620 likes | 641 Views
IPM lecture 4 January 26, 2010. Using pesticides Reference- Chapter 11. The Pest Management Tool Kit. Ecological (cultural) controls Mechanical controls Physical controls Biological controls Chemical controls Genetic controls Regulatory controls. Effective use Choosing an insecticide
E N D
IPM lecture 4 January 26, 2010 Using pesticidesReference- Chapter 11
The Pest Management Tool Kit • Ecological (cultural) controls • Mechanical controls • Physical controls • Biological controls • Chemical controls • Genetic controls • Regulatory controls
Effective use Choosing an insecticide Choosing a dosage Timing of the application Coverage of application Pesticide Applicator Safety (PPE) Using insecticides for pest management
What is a pesticide? • Risk associated with the use of a pesticide • Types of pesticides • Pesticide Regulation • The label • Pesticide safety • Toxicology • Types and Formulations • Equipment and calibration Pesticides
Approx 1.2 Billion pounds of pesticides are produced annually in just the US Sales exceed 11 Billion dollars Proportionate by groups: Ag-77%, 14% Govt/Industry and 9% home and garden Approx 85% of all households have at least one kind of pesticide EPA – 220 insecticidal active ingredient registered factoids
Chlorinated hydrocarbons-DDT and chlordane Pyrethriods Carbamates Neonicotinoids Phenylpyrazoles IGR’s Botanicals Fumigants Background and common Types
Advantages • Effectiveness • Rapid • Economical • Easy to apply • Disadvantages • Frequency of use-resistance, pest resurgence and pest replacement Pesticides in general
Dry • Dusts (D) • Granules(G) • Wettable powders (WP) • Soluble Powders (SP) • Dry Flowables (DF) • Water-soluble packets (WSP) • Baits (B) • Slow release (SR) Formulations
Liquid • Emulsifiable Concentrates (EC or E) • Solutions (S) • Flowables (F) • Aerosols (A) • Liquid gas (F) (fumigants) Formulations
Names and Nomenclature • Common and Trade names • Formulation-Active and inert ingredients • Groups or Classifications • Stomach • Contact • Fumigant Common Pesticides-Insecticides
Synergists Solvents Diluents Surfactants Stickers Deoderants Chemicals used with insecticides
Regulatory Control “Control” the power to direct, manage, oversee and/or restrict the affairs, business or assets of a person or entity Regulatory Definition of Pesticide FIFRA (1947) • Any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest • Pest: insect, rodent, plant, or animal life or viruses, bacteria, or other microorganisms, except viruses, bacteria, or other microorganisms on or in living man or other animals • Pesticide includes plant regulators, defoliants, or desiccants • Pesticide includes disinfectants
Federal Government-Environmental Protection Agency (USEPA) States Arizona Department of Agriculture Arizona Office of Pest Management
Risk assessment attempts to estimate the expected toxicity's or potential effects from a substance on an exposed human population. This is conducted by examining both toxicological and epidemiological data. Risk assessment is often used to help establish permissible levels of exposure to a specific material. As stated above, the NOEL limits are adjusted with a 100-fold safety factor to establish limits that are deemed "safe" for the majority of the population. While this may work for direct toxic effects, it may not be so simple for carcinogens. In the United States the EPA limits exposures to potential carcinogens by simply assuming there is no threshold for the dose-response relationship. The EPA then determines the quantity of MDD an individual could be exposed to in a lifetime and sets a limit that this dose should not increase the probability of cancer in more than one in a million individuals. Risk Assessment Risk= Toxicity X Exposure Risk is voluntary or non-voluntary
Eyes Dermal Oral Inhalation Exposure Routes
Toxicology is the study of harmful effects to living organisms from substances which are foreign to them. The toxins may be naturally occurring in the environment or synthetic chemicals. The following definitions will describe some basic concepts in toxicology. Overview of General Toxicology
There are two general types of toxic effect: Lethal Effects: resulting in the death of individuals Sublethal Effects: other effects not directly resulting in death
There are four basic types of damage caused by toxic materials: • Physiological damage: reversible/irreversible damage to the health of the organism • Carcinogenesis: induction of cancer • Mutagenesis: induction of genetic damage / mutation(s) • Teratogenesis: induction of birth defects
Toxicity can be generally broken down into two categories: acute toxicity refers to the rapid development of symptoms/effects after the intake of relatively high doses of the toxicant. Acute toxicity refers to immediate harmful effects generated by sufficiently large doses. chronic toxicityrefers to the harmful effects of long-term exposure to relativelylow doses of toxicant. This would include traces of pesticides in foods, air pollution, etc. A single compound may generate both acute and chronic toxic effects depending on the dose and duration of exposure.
Manufacture Submittal to EPA for registration Series of Toxicological Studies Risk factors One Crop (Cotton, Corn, Small grains) Other food crops (+ non-food) EPA set a tolerance –not residues EPA-labels the pesticide-it’s the LAW Individual states-(SLN’s) Overview Registration Process
The Food Quality Protection Act (FQPA) of 1996 requires EPA to make sure that all exposure pathways are taken into account (a concept called "aggregate exposure"), and states that food tolerances must be reduced if the risk cup is too full. FQPA also charges EPA to determine the total or "cumulative risk" posed by the groups of pesticides with common mechanisms of action Currently-Food Quality and Protection Act
• Abolished Delaney Clause for pesticides • Negligible risk (1 in a million ) for carcinogens, de minimus • 10x safety factor for children • Risk cup Food Quality Protection Act 1996
The risk cup is the Environmental Protection Agency's (EPA's) conceptual approach to estimating total pesticide exposure and risk. EPA believes that about 80% of a typical U.S. citizen's pesticide intake occurs through food, and that the remaining 20% comes from drinking water and residential exposures. These fractions clearly differ from compound to compound, but for the organophosphate (OP) pesticides, this accurately characterizes EPA's current picture of the risk cup. • EPA uses the risk cup analogy to describe how tolerances will be set under FQPA. A full cup represents the amount of pesticide that a person could receive every day for 70 years without significant health risk. RISK CUP
Modern insect management makes the transition from broad-spectrum neurotoxins to selective insecticides Insecticides: 1972 to Present BT protoxin protein (MW = 134,000)) (Pyrethroid (MW = 391)
Nervous System Energy Production Water Balance A Diversity of Physiological Targets Cuticle Production Endocrine System
Muscle Poisons • Physical toxicants • Nerve Poisons • Narcotics • Synaptic poisons • Axonic poisons Insecticide Toxicity - Mode of Action
Review of Neurotoxins: WWII to 1972 Mode of Action ORGANOCHLORINES DDT, endosulfan 1940 Broad-spectrum Neurotoxin ORGANOPHOSPHATES phosdrin, dimethoate 1946 Broad-spectrum Neurotoxin CARBAMATES Sevin, Lannate 1956 Broad-spectrum Neurotoxin FORMAMIDINES Fundal, Galecron 1965 Broad-spectrum Neurotoxin PYRETHROIDS Ambush, Pounce 1972 Broad-spectrum Neurotoxin Adapted from Source: John Palumbo, Univ. of AZ
Insecticide Toxicity Stimulus
Seta Muscle Insecticide Toxicity Stimulus Direction of impulse Acetylcholine is released to transmit impulse across the synapse
Seta Muscle Motor neuron Sensory neuron Synapse Impulse crosses over. Then, an enzyme called Cholinesterase clears the acetylcholine from the synapse
Seta Muscle Insecticide Toxicity Stimulus Direction of impulse With cholinesterase deactivated, acetylcholine cannot be cleared so the nerves keep “firing”
Pyrethroid Insecticides—disrupt propagation of nerve impulses within the nerve cell. Nerve Cell (Neuron) Presynaptic Nerve Terminal Impulse propagation Na+ K+ Axon Soma Pyrethroids prevent ion channel closure; continued electrical impulse (rapid muscular paralysis)
New Developments • Since 1992: NEONICOTINOIDS Admire, Provado SPINOSYNS Success DIACYLHYDRAZINE Confirm, Intrepid Bt COTTON Bollguard PYRIDINE IGR Knack PYRROLES Alert • Less broad-spectrum • Often shorter-lived • Often more environ- • mentally benign • Often more favorable • to natural enemies • Often less toxic to humans • Often more expensive THIADIAZINE IGR Applaud, Courier OXADIAZINE Avaunt, MACROCYCLACTON Proclaim PYRIDINE Fulfill KETONOL Oberon PHENYLPYRAZOLE Regent
Imidacloprid blocking acetyl choline receptor Acetyl choline released into synapse Acetyl cholinesterase Neonicotinoids act at the post synaptic nicotinic acetylcholine receptor
Imidacloprid Neonicotinoid compound
New Developments • Since 1992: NEONICOTINOIDS Admire, Provado SPINOSYNS Success DIACYLHYDRAZINE Confirm, Intrepid Bt COTTON Bollguard PYRIDINE IGR Knack PYRROLES Alert • Less broad-spectrum • Often shorter-lived • Often more environ- • mentally benign • Often more favorable • to natural enemies • Often less toxic to humans • Often more expensive THIADIAZINE IGR Applaud, Courier OXADIAZINE Avaunt, MACROCYCLACTON Proclaim PYRIDINE Fulfill KETONOL Oberon PHENYLPYRAZOLE Regent
Spinosad Success, Conserve activation of nicotinic acetylcholine receptors Fermentation product of the soil actinomycete Saccharopolyspora spinosa
Nervous System Energy Production Water Balance Modes of Action of Insecticides Cuticle Production Endocrine System
New Developments • Since 1992: NEONICOTINOIDS Admire, Provado SPINOSYNS Success DIACYLHYDRAZINE Confirm, Intrepid Bt COTTON Bollguard PYRIDINE IGR Knack PYRROLES Alert • Less broad-spectrum • Often shorter-lived • Often more environ- • mentally benign • Often more favorable • to natural enemies • Often less toxic to humans • Often more expensive THIADIAZINE IGR Applaud, Courier OXADIAZINE Avaunt, MACROCYCLACTON Proclaim PYRIDINE Fulfill KETONOL Oberon PHENYLPYRAZOLE Regent
Uncouples oxidative phosphorylation (ETS)) Chlorfenapyr--A Mitochondrial Energy Disrupters Mitochondria—The cells energy factory
17 hours till start running out of energy Die nose-down at 28 hours Chlorfenapyr kill
New Developments • Since 1992: NEONICOTINOIDS Admire, Provado SPINOSYNS Success DIACYLHYDRAZINE Confirm, Intrepid Bt COTTON Bollguard PYRIDINE IGR Knack PYRROLES Alert • Less broad-spectrum • Often shorter-lived • Often more environ- • mentally benign • Often more favorable • to natural enemies • Often less toxic to humans • Often more expensive THIADIAZINE IGR Applaud, Courier OXADIAZINE Avaunt, MACROCYCLACTON Proclaim PYRIDINE Fulfill KETONOL Oberon PHENYLPYRAZOLE Regent
Nervous System Energy Production Water Balance Modes of Action of Insecticides Cuticle Production Endocrine System