IPM lecture 4 January 26, 2010

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)

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

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

Chlorinated hydrocarbons-DDT and chlordane

Pyrethriods Carbamates Neonicotinoids Phenylpyrazoles IGR’s Botanicals Fumigants

Advantages Effectiveness Rapid Economical Easy to apply

Disadvantages Frequency of use-resistance, pest

resurgence and pest replacement

Dry Dusts (D) Granules(G) Wettable powders (WP) Soluble Powders (SP) Dry Flowables (DF) Water-soluble packets (WSP) Baits (B) Slow release (SR)

Liquid Emulsifiable Concentrates (EC or E) Solutions (S) Flowables (F) Aerosols (A) Liquid gas (F) (fumigants)

Names and Nomenclature Common and Trade names Formulation-Active and inert ingredients

Groups or Classifications Stomach Contact Fumigant

Synergists Solvents Diluents Surfactants Stickers Deoderants

Regulatory Control

“Control” the power to direct, manage, oversee and/or restrict the affairs, business or assets of a person or entity

FIFRA (1947)• Any substance or mixture of substancesintended for preventing, destroying, repelling,or mitigating any pest• Pest: insect, rodent, plant, or animal life orviruses, bacteria, or other microorganisms,except viruses, bacteria, or othermicroorganisms on or in living man or otheranimals• Pesticide includes plant regulators, defoliants,or desiccants• Pesticide includes disinfectants

Regulatory Definition of Pesticide

Federal Government-Environmental Protection Agency (USEPA)

States

Arizona Department of Agriculture

Arizona Office of Pest Management

The Pesticide label is the LAW

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= Toxicity X Exposure

Risk is voluntary or non-voluntary

Eyes Dermal Oral Inhalation

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.

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 toxicity refers to the harmful effects of long-term exposure to relatively low 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)

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

• Abolished Delaney Clause for pesticides

• Negligible risk (1 in a million ) for carcinogens, de minimus

• 10x safety factor for children • Risk cup

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.

Modern insect management makes the transition from broad-spectrum neurotoxins to selective insecticides

(Pyrethroid (MW = 391) BT protoxin protein (MW = 134,000))

Insecticides: 1972 to Present

A Diversity of Physiological Targets

Nervous System Energy Production

Cuticle Production

Water Balance

Endocrine System

Muscle Poisons Physical toxicants Nerve Poisons

Narcotics Synaptic poisons Axonic poisons

ORGANOCHLORINES DDT, endosulfan

ORGANOPHOSPHATES phosdrin, dimethoate

CARBAMATES Sevin, Lannate

FORMAMIDINES Fundal, Galecron

PYRETHROIDSAmbush, Pounce

1940

1946

1956

1965

1972

Review of Neurotoxins: WWII to 1972 

Adapted from Source: John Palumbo, Univ. of AZ

Mode of Action

Broad-spectrum Neurotoxin

Broad-spectrum Neurotoxin

Broad-spectrum Neurotoxin

Broad-spectrum Neurotoxin

Broad-spectrum Neurotoxin

Muscle

Seta

Motor NeuronSensoryNeuron

Synapse

A Simple Nerve Pathway

Stimulus

Insecticide Toxicity

Muscle

Seta

Acetylcholine is released to transmit impulse across the synapse

Direction of impulse

Insecticide Toxicity

Stimulus

Muscle

Seta

Impulse crosses over. Then, an enzyme called Cholinesterase clears the acetylcholine from the synapse

Sensoryneuron

Synapse

Motor neuron

Muscle

Seta

Direction of impulse

With cholinesterase deactivated, acetylcholine cannot be cleared so the nerves keep “firing”

Insecticide Toxicity

Stimulus

Nerve Cell (Neuron) Presynaptic

Nerve Terminal

Impulse propagation

SomaAxon

Na+

K+

Pyrethroids prevent ion channel closure; continued electrical impulse (rapid muscular paralysis)

New Developments

NEONICOTINOIDS Admire, Provado

SPINOSYNS Success

PYRROLES Alert

DIACYLHYDRAZINE Confirm, Intrepid

PYRIDINE IGR  Knack

THIADIAZINE IGR  Applaud, Courier

Bt COTTON Bollguard

PYRIDINE Fulfill

MACROCYCLACTON   Proclaim

OXADIAZINE   Avaunt,

•  Since 1992:

KETONOLOberon

PHENYLPYRAZOLERegent

•  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

Imidacloprid blocking acetyl choline receptor

Acetyl cholinesterase

Acetyl choline released into synapse

Imidacloprid

Neonicotinoid compound

New Developments

NEONICOTINOIDS Admire, Provado

SPINOSYNS Success

PYRROLES Alert

DIACYLHYDRAZINE Confirm, Intrepid

PYRIDINE IGR  Knack

THIADIAZINE IGR  Applaud, Courier

Bt COTTON Bollguard

PYRIDINE Fulfill

MACROCYCLACTON   Proclaim

OXADIAZINE   Avaunt,

•  Since 1992:

KETONOLOberon

PHENYLPYRAZOLERegent

•  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

activation of nicotinic acetylcholine receptors 

Fermentation product of the soil actinomycete Saccharopolyspora spinosa 

Success, Conserve

Spinosad

Modes of Action of Insecticides

Nervous System Energy Production

Cuticle Production

Water Balance

Endocrine System

New Developments

NEONICOTINOIDS Admire, Provado

SPINOSYNS Success

PYRROLES Alert

DIACYLHYDRAZINE Confirm, Intrepid

PYRIDINE IGR  Knack

THIADIAZINE IGR  Applaud, Courier

Bt COTTON Bollguard

PYRIDINE Fulfill

MACROCYCLACTON   Proclaim

OXADIAZINE   Avaunt,

•  Since 1992:

KETONOLOberon

PHENYLPYRAZOLERegent

•  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

Alert, Pirate, Stalker

Uncouples oxidative phosphorylation (ETS))

Mitochondria—The cells energy factory

17 hours till start running out of energy

Die nose-down at 28 hours

New Developments

NEONICOTINOIDS Admire, Provado

SPINOSYNS Success

PYRROLES Alert

DIACYLHYDRAZINE Confirm, Intrepid

PYRIDINE IGR  Knack

THIADIAZINE IGR  Applaud, Courier

Bt COTTON Bollguard

PYRIDINE Fulfill

MACROCYCLACTON   Proclaim

OXADIAZINE   Avaunt,

•  Since 1992:

KETONOLOberon

PHENYLPYRAZOLERegent

•  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

Modes of Action of Insecticides

Nervous System Energy Production

Cuticle Production

Water Balance

Endocrine System

Juvenile hormone analogs or mimics Chitin inhibitors (benzoylphenyl ureas)

Additional larval stage

Insect Growth Regulators (IGR’S)

High levels of JH at the wrong time produce a variety of maladies including: egg mortality, sterilization of females, and pupal death. They can result in an additional larval stage (much larger) than then dies because it can’t molt to the adult stage

Knack, Distance, Esteem

Acts like exogenous juvenile hormone, thus disrupting egg and pupal development

Affect insect’s ability to molt by disrupting the biosynthesis of chitin

Normal

CSI affected

Termite workers

Chitin synthesis inhibitorsAffect the ability of insects to produce new exoskeletons when molting

Epicuticle

Epidermis

ExocuticleEndocuticle

Modes of Action of Insecticides

Nervous System Energy Production

Cuticle Production

Water Balance

Endocrine System

Fulfill, Chess

Modes of Action of Insecticides

Nervous System Energy Production

Cuticle Production

Water Balance

Endocrine System

None of the Above