Horticultural Entomology: Chemical Control and Synthetic Insecticide Groups

Practice vocabulary flashcards covering chemical control tactics, synthetic insecticide classes, modes of action, regulatory standards, toxicity classifications, and resistance management strategies.

Mode of Action (MoA)

The mechanism by which a pharmacologically active substance produces an effect on a living organism, typically identifying the specific molecular targets to which it binds or whose biochemical action it influences.

Group 1 Insecticides (MoA Target)

Acetylcholinesterase inhibitors; includes synthetic groups such as Carbamates (1A) and Organophosphates (1B).

Group 2 Insecticides (MoA Target)

GABA-gated chloride channel antagonists; includes Organochlorines (2A) and Phenylpyrazoles (2).

Group 3 Insecticides (MoA Target)

Sodium channel modulators; includes Pyrethroids (3).

Group 4 Insecticides (MoA Target)

Acetylcholine receptors; includes Neonicotinoids (4A).

Pesticide Tolerance

The maximum pesticide residue amount allowed to remain in or on each treated food commodity, established by the EPA under the standard of 'reasonable certainty of no harm from aggregate exposure.'

Human Hazard Potential

The total health risk of an insecticide, defined by the formula: $\text{Human hazard potential} = \text{toxicity of active ingredient} + \text{chance of exposure}$.

Acute Toxicity

Illness or death resulting from a single dose or single exposure to a pesticide.

Chronic Toxicity

Illness or death that develops as a result of long-term exposure to low levels of insecticides.

CAUTION

The EPA signal word indicating a pesticide product is slightly toxic if eaten, absorbed through the skin, or inhaled, or causes slight eye or skin irritation.

WARNING

The EPA signal word indicating a pesticide product is moderately toxic if eaten, absorbed through the skin, or inhaled, or causes moderate eye or skin irritation.

DANGER

The EPA signal word indicating a product is highly toxic by at least one exposure route or corrosive causing irreversible eye or skin damage; accompanied by the word 'POISON' in red letters if highly toxic.

Organochlorines (OCs)

A class of broad-spectrum synthetic insecticides acting as axonic poisons; notable for environmental persistence, fat-solubility resulting in biomagnification, and chronic vertebrate effects.

Organophosphates (OPs)

Synthetic organic insecticides that function as synaptic poisons by inhibiting acetylcholinesterase; examples include Malathion, Methyl parathion, Diazinon, and Chlorpyriphos (Lorsban®, Dursban®).

Carbamates

A class of broad-spectrum synthetic insecticides acting as synaptic poisons via acetylcholinesterase inhibition, with persistence comparable to organophosphates and known toxicity to Hymenoptera.

Pyrethroids

Synthetic analogs of natural pyrethrum engineered to be stable in UV light; act as axonic poisons effective at low rates ($< 0.1\,\text{lb. per acre}$) with low mammalian toxicity, but toxic to fish and non-target invertebrates.

Neonicotinoids

A synthetic insecticide class introduced in the early 1990s as synthetic analogs of nicotine; they act as synaptic poisons by mimicking acetylcholine at acetylcholine receptors.

Dormant Oils

Heavy-grade refined petroleum oils applied as winter sprays on deciduous fruit trees to kill scales, mites, and insect or mite eggs by clogging spiracles.

Summer Oils

Light-grade refined petroleum oils with lower viscosity applied within the growing season to control scales, mites, and aphids through suffocation while minimizing phytotoxicity.

Insecticidal Soaps

Soaps formulated with potassium salts of fatty acids as the active ingredient; control soft-bodied insects by stripping protective waxes from the cuticle and disrupting the nervous system.

Organic Materials Review Institute (OMRI)

An organization that evaluates and provides authoritative catalogs and directories of products and generic materials allowed for certified organic production, handling, and processing.

Insecticide Resistance

A heritable change in the sensitivity of a pest population reflected in the repeated failure of a product to achieve the expected level of control when used according to label recommendations.

Biochemical Resistance

A physiological mechanism of insecticide resistance where pest enzymes detoxify or metabolize the chemical before it reaches its target site.

Physiological Resistance

Resistance mechanisms involving alterations in the insect's physiology to reduce chemical impact, including excretion, sequestration, thickened waxy cuticle, or modification of target receptors.

Cross-Resistance

The phenomenon in which an insect population resistant to one insecticide becomes resistant to other insecticides without prior exposure, usually due to shared chemical structures or identical modes of action.

Management by Moderation

An insecticide resistance strategy that reduces selection pressure by limiting chemical contact and conserving susceptible genes through less-frequent applications and short-residual compounds.

Management by Multiple Attack

An insecticide resistance strategy that lowers selection pressure from any single factor by using insecticide mixtures, rotating modes of action, or applying unrelated compounds in mosaic spatial patterns.