This page gives information plant protection/pest control agents grouped as: - Fungicides
- Herbicides
- Insecticides, Acaricides, Nematicides, etc.
- Molluscicides
- PlPhasmohabditis hermaphroditaant Growth Modifiers
- Rodenticides
- Spray oils and Adjuvants
v. 24 November 2009 |
Fungicides The term “fungicide” is also used for substances active against Oomycetes (e.g. Phytophthora spp.) that are no longer classified as fungi. MoA groups that include compounds active against oomycetes are marked with §O. | | Multiple site of action (M): often protectant | | MoA group | Chemistry | example(s) | | Multi-site M1 | Copper fungicides §O
Bordeaux mixture consists of equal parts of ~sulphate and lime (calcium hydroxide) | Copper: ~ammonium carbonate, ~hydroxide, ~oxide, ~oxychloride, ~sulphate, etc. | | M2 | Sulphur | sulfur | | M3 | Dithiocarbamates §O | ferbam, maneb, mancozeb, metam (also herbicide & nematicide), thiram, zineb, ziram (also a vertebrate repellent) | | M4 | Pthalimides | captan, captafol, folpet | | M5 | Chloronitriles | chlorothalonil | | M6 | Sulphamides | dichlofluanid, tolylfluanid | | M7 | Guanidines | dodine |
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| Systemic – curative | | MoA group | Chemistry | example(s) | | A | Disruption of fungal nucleic acid synthesis:
A1: RNA polymerase (oomycete fungicides) | Four MoA groups Phenylamides §O | benalaxyl, metalaxyl (resolved metalaxyl-M is mefenoxam) | | | A2 | Hydroxy-pyrimidines | buprimate, dimethirimol | | | A3-A4: DNA inhibition | A3 Heteroaromatics §O
A4 Carboxylic acids | hymexazole, octhilinone
oxolinic acid | | B | Inhibition of mitosis and cell division | | | | B1-B3: Inhibition of beta-tubulin assembly | B1: Benzamidazoles
B2: N-phenyl carbamates
B3: Benzamides §O | benomyl, carbendazim, fuberidazole
diethofencarb
zoxamide | | | B4-B5: cell division | B4: Phenylurea
B5: Benzamide §O | pencycuron
fluopicolide | | C | Respiration inhibitors – large group including: | | | | C2: succinate dehydrogenase | Carboxamides: 6 classes including Oxathiins | boscalid
flutolanil, oxycarboxin | | | C3: QoI – Quinone Outside (cytochrome) Inhibitors | Strobilurins etc.:
8 chemical classes
broad spectum incl. §O | azoxystrobin, pyraclostrobin, fluoxastrobin, trifloxystrobin
fenamidone | | | C4: QiI – Quinone Inside Inhibitors | 2 chemical classes §O | cyazofamid, amisulbrom (newer a.i. for Phytophthora etc.) | | | C5: uncouplers of oxidative phosphorylation | 3 chemical classes including dinitrophenyl crotonates | binapacryl (was also acaricide), dinocap | | | C6: inhibitors of ATP synthase | Organo-tin compounds | fentin acetate | | | C1, C7 | 2 chemical classes | | | D | Other mechanisms that inhibit protein synthesis | D1: Anilinopyrimidines | cyprodinil | | | D2-D5 | 4 classes of antibiotics | kasugamicin | | E | Signal transduction inhibitors | Quinolines, Phenylpyrroles, Dicarboximides | iprodione | | F | Lipid synthesis: cell membranes and walls | | | | F2: Inhibits phospholipid synthesis in membrane
(esp. Pyricularia oryzae) | phosphorothiolates,
dithiolanes | edifenphos, iprobenfos (IBP)
isoprothiolane | | | F3: lipid peroxidation | AH fungicides (aromatic hydrocarbons) §O | tolclofos-methyl, etridiazole | | | F4: cell membrane permability | Carbamates §O | propamocarb hydrochloride, prothiocarb | | | F5: cell wall deposition | Carboxylic Acid Amides (CAA) §O
– 3 chemical groups | dimethomorph (cinnamic acid amide), iprovalicarb, fluazinam
mandipropamid | | G | Disruption of membrane function: sterol biosynthesis inhibitors (SBI) | | | | G1: De-Methylation Inhibitor (DMI) fungicides | Pyridines, Pyrimidines
Imidazoles
and Triazoles | pyrifenox, fenarimol
imazalil, procloraz
bitertanol, cyproconazole, difenoconazole, fluquinconazole, hexaconazole, myclobutanil, propriconazole, prothioconazole, tebuconazole, triadimefon, triadimenol | | | G2-G4 | Morpholines and
6 other chemical classes | tridemorph, fenpropimorph fenhexamid, spiroxamine | | H | Glucan synthesis antibiotic | 2 classes of antibiotics | validamycin A (for Rhizoctonia solani) | | I | Melanin synthesis in cell wall | 6 chemical classes | tricyclazole (for Pyricularia oryzae) |
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| Host plant defence induction (P) and other (sometimes unknown) mechanisms | | P | Salicylic acid pathway | ‘Plant activators’ | acibenzolar | | U | Other elicitors of Systemic Acquired Resistance (SAR) | phosphonate fungicides §O | fosetyl aluminium; potassium phosphonate | | | microtubule disruption (poss.) | U5: thiazole carboxamide §O | ethaboxam | | X | Unknown MoA | | cymoxanil, triazoxide | | Biological | | | | | Hyper-parasites | mycofungicide | Ampelomyces quisqualis | | | Typically antagonists | viral | mosaic virus mild strains | | | bacterial | Bacillus subtilis | | | fungal §O | Trichoderma: many spp |
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| Spray oils and Adjuvants | Various oils are known to have acaricidal, fungicidal, insecticidal, herbicidal and spray adjuvant properties in their own right or may enhance. Examples include: - “dormant oils” or “winter washes” are usually petroleum-based which are acaricides, insecticides and ovicides
- fatty acid emulsions are used as broad spectrum contact insecticides
- banana spray oil (BSO) is fungicidal for sigatoka disease (Mycosphaerella spp)
- In N. America brush may sprayed with a herbicide in diesel oil as a carrier; many herbicide activators are emulsifiable light oils containing variable amounts of surfactants to emulsify the oil and penetrate waxy weed leaves.
- a number of emulsified oils are used as spray adjuvants which are not very pesticidal themselves, but when added to the tank mixture, improve the performance of the pesticide. Major functions are products that (examples of product names are for illustration and not necessarily recommendations) affect:
| | Adjuvant function | Examples | 1. Formulation and tank mix
Compatibility agents, Defoaming agents, thickeners, etc. | | Buffers (or pH modifiers) | Often containing phosphoric acid or a salt of phosphoric acid | 2. Atomisation and drift
a. droplet size spectrum
b. evaporation
(humectants affect droplet survival and
deposit after contact) | Certain compounds can increase the viscosity and surface tension causing and increase in spray VMD and decrease the proportion of small droplets. | | 3. Retention and Deposit Modification on Plant surfaces | | Surfactants (wetting/spreading agents) | Alkyl-Aryl-Poly-Oxy-Ethylenates, ‘Activator’, ‘Agral’ | Stickers (sometimes called extenders) to
increase ‘rain-fastness’, etc. | Often polymers and organosilicones such as ‘Silwet’ | 4. Plant cuticle penetrants
(Often also enhance retention, as above) | emulsified oils (typically <5% emulsifier), ‘Codacide’, ‘Natur’l oil’ |
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| Plant Growth Modifiers (or ~ Regulators) | | A number of non- pesticidal substances are frequently procured and stored together with pest control agents. Since the term “pesticide” has become controversial, a number of products have been marketed as “plant tonics” or similar – that may have various modes of action and include mixtures containing micronutrients etc. | - Various chemicals encourage fruit set including: abscisic acid (ABA), gibberellic acid and carbaryl (which is also an insecticide). 1-napthylacetic acid and 4-indol 3-YL butyric acid are members of a group of synthetic auxins (and more active molecules are herbicidal) which prevents premature flower and fruit drop and stimulates root formation in cuttings.
| - Foliar nutrient products may contain plant fertilizers such as N,P,K, minor nutrients such as Sulfur and Zinc, and a variety of trace elements such as Boron. They may also contain a relatively small amount of surfactant.
| - Plant growth regulators (PGR) include 2-chloroethylphosphonic acid (CEPA or ethephon): which penetrates into plant tissues and decomposes into ethylene which affects various growth processes, including: ripening in fruits, latex flow in rubber, flowering and lateral branching in ornamentals. Compounds such as chlormequat chloride regulate growth by inhibiting giberellin synthesis, thus shortening stems and producing more compact, sturdier plamts. Paclobutrazol is a triazole which inhibits sterol as well as giberellin biosynthesis so it also has some fugicidal activity (against mildews and rusts). Another PGR, daminozide (‘Alar’) was withdrawn in 1989, when it was withdrawn by the manufacturer in response to public fears over safety.
| - Some molecules exhibit different effects at different concentrations. For example, nonanoic acid is used for blossom thinning in apples and pears, but is herbicidal at higher dosages.
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Herbicides The HRAC system differs somewhat from that of the
Weed Science Society of America (WSSA) | | Contact, desiccant | | MoA group | Chemistry | example(s) | | D | Photosystem I (electron transport): contact & desiccant action | Bipyridylium | diquat, paraquat | | M | Cell membrane disruption, contact action | Dinitrophenol | DNOC | | Z. | Unknown mechanisms, contact action | Organoarsenical | MSMA (methyl arsonic acid) | | | Multi-site soil sterilants
(also nematodes, fungi) | Various | dazomet, metam (methyl-dithiocarbamic acid): also ~ammonium, ~Na & K salts | | | Desiccants etc. | Inorganic | sodium chlorate, sulphuric acid | | Systemic | | MoA group | Chemistry | example(s) | | A | Inhibits fatty acid synthesis (ACCase inhibitors) | 3 chemical classes:
‘FOP’ hebicides‘DIM’ herbicides‘DEN’ herbicides | clodinafop-propargyl, diclofop-methyl, fenoxaprop-P-ethyl, fluazifop-P-butyl
clethodim, cycloxydim, sethoxydim, tralkoxydim
pinoxaden | | B | Inhibits plant amino acid synthesis: acetolactate synthase (ALS) | Imidazolinones Sulfonylureas
+ 3 classes | imazapyr, imazethapyr,
amidosulfuron, bensulfuron- methyl, iodosulfuron-methyl-sodium, mesosulfuron-methyl, metsulforon-methyl, pyriftalid, propoxycarbazone-sodium, trifloxysulfuron-sodium | | C | Inhibits photosynthesis (photosystem II) | | | | C1 | Triazines,
TriazinonesPhenyl-carbamates
+ 3 classes | ametryne, atrazine, simazine
hexazinone, metamitron, metribuzin
desmedipham, phenmedipham
bromacil | | | C2 | substituted ureas | diuron, isoproturon, linuron, propanil, tebuthiuron | | | C3 | nitriles + 2 classes | bromoxynil, ioxynil (also octanoate ester & Na+ salt) | | E | Inhibits protoporphyrinogen oxidase, leading to irreversible cell membrane damage | Diphenylethers +
8 other classes of often selective herbicides with contact action and only limited translocation | oxyfluorfen
oxadiazon
fomesafen | | F | Bleaching: inhibition of carotenoid biosynthesis | | | | F1:at the phytoene desaturase step (PDS) | Pyridazinones + other classes | norflurazon,
diflufenican, flurtamone | | | F2:of 4-hydroxyphenyl-pyruvate-dioxygenase
(4-HPPD) | triketones + 3 classes | mesotrione (for broad-leaved weeds in Maize) | | | F3: inhibition of lycopene cyclase and unknown target | triazole
+ 3 other classes | amitrole,
clomazone | | G | Inhibition of essential
aromatic amino acid synthesis (EPSPS) in chlororplasts | Organophosphate glycene | glyphosate: ~trimesium ~isopropylammonium, sulfosate | | H | Glutamine synthetase inhibitor: accumulates ammonium ions, inhibits photosynthesis | Phosphinic acid | glufosinate-ammonium | | I | Inhibition of dihydropterate synthase causing slow chlorosis | Carbamate | asulam | | K | Inhibition of mitosis and cell division | CIPC etc. often used as potato sprouting inhibitors | | | K1 | Dintroanilines | pendimethalin, trifluralin | | | K2 | Carbamate | chlorpropham (CIPC) | | | K3 | Chloracetamides + 4 other classes | acetochlor, alachlor, dimethanamid, butachlor, pretilachlor, metolachlor, etc
flufenacet | | L | Inhibition of cell wall synthesis | 4 classes | dichlobenil, isoxaben | | N | Inhibition of lipid synthesis (not A) | Thiocarbamates
+ 2 classes | ethofumesate, molinate, thiobencarb (benthiocarb)
dalapon (acid & sodium salt) | | O | Synthetic auxins
(also plant growth modifiers) | Phenoxy-carboxylic-acids | 2,4-D (acid & various salts: commonly ~amine & ~isopropyl ester), 2,4,5-T*, MCPA, MCPB, mecoprop-P (MCPP) | | | | *: withdrawn due to dioxin (TCDD) contaminants | | | | Pyridine carboxylic acids | aminopyralid, clopyralid, fluroxypyr, picloram, triclopyr | | | | + 3 other classes | dicamba | | P | Inhibits auxin transport | Phthalamate | naptalam | | | Herbicide safeners are admixed in order to selectively protect crop plants from herbicide damage without reducing activity in target weeds, and are usually used commercially to improve herbicide selectivity between crop and weed species. They may also be applied as seed dressings. | cloquintocet-mexyl, cyometrinil, dichlormid, fenclorim, fluxofenim, flurazole, furilazole, oxabetrinil, naphthalic anhydride (NA) | | | | | | Biological
Mycoherbicide | e.g. specific to Northern joint vetch: Aeschnomene virginica | Colletotrichum gloeosporioides f.p. aeschnomene |
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| Insecticides, Acaricides, Nematicides, etc. | | Neurotoxic | | MoA group | Chemistry | example(s) | | 1 | Acetylcholinesterase (AChE) inhibitors
Because the AChE mechanism in insect synapses are similar to that of mammals, group 1 compounds are often Extremely or Highly Hazardous although there are exceptions such as temephos).
This group contains a number of systemic compounds (e.g. carbofuran, carbosulfan, dimethoate, monocrotophos). | | | 1A | Carbamates | aldicarb, bendiocarb, carbaryl, carbofuran (not GR), carbosulfan, dioxacarb, ethiofencarb, fenobucarb (BPMC), isoprocarb (MIPC), methiocarb (also a molluscicide), methomyl, metolcarb (MTMC), oxamyl, pirimicarb, promecarb, propoxur, thiodicarb (molluscicide), thiofanox | | | 1B | Organophosphates: | acephate, azinphos (usu. ~methyl), cadusafos, chlorfenvinphos, chlorpyrifos (usu. ~ethyl), chlorpyrifos-methyl, demeton-s-methyl, diazinon, dichlorvos (DDVP), dicrotophos, dimethoate, disulfoton, ethoprophos, fenitrothion, fenthion, fosthiazate (nematicide), heptenophos, malathion, methamidophos, methidathion, mevinphos, monocrotophos, naled, omethoate, oxydemeton-methyl, parathion (usu. ~methyl), phenthoate, phorate, phosalone, phosmet, phosphamidon, phoxim, pirimiphos (usu. ~methyl), profenofos, quinalphos, temephos, thiometon, triazophos, trichlorfon, vamidothion | | 2 | GABA-gated chloride channel antagonists | | | | Cyclodienes and other organo-chlorines (OCs) | HCH (lindane, gamma BHC), aldrin, dieldrin, chlordane, endosulfan | | | Phenylpyrazoles (Fiproles) | fipronil | | 3 | Sodium channel modulators | OC | DDT | | | pyrethrum & pyrethrins | bioallethrin, bioresmethrin, pyrethrum, resmethrin, tetramethrin | | | pyrethroids | bifenthrin, beta-cyfluthrin, cyhalothrin (unresolved), lambda-cyhalothrin, cypermethrin (and resolved alpha~), deltamethrin, esfenvalerate, etofenprox, fenpropathrin, fenvalerate, flucythrinate, silafluofen, tau-fluvalinate, permethrin, tefluthrin, metofluthrin | | 4 | Acetylcholine receptor (nAChR) agonists | | | | 4A | Neonicotinoids | acetamiprid, clothianidin, imidacloprid, nitenpyram, thiacloprid, thiamethoxam | | | 4B | nicotine | | | 5 | nAChR agonists: Allosteric (not group 4) | Macrocyclic lactones (Spinosyns) | spinosad | | 6 | Chloride channel activators (insecticides & acaricides) | Avermectins, Milbemycins | abamectin, emamectin benzoate
milbemectin | | 14 | nAChR channel blockers | Nereistoxin analogues | cartap, thiosultap (various anions), thiocyclam | | 22 | Voltage dependent sodium channel blocker | Oxadiazine | indoxacarb | | 25 | Neuroactive acaricide (unknown mode of action) | | bifenazate |
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| Group 11 etc. | Microbial or derived disruptors of insect midgut membranes | | | Toxins produced by the bacterium Bacillus thuringiensis (Bt): Bt sprays and Cry proteins expressed in transgenic Bt crop varieties (specific cross-resistance sub-groups) | | 11A1 | For Diptera | Bacillus thuringiensis subsp. israelensis | | 11A2 | For mosquito larvae | Bacillus sphaericus | | 11B1 | Lepidoptera esp. Noctuidae | Bacillus thuringiensis subsp. aizawai | | 11B2 | Esp. Lepidoptera: e.g. Plutella | Bacillus thuringiensis subsp. kurstaki | | 11C | For Coleoptera | Bacillus thuringiensis subsp. tenebrionis | | | | | | Other Microbial | EntomoPathogenic Fungi (EPF), nematodes (EPN) and viruses (EPV) | | EPF | Beauveria bassiana, Metarhizium anisopliae, Paecilomyces fumosoroseus | | EPN | Heterorhabditis megidis, Steinernema spp. | | EPV | Various nuclear poly-hedrosis viruses (NPV) and granulo-viruses (GV): often highly specific, especially used against Lepidoptera
e.g. Spodoptera exigua nuclear polyhedrosis virus |
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| Cuticle Synthesis, Moulting & Metamorphosis | | MoA group | Chemistry | example(s) | | 7 | Juvenile hormone mimics and analogues | | fenoxycarb, methoprene, pyriproxyfen | Groups 15-17: Inhibitors of chitin biosynthesis
(insect growth regulators or IGRs) | | | 15 | for Lepidoptera,
Isoptera, etc. | Benzoylureas | bistrifluron, flucycloxuron, noviflumuron, diflubenzuron, teflubenzuron, chlorfluazuron, flufenoxuron, lufenuron, hexaflumaron, novaluron, triflumuron | | 16 | for Hemiptera | | buprofezin | | 17 | for Diptera | | cyromazine | | 18 | Ecdysone agonist / molting disruptors | A. Diacylhydrazines B. Azadirachtin | chromafenozide,methoxyfenozide, tebufenozide
azadirachtin |
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Disruptors of Various other Metabolic Processes
Many groups acting on a wide range of metabolic processes including: | | MoA group | Chemistry | example(s) | | 12 | Inhibitors of oxidative phosphorylation, disruptors of ATP formation (inhibitors of ATP synthase) | Diafenthiuron
Organotin acaricidesothers | diafenthiuron
cyhexatin,
fenbutatin oxide
propargite, tetradifon | | 13 | Uncouplers of oxidative phosphorylation via disruption of proton gradient | chlorfenapyr, DNOC | | 19 | Octopaminergic (nervous system) agonist acaricide & insecticide (probably loss of feeding and adhesion) | amitraz | | 20 | Mitochondrial complex III electron transport inhibitors | various | hydramethylnon, acequinocyl, fluacrypyrim | | 21 | Mitochondrial complex I electron transport inhibitors | Rotenone,
METI acaricides | rotenone,
fenpyroximate, tebufenpyrad | | 23 | Inhibitors of lipid synthesis | Tetronic acid derivatives | spirodiclofen, spiromesifen, spirotetramat | | 24 | Mitochondrial complex IV electron transport inhibitors | Precursors of fumigant:
phosphine (PH3)
(see also: rodenticides) | aluminium phosphide, magnesium phosphide, | | 28 | Ryanodine receptor modulators: sustained contraction of insect muscle | Diamides | flubendiamide |
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| Non-specific, Unknown and Miscellaneous MoA | | MoA group | Chemistry | example(s) | | 8 | Inorganic fumigants with non-specific MoA | see also: group 24 | methyl bromide, chloropicrin, sulfuryl fluoride | | 9 | Various compounds of non-specific mode of action
(selective feeding blockers) | cryolite, pymetrozine, flonicamid. | | 10 | acaricidal growth inhibitors | various | clofentezine, hexythiazox, etoxazole | | 27 | Synergists
27A: P450-dependent mono-oxygenase inhibitors | | piperonyl butoxide | | | 27B: Esterase inhibitors | | tribufos (DEF) | | un | Unknown mode of action | various | dicofol, pyridalyl |
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| Repellents, attractants and other modifiers of insect behaviour | | Insect repellents | | DEET, citronella oil | | Pheromones | Many, specific | | Baiting attractants | | methyl eugenol | | Bird/rodent repellent | also a fungicide (FRAC M) | ziram |
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Molluscicides RHS guide to slug control | | MoA | Chemical Group | example(s) | | | | | | Destruction of mucus cells: slugs secrete slime copiously and desiccate | tetramer of acetaldehyde | metaldehyde (contact and stomach action) | | Neurotoxic (also insecticides) | carbamates | thiodicarb, methiocarb | | Respiration inhibitor: probably oxygen uptake, and carbohydrate metabolism | clonitralid-olamine (Germany) | niclosamide (rice golden apple snail and WHO approved for vectors of schistosomiasis) | | Pathological changes to slug digestive system | inorganic | ferric-III-phosphate | | | | | Biological
(with power of search) | pathogenic nematode | Phasmohabditis hermaphrodita |
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Rodenticides | | MoA group | Chemistry/type | example(s) | | The older, acute toxicants rapidly became ineffective due to ‘bait shyness’: where rats learned to associate the food bait with the poison. Earlier chronic poisons (e.g. warfarin) have been replaced with a number of ‘second generation’ anti-coagulants that only require a single feed by the pest and have a delayed action; this reduces the problem of bait shyness. For obvious reasons, chemical rodenticides are highly toxic by nature, hence the interest in developing biological alternatives. | | Acute toxin | reacts with stomach acids to produce phosphine
(see also: fumigants) | zinc phosphide,
magnesium phosphide | | Hypercalcemia etc. | organic:
single dose | bromethalin,
cholecalciferol (Vitamin D3) | | Anti-coagulants | 1st generation | chlorophacinone, pindone, coumatetralyl, warfarin | | | 2nd generation
(single dose) | brodifacoum, difenacoum, bromadiolone, flocoumafen | | Biological | | Sarcocystis singaporensis: specific to Rattus & Bandicota spp Barn owls |
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NOTE: these pages are for guidance only and no responsibility can be taken for any errors that may be present. Likewise, inclusion of compounds or products does not imply recommendation or otherwise. |
