Protecting Military Personnel by Controlling HostSeeking Arthropods

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Protecting Military Personnelby Controlling
Host-Seeking Arthropods

• Brian Quinn
• USDA/ARS/CMAVE/MFRU
• Gainesville, Florida

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Topics

• Screening endemic plants for toxicant and
  repellent compounds
• Barrier spraying with cyfluthrin
• Evaluation of thermal foggers

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Screening Endemic Plants for New Toxicants and
Repellents

• Plants were extracted with three different
  solvents (hexane, dichloromethane, and methanol)
  to collect a wide range of organic compounds
• Extracts were concentrated and analyzed by GC/MS
  to determine chemical components

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Screening Endemic Plants (cont.)

• List of candidate plants prepared by examining
  older literature on plant use by settlers and
  Native Americans as well as current literature
• Certain plant families from southeastern US were
  highlighted after multiple species within the
  families were found to have bioactive compounds

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Bioassays for Plant Extracts

• Extracts are evaluated for toxicity using the WHO
  topical assay
• Repellency of the same extract is evaluated using
  the cloth patch test

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Etonia rosemary (Conradina etonia)
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Chromatogram of Etonia Rosemary
Camphor
Eucalyptol
Caryophyllene oxide
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Mass Spectrum of Camphor
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Summary Native Plant Extraction

• To date, 33 plant extracts have been prepared and
  these have been evaluated for bioactivity against
  Aedes aegypti mosquitoes
• Individual chemical components identified by
  GC/MS from these extracts are currently being
  evaluated for repellency and toxicity to
  mosquitoes

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Summary (cont.)

• Military relevance New repellents and
  insecticides needed to combat vector-borne
  diseases natural products are often more
  acceptable to the public, including deployed
  military personnel.
• Future work Evaluate additional chemical
  components with bioactivity against biting
  insects.

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Barrier Spraying

• Adulticide technique for controlling biting
  insects in a designated area
• Utilization could provide effective and lasting
  control while using much less product than in
  space sprays
• Different leaf integuments may influence residual
  pesticide concentrations and efficacy

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Barrier Spraying Methodology

• Backpack sprayer used to coat plants with Tempo
  (a.i. cyfluthrin)
• Samples taken weekly for bioassays and chemical
  analysis
• Bioassay modeled after the WHO tarsal contact
  method
• Pesticide residue testing- soon to be completed

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Barrier Spraying Methodology

• Plants used in this study
• Southern Magnolia (Magnolia grandiflora)
• Salt Cordgrass (Spartina bakeri)
• American Beautyberry (Callicarpa americana)

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Southern Magnolia
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Salt Cordgrass
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American Beautyberry
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Mixing the Cyfluthrin Formulation
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Plants Before Application
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Low Volume Application of Tempo on Cordgrass
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Plants after Application
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Summary Barrier Spraying

• Military relevance When applied properly,
  barrier sprays have the potential to effectively
  protect encampments from biting insects at a
  fraction of the cost of space spraying.
• Future work Continue collaborative studies with
  NECE to evaluate additional application equipment
  and adulticides under different climatic
  conditions.

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Thermal Fogger Study

• Four major equipment manufacturers, industry
  colleagues, military personnel, and ARS
  scientists collaborated to study droplet size and
  pesticide degradation at NECE from January 22-24,
  2007.
• Twelve thermal foggers were evaluated using the
  following five formulations Anvil 1010
  (d-phenothrin), Fyfanon (malathion), Kontrol
  30-30 (permethrin), Aqua-Reslin (permethrin), and
  Aqualuer (permethrin).

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Thermal Fogger Evaluation

• Analyzed prepared formulations
• Collected fog and analyzed the insecticide
  generated by the different thermal foggers to
  determine the pesticide concentrations
• Compared initial formulation with output.

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Thermal Fogger Evaluation

• Droplet size evaluation performed by Clint
  Hoffmann (APMRU/ARS) using a laser array
  apparatus
• Teflon-coated slide method used by NECE personnel
  to measure droplet size
• AIMS (hot wire) method operated by Todd Gwinn of
  ADAPCO

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Collecting Fog Samples from Dyna Fog
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Collecting Fog Samples from London Fog
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Beaker with Pesticide Fog
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Transferring Sample from Beaker to Vials
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Summary Thermal Foggers

• Pesticide degradation in thermal foggers has been
  poorly studied in the past. These data will be
  used to provide guidance for assigning future
  national stock numbers (NSN) to thermal foggers
  for use by military personnel.
• Military relevance Thermal foggers are powerful
  tools for effectively applying adulticides over a
  large area. Currently, there are only three
  thermal foggers with an NSN.

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Acknowledgements

• DWFP funding
• CMAVE staff
• NECE staff Todd Walker and Vincent Smith
• Thermal fogger manufacturers
• Todd Gwinn ADAPCO
• Clint Hoffmann APMRU/ARS

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