Regulatory Directive: Voluntary Pesticide Resistance-Management Labelling Based on Target Site/Mode of Action
October 6, 1999
ISBN: N/A
Cat. No.: N/A
(DIR99-06)
The Pest Management Regulatory Agency (PMRA) has introduced a voluntary pesticide resistance-management labelling initiative based on target site/mode of action for agricultural uses of herbicides, fungicides/bactericides and insecticides/acaricides. This document provides schemes of classification of pesticides according to their sites/modes of action (Appendices I-III), a standard format for showing group identification symbols on the end-use product labels, and guidelines for labelling resistance-management strategies in the use directions. It covers both new products governed by the registration process and old (existing) products governed by the re-evaluation process.
This document replaces Regulatory Proposal Pro96-03, Pesticide Resistance Management Labelling, published for public comments in December 1996. Comments received were taken into consideration in the final version of the guidelines.
Canada, the United States (U.S.) and Mexico, working cooperatively under the auspices of the North American Free Trade Agreement (NAFTA), are developing and publishing these guidelines for voluntary pesticide resistance-management labelling to a uniform standard for implementation in North America. This activity forms part of the work done by the Risk Reduction Subcommittee of the NAFTA Technical Working Group (TWG) on Pesticides. A uniform approach across North America will help reduce the development of pesticide resistance and support joint registration decisions by providing consistency in the resistance-management labelling being considered for approval in any or all of the NAFTA countries.
Table of Contents
- 1.0 Scope
- 2.0 Implementation
- 3.0 Introduction
- 4.0 Site of Action Grouping and Identification Symbol
- 5.0 Resistance-Management Statements
- 6.0 Pesticides of Unspecified Groups
- Appendix I Herbicide Groups Based on Sites of Action
- Appendix II Fungicide/Bactericide Groups Based on Activity Group/Sites of Action
- Appendix III Insecticide and Acaricide Groups Based on Sites of Action
1.0 Scope
This Directive applies to resistance-management labelling for herbicide, fungicide/ bactericide and insecticide/acaricide products that are intended for general agricultural use. This document covers both new products governed by the registration process and old (existing) products governed by the re-evaluation process.
2.0 Implementation
The implementation of this program is to be on a voluntary basis by the pesticide industry. Close cooperation of all registrants is required to achieve this important task. Registrants are encouraged to add the resistance-management grouping symbols and statements to both new and existing product labels. Revisions to labels for existing products can be made at the next printing of the labels. All new and existing products are encouraged to have the resistancemanagement grouping symbols and statements on the label by January 1, 2004. Information on amending labels can be obtained from the PMRA Information Service at 1-800-267-6315 (toll-free within Canada) or (613) 736-3799. In view of the importance of resistance management to a sustainable pest-management system, the PMRA will closely monitor the progress of the industry's implementation of resistance-management labelling.
3.0 Introduction
The PMRA, the U.S. Environmental Protection Agency (EPA) and the Cicoplafest of Mexico are committed to encouraging the development of sustainable pest-management systems. Under the auspices of NAFTA, Canada, the U.S. and Mexico have joined together to develop and publish guidelines for voluntary pesticide resistance-management labelling for implementation in North America. The development of these guidelines is part of the activities of the Risk Reduction Subcommittee of the NAFTA TWG on Pesticides. A uniform approach across North America will help reduce the development of pesticide resistance and support joint registration decisions by providing consistency in resistance-management labelling being considered for approval in any or all of the NAFTA countries.
Pesticide resistance, defined for the purpose of this document as a heritable and significant decrease in the sensitivity of a pest population to a pesticide, reduces the field performance of pesticides. Pests include insects, mites, weeds, fungi and bacteria. The management of pesticide resistance development is an important part of sustainable pest-management and this, in conjunction with alternative pest-management strategies and integrated pest-management (IPM) programs, can make significant contributions to reducing risks to humans and the environment. In support of this goal, the purpose of this document is to provide guidance on resistance-management labelling to registrants.
Pesticides are important pest-management tools. Many pesticides have gradually lost their effectiveness due to the development of resistance by pests. An important proactive pesticide resistance-management strategy is to avoid the repeated use of a particular pesticide, or pesticides, that have a similar site of action, in the same field, by rotating pesticides with different sites of action. This approach will slow the development of one important type of resistance, target-site resistance, without resorting to increased rates and frequency of application and will prolong the useful life of pesticides.
A resistance-management strategy should also consider more detailed information regarding cross-resistance between pesticides with different modes of action resulting from the development of other types of resistance (e.g., enhanced metabolism, reduced penetration, or behavior changes). All members of a class may not be cross-resistant based merely on mode of action. However, this labelling initiative will provide pesticide users with easy access to important information regarding target-site resistance, the cornerstone of most resistancemanagement programs.
To ensure consistency in pesticide grouping and labelling, and to contribute to the management of the pesticide-resistance problem, the following guidelines have been developed for agricultural uses of herbicides, fungicides/bactericides and insecticides/acaricides. The following classification schemes are based on target site of action.
4.0 Site of Action Grouping and Identification Symbol
Herbicides, fungicides/bactericides and insecticides/acaricides are separately grouped according to their primary sites of action (or target site modes of action) by various technical/research committees consisting of representatives of the pesticide industry, researchers, extension specialists and regulatory officials. The industry committees providing guidance on the pesticide groupings were the Herbicide Resistance Action Committee (HRAC), the Fungicide Resistance Action Committee (FRAC) and the Insecticide Resistance Action Committee (IRAC). Primary guidance for herbicides was provided by the Weed Science Society of America (WSSA). The site of action groups plus the identifier numbers for herbicides, fungicides/bactericides and insecticides/acaricides are located in Appendix I, II and III, respectively.
The site of action identification symbol should be shown on all end-use product labels (except products for homeowner/residential uses) in a standard format as outlined below, and should:
- be located on the front panel (preferably at the upper right corner), surrounded by a black rectangle;
- be in black on a white background except the site of action number(s), which is to be white on a black background with a clear white gap between the site of action number(s); and
- include the words "Group" and "Herbicide" or "Fungicide" or "Insecticide" in capital letters, and between these words the number(s) representing the site of action group(s) of each active ingredient(s). Where a product has two or more active ingredients, and these are represented by two or more sites of action, then two or more appropriate site of action identifier numbers should be used. For products containing an active ingredient that has multiple sites of action, the letter "M" should be used to represent the site of action group. Alternatively, if sites of action are known, specify each site of action by the appropriate number.
Example 1: Product containing one or more active ingredients of the same site of action.
Example 2: Product containing two or more active ingredients represented by two or more sites of action.
Example 3: Outside label for prepackaged products where each component is in a different container.
Example 4: Premixture of a fungicide and an insecticide.
5.0 Resistance-Management Statements
Resistance-management statements are recommended to be included in the use directions for all end-use products for the control of weeds, plant pathogens (diseases), insects and arthropods (except products for homeowner/residential uses) under the heading "Resistance-Management Recommendations". The section "Resistance-Management Recommendations" should be segregated under the "General" portion of "Use Directions" in the U.S., and under "Use Directions" in Canada. Product-specific labelling is recommended. The recommended standard resistance-management labelling statements listed below focus on the prevention and mitigation of pest resistance and should be used where applicable. Efforts should be made to include all appropriate active ingredients and products. These recommendations should also be included in any product-specific literature.
5.1 Herbicides
For resistance management, (name of product) is a Group (site of action group number) herbicide. Any weed population may contain or develop plants naturally resistant to (name of product) and other Group (site of action group number) herbicides. The resistant biotypes may dominate the weed population if these herbicides are used repeatedly in the same field. Other resistance mechanisms that are not linked to site of action, but specific for individual chemicals, such as enhanced metabolism, may also exist. Appropriate resistance-management strategies should be followed.
To delay herbicide resistance:
- Where possible, rotate the use of (name of product) or other Group (site of action group number) herbicides with different herbicide groups that control the same weeds in a field.
- Use tank mixtures with herbicides from a different group when such use is permitted.
- Herbicide use should be based on an IPM program that includes scouting, historical information related to herbicide use and crop rotation, and considers tillage (or other mechanical), cultural, biological and other chemical control practices.
- Monitor treated weed populations for resistance development.
- Prevent movement of resistant weed seeds to other fields by cleaning harvesting and tillage equipment and planting clean seed.
- Contact your local extension specialist or certified crop advisors for any additional pesticide resistance-management and/or integrated weed-management recommendations for specific crops and weed biotypes.
- For further information or to report suspected resistance, contact (company representatives) at (toll free number) or at (Internet site).
Note The above is a standard statement for products containing one or more active ingredients from the same group. For products containing two or more active ingredients from different groups, the statement should be modified to reflect the situation.
For example:
For resistance management, please note that (name of product) is both a Group (site of action group number) and a Group (site of action group number) herbicide. Any weed population may contain plants naturally resistant to Group (site of action group number) and/or Group (site of action group number) herbicides. The resistant biotypes may dominate the weed population if these herbicides are used repeatedly in the same fields.
5.2 Fungicides and Bactericides
For resistance management, please note that (name of product) contains a Group (group number) (fungicide/bactericide). Any (fungal/bacterial) population may contain individuals naturally resistant to (name of product) and other Group (group number) (fungicides/bactericides). A gradual or total loss of pest control may occur over time if these (fungicides/bactericides) are used repeatedly in the same fields. Other resistance mechanisms that are not linked to site of action but specific for individual chemicals, such as enhanced metabolism, may also exist. Appropriate resistance-management strategies should be followed.
To delay fungicide/bactericide resistance:
- Where possible, rotate the use of (name of product) or other Group (site of action group number) fungicides/bactericides with different groups that control the same pathogens.
Note This statement may be modified if repeated application is necessary, e.g., Avoid application of more than (maximum number) and consecutive sprays of (name of product) or other (fungicides/bactericides) in the same group in a season.
- Use tank mixtures with fungicide/bactericides from a different group when such use is permitted.
- Fungicide/bactericide use should be based on an IPM program that includes scouting, historical information related to pesticide use and crop rotation and considers cultural, biological and other chemical control practices.
- Monitor treated fungal/bacterial populations for resistance development.
- If disease continues to progress after treatment with this product, do not increase the use rate. Discontinue use of this product, and switch to another (fungicide/bactericide) with a different target site of action, if available.
- Contact your local extension specialist or certified crop advisors for any additional pesticide resistance-management and/or IPM recommendations for specific crops and pathogens.
- For further information and to report suspected resistance, contact (company representatives) at (toll free number) or at (Internet site).
Note The above is a standard statement for products containing one or more active ingredients from the same group. For products containing two or more active ingredients from different groups, the statement should be modified to reflect the situation.
For example:
For resistance management, please note that (name of product) contains both a Group (group number) and Group (group number) fungicide/bactericide. Any fungal/bacterial population may contain individuals naturally resistant to (name of product) and other Group (group number) or Group (group number) fungicides/bactericides. A gradual or total loss of pest control may occur over time if these (fungicides/bactericides) are used repeatedly in the same fields.
5.3 Insecticides and Acaricides
For resistance management, please note that (name of product) contains a Group (group number) insecticide (or acaricide). Any (insect/mite) population may contain individuals naturally resistant to (name of product) and other Group (group number) (insecticides/acaricides). The resistant individuals may dominate the insect/mite population if this group of insecticides/acaricides are used repeatedly in the same fields. Other resistance mechanisms that are not linked to site of action but are specific for individual chemicals, such as enhanced metabolism, may also exist. Appropriate resistance-management strategies should be followed.
To delay insecticide resistance:
- Where possible, rotate the use of (name of product) or other Group (site of action group number) insecticides/acaricides with different groups that control the same pests in a field.
Note The above statement may be modified on a pest by pest basis if a number of applications each year are necessary, e.g., Avoid application of more than (maximum number) and consecutive sprays of (name of product) or other insecticides in the same group in a season.
- Use tank mixtures with insecticides/acaricides from a different group when such use is permitted.
- Insecticide/acaricide use should be based on an IPM program that includes scouting, record keeping, and considers cultural, biological and other chemical control practices.
- Monitor treated pest populations for resistance development.
- Contact your local extension specialist or certified crop advisors for any additional pesticide resistance-management and/or IPM recommendations for the specific site and pest problems in your area.
- For further information or to report suspected resistance contact (company representatives) at (toll free number) or at (Internet site).
Note The above is a standard statement for products containing one or more active ingredients from the same group. For products containing two or more active ingredients from different groups, the statement should be modified to reflect the situation.
For example:
For resistance management, please note that (name of product) contains both a Group (group number) and Group (group number) insecticides/acaricides. Any insect/mite population may contain individuals naturally resistant to (name of product) and other Group (group number) or Group (group number) insecticides/ acaricides. The resistant individuals may dominate the insect/mite population if these insecticides/acaricides are used repeatedly in the same fields.
6.0 Pesticides of Unspecified Groups
Some herbicides, fungicides, bactericides, insecticides and acaricides have not been assigned to any particular target site/mode of action group or have not been shown on the lists in this document because of the lack of clear understanding of their target site/mode of action or the absence of a history of resistance development for the product. The registrants should establish the appropriate group identifications for their products in consultation with representatives of the pesticide industry, researchers, extension specialists and regulatory officials. The use directions should include the appropriate resistance-management statements for this product, i.e., herbicides, fungicides/ bactericides and insecticides/acaricides.
The above procedure also applies to new pesticides when they are registered for use. The pesticide lists (Appendices I-III) will be updated from time to time (approximately annually) to include product names and/or new/revised site/mode of action classification. The revised appendicies will be posted on the Agency's web site under the title of this Regulatory Directive. Hard copies will be made available from the Agency upon request.
Appendix I Herbicide Groups Based on Sites of Action
This list is based on the Herbicide Classification of the Weed Science Society of America (Weed Technology, 1997, 11:384-393). Microbial herbicides are not included.
Group 1
Site of Action: Inhibitors of acetyl CoA carboxylase ACCase
Chemical Family: Aryloxyphenoxy propionates
Active Ingredient:
- clodinafop-propargyl
- diclofop-methyl
- fenoxaprop-ethyl
- fenoxaprop-p-ethyl
- fluazifop-p-butyl
- fluazifop-butyl
- quizalofop-ethyl
- quizalofop-p-ethyl
Chemical Family: Cyclohexanediones
Active Ingredient:
- clethodim
- sethoxydim
- tralkoxydim
Group 2
Site of Action: Inhibition of acetolactate synthase (ALS) and also called aceto-hydroxyacid synthase (AHAS)
Chemical Family: Sulfonylureas
Active Ingredient:
- chlorimuron
- chlorsulfuron
- ethametsulfuron-methyl
- metsulfuron-methyl
- nicosulfuron
- prosulfuron
- rimsulfuron
- sulfosulfuron
- thifensulfuron-methyl
- triasulfuron
- tribenuron-methyl
- triflusulfuron-methyl
Chemical Family: Imidazolinones
Active Ingredient:
- imazamethabenz
- imazamox
- imazapyr
- imazethapyr
Chemical Family: Pyrimidinylthio-benzoateFootnote 4
Chemical Family: Triazolopyrimidime
Active Ingredient:
- flumetsulam
Group 3
Site of Action: Microtubule assembly inhibitors
Chemical Family: Dinitroanilines
Active Ingredient:
- ethalfluralin
- pendimethalin
- trifluralin
Chemical Family: Pyridazine
Active Ingredient:
- dithiopyr
Site of Action: Unknown
Chemical Family: None
Active Ingredient:
- chlorthal-dimethyl (DCPA)
Group 4
Site of Action: Synthetic auxins (action like indoleacetic acid)
Chemical Family: Phenoxys
Active Ingredient:
- 2,4-D
- 2,4-DB
- dichlorprop (2,4-DP)
- MCPA
- MCPB
- mecoprop (MCPP)
Chemical Family: Benzoic acids
Active Ingredient:
- dicamba
Chemical Family: Carboxylic acids
Active Ingredient:
- clopyralid
- fluroxypyr
- picloram
- triclopyr
Chemical Family: Quinoline carboxylic acid
Active Ingredient:
- quinclorac
Chemical Family: Semicarbazone
Active Ingredient:
- diflufenzopyr
Group 5
Site of Action: Inhibitors of photosynthesis at photosystem II Site A
Chemical Family: Triazines
Active Ingredient:
- atrazine
- cyanazine
- prometon
- prometryn
- simazine
Chemical Family: Triazinones
Active Ingredient:
- hexazinone
- metribuzin
Chemical Family: Uracils
Active Ingredient:
- bromacil
- terbacil
Chemical Family: Pyridazinone
Active Ingredient:
- pyrazon
Chemical Family: Phenyl-carbamates
Active Ingredient:
- desmedipham
- phenmedipham
Group 6
Site of Action: Similar to group 5, but different binding behavior
Chemical Family: Nitriles
Active Ingredient:
- bromoxynil
Chemical Family: Benzothiadiazoles
Active Ingredient:
- bentazon
Chemical Family: Phenyl-pyridazine
Active Ingredient:
- pyridate
Group 7
Site of Action: Inhibitors of photosynthesis at photosystem II Site B
Chemical Family: Ureas
Active Ingredient:
- diuron
- linuron
- metobromuron
- monolinuron
- siduron
- tebuthiuron
Chemical Family: Amide
Active Ingredient:
- propanil
Group 8
Site of Action: Inhibition of lipid synthesis, not ACCase inhibition
Chemical Family: Thiocarbamates
Active Ingredient:
- butylate
- cycloate
- EPTC
- pebulate
- triallate
- vernolate
Chemical Family: None
Active Ingredient:
- bensulide
Site of Action: Unknown
Chemical Family: None
Active Ingredient:
- difenzoquat
Group 9
Site of Action: Inhibitors of 5- enolpyruvylshikimate-3- phosphate (EPSP) synthase
Chemical Family: None
Active Ingredient:
- glyphosate
Group 10
Site of Action: Inhibitors of glutamine synthetase
Chemical Family: None
Active Ingredient:
- glufosinate-ammonium
Group 11
Site of Action: Bleaching: Inhibitors of carotenoid biosynthesis (unknown target)
Chemical Family: Triazole
Active Ingredient:
- amitrole
Group 12
Site of Action: Bleaching: Inhibitors of carotenoid biosynthesis at the phytoene desaturase step (PDS)
Chemical Family: PyridazinoneFootnote 4
Chemical Family: NicotinanilideFootnote 4
Chemical Family: Others
Active Ingredient:
- fluridoneFootnote 4
- flurochloridoneFootnote 4
Group 13
Site of Action: Bleaching: Inhibition of all diterpenes
Chemical Family: Isoxazolidinone
Active Ingredient:
- clomazone
Group 14
Site of Action: Inhibitors of protoporphyrinogen oxidase (PPO)
Chemical Family: Diphenylethers
Active Ingredient:
- acifluorfen
- fomesafen
- oxyfluorfen
Chemical Family: N-phenylphthalimidesFootnote 4
Chemical Family: Oxadiazole
Active Ingredient:
- oxadiazon
Chemical Family: TriazolinoneFootnote 4
Group 15
Site of Action: Unknown
Chemical Family: Chloroacetamides
Active Ingredient:
- metolachlor
- s-metolachlor
- propyzamide
- dimethenamid
Chemical Family: Acetamides
Active Ingredient:
- napropamide
Chemical Family: OxyacetamidesFootnote 4
Group 16
Site of Action: Unknown
Chemical Family: Benzofuran
Active Ingredient:
- ethofumesate
Group 17
Site of Action: Unknown
Chemical Family: Organoarsenicals
Active Ingredient:
- Arsenic, present as monosodium salt of methylarsonic acid (MSMA)
Group 18
Site of Action: Inhibits dihydropteroate (DHP) synthase step
Chemical Family: Carbamate
Active Ingredient:
- asulam
Group 19
Site of Action: Inhibits indoleacetic acid action
Chemical Family: Phthalamate
Active Ingredient:
- naptalam
Group 20
Site of Action: Inhibits cell wall synthesis Site A
Chemical Family: Nitrile
Active Ingredient:
- dichlobenil
Group 21
Site of Action: Inhibits cell wall synthesis Site B
Chemical Family: Benzamide
Active Ingredient:
- isoxaben
Group 22
Site of Action: Photo system I-electron diverters
Chemical Family: Bipyridyliums
Active Ingredient:
- diquat
- paraquat
Group 23
Site of Action: Inhibitors of mitosis
Chemical Family: Carbamates
Active Ingredient:
- chlorpropham
Group 24
Site of Action: Uncoupling membrane disruptors
Chemical Family: Dinitrophenol
Active Ingredient:
- dinoseb
Group 25
Site of Action: Unknown
Chemical Family: Arylaminopropionic acid
Active Ingredient:
- flamprop-methyl
Group 26
Site of Action: Unknown
Chemical Family: None
Active Ingredient:
- trichloroacetic acid (TCA)
Group 27
Site of Action: Unknown
Chemical Family: Various
Active Ingredient:
- bromobutideFootnote 4
- cinmethylinFootnote 4
- dymronFootnote 4
- flupoxamFootnote 4
Group 28
Site of Action: Inhibition of 4-hydroxyphenyl- pyruvatedioxygenase (4-HPPD)
Chemical Family: benzoylisoxazoleFootnote 4
Chemical Family: IsoxazoleFootnote 4
Chemical Family: PyrazoleFootnote 4
Chemical Family: TriketoneFootnote 4
Appendix II Fungicide/Bactericide Groups Based on Activity Group/Sites of Action
This list is based on the fungicide listing compiled by the Fungicide Resistance Action Committee (FRAC). FRAC is a Specialist Technical Group of the Global Crop Protection Federation (GCPF). Microbial fungicides are not included.
Group 1
Activity Group/ Site of Action: Inhibition of tubulin formation
Chemical Group: Benzimidazole
Active Ingredient:
- benomyl
- carbendazim
- thiabendazole
- thiophanate-methyl
Group 2
Activity Group/ Site of Action: Affect cell division, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) synthesis, and metabolism
Chemical Group: Dicarboximide
Active Ingredient:
- iprodione
- vinclozolin
Group 3
Activity Group/ Site of Action: Demethylation Inhibitor (DMI): Inhibition of demethylation in sterol biosynthesis
Chemical Group: ImidazolesFootnote 4
Chemical Group: Piperazine
Active Ingredient:
- triforine
Chemical Group: PyridineFootnote 4
Chemical Group: PyrimidinesFootnote 4
Chemical Group: Triazoles (includes conazoles)
Active Ingredient:
- myclobutanil
- difenoconazole
- propiconazole
- triadimenol
Group 4
Activity Group/ Site of Action: Phenylamides Affect RNA synthesis
Chemical Group: Acylamines
Active Ingredient:
- metalaxyl
- metalaxyl M
Chemical Group: OxazolidinonesFootnote 4
Chemical Group: ButyrolactonesFootnote 4
Group 5
Activity Group/ Site of Action: Morpholines Inhibition of an isomerase in sterol biosynthesis
Chemical Group: Morpholines
Active Ingredient:
- dimethomorph
- dodemorph
Chemical Group: PiperidineFootnote 4
Chemical Group: SpiroketalamineFootnote 4
Group 6
Activity Group/ Site of Action: Phosphorothiolate Inhibition of chitin and phospholipid synthesis
Chemical Group: OrganophosphorousFootnote 4
Group 7
Activity Group/ Site of Action: Oxathiin Affect mitochondrial transport chain
Chemical Group: Anilide (Oxathiin)
Active Ingredient:
- carbathiin (carboxin)
- oxycarboxin
Group 8
Activity Group/ Site of Action: Hydroxyprimidine
Chemical Group: PyrimidinolFootnote 4
Group 9
Activity Group/ Site of Action: Anilinopyrimidine Inhibition of amino acid synthesis
Chemical Group: Anilinopyrimidine
Active Ingredient:
- cyprodinil
Group 10
Activity Group/ Site of Action: N-Phenyl carbamates Interfere with cell division
Chemical Group: DiethofencarbFootnote 4
Group 11
Activity Group/ Site of Action: Strobilurin Type Action and Resistance (STAR) Inhibit mitochondrial respiration
Chemical Group: StrobilurinFootnote 4
Chemical Group: OxazolidinedioneFootnote 4
Group 12
Activity Group/ Site of Action: Phenylpyrroles
Chemical Group: Phenylpyrroles
Active Ingredient:
- fludioxonil
Group 13
Activity Group/ Site of Action: Quinolines
Chemical Group: Quinoline
Active Ingredient:
- quinoxyfen
Group 14
Activity Group/ Site of Action: Aromatic hydrocarbons
Chemical Group: Chlorophenyl
Active Ingredient:
- dicloran quintozene (PCNB)
Chemical Family: Thiadiazole
Active Ingredient:
- etridiazole
Group 15
Activity Group/ Site of Action: Cinnamic acids
Chemical Group: Cinnamic acidFootnote 4
Group 16
Activity Group/ Site of Action: Melanin Biosynthesis Inhibitors (MBI)
Chemical Group: Reductase inhibitorsFootnote 4
Chemical Group: Dehydratase inhibitorsFootnote 4
Group 17
Activity Group/ Site of Action: Hydroxyanilide
Chemical Group: HydroxyanilideFootnote 4
Group 18
Activity Group/ Site of Action: Antibiotics
Chemical Group: Antibiotics
Active Ingredient:
- streptomycin
Group 19
Activity Group/ Site of Action: Polyoxins
Chemical Group: PolyoxinFootnote 4
Group 20
Activity Group/ Site of Action: Phenylurea
Chemical Group: PhenylureaFootnote 4
Group 21
Activity Group/ Site of Action: Plant host defence inducers
Chemical Group: Benzothiadiazole (BTH)Footnote 4
Group U
Activity Group/ Site of Action: Unknown Miscellaneous
Chemical Group: Amino acid amideFootnote 4
Chemical Group: Carbamate
Active Ingredient:
- propamocarb
Chemical Group: Cyano-acetamide oximeFootnote 4
Chemical Group: Organo-tins
Active Ingredient:
- tri-phenyl tins
- dinocap
- fenfuram
- fosetyl-aluminum
Group M
Activity Group/ Site of Action: Multi-site activity
Chemical Group: Inorganics
Active Ingredient:
- copper (hydroxide)
- copper (oxychloride)
- copper (sulphate)
- sullphur (wettable)
Chemical Group: Dithiocarbamates and relatives
Active Ingredient:
- ferbam
- mancozeb
- maneb
- metiram
- thiram
- zineb
- ziram
Chemical Group: Phthalimide
Active Ingredient:
- captan
- folpet
Chemical Group: Chloronitrile
Active Ingredient:
- chlorothalonil
Chemical Group: SulphamideFootnote 4
Chemical Group: Guanidine
Active Ingredient:
- dodine
Chemical Group: Anilazine
Active Ingredient:
- anilazine
Chemical Group: Phenyl-pyridinamineFootnote 4
Chemical Group: Quinoxaline
Active Ingredient:
- chinomethionat (oxythiquinox)
Appendix III Insecticide and Acaricide Groups Based on Sites of Action
The classification scheme was developed in consultation with the Insecticide Resistance Action Committee (IRAC). IRAC is a Specialist Technical Group of the Global Crop Protection Federation (GCPF). It is recognized that resistance of insects and mites to insecticides and acaricides can also result from enhanced metabolism, reduced penetration or behavioral changes that are not linked to any site of action classification, but are specific for individual chemicals or chemical groups. All members of a class may not be cross-resistant based merely on site of action. Most biological insecticides are not included in this Appendix because they are thought not to pose a great concern for resistance development. Microbial products involving Bacillus sp. are included as well as products derived from the Neem tree such as azadirachtin.
Group 1A
Site of Action: Acetylcholinesterase inhibitors
Inhibition of the enzyme acetylcholinesterase, interrupting the transmission of nerve impulses
Chemical Group: Carbamates
Active Ingredient:
- aldicarb
- aminocarb
- bendiocarb
- carbaryl
- carbofuran
- formetanate hydrochloride
- methiocarb
- methomyl
- oxamyl
- pirimicarb
- propoxur
Group 1B
Site of Action: Acetylcholinesterase inhibitors
Inhibition of the enzyme acetylcholinesterase, interrupting the transmission of nerve impulses
Chemical Group: Organophosphates
Active Ingredient:
- acephate
- azamethiphos
- azinphos-methyl
- chlorfenvinphos
- chlorpyrifos
- coumaphos
- diazinon
- dichlorvos (DDVP)
- dimethoate
- disulfoton
- ethion
- fenitrothion
- fensulfothion
- fenthion
- fonofos
- malathion
- methamidophos
- methidathion
- naled
- oxydemeton-methyl
- parathion
- phorate
- phosalone
- phosmet
- sulfotep
- temephos
- terbufos
- tetrachlorvinphos
- trichlorfon
Group 2A
Site of Action: Gamma-aminobutyric acid (GABA)-gated chloride channel antagonists
Interferes with GABA receptors of insect neurons, leading to repetitive nervous discharges
Chemical Group: Chlorinated cyclodienes
Active Ingredient:
- endosulfan
- dienochlor
Chemical Group: Polychlorocycloalkanes
Active Ingredient:
- lindane
Group 2B
Site of Action: GABA-gated chloride channel antagonists
Interferes with GABA receptors of insect neurons, leading to repetitive nervous discharges - fiprole site
Chemical Group: PhenylpyrazolesFootnote 4
Group 3
Site of Action: Sodium channel modulators
Acts as an axonic poison by interfering with the sodium channels of both the peripheral and central nervous system stimulating repetitive nervous discharges, leading to paralysis
Chemical Group: diphenylethanes
Active Ingredient:
- dicofol
- methoxychlor
Chemical Group: Synethetic pyrethroids
Active Ingredient:
- d-allethrin
- d-trans allethrin
- cyfluthrin
- cypermethrin
- deltamethrin
- fenpropathrin
- fenvalerate
- flucythrinate
- tau-fluvalinate
- permethrin
- resmethrin
- tefluthrin
- tetramethrin
Chemical Group: Pyrethrins
Active Ingredient:
- pyrethrins
Group 4
Site of Action: Acetylcholine receptor agonists/antagonists
Binds to nicotinic acetylcholine receptor, disrupting nerve transmission
Chemical Group: Chloronicotines (nitroguanidines)
Active Ingredient:
- imidacloprid
Chemical Group: Nicotine CartapFootnote 4 BensultapFootnote 4
Active Ingredient:
- nicotine
Group 5
Site of Action: Acetylcholine receptor modulators
Alters acetylcholine receptor site and disrupts binding
Chemical Group: SpinosynsFootnote 4
Group 6
Site of Action: Chloride channel activators
Interferes with the GABA nerve receptor of insects.
Chemical Group: Avermectin
Active Ingredient:
- abamectin
Chemical Group: MilbemycinFootnote 4
Group 7
Site of Action: Juvenile hormone mimics (insect growth regulator)
Mimic juvenile hormones, which prevent moulting from the larval to the adult stage
Chemical Group: Juvenile hormone analogues
Active Ingredient:
- methoprene
Group 8A
Site of Action: Unknown or non-specific site of action (fumigants)
Chemical Group: Fumigant
Active Ingredient:
- methyl bromide
Group 8B
Site of Action: Unknown or non-specific site of action (fumigants)
Chemical Group: Fumigant
Active Ingredient:
- aluminum phosphide
Group 9A and 9B
Site of Action: Compounds of unknown or non-specific site of action (feeding disruptors)
Chemical Group: Feeding disruptorsFootnote 4 (pymetrozine, cryolite)
Group 10
Site of Action: Compounds of unknown or non-specific site of action (mite growth inhibitors)
Chemical Group: Mite growth inhibitors (ovicide)
Active Ingredient:
- clofentezine
Group 11
Site of Action: Microbial disruptors of insect mid-gut membranes (includes Cry proteins expressed in transgenic plants)
Organism has protein inclusions that are released in the gut of the target pest resulting in gut paralysis and a cessation of feeding
Chemical Group: Bt Microbials (biological insecticide/larvicide)
Active Ingredient:
- Bacillus thuringiensis var. Aizawai, encapsulated delta endotoxin
- Bacillus thuringiensis var. Tenebrionis
- Bacillus thuringiensis var. Israelensis
- Bacillus thuringiensis var. Kurstaki
Group 12
Site of Action: Inhibition of oxidative phosphorylation at the site of dinitrophenol uncoupling [disrupt adenosine triphosphate (ATP) formation]
Chemical Group: Organotin matricides
Active Ingredient:
- fenbutatin oxide
Group 13
Site of Action: Uncoupler of oxidative phosphorylation (disrupt H proton gradient formation)
Chemical Group: Pyrrole compoundFootnote 4 (broad spectrum contact and stomach poison)
Group 14
Site of Action: Inhibit magnesium - stimulated ATPase
Chemical Group: Sulfite ester matricides
Active Ingredient:
- propargite
Group 15
Site of Action: Inhibit chitin biosynthesis
Chemical Group: Substituted benzoylurea
Active Ingredient:
- diflubenzuron
Group 16
Site of Action: Inhibit chitin biosynthesis type 1 - Homopteran
Chemical Group: ThiadiazineFootnote 4
Group 17
Site of Action: Inhibit chitin biosynthesis type 2- Dipteran
Chemical Group: Triazine
Active Ingredient:
- cyromazine
Group 18
Site of Action: Ecdysone agonist/disruptor
Disrupts insect molting by antagonizing the insect hormone ecdysone
Chemical Group: Benzoic acid hydrazide
Active Ingredient:
- tebufenozide
Chemical Group: BotanicalFootnote 4 (Neem oil or azadirachtin)
Group 19
Site of Action: Octopaminergic agonist
Chemical Group: Triazapentadiene
Active Ingredient:
- amitraz
Group 20
Site of Action: Site II electron transport inhibitors
Chemical Group: None
Active Ingredient:
- hydramethylnon
Group 21
Site of Action: Site I electron transport inhibitors
Chemical Group: Botanical
Active Ingredient:
- rotenone
Chemical Group: Pyridazinone
Active Ingredient:
- pyridaben
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