Instructor:

Donald E. Mullins
Course Coordinator

Lectures:

Monday & Wednesday
11:15 am - 12:05 pm
220 Price Hall

Laboratories:

Tuesday 2:00 pm - 4:50 pm
Price 220 Hall

Course Info:

ENT/PPWS 4264
CRN 12773/14642
3 Credit Hours

WWW Contact:

Webmaster

Pesticide Usage

 

Lecture 11 Outline

February "21, 2007"

(Makeup lecture)

Insecticides

Donald E. Mullins

Department of Entomology

Reading assignment = Ware & Whitacre: Chapters 4 and 17

(A PDF of the Powerpoint lecture is available.. Click here)

IV. Organophosphates (continued from Lecture 10)

  • Mode of action:
    • latent period (activation)
    • acetylcholine esterase inhibition:
    • antidotes for organophosphate poisoning
      • atropine sulfate
      • oxime antidote = 2-PAM
  • Metabolism:
    • Phosphatase
    • O-demethylase or O-dealkylase
    • Carboxyesterase
     

V. Carbamates:

  • General characteristics:
    • derivatives of carbamic acid
    • broad spectrum
    • Hymenoptera sensitivity
    • easily hydrolyzable
    • activation reactions
    • systemic
    • solubility
    • plant metabolism
    • (acetyl) choline esterase inhibitors
  • Carbamate examples:
    • Carbaryl (Sevin)
      • AOT = 307 to 750 mg/kg
    • Carbofuran (Furadan)
      • AOT = 8 mg/kg
    • Aldecarb (Temik)
      • insecticide, acaracide, nematicide
      • systemic
      • AOT = 0.9 mg/kg
    • Propoxur (Baygon)
      • AOT = 95 mg/kg
  • Mode of action
    • synaptic poison
    • cholinesterase inhibitor
    • differences: (recovery)
    • mammalian toxicology
    • antidote = atropine ?; not 2-PAM
  • Metabolism:
    • hydrolysis
    • N-dealkylation
    • O-dealkylation
    • hydroxylation
    • conjugation
    • sulfur oxidation

VI. Botanicals

  • Pyrethrins/Pyrethroids
    • Historical & interest
    • Pyrethrins naturally occurring
      • chrysanthemum flowers
      • hand harvesting
      • AOT = 1500 mg/kg
      • 1880's louse powder
      • cyclopropane carboxylate
      • knockdown..reversible
      • unstable in sunlight
      • synergized
    • Synthetic pyrethroids
      • photostable
      • more active 0.1 to 0.01 lbs/acre
      • "first" generation
        • Allethrin
      • "second" generation:
        • tetramethrin
        • resmethrin
        • bioresmethrin
      • "third" generation:
        • permethrin
      • "fourth" generation:
        • cypermethrin
        • cyfluthrin
        • deltamethrin
        • acrinathrin
        • imiprothrin
        • gamma-cyhalothrin
    • Mode of action
      • Type I (negative temperature coefficient)
      • Type II (positive temperature coefficient)
    • Metabolism:
      • Pyrethroids: oxidation, hydroxylation & conjugation
      • Synthetics: esterase, oxidase & conjugation