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UNDERSTANDING AND PREVENTING INSECTICIDE RESISTANCE

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UNDERSTANDING AND PREVENTING INSECTICIDE RESISTANCE Powered By Docstoc
					   UNDERSTANDING AND
  PREVENTING INSECTICIDE
RESISTANCE AND NEW R&D IN
   VECTOR PEST CONTROL
                 BY:

            DR. BILL DONAHUE
     SIERRA RESEARCH LABORATORIES
                      RESISTANCE

   The ability of a significant portion of a pest population
    to survive a pesticide at rates that once killed most
    individuals of that population.

   A genetic change in response to selection.

   A natural process controlled by genetics and expressed
    in specific biochemical processes.
              TYPES OF RESISTANCE

   Metabolic – changes in detoxification (enzyme)
    system within the arthropod.

   Target Site Insensitivity - receptors

   Reduced Penetration - arthropod cuticle or plant
    surfaces (leaves)

   Behavioral - avoidance
               HISTORICAL PRESPECTIVE

   1914 – San Jose Scale (insect) insensitive to lime sulfur
   1946 – Resistance documented in 11 species of arthropods
   1947 – DDT resistance first reported
   1962 – Silent Spring – Environmental awareness of pesticides
   1948 – 1983 - # of arthropod species demonstrating resistance
    doubles about every 6 years.
   1988 – 504 species of arthropods are resistant to one or more
    pesticides
             REASONS FOR RESISTANCE

   High Intensity Cropping Systems – Agriculture
   Food Production Animal Operations
   Disease Vector Control Programs
   Urban Pest Control Programs
   Commodity Treatments

   Routine pest control relying primarily on chemical
    control, often a single pesticide or class of pesticides.
        TIME UNTIL DEVELOPMENT OF
                RESISTANCE

   Organophosphates – 14 years
   Organochlorines (DDT) – 7 years
   Carbamates – 5 years
   Pyrethroids – 4 years
   IGR‟s, Bacterial Insecticides, Avermectins
   New Compounds?
   Formulations – Cockroach Gel Baits, Ear Tags
                   The Way It Was




DDT was hailed as “the
miracle insecticide” and
“almost perfect control
 product for this pest”
                               Resistance was observed
                               after only 5 years of use.
         Insecticide Resistance
                    Bed Bugs

   1930‟s – 40‟s: DDT insecticide of choice
   1952-1956 DDT resistance wide spread
   1950‟s: Malathion insecticide of choice
   1960-2000: Low incidence of bed bugs world wide
   1990‟s: Pyrethroids insecticides of choice
Pessimist View of Resistance


Resistance is sure to develop and there is
      nothing we can do about it!
  Optimist View of Resistance


When you can’t change the direction of the
       wind – adjust you sails!
        Why Does Resistance Develop?

   Resistance is quick to develop to compounds with high
    effective kill, long residual and are highly selective at a
    single biochemical target site.

   Why? High Selection Pressure within the Population!
    How Can We Slow Down Resistance?

   Resistance is slow to develop with inefficient, short
    residual compounds because selection pressure is low!
   Select compounds that interfere with multiple
    biochemical or physiological systems.
   Mixtures like Botanical Insecticides, Synergists, IGR‟s
   Refugia – A source of susceptible individuals (genetic)
    within a population – Don‟t Kill „em All!
   Integrated Pest Management – Ecology in Action!
       INSECTICIDE RESISTANCE IN FLEAS

   8 Species of fleas demonstrated resistance including cat fleas

   Low Resistance Ratios (same for German Cockroaches)

   High Strain Variability – Relatively Isolated Populations

   Much Insecticide Resistance Ascribed to Cat Fleas may be
    Variation in Flea Susceptibility.
The Modern Environmental Movement
        NEW INSECT CONTROL STRATEGY

   Reduce Reproductive Potential
   Extend Generation Time
   Early Season Treatment
   Season Long Control
   Breaking the Life Cycle
   Target most Vulnerable Life Stage
   Planned & Integrated Control Methods
   Education, Knowledge & Surveillance
   Least Toxic Approach – Chemical, Mechanical, Cultural Control
    Techniques
   SO WHERE DO WE START?




 Pesticides must be used judiciously in an
    IPM program so as to preserve cost
     effective pesticides and maintain
susceptible individuals in a pest population
INTEGRATED PEST MANAGEMENT

IPM – An ecology-based control system which
  combines many techniques in an organized program
  to keep pest populations below levels of economic
  damage or nuisance.

Control techniques are selected and applied to
 minimize risk to human health, beneficial and non-
 target organisms, and the environment.
       COMPONENTS OF AN IPM PROGRAM

   Natural Control – Use or Enhance What‟s There, Biological
    Control – Parasites, Predators and Pathogens

   Cultural Control – Modify Existing Practices such as
    Temperature, Watering, Fertilizing

   Mechanical/Physical Control – Specialized Equipment or
    Practices Such as Mowing and Tilling

   Chemical Control – Many Choices – Least Toxic Approach!
        ELEMENTS OF AN IPM PROGRAM

Knowledge – Pest Biology and Ecology

Integrated System of Strategies – A Plan With Depth

Surveillance and Monitoring – Visual, Traps, Data Recorders

Continuous Evaluation and Updates – Is the Plan Working?

Education – New Information, Update the Plan
Resistance Management - Bioassays
         Discovering New Chemistries
           From Concept to Reality

 Chemical Synthesis and Basic Research
 Laboratory Bioassays – Multiple Tiers

 Field Testing – Multiple Geographical Sites

 Toxicology Studies from Cells to the Environment

 Product Chemistry, Packaging & Stability

 Regulatory – EPA, States , Global/International

 Marketing & Sales

 Technical Support
            Bioassay Techniques
   Dose Response - Adult Fleas on filter paper, nylon
    discs, spun glass wool, dog hair, carpet, sand/soil.
    Evaluate technical materials or formulations
   Topical Bioassays - Adult Fleas
   Treated Media or Substrates - Larval Fleas
   Artificial Membrane Feeding Systems - Eggs and
    Adults - Systemic or Contact Effects
Screening New Chemistries
       Bioassay Evaluations




                                Residual Evaluations
Knockdown Evaluations
                              Test #1 1, 9, 13, 20 & 28 days
@ 1, 2, 4, 8 & 24 hours
                              Test #2 1, 7, 14, 28, 45, 59 & 91
Flea & Tick Screening
 New Compounds
On Farm Surveillance
Disease



          Food Poisoning
          Pink Eye
          Myiasis
          Bacteria, Viruses, Protozoa
          Annoyance
                        Ticks in the Urban Environment




Wildlife, Pets - Activities, Wooded Environments
      Disease Potential, Lyme Disease
      Public Perception - Monitoring
Tick Habitats - Rural
          RESEARCH AND NEW PRODUCTS

   Repellents – People, Pets & Livestock, Environmental

   Acaricides – New Compounds, Formulations, Traps

   Habitat Modification, Mapping (GIS), Models

   Field & Lab Research – Acarology, Epidemiology

   Basic Physiology – “Tick Spit” - Vaccines
                      Nuisance Fly Control

   House Flies, (Musca domestica); Stable Flies, (Stomoxys calcitrans);
    Little House Fly, (Fannia canicularis).
   Season – Late Spring through Late Fall
   Pest Control Measures – Truck Mounted Sprayers (mist blowers)

  Integrated Pest Management
 Other Measures? Light traps,

Sticky Ribbons, Parasitic Wasps,
Manure Management, Vacuum,
Baits
                         Results



Fly Counts from pans –
Visual or Volumetric
            Where Do We Go From Here?

   Identify Current Problems or Concerns
   Determine the Magnitude of the Problem
   Surveillance and Monitoring
   Develop Long Term Strategies
   Integrated Pest Management (IPM)
   Evaluate New Products
   Product Stewardship
QUESTIONS ?



QUESTIONS ?

				
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posted:8/13/2011
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