• Questions ?

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Outline

• Introduction
• State of the Science
• Research Extension Priorities
• Questions ?

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TACTICS OF INTEGRATED PEST MANAGEMENT
BIOLOGICAL
CULTURAL
CHEMICAL
PHYSICAL
PREVENTION
IMPORTATION
AUGMENTATION
CONSERVATION
INORGANIC
ORGANIC
Fortuitous
NATURAL
SYNTHESIZED
NATURAL
SYNTHESIZED
Relative Degree of Sustainability
PERMANENT
TEMPORARY
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What is Biological Control ?

• Planned Use of Undomesticated Organisms to Reduce
  the Vigor, Reproductive Capacity, or Density of
  Weeds (DeLoach 1997).
• Four Categories
• Augmentation (Arthropods, Pathogens, Fish)
• Conservation (Arthropods, Habitat Manipulation)
• Importation or Classical (Arthropods, Pathogens)
• Fortuitous (Arthropods, Pathogens)

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Importation (Classical) BioControl

• Introduction and Release of Host Specific Natural
  Enemies from the Weeds Native Range to Reduce
  Its Growth, Reproduction or Density in the
  Adventive1 Range
• 1Arrived into a specified geographical region
  from elsewhere by ANY means.

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Enemy Release Hypothesis Conceptual Basis
for Weed BioControl

• Native Host Specific Enemies Strongly Control the
  Abundance and/or Distribution of Native Plants
• Escape from Host Specific Enemies is a Key
  Contributor to Exotic Plant Success
• Enemy Escape Benefits Exotics Because They Gain a
  Competitive Advantage Over Native Plants as a
  Result of Being Liberated from Their Pests

(Williams 1954)
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Objective of Classical BioControl

• Introduce or Apply Natural Enemies to Suppress
  and Maintain the Density of the Weed at
  ACCEPTABLE Levels
• Biological Control is NOT Eradication

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How Does BioControl Work ?

• Weed establishes equilibrium density (ED) above
  economic injury level (EIL)
• Natural enemy lowers ED maintains it
  below EIL
• ED - Long term mean density
• EIL Lowest density causing economic or
  ecological damage

Weed
Natural Enemy
ED
EIL
NUMBER
ED
TIME
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Advantages of Classical Weed BC

• Minimal Impact on Non-targets
• Environmentally Friendly
• Classical Biocontrol is Permanent
• Suitable for Weeds of Natural and Reclamation
  Areas
• Minimal Disturbance

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Costs/Benefits of BioControl
Release of Bioagent
Benefits ()
Time
Maintenance Monitoring
Costs (-)
Research Development
(after Mentz 1987)
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Disadvantages of Classical BC

• Control is Not Immediate (510 years)
• Little Interest in Commercialization
• Unpredictable
• Some Natural Enemies Fail to Establish
• Some Natural Enemies are Ineffective
• Abiotic and Biotic Interference

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BioControl Pipeline
Credit USDA, ARS
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New Quarantine Facilities
USDA-ARS Laboratory, Ft. Lauderdale
UF/DACS Laboratory, Ft. Pierce
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Defining BioControl Success(in Operational Terms)

• Complete- No other control
• methods are needed
• Substantial- Other methods needed but at
  reduced level
• Goal of IWM
• Negligible- Other methods are
• required
• (Hoffmann 1998)

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Messersmith and Adkins. 1995. Weed Technol.
9199-208.
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Florida BioControl Examples

• Complete- No other control
• methods are needed
• Substantial- Other methods needed but at
  reduced level
• Negligible- Other methods are
• required
• (Hoffmann 1998)

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BioControl of Alligatorweed circa 1960s
Agasicles Beetle
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BioControl Successes

• Complete- No other control
• methods are needed
• Substantial- Other methods needed but at
  reduced level
• Negligible- Other methods are
• required
• (Hoffmann 1998)

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BioControl of Waterhyacinth circa 1970s
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BioControl of Melaleuca circa 2000
WEEVIL ADULT
PSYLLID ADULT
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Florida BioControl Examples

• Complete- No other control
• methods are needed
• Substantial- Other methods needed but at
  reduced level
• Negligible- Other methods are
• required
• (Hoffmann 1998)

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BioControl of Waterlettuce circa 1980s
Neohydronomus Weevil
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BioControl of Hydrilla Florida, ca. 1980s
HYDRELLIA FLY LARVA
GRASS CARP
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Factors Impacting Hydrellia

• Hydrilla Mat Surface Temperature

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Factors Impacting Hydrellia
TRICHOPRIA WASP

• Parasitism
• Significant
• Upwards of 30
• Late in growing
• season
• Pupal parasitoid behavior
• Selects wide range
• Stage chosen
• most successful

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Factors Impacting Hydrellia

• Predation by Damselfly Dragonfly Naiads

HYDRELLIA DENSITY (no. / m2)
DRAGONFLY DENSITY (no. / m2)
UK
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Outline

• Introduction
• State of the Science
• Research Extension Priorities
• Questions ?

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Waterhyacinth- New Agents
Megamalus scutellaris (Hem Delphacidae)
Female
Male
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Hydrilla in Florida

• Chronology of Events
• 1960- Introduced into Crystal River, FL
• 1968- Correctly IDd herbicides ineffective
• 1970s- Rapid spread throughout Florida
• 1972- Release of grass carp
• 1980- Use of fluridone (Sonar) herbicide
• 1987- First biocontrol agent introduced
• 1992- Discovery of midge at Crystal River
• 2000- Fluridone resistance confirmed
• 2005- Renewed interest in biocontrol

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Surveys for New Hydrilla BioControls East
Africa, September 2005
FDEP Grant 05071948
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Burundi Survey, Sep 2005
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Burundi Survey, Sep 2005
Bagous sp. (coenosus species group)
Polypedilum sp. ?
Overholt and Cuda (2005)
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Hydrilla Bioherbicides
UF
Mycoleptodiscus terrestris (Native Fungal
Pathogen)
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Hydrilla Bioherbicides
Plectosporium tabanicum (Native Fungal Pathogen)
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Hygrophila
Melanagromyza sp. (Dip Agromyzidae)
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Hygrophila Surveys, Sep 2007
Delhi
Bangalore
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Brazilian Peppertree
1
6
2

• Thrips
• - Damages Shoots
• 2. Sawfly
• - Defoliator
• 3. Seed Wasp
• - Attacks Fruits
• 4. Weevil
• - Stem Feeder
• 5. Psyllid
• - Galls Leaves
• 6. Leafroller
• - Defoliator

3
5
(Fortuitous)
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Approved for Release- May 07
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BP Intraspecific Hybridization Pattern
Curitiba
Williams et al. (2005)
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BioControl Agent Survival on Florida BP Genotypes
a
a
a
a
a
b
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Simulated Herbivory StudiesUF/IFAS, IRREC, Ft.
Pierce
Treadwell and Cuda (2007)
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Apocnemidophorus pipitzi (Faust) (Col
Curculionidae)
Larval survival after 3 d
Larval survival before pupation
Pupation
Larval survival after 3 d
Larval survival before pupation
Pupation
Larval survival after 3 d
Larval survival before pupation
Pupation
Figure 5 Percentage ( std) of larval survival
and pupation of H. hubrichi Significant
differences, P lt 0.05
Figure 5 Percentage ( std) of larval survival
and pupation of H. hubrichi Significant
differences, P lt 0.05
Figure 5 Percentage ( std) of larval survival
and pupation of H. hubrichi Significant
differences, P lt 0.05
Figure 5 Percentage ( std) of larval survival
and pupation of H. hubrichi Significant
differences, P lt 0.05
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Weevil Exit Hole Larval Tunnels
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BP Pathogen

• BP Invades Coastal Habitats Prone to
• Flooding
• Several Insect BioControl Agents Unable to
• Complete Life Cycles in Hydrated or Saline
  Soils
• High Humidity Conditions Conducive to
• Establishment of Fungi

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Fungus Host Range Tests
Septoria fungus
1Anacardiaceae
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Brazilian Peppertree Management Plan

• 1997 Management Plan Revised
• April 2006
• 2nd Edition Available
• In Print and On-Line

http//www.fleppc.org/Manage_Plans/schinus.pdf
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(No Transcript)
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Skunk Vine
Leaf Beetle Adult
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Tropical Soda Apple
Leaf Beetle Adult Larva
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Cogon Grass
Bipolaris sacchari fungus
Cogan Grass Infestation (left) and Treatment Plot
with BioHerbicide
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Climbing Ferns
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Strawberry Guava
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Purple Sesban, Rattlebox
J. Hoffmann, Capetown Univ.
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Chinese Tallow
E. Siemann, Rice Univ.
Leaf Beetle Adult
Plant Sucking Aphid
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Fortuitous (Adventive) BioControl

• Regulation of a Weed Population by a Natural
  Enemy that Has Arrived from Elsewhere Without
  Deliberate Introduction
• No Active Human Involvement

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Hydrilla Midge Cricotopus lebetis Sublette

• Identified Dec 1998
• Collected in 1959, Natchitoches, LA
• Described 1964
• Hydrilla in Louisiana ?
• Natchitoches,1973
• Immigrant or native species????

Epler et al. (2000)
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Larvae and Associated Tip Damage
Cuda et al. (1999, 2002)
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Block 1 Control
Block 1 Midge
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Brazilian Peppertree
Seed Wasp
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West Indian Marsh Grass
Blissid Bugs
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Chinese Privet
Weevil Adult Larva
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Outline

• Introduction
• State of the Science
• Research Extension Priorities
• Questions ?

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Research Extension Priorities

• Biotype Matching in Host Range Testing
• Genetic Diversity of BioAgents Plants
• DNA Analysis Testing of Hybrids
• Brazilian Peppertree, Hydrilla, Melaleuca,
  Hygrophila
• Outreach / Technology Transfer of Biological
  Control
• Increase Training in Identification and Use
  of Biocontrol Technologies
  (e.g., TAME Melaluca)

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Research Extension Priorities

• Mass Rearing of Biocontrol Agents
• Better Control in Shorter Time
• Improve Perception of Safety Efficacy of
  Biological Control
• Promote IPM Approach to Invasive Weed Control
• Integration Leads to Greater Acceptance of
  Biological Controls
• Funding
• Need to Continue Programs

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Outline

• Introduction
• State of the Science
• Research Extension Priorities
• Questions ?