Planning an Insect Pest Management System from the Ground Up (with examples from organic research)

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Planning an Insect Pest Management System from
the Ground Up(with examples from organic
research)

• Geoff Zehnder, Sustainable Agriculture Program,
  Clemson University
• zehnder_at_clemson.edu

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Integrated Pest Management (IPM)
Integrated pest management (IPM) is a pest
control strategy that uses a variety of
complementary strategies including biological
and cultural management, mechanical and physical
controls, and genetic and pesticides when needed
(source Wikipedia).
Interesting fact For their leadership in
developing and spreading IPM worldwide, Dr. Perry
Adkisson (Texas AM) and Dr. Ray Smith (UC
Berkeley) received the 1997 World Food Prize.
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Integrated Pest Management

• Concept developed in the 1950s
• Early proponents emphasized ecological approaches
  for more permanent solutions
• Conventional agriculture
• Reactive approaches dominate
• Pesticides are relatively cheap (ecological and
  societal costs not factored)
• IPM Continuum culminates in biologically based
  strategies

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Organic Pest ManagementEmphasizes Preventative
Practices
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1st Phase Strategies(Foundation of Organic Pest
Management)

• Cultural practices implemented in the initial
  stages of organic farm planning
• Prevent and avoid problems beforehand
• Have roots in traditional agriculture

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Strategies Underlying 1st Phase Practices
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Farm Site Selection

• Pest management not usually most important
  consideration, but
• Many organic farms are located in regions where
  climate is unfavorable for pest outbreaks
• Example plum curculio
• In general, higher, cooler
• and dryer regions support
• fewer insect pests

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Crop Isolation/Rotation

• Most effective against pests that disperse short
  distances and/or that overwinter near host crop
  fields.

Colorado potato beetle
Carrot fly
Onion maggot
Learn about key pest (insect and disease) host
range and biology/behavior to help with crop
rotation plan
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Woody Borders

• Modeling studies indicate that woody field
  borders influence insect pest populations
• Habitat for natural enemies
• Can inhibit movement of pests into fields

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Isolation of Susceptible CropsIn Space or Time

• Insect transmitted virus diseases
• Depending on the virus/vector, new crops should
  be isolated from sources of inoculum (infested
  fields, weed hosts, etc)

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Rotation with Cover Crops

• Beneficial, but be aware of secondary effects
• Allelopathy may suppress crop growth
• Examples barley, oat, wheat, rye, canola,
  mustards, fescues,
• May harbor secondary pests
• i.e. wireworms attracted to grass cover crops

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Rotation with Biofumigation Crops

• Brassica crops (mustards, rape, etc.)
• Plant defense compounds
• Glucosinolates converted to isothiocyanates
• Soil concentrations high enough to kill
  pathogens, weed seeds, soil insects

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Soil Quality ManagementDoes it affect
above-ground pest damage?
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Organic farming proponents have long held the
view that the likelihood of pest outbreaks is
reduced in healthy soil

• Sir Albert Howard. 1940.
• RC Oelhaf. 1978
• MC Merrill. 1983

• Belowground and aboveground habitat
  management is equally important
• Plant resistance is linked to optimal physical,
  chemical and biological properties of soil

Miguel Altieri (UC Berkeley)
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European Corn Borer Infestation Reduced on
Plants Grown in Organic Soils

• Compared egg-laying on plants grown in soil from
  organic vs conventional farms
• Significantly more ECB eggs laid on plants in
  conventional soil
• Egg-laying was more variable on plants in
  conventional soils.
• Variability in egg-laying affected by plant
  mineral balance
• Hypothesis biological buffering in org. soils

Research by Dr. Larry Phelan Ohio State
University
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Reduced development of Colorado potato beetle on
potato grown in organic soil
Research by Alyokhin Atlihan, 2005
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Mulch an IPM tool

• Can help reduce problems with
• Colorado potato beetle
• Aphid and thrips transmitted viruses
• May exacerbate some insect problems
• Squash bug
• Planthopper

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Melon-Virus ExperimentsCover crop as camouflage

• Annual rye planted between rows in late fall
• Virus incidence lower in cover crop treatments
• Reflective mulch also reduced virus incidence

Plants Infected with WMV
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Conservation tillage

• Favors rich soil biota
• Greater abundance and diversity of soil microbes
  in conservation tillage
• Favors greater numbers of predatory arthropods
  (spiders, beetles)

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Host Plant Resistance

• Resistance vs. Tolerance
• Limited application for control of insect pests
  in conventional agriculture
• Efficacy of synthetic insecticides
• Low tolerance for cosmetic damage
• Partial plant resistance not acceptable

Whitefly Damage Hairy vs. Smooth Leaf Cotton
Corn Earworm Cant easily penetrate tight husk
varieties
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Prince Hairy PotatoFrom Cornell Breeding
Program
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Moderate HPR is preferable in sustainable/organic
systems

• Low-level pest densities support natural enemy
  populations
• Manipulate planting and harvest dates for optimum
  effect
• Demand may provide commercial incentives for seed
  companies to expand screening programs

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Second Phase StrategiesVegetation Management

• Make habitat less suitable for pests attractive
  to natural enemies
• Terms include
• Habitat enhancement
• Farmscaping
• Ecological Engineering
• Conservation biological control
• Intercropping
• Trap Cropping

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Plant Diversification

• Provides food and shelter for natural enemies
  (predators and parasites)
• Favorable microclimate
• Alternative hosts or prey
• Supply of nectar and pollen
• Enhances top-down action of natural enemies on
  pests.

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Beetle BanksIsland Habitats on Farms

• Permanently vegetated raised strips across fields
  (grasses, perennials). Refuge for
• Predatory beetles
• Spiders
• Birds
• Small mammals
• Primarily used in large fields (cereal, row
  crops)
• Winter home for gt 1000 predatory invertebrates
  per square meter (Thomas et al. 1992)

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Conservation Strips

• Mixture of forbs and grasses
• Combines beetle bank and insectary strip
  concepts
• Increases rates of predation
• Management of weed strips can be used in this
  context

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Intl. Organic Research Institute in Switzerland
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Flowering Insectary Strips

• Provides pollen and nectar
• Attracts and keeps natural enemies in area
• Provisioned natural enemies have increased
  longevity, fecundity

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Evaluation of Wildflower Strips to Enhance
Biocontrol in CabbagePfiffner et al. 2003

• Treatments
• Strips adjacent
• Strips 10-90 meters
• Cabbage with no strips
• Higher rate of parasitism next to strips
• Parasitism increased with proximity to strips
• Scale/size of strips relative to crops important

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Chocolate-box Ecology?

• Flowering plants added without prior testing
• Parasitic wasps visit an ave. of only 2.9 plant
  species
• Researchers now screen plants for optimal species
• Farmers collect info on key pests, natural
  enemies to design effective farmscapes
• www.attra.org

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Intercropping

• Resource concentration hypothesis (Root 1973)
• Concentrated areas of host plants are easier for
  insect pests to find and colonize
• Interferes with pests in a bottom-up manner

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Trap Cropping

• Attractiveness and relative size in the landscape
  are key factors
• Examples
• Blue Hubbard around summer squash Pumpkins
  around melons (cuc. beetle)
• Cherry peppers around bell pepper (pepper maggot)
• Collards around cabbage (DBM)

Top Sam Pair, USDA-ARS, Lane, OK Bottom Randy
Blackmer, Dale, CT
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Third Phase StrategiesRelease of Biological
Control Agents

• Predators, parasitoids
• Microbial agents
• Selectivity
• Allow for rapid response to pest problems
• Most research in greenhouse systems

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Biocontrol Agent Success in Commercial
GreenhousesPredatory Mites Orius spp.
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Release of Biocontrol Agents in Field-Grown
Organic CropsExperimental Successes

• Parasitoids
• caterpillars in vegetables, aphids in wheat,
  leafhopper in vineyards
• Mite, ladybug and lacewing predators
• spider mites, aphids and leafhoppers in vineyards
  and apple orchards

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Release of Biocontrol Agents in Field-Grown
Organic CropsExperimental Failures
Cherry fruit fly on sweet cherry
Grape mealybug on grape
Incompatible life histories of pest and
biocontrol agent, or disruption of agents by
other natural enemies
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Biocontrol LandmarkBacillus thuringiensis

• 1901 Silkworm sudden collapse disease
• 1911 Named by Ernst Berliner (Thuringia)
• Farmer use in 1920s France Sporine
• EPA registration in 1961
• Thousands of strains active against caterpillars,
  beetles, flies
• Toxin attacks gut cells

Bt spore crystals Courtesy of Rosemary Walsh,
EMF-LSC, Penn State
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Biocontrol LandmarkCodling Moth Granulosis Virus

• Isolated from codling moth in 1963
• Europe
• 1979 Apple Biological Control Program
• Three commercial formulations widely used
• U.S.
• Two commercial formulations little use

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Of Less ImportanceEntomopathogenic Fungi and
Nematodes
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Why is Use of Biological Control Agents Limited?

• Commercial development restricted only to those
  with potential market for large acreage crops
• Many effective agents for less important pests
  never pass beyond developmental stage
• Mass rearing techniques
• Small companies limited technology
• Suboptimal quality in past but improving
• But used regularly in organic farming
• Research needed on how to integrate use of
  biocontrol agents with other strategies

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4th Phase Strategies

• Insecticides of biological, mineral origin
• Pheromones
• Repellents
• Mineral oils, insecticidal soaps
• Non-synthetic origin (except pheromones)

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Organic Insect Control ProductsCurrent Trends in
Organic Farming

• Reduced pyrethrin use non-target effects
• Azadirachtin (neem) use is increasing
• Successful experiments against several pests
  including aphids and some chewing insects
• Spinosad one of few new approved materials
• Fermentation product of bacterium
  Saccharopolyspora spinosa
• Successfully tested worldwide against a variety
  of pests/crops

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Quassia Extract (bitter wood)Quassia amara

• Many active compunds alkaloids, triterpenes and
  bitter principles (quassin)
• 50X more bitter than quinine herbal remedy
• Used mostly in Europe
• Mosquito larvacide
• To control aphids in cereal crops
• To control wooly apple aphid in tree fruit

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Kaolin Clay

• Surround WP
• Used as a repellent alters feeding, oviposition
  behavior of insect pests
• Most use in tree fruit, grapes

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Specialized Application
Dropleg application of Bacillus thuringiensis
var. kurstaki against lepidopterans in leek. The
application from top and bottom increases
efficacy of Bt applications. Photo Eric Wyss,
FiBL
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Limits of OMRI-Approved Insecticides, etc

• Degrade quickly low potency short residual
  activity
• Must integrate with other strategies
• More research needed
• Develop treatment thresholds for organic systems
  where natural enemies are prevalent
• Commercial development
• EPA fast-track registration
• Limited by markets

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Organic Insect Pest ManagementFuture Directions

• Integration of tactics i.e. 2nd and 3rd phase
  strategies Example

Egg parasite Longevity and survival enhanced by
nectar plants
Pest Brown apple moth
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Attract Kill

• Products mix pest attractants (pheromones) with
  insecticide

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Attract Reward

• Attract (4th phase)
• Lures with synthetic plant volatiles
• Attract beneficial insects
• Reward (2nd phase)
• Pollen, nectar plants
• Enhance level of pest control

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Valuing Ecosystem Services

• Ecosystem services are the conditions and
  processes through which natural ecosystems, and
  the species that make them up, sustain and
  fulfill human life (Daily 1997).

The value of global Ecosystem Services estimated
at 33 trillion (Costanza et al., 1997).
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Dr. H.S. SandhuLincoln University, New Zealand

• Assessing the predation rate of aphids
  (Acyrthosiphon pisum Harris)
• Assessing the predation rates of blow fly eggs
  (Calliphora vicina R.D.) simulating carrot rust
  fly eggs (Psila rosae Fab.)

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Experimental assessment of ES in arable fields
29 Study Sites (14 Organic and 15 Conventional
fields) (a)
(b)
Lincoln
Rakaia river
N
Leeston
Ashburton
Fig. (a) Map of New Zealand study area
(Canterbury). (b) Location of selected
arable organic ( ) and conventional fields (
)
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Predation rates of aphids and fly eggs in
selected arable fields
Fig. Predation rates
(removal/24h) of aphids
and fly eggs in selected fields
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Ground living polyphagous predators Are they
any value?
Dollar value of biological control of
aphids in selected organic fields
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More Information

• More information on insect management for organic
  farms can be found at
• http//attra.org/pest.html
• http//www.extension.org/article/18593
• http//www.sare.org/publications/insect.htm

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Acknowledgements

• This presentation address general organic
  production practices. It is to be to use in
  planning and conducting organic horticulture
  trainings. The presentation is part of project
  funded by a Southern SARE PDP titled Building
  Organic Agriculture Extension Training Capacity
  in the Southeast
• Project Collaborators
• Elena Garcia, University of Arkansas CESHeather
  Friedrich, University of ArkansasObadiah Njue,
  University of Arkansas at Pine BluffJeanine
  Davis, North Carolina State UniversityGeoff
  Zehnder, Clemson UniversityCharles Mitchell,
  Auburn UniversityRufina Ward, Alabama AM
  UniversityKen Ward, Alabama AM UniversityKaren
  Wynne, Alabama Sustainable Agriculture Network