Classification of pesticides Revised 5 March 2013

Transcription

1 Classification of pesticides Revised 5 March 2013 Pesticides There were approximately 194 active ingredients registered in Oregon in 2012 for use by homeowners. That amounts to about 1,750 unique product labels! Fungicides 26 active ingredients (Jerry s currently has 18) Herbicides 46 active ingredients (Jerry s currently has 36) Insecticides 74 active ingredients (Jerry s currently has 56) Miscellaneous i.e. molluscicides, rodenticides, etc. Copper products copper ammonium complex copper octanoate DMI s myclobutanil propiconazole tebuconazole triforine Others Bacillus subtilis captan chlorothalonil lime sulfur sulfur Botanicals & Microbials B.t. neem pyrethrins acetamiprid imidacloprid thiamethoxam Preemergent Postemergent Neonicotinoids Organophosphates & Carbamates acephate carbaryl malathion Synthetic Pyrethroids bifenthrin cyfluthrin permethrin Others oils soaps Selective benefin dithiopyr indaziflam isoxaben oryzalin pendimethalin prodiamine trifluralin Non- Selective (Soil Sterilants) imazapyr prometon Selective Non- Selective Dicots (growth regulators) Monocots Systemic Contact 2,4-D dicamba MCPA triclopyr fenoxaprop fluazifop sethoxydim glyphosate diquat Page 1 of 21

2 Preface to Tables of Pesticide Characteristics Content edited by Jeff Choate on 1 April The tables on the following pages list select characteristics of pesticides registered for use by homeowners in Oregon. A separate table is dedicated to each of the following groups of pesticides. Fungicides Herbicides Insecticides Miscellaneous, including: Insect Attractants Insect Repellents Molluscicides Moss Control Plant Growth Regulators Rodenticides Synergists The characteristics listed in each of these tables include the following (an abbreviated set of characteristics is listed for the Miscellaneous pesticides). Active ingredient Resistance Group Leaching Potential Soil Half-life Sorption Coefficient (K OC ) Water Solubility Activity (e.g., acaricide, insecticide, miticide) [Insecticides only] Notes Resistance Group Resistance Groups represent pesticides with similar modes of action. A mode of action describes the particular biochemical means by which a pesticide exerts its pesticidal activity within an organism. When possible, alternate among pesticides of different Resistance Groups from one application to the next. Avoid using products from the same Resistance Group repeatedly, as organisms may develop resistance to all pesticides in that Resistance Group as a result. This is of particular concern when using bactericides and fungicides, as the rapid rate of microbial reproduction can lead to resistance much more quickly than for organisms with slower rates of reproduction. Note: Resistance Group U includes pesticides with an unknown mode of action. These pesticides generally are diverse with regard to their chemistry, so there is a low chance of resistance developing when switching among pesticides in this group. Page 2 of 21 Page 1 of 2

3 Leaching Potential The leaching potentials listed for pesticides on the following pages are from the Windows Pesticide Screening Tool (WIN-PST) available from the Natural Resources Conservation Service (NRCS) at Leaching potential is a qualitative rating that ranks pesticides into one of the following four categories with regard to a pesticide s potential to move toward groundwater. Very Low Low Intermediate High These categories are based on three pesticide properties: (1) soil half-life; (2) sorption coefficient; and (3) water solubility. Soil Half-life Soil half-life is a measure of the persistence of a pesticide in soil. Pesticides can be categorized on the basis of their half-life as nonpersistent, degrading to half the original concentration in less than 30 days; moderately persistent, degrading to half the original concentration in 30 to 100 days; or persistent, taking more than 100 days to degrade to half the original concentration. Soil half-life values are approximations and may vary greatly, because persistence is sensitive to variations in site, soil, and climate. Note: soil half-life values expressed here are more accurately referred to as field dissipation half-life, which is the time it takes for pesticides to degrade to 10% of the original concentration (approximately 4 half-lives). Sorption Coefficient (K OC ) The Sorption Coefficient, denoted as K OC, is a unit-less value that describes the tendency of a pesticide to bind to soil particles. Sorption (binding) retards movement and also may increase persistence because the pesticide is protected from degradation. Pesticides with K OC values greater than 1,000 tend to bind to clay particles and organic matter in the soil, whereas pesticides with K OC values less than 500 tend to move with soil water. The sorption coefficient is derived from laboratory data, but many soil and pesticide factors may influence the actual sorption of a pesticide to soil. Water Solubility Water Solubility describes the amount of pesticide that will dissolve in a known amount of water. Pesticides with a solubility greater than 1,000 milligrams per liter (mg/l) are considered highly soluble, whereas pesticides with a solubility less than 10 mg/l are considered to have low solubility. Highly soluble pesticides are more likely to be removed from the soil by runoff or by moving below the root zone with excess water. Note: The pesticide characteristics described above provide an estimate of pesticide persistence in the environment and the potential for movement toward groundwater. Many environmental factors also are involved in determining the actual persistence of a pesticide in the environment and whether or not the pesticide will move toward groundwater. Such factors include, but are not limited to, temperature, moisture, soil texture, organic matter content, ph, mineralogy, and slope. Page 3 of 21 Page 2 of 2

4 FUNGICIDES organized by active ingredient Active Ingredient FRAC* Group Leaching Potential Soil Half-life (days) Sorption Coefficient (soil K OC ) Water Solubility (mg/l) Notes azadirachtin (neem) U** High narrow-spectrum (powdery mildews); eradicant; protectant; organic; also an insecticide*** Bacillus subtilis 44 Low protectant; organic (microbial) captan M4 Low broad-spectrum; protectant; incompatible with oil sprays & strong alkalines chloroneb 14 Low for use on turfgrass chlorothalonil M5 Low broad-spectrum; protectant cinnamaldehyde U** Low Narrow-spectrum (powdery mildews); very short residual; also an insecticide clarified hydrophobic neem oil U** Low 12 10, narrow-spectrum (powdery mildews); eradicant; protectant; organic; also an insecticide*** copper ammonium complex M1 broad-spectrum; protectant; organic; bactericide copper octanoate (copper soap) M1 Very Low , broad-spectrum; protectant; organic; bactericide copper sulfate M1 Very Low ,720 10,000 broad-spectrum; organic; bactericide; protectant difenoconazole 3 Low broad-spectrum; curative; locally systemic; protectant kaolin U** Low organic (kaolin is a type of clay); also an insecticide lime sulfur (calcium polysulfide) M2 broad-spectrum; eradicant; organic; also an insecticide; do not apply to evergreens myclobutanil 3 Intermediate broad-spectrum; curative; locally systemic; protectant oil, botanical U** Low 12 10,000 narrow-spectrum (powdery mildews); eradicant; organic (botanical); includes canola, jojoba; also an insecticide 0.1 Note: botanical oils generally have a greater potential for phytotoxicity than petroleum distillates. oil, mineral (petroleum distillate) U** Low narrow-spectrum (powdery mildews); eradicant; organic; also an insecticide; do not use near sulfur applications phosphorous acid 33 High ,000 narrow-spectrum; protectant; systemic potassium bicarbonate U** High ,000 eradicant; organic; effectively controls powdery mildew potassium laurate (salts of fatty acids; soap) U** Low narrow-spectrum (powdery mildews); organic; also an insecticide propiconazole 3 Intermediate broad-spectrum; curative; locally systemic; protectant sulfur M2 High insecticide (miticide); good for powdery mildews, although control is poor at temperatures below 65 F tebuconazole 3 Intermediate broad-spectrum; curative; locally systemic; protectant thiophanate-methyl 1 Low broad-spectrum; protectant; locally systemic Tricoderma Spp. U** microbial; soil fungicide for control of root rot diseases; protectant triforine 3 Low broad-spectrum; curative; locally systemic; protectant triticonazole 3 High broad-spectrum; curative; locally systemic; protectant *FRAC = Fungicide Resistance Action Committee **U = Unknown Mode of Action ***Overall, the neem oils have not done as well for disease management as other horticultural oils in western Oregon. Page 4 of 21 Content edited by Jeff Choate on 11 October 2012.

5 FUNGICIDES organized by FRAC* Code FRAC* Group Active Ingredient Leaching Potential Soil Half-life (days) Sorption Coefficient (soil K OC ) Water Solubility (mg/l) Notes 1 thiophanate-methyl Low broad-spectrum; protectant; locally systemic 3 difenoconazole Low broad-spectrum; curative; locally systemic; protectant 3 myclobutanil Intermediate broad-spectrum; curative; locally systemic; protectant 3 propiconazole Intermediate broad-spectrum; curative; locally systemic; protectant 3 tebuconazole Intermediate broad-spectrum; curative; locally systemic; protectant 3 triforine Low broad-spectrum; curative; locally systemic; protectant 3 triticonazole High broad-spectrum; curative; locally systemic; protectant 14 chloroneb Low for use on turfgrass 33 phosphorous acid High ,000 narrow-spectrum; protectant; systemic 44 Bacillus subtilis Low protectant; organic (microbial) M1 copper ammonium complex broad-spectrum; protectant; organic; bactericide M1 copper octanoate (copper soap) Very Low , broad-spectrum; protectant; organic; bactericide M1 copper sulfate Very Low ,720 10,000 broad-spectrum; organic; bactericide; protectant M2 lime sulfur (calcium polysulfide) broad-spectrum; eradicant; organic; also an insecticide; do not apply to evergreens M2 sulfur High insecticide (miticide); good for powdery mildews, although control is poor at temperatures below 65 F M4 captan Low broad-spectrum; protectant; incompatible with oil sprays & strong alkalines M5 chlorothalonil Low broad-spectrum; protectant U** azadirachtin (neem) High narrow-spectrum (powdery mildews); eradicant; protectant; organic; also an insecticide*** U** cinnamaldehyde Low Narrow-spectrum (powdery mildews); very short residual; also an insecticide U** clarified hydrophobic neem oil Low 12 10, narrow-spectrum (powdery mildews); eradicant; protectant; organic; also an insecticide*** U** kaolin Low organic (kaolin is a type of clay); also an insecticide U** oil, botanical Low 12 10, Note: botanical oils generally have a greater potential for phytotoxicity than petroleum distillates. U** oil, mineral (petroleum distillate) Low narrow-spectrum (powdery mildews); eradicant; organic; also an insecticide; do not use near sulfur applications U** potassium bicarbonate High ,000 eradicant; organic; effectively controls powdery mildew U** potassium laurate (salts of fatty acids; soap) Low narrow-spectrum (powdery mildews); organic; also an insecticide U** Tricoderma Spp. microbial; soil fungicide for control of root rot diseases; protectant *FRAC = Fungicide Resistance Action Committee **U = Unknown Mode of Action ***Overall, the neem oils have not done as well for disease management as other horticultural oils in western Oregon. Page 5 of 21 Content edited by Jeff Choate on 11 October 2012.

6 HERBICIDES organized by active ingredient Active Ingredient HRAC* Group Leaching Potential Soil Half-life (days) Sorption Coefficient (soil K OC ) Water Solubility (mg/l) Notes 2,4-D 2-ethylhexyl ester O Intermediate postemergent; selective (broadleaf); systemic 2,4-D acid O Intermediate postemergent; selective (broadleaf); systemic 2,4-D dimethylamine salt O Intermediate ,000 postemergent; selective (broadleaf); systemic acetic acid U** Intermediate ,000 postemergent; organic ammonium salts of fatty acids U** organic; postemergent; also a moss control benefin (benfluralin) K1 Low preemergent bromacil C1 High pre- and postemergent control of grass and broadleaves carfentrazone E Low postemergent clopyralid, monoethylamine salt O High ,000 selective (broadleaf) corn gluten meal U** Low organic (botanical); preemergent; contains nitrogen dicamba O High selective (broadleaf); systemic dicamba, dimethylamine salt O High ,000 selective (broadleaf); systemic dicamba, potassium salt O High ,000 selective (broadleaf); systemic dichlobenil L Intermediate preemergent dichlorprop (2,4-DP) O Low selective (broadleaf); systemic dichlorprop (2,4-DP), dimethylamine salt O Intermediate ,000 selective (broadleaf); systemic diquat dibromide salt D Very Low ,000, ,000 contact; desiccant dithiopyr K1 High preemergent diuron C2 Intermediate primarily preemergent; pond/fountain fenoxaprop-p-ethyl A Low postemergent graminicide fluazifop-p-butyl A Low postemergent graminicide; annual and perennial species fluridone F1 Low aquatic fluroxypyr O Intermediate ,000 selective (broadleaf); postemergent glufosinate H Low ,370,000 broad spectrum; limited translocation glyphosate G Low 47 3,500 12,000 nonselective; postemergent; systemic glyphosate, isopropylamine salt G Very Low 47 24, ,000 nonselective; postemergent; systemic imazapic, ammonium salt B High ,000 postemergent imazapyr, isopropylamine salt B High ,000 nonselective; pre- and/or postemergent indaziflam L Intermediate preemergent; broad spectrum control of annual weeds iron HEDTA U** postemergent; selective (broadleaf); also a moss killer isoxaben L Low selective (broadleaf) limonene U** organic (botanical); postemergent maleic hydrazide U** Intermediate MCPA O Intermediate postemergent; selective (broadleaf); systemic MCPA 2-ethylhexyl ester O Low postemergent; selective (broadleaf); systemic MCPA, dimethylamine salt O High ,000 postemergent; selective (broadleaf); systemic MCPP (mecoprop) O High selective (broadleaf); systemic MCPP (mecoprop), dimethylamine salt O High ,000 selective (broadleaf); systemic MCPP-P O selective (broadleaf); systemic MCPP-P (mecoprop-p) potassium salt O selective (broadleaf); systemic MCPP-P dimethylamine salt O selective (broadleaf); systemic mesotrione, ph 4.5 F2 Low pre- and postemergent; residual; selective (broadleaf); systemic mesotrione, ph 7.7 F2 High pre- and postemergent; residual; selective (broadleaf); systemic oryzalin K1 Low preemergent oxyfluorfen E Very Low , pre- and/or postemergent pelargonic acid U** organic (botanical) pendimethalin K1 Low preemergent penoxsulam B Intermediate postemergent; residual; selective (broadleaf); systemic potassium laurate (salts of fatty acids; soap) U** Low postemergent; effective against lichen and liverworts prodiamine K1 Very Low , preemergent prometon C1 High nonselective; pre- and postemergent; residual quinclorac L, O High selective (broadleaf); postemergent sethoxydim A Low postemergent graminicide, annual and perennial species siduron (tupersan) C2 Intermediate preemergent graminicide, annual species sodium lauryl sulfate U** Low sulfentrazone E High preemergent triclopyr O High systemic triclopyr, butoxyethyl ester O Intermediate systemic triclopyr, triethylamine salt O High ,100,000 systemic trifluralin K1 Low preemergent *HRAC = Herbicide Resistance Action Committee **U = Unknown Mode of Action Page 6 of 21 Content edited by Jeff Choate on 11 October 2012.

7 HERBICIDES organized by HRAC* Group HRAC* Group Active Ingredient Leaching Potential Soil Half-life (days) Sorption Coefficient (soil K OC ) Water Solubility (mg/l) Notes A fenoxaprop-p-ethyl Low postemergent graminicide A fluazifop-p-butyl Low postemergent graminicide; annual and perennial species A sethoxydim Low postemergent graminicide, annual and perennial species B imazapic, ammonium salt High ,000 postemergent B imazapyr, isopropylamine salt High ,000 nonselective; pre- and/or postemergent B penoxsulam Intermediate postemergent; residual; selective (broadleaf); systemic C1 bromacil High pre- and postemergent control of grass and broadleaves C1 prometon High nonselective; pre- and postemergent; residual C2 diuron Intermediate primarily preemergent; pond/fountain C2 siduron (tupersan) Intermediate preemergent graminicide, annual species D diquat dibromide salt Very Low ,000, ,000 contact; desiccant E carfentrazone Low postemergent E oxyfluorfen Very Low , pre- and/or postemergent E sulfentrazone High preemergent F1 fluridone Low aquatic F2 mesotrione, ph 4.5 Low pre- and postemergent; residual; selective (broadleaf); systemic F2 mesotrione, ph 7.7 High pre- and postemergent; residual; selective (broadleaf); systemic G glyphosate Low 47 3,500 12,000 nonselective; postemergent; systemic G glyphosate, isopropylamine salt Very Low 47 24, ,000 nonselective; postemergent; systemic H glufosinate Low ,370,000 broad spectrum; limited translocation K1 benefin (benfluralin) Low preemergent K1 dithiopyr High preemergent K1 oryzalin Low preemergent K1 pendimethalin Low preemergent K1 prodiamine Very Low , preemergent K1 trifluralin Low preemergent L dichlobenil Intermediate preemergent L indaziflam Intermediate preemergent; broad spectrum control of annual weeds L isoxaben Low selective (broadleaf) L, O quinclorac High selective (broadleaf); postemergent O 2,4-D 2-ethylhexyl ester Intermediate postemergent; selective (broadleaf); systemic O 2,4-D acid Intermediate postemergent; selective (broadleaf); systemic O 2,4-D dimethylamine salt Intermediate ,000 postemergent; selective (broadleaf); systemic O clopyralid, monoethylamine salt High ,000 selective (broadleaf) O dicamba High selective (broadleaf); systemic O dicamba, dimethylamine salt High ,000 selective (broadleaf); systemic O dicamba, potassium salt High ,000 selective (broadleaf); systemic O dichlorprop (2,4-DP) Low selective (broadleaf); systemic O dichlorprop (2,4-DP), dimethylamine salt Intermediate ,000 selective (broadleaf); systemic O fluroxypyr Intermediate ,000 selective (broadleaf); postemergent O MCPA Intermediate postemergent; selective (broadleaf); systemic O MCPA 2-ethylhexyl ester Low postemergent; selective (broadleaf); systemic O MCPA, dimethylamine salt High ,000 postemergent; selective (broadleaf); systemic O MCPP (mecoprop) High selective (broadleaf); systemic O MCPP (mecoprop), dimethylamine salt High ,000 selective (broadleaf); systemic O MCPP-P selective (broadleaf); systemic O MCPP-P (mecoprop-p) potassium salt selective (broadleaf); systemic O MCPP-P dimethylamine salt selective (broadleaf); systemic O triclopyr High systemic O triclopyr, butoxyethyl ester Intermediate systemic O triclopyr, triethylamine salt High ,100,000 systemic U** acetic acid Intermediate ,000 postemergent; organic U** ammonium salts of fatty acids organic; postemergent; also a moss control U** corn gluten meal Low organic (botanical); preemergent; contains nitrogen U** iron HEDTA postemergent; selective (broadleaf); also a moss killer U** limonene organic (botanical); postemergent U** maleic hydrazide Intermediate U** pelargonic acid organic (botanical) U** potassium laurate (salts of fatty acids; soap) Low postemergent; effective against lichen and liverworts U** sodium lauryl sulfate Low *HRAC = Herbicide Resistance Action Committee **U = Unknown Mode of Action Page 7 of 21 Content edited by Jeff Choate on 11 October 2012.

8 Characteristics of Common Growth Regulator Herbicides Adapted from the Pacific Northwest Weed Management Handbook & personal communications with Tom Cook, Oregon State University Extension Turfgrass Specialist Content edited by Jeff Choate on 11 February 2008 Growth regulator herbicides are also known as synthetic auxins, because their effects on plants mimic those of naturally occurring plant hormones called auxins. In extremely small doses, synthetic auxin herbicides stimulate plant growth, but in proper concentrations, synthetic auxins disrupt numerous biochemical pathways and will kill susceptible plants. Most growth regulator herbicides can be categorized as one of three types: phenoxy (2,4-D; 2,4-DP; MCPA; MCPP), benzoic acid (dicamba), or pyridine (triclopyr). All of these are selective, broadleaf herbicides, meaning they will kill broadleaf weeds without harming grasses when used according to label directions. Quinclorac is a member of a relatively new type of growth regulators known as quinolines. These herbicides are effective against broadleaf weeds in addition to controlling some weedy grass species without harming most turfgrass varieties when used according to label directions. No single, selective herbicide controls all broadleaf weeds commonly found in turf. The combination of two or more selective herbicides can dramatically increase the spectrum of weed control. As such, most growth regulator herbicides are available as mixtures. For example, Trimec is a combination of MCPP, 2,4-D and dicamba. Additionally, use of adjuvants (e.g., surfactants, spreaders, stickers, etc.) will improve the efficacy of any of these herbicides. Read product labels carefully to determine whether adjuvants have been added already or if additional adjuvants should be added. Growth regulator herbicides generally are formulated as amine salts or low-volatile esters. Ester formulations are more quickly absorbed into plants than their amine counterparts, but the same chemical property that accounts for this faster absorption also makes ester formulations more volatile. This means that ester formulations are more likely than amine formulations to cause drift injury to non-target plants, especially in warm temperatures. Ester formulations are the materials of choice in early spring, late fall, and during rainy weather. Sodium and potassium salt formulations are also available and are considered non-volatile. Formulation seems to have no effect on long-term weed control in common uses. With all of these products, when applied at temperatures from 60 to 80 F, symptoms will show in 3 to 7 days after treatment. Death will generally take 3 to 6 weeks. In research at Oregon State University, single treatments have consistently resulted in less than 50% weed control. When a second treatment is made 2 to 3 weeks after the first treatment, the kill percentage goes up to 90 to 100% for most weeds. As temperatures rise above 85 F, the potential for turf phytotoxicity increases and weed control decreases. Page 8 of 21 Page 1 of 2

9 Phenoxy herbicides 2,4-D is primarily a foliar-absorbed, translocated herbicide, although it can be root-absorbed as well. It is available in amine salt or low-volatile ester formulations. 2,4-D is generally effective on many weeds, including dandelion, false dandelion and plantains, but it is weak on clover and other hard-to-kill weeds. 2,4-D is best used in mixtures for broad-spectrum weed control. Dichlorprop (2,4-DP) is primarily a foliar-absorbed, translocated herbicide, although it can be rootabsorbed as well. It is available in ester and potassium salt formulations. Its weed control spectrum is limited when used alone. In mixtures, it generally is more active than MCPP, which it replaces. The most common products containing 2,4-DP currently seem to be hose-end weed-and-feed products. MCPA is primarily a foliar-absorbed, translocated herbicide, although it can be root-absorbed as well. It is available in amine salt, sodium salt and ester formulations. Its activity and spectrum of weed control are very similar to 2,4-D. MCPP (mecoprop) is a foliar-absorbed, translocated herbicide available in amine and potassium salt formulations. It is effective on chickweeds when used alone but is weak on other broadleaf weeds. It is best used in mixtures with 2,4-D and dicamba where it broadens the spectrum of weed control. MCPP is almost worthless by itself, but in mixtures it will help control clover and mousear chickweed. It is generally the weakest of the herbicides listed here. Benzoic acid herbicides Dicamba is a foliar- and root-absorbed translocated herbicide available in dimethylamine and sodium salt formulations. It is the only herbicide listed here with significant potential for root uptake; despite this fact, it will still primarily be taken up through foliar absorption when used according to the label. It is active on a wide range of weeds including clovers, chickweeds, and yarrow. It is weak on Oxalis sp. (woodsorrel), violets, plantains, and pineappleweed among others. Dicamba is widely used in mixtures to broaden the spectrum of weed control. Dicamba is more mobile than other common broadleaf herbicides due to its high water solubility. Used repeatedly at high rates, it can injure nontarget trees and shrubs via root uptake. As formulated in mixtures, dicamba is generally safe when applied at label rates. Pyridine herbicides Triclopyr is a foliar- and root-absorbed, translocated herbicide available in amine salt and ester formulations. It is effective against clovers, violets, ground ivy, and Oxalis. Triclopyr generally is less effective by itself than in mixtures. It can be tank-mixed with commonly used three-way herbicide mixtures such as Trimec (MCPP + 2,4-D + dicamba) to increase the weed control spectrum. Do not apply to exposed roots of shallow-rooted trees and shrubs. In the ester form, triclopyr is quite volatile and is probably more likely than the other herbicides listed here to damage non-target plants. Keep out of lakes, streams, and ponds. Toxic to fish. Quinoline herbicides Quinclorac is a foliar- and root-absorbed, translocated herbicide with both pre- and postemergence activity. It is effective against tough weeds, including English daisy and speedwell (Veronica species). Additionally, quinclorac controls certain weedy grass species, including crabgrass. Quinclorac has 60 to 90 day residual control of annual and perennial weeds through uptake by germinating seeds. Do not mow within 2 days before or after application. Mulch clippings on the site the first 3 mowings after applying. Fine fescues and creeping bentgrasses are only moderately tolerant. Page 9 of 21 Page 2 of 2

10 Photos courtesy of Arnold Appleby, Don Morishita and Ray William. Decayed base caused by dicolofop (Group A: ACCase inhibitor) on grass. Photos courtesy of Arnold Appleby, Don Morishita and Ray William. Purple veins caused by imazethapyr (Group B: ALS inhibitor) on corn. Photos courtesy of Arnold Appleby, Don Morishita and Ray William. Interveinal chlorosis caused by soil uptake of bromacil + diuron (Groups C1 & C2: PS II inhibitors) by Ash. Page 10 of 21 1

11 Photos courtesy of Arnold Appleby, Don Morishita and Ray William. Marginal necrosis caused by bentazon (Group C3: PS II inhibitor) on bean. Photos courtesy of Arnold Appleby, Don Morishita and Ray William. Necrotic spots caused by paraquat (Group D: PS I inhibitor) on soybean. Photos courtesy of Arnold Appleby, Don Morishita and Ray William. Necrotic spots caused by diquat (Group D: PS I inhibitor) on corn. Page 11 of 21 2

12 Photos courtesy of Arnold Appleby, Don Morishita and Ray William. Bleaching caused by amitrole (Group F3: carotenoid inhibitor) on potato. Photos courtesy of Arnold Appleby, Don Morishita and Ray William. Chlorosis caused by glyphosate (Group G: EPSP synthase inhibitor) on bean. Photos courtesy of Arnold Appleby, Don Morishita and Ray William. Clubbed roots caused by trifluralin (Group K1: microtubule assembly inhibitor) on beans. Page 12 of 21 3

13 Photos courtesy of Arnold Appleby, Don Morishita and Ray William. Purple coloration (P-deficiency) caused by trifluralin (Group K1: microtubule assembly inhibitor) on orchardgrass. Photos courtesy of Arnold Appleby, Don Morishita and Ray William. Crinkling/puckering caused by alachlor (Group K3: inhibition of VLCFAs [cell division inhibitor]) on potato. Photos courtesy of Arnold Appleby, Don Morishita and Ray William. Stringing/leaf strapping caused by EPTC (Group N: lipid synthesis inhibitor) on bean. Page 13 of 21 4

14 Photos courtesy of Arnold Appleby, Don Morishita and Ray William. Parallel veins ( fanleaf ) caused by 2,4-D (Group O: synthetic auxin) on grape. Photos courtesy of Arnold Appleby, Don Morishita and Ray William. Epinasty caused by dicamba (Group O: synthetic auxin) on potato. Photos courtesy of Arnold Appleby, Don Morishita and Ray William. Epinasty caused by clopyralid (Group O: synthetic auxin) on potato. Page 14 of 21 5

15 INSECTICIDES organized by active ingredient Active Ingredient IRAC* Group Leaching Potential Soil Half-life (days) Sorption Coefficient (soil K OC) Water Solubility (mg/l) Activity Notes acephate 1 Low ,000 insecticide contact; systemic abamectin 6 Low acaricide; insecticide; miticide acetamiprid 4 Intermediate insecticide allethrin 3 High insecticide arsenic trioxide U** insecticide azadirachtin (neem) U** High insecticide; miticide, nematicide organic (botanical); also a fungicide Bacillus thuringiensis Ssp. Israelensis 11 Low insecticide mosquito larvicide; organic (microbial) Bacillus thuringiensis Ssp. Kurstaki 11 Low insecticide caterpillar larvicide; organic (microbial) beta-cyfluthrin 3 Very Low 13 64, insecticide contact bifenthrin 3 Very Low , acaricide; insecticide; miticide; termiticide broad-spectrum boric acid U** High ,200 insecticide larvicide; some may be considered organic boron sodium oxide pentahydrate U** insecticide larvicide; some may be considered organic carbaryl 1 Low acaricide; insecticide broad-spectrum; can cause spider mite outbreaks chlorantraniliprole 28 Very Low ,000 1 insecticide chlorpyrifos 1 Low insecticide broad-spectrum cinnamaldehyde U** Low insecticide organic (botanical); also a fungicide clarified hydrophobic neem oil U** Low 12 10, insecticide; miticide, nematicide organic (botanical); also a fungicide clothianidin 4 High insecticide cyfluthrin 3 Very Low , insecticide contact cypermethrin 3 Very Low 77 42, acaricide; insecticide contact DDVP (dichlorvos, dichlorovos) 1 Very Low ,000 acaricide; insecticide contact; stomach poison deltamethrin 3 Very Low , insecticide contact diatomaceous earth U** insecticide organic; causes dehydration diflubenzuron 15 Low 10 10, insecticide; termiticide Insect Growth Regulator (IGR); larvicide dinotefuran 4 High ,830 insecticide disodium octaborate tetrahydrate U** insecticide larvicide; some may be considered organic disulfoton (di-syston) 1 Intermediate acaricide; insecticide systemic d-trans allethrin (bioallethrin) 3 High insecticide esfenvalerate 3 Low insecticide broad-spectrum; contact etofenprox 3 Very Low 11 94, insecticide to reach the homeowner market eugenol U** Low 12 3,500 1 insecticide; insect repellent organic (botanical) fenvalerate 3 Low acaricide; insecticide broad-spectrum; contact fipronil 2 Intermediate acaricide; insecticide gamma-cychalothrin 3 insecticide halofenozide 18 Intermediate insecticide Insect Growth Regulator (IGR); turf insect control hydramethylnon 20 Very Low , insecticide hydroprene 7 Low insecticide selective (Blattaria, Coleoptera, Orthoptera) imidacloprid 4 High insecticide imiprothrin 3 insecticide indoxacarb 22 Low insecticide kaolin U** Low insecticide organic (kaolin is a type of clay); also a fungicide lambda-cyhalothrin 3 Very Low , acaricide; insecticide; miticide lime sulfur U** insecticide (scalecide); miticide do not apply to evergreens limonene U** insecticide organic (botanical) linalool U** Low insecticide organic (botanical) malathion 1 Low acaricide; insecticide methomyl 1 High ,000 insecticide methoprene 7 Low insecticide Insect Growth Regulator (IGR) metofluthrin 3 Low insecticide nithiazine 4 insecticide oil, botanical U** Low 12 10, insecticide (scalecide); miticide Note: botanical oils generally have a greater potential for oil, mineral (petroleum distillate) U** Low insecticide (scalecide); miticide organic; also a fungicide; do not use near sulfur applications permethrin 3 Very Low , acaricide; insecticide; termiticide contact phenothrin 3 Very Low 1 180, insecticide contact, stomach phenylethyl propionate U** Low insecticide organic (botanical) potassium laurate (salts of fatty acids; soap) U** Low insecticide organic (soap); also a fungicide prallethrin 3 Low insecticide propoxur 1 High insecticide pyrethrins 3 Very Low , insecticide organic (botanical); contact pyriproxyfen (Nylar) 7 Very Low 10 16, insecticide Insect Growth Regulator (IGR) resmethrin 3 Very Low , insecticide contact sodium borate (borax) 8 High ,600 insecticide larvicide; some may be considered organic sodium lauryl sulfate U** Low insecticide organic (soap) Spinosyn A 5 Low , insecticide organic Spinosyn D 5 Very Low , insecticide organic sulfluramid U** acaricide; insecticide sulfur U** High acaricide; insecticide do not mix with soaps or oils; organic; also a fungicide sumithrin (d-phenothrin) 3 Very Low insecticide tau-fluvalinate 3 Very Low 30 1,000, acaricide; insecticide, miticide broad spectrum; contact; stomach poison tetramethrin 3 Very Low insecticide contact thiamethoxam 4 High insecticide tralomethrin 3 Very Low , insecticide contact trichlorfon 1 High ,000 acaricide; insecticide contact; stomach poison zeta-cypermethrin 3 Very Low 14 42, insecticide contact; stomach poison *IRAC = Insecticide Resistance Action Committee **U = Unknown Mode of Action Page 15 of 21 Content edited by Jeff Choate on 11 October 2012.

16 INSECTICIDES organized by IRAC* Group IRAC* Group Active Ingredient Leaching Potential Soil Half-life (days) Sorption Coefficient (soil K OC) Water Solubility (mg/l) Activity Notes 1 acephate Low ,000 insecticide contact; systemic 1 carbaryl Low acaricide; insecticide broad-spectrum; can cause spider mite outbreaks 1 chlorpyrifos Low insecticide broad-spectrum 1 DDVP (dichlorvos, dichlorovos) Very Low ,000 acaricide; insecticide contact; stomach poison 1 disulfoton (di-syston) Intermediate acaricide; insecticide systemic 1 malathion Low acaricide; insecticide 1 methomyl High ,000 insecticide 1 propoxur High insecticide 1 trichlorfon High ,000 acaricide; insecticide contact; stomach poison 2 fipronil Intermediate acaricide; insecticide 3 allethrin High insecticide 3 beta-cyfluthrin Very Low 13 64, insecticide contact 3 bifenthrin Very Low , acaricide; insecticide; miticide; termiticide broad-spectrum 3 cyfluthrin Very Low , insecticide contact 3 cypermethrin Very Low 77 42, acaricide; insecticide contact 3 deltamethrin Very Low , insecticide contact 3 d-trans allethrin (bioallethrin) High insecticide 3 esfenvalerate Low insecticide broad-spectrum; contact 3 etofenprox Very Low 11 94, insecticide to reach the homeowner market 3 fenvalerate Low acaricide; insecticide broad-spectrum; contact 3 gamma-cychalothrin insecticide 3 imiprothrin insecticide 3 lambda-cyhalothrin Very Low , acaricide; insecticide; miticide 3 metofluthrin Low insecticide 3 permethrin Very Low , acaricide; insecticide; termiticide contact 3 phenothrin Very Low 1 180, insecticide contact, stomach 3 prallethrin Low insecticide 3 pyrethrins Very Low , insecticide organic (botanical); contact 3 resmethrin Very Low , insecticide contact 3 sumithrin (d-phenothrin) Very Low insecticide 3 tau-fluvalinate Very Low 30 1,000, acaricide; insecticide, miticide broad spectrum; contact; stomach poison 3 tetramethrin Very Low insecticide contact 3 tralomethrin Very Low , insecticide contact 3 zeta-cypermethrin Very Low 14 42, insecticide contact; stomach poison 4 acetamiprid Intermediate insecticide 4 clothianidin High insecticide 4 dinotefuran High ,830 insecticide 4 imidacloprid High insecticide 4 nithiazine insecticide 4 thiamethoxam High insecticide 5 Spinosyn A Low , insecticide organic 5 Spinosyn D Very Low , insecticide organic 6 abamectin Low acaricide; insecticide; miticide 7 hydroprene Low insecticide selective (Blattaria, Coleoptera, Orthoptera) 7 methoprene Low insecticide Insect Growth Regulator (IGR) 7 pyriproxyfen (Nylar) Very Low 10 16, insecticide Insect Growth Regulator (IGR) 8 sodium borate (borax) High ,600 insecticide larvicide; some may be considered organic 11 Bacillus thuringiensis Ssp. Israelensis Low insecticide mosquito larvicide; organic (microbial) 11 Bacillus thuringiensis Ssp. Kurstaki Low insecticide caterpillar larvicide; organic (microbial) 15 diflubenzuron Low 10 10, insecticide; termiticide Insect Growth Regulator (IGR); larvicide 18 halofenozide Intermediate insecticide Insect Growth Regulator (IGR); turf insect control 20 hydramethylnon Very Low , insecticide 22 indoxacarb Low insecticide 28 chlorantraniliprole Very Low ,000 1 insecticide U** arsenic trioxide insecticide U** azadirachtin (neem) High insecticide; miticide, nematicide organic (botanical); also a fungicide U** boric acid High ,200 insecticide larvicide; some may be considered organic U** boron sodium oxide pentahydrate insecticide larvicide; some may be considered organic U** cinnamaldehyde Low insecticide organic (botanical); also a fungicide U** clarified hydrophobic neem oil Low 12 10, insecticide; miticide, nematicide organic (botanical); also a fungicide U** diatomaceous earth insecticide organic; causes dehydration U** disodium octaborate tetrahydrate insecticide larvicide; some may be considered organic U** eugenol Low 12 3,500 1 insecticide; insect repellent organic (botanical) U** kaolin Low insecticide organic (kaolin is a type of clay); also a fungicide U** lime sulfur insecticide (scalecide); miticide do not apply to evergreens U** limonene insecticide organic (botanical) U** linalool Low insecticide organic (botanical) U** oil, botanical Low 12 10, insecticide (scalecide); miticide Note: botanical oils generally have a greater potential for U** oil, mineral (petroleum distillate) Low insecticide (scalecide); miticide organic; also a fungicide; do not use near sulfur applications U** phenylethyl propionate Low insecticide organic (botanical) U** potassium laurate (salts of fatty acids; soap) Low insecticide organic (soap); also a fungicide U** sodium lauryl sulfate Low insecticide organic (soap) U** sulfluramid acaricide; insecticide U** sulfur High acaricide; insecticide do not mix with soaps or oils; organic; also a fungicide *IRAC = Insecticide Resistance Action Committee **U = Unknown Mode of Action Page 16 of 21 Content edited by Jeff Choate on 11 October 2012.

17 Pyrethrins, Pyrethrum, & Pyrethroids There are several terms used to describe many of the insecticides on the market today, and these terms are easily confused with one another: pyrethrin(s) pyrethrum pyrethroid(s) There are six pyretrhins (each one is a pyrethrin): 1. cinerin I 2. cinerin II 3. jasmolin I 4. jasmolin II 5. pyrethrin I 6. pyrethrin II These pyrethrins are naturally occurring insecticides derived from the flowers of Chrysanthemum cinerariaefolium. Due to their relatively low mammalian toxicity, these pesticides have acquired a large market share of the insecticides, especially since their more toxic predecessors, namely the organophosphates, gradually are being phased out of use. Pyrethrum is simply a mixture of pyrethrins. Pyrethroids, on the other hand, are synthetic variations of pyrethrins (each variation is a pyrethroid). These are sometimes referred to as synthetic pyrethroids, although this is a redundant term, because a pyrethroid is synthetic by definition. The following excerpt is from the Farm Chemicals Handbook 2000 by Meister Publishing Company: Pyrethrins: PROPERTIES: A botanical insecticide whose active principles are pyrethrins I and II (esters of pyrethrolone and chrysanthemic acid and pyrethroic acid), cinerins I and II (esters of cinerolone and chrysanthemic and pyrethroic acids), and jasmolin I and II (jasmoline and chrysanthemic and pyrethroic acids), collectively known as the pyrethrins. The plant Chrysanthemum cinerariaefolium, and the flowers are the source of the principles. The flowers and extracts are principally imported from Kenya, Rwanda, Tanzania, and Ecuador. Pyrethrum dried flowers contain % pyrethrins. The crude extract or oleoresin contains 50-60% pyrethrins and most refined grade (pale) about 50% (20% in U.S.) pyrethrins by dewaxing and decoloring. Formerly the dried flowers were known as Dalmatian insect flowers; the powdered flowers as insect powder. ACTION: Contact insecticide. USE: Because of their safety, pyrethrum extracts are used extensively in stock sprays, aerosols, industrial sanitation sprays, and to protect stored food in warehouses, etc. These Page 17 of 21 Content edited by Jeff Choate on 23 January Page 1 of 2

18 pyrethrins may be extracted in kerosene, alcohol, acetone, or ethylene dichloride for formulation in dust, sprays, etc. They are incompatible with lime and ordinary soaps because acids and alkalies speed up the processes of hydrolysis. Pyrethrins have proved to be stable for long periods in water-base aerosols where modern emulsifiers give neutral water systems. Pyrethrins are oxidized on exposure to the air and stored flowers may lose 20% of their activity in a year. Impregnated and stabilized dusts are less susceptible to oxidation than dusts made from ground flowers. Oxidation is not a problem in stabilized oil concentrates. Oxidation can be inhibited with materials such as hydroquinone, pyrogallol, isopropyl cresol, tannic acid, and other antioxidants. FORMULATIONS: Concentrate in oil and water, usually containing synergists (such as piperonyl butoxide); in impregnated and stabilized dust concentrates; and in dilute dusts made from ground flowers. In recent years a low-color, 20% pyrethrin extract in oil has become the standard item of the industry, although less concentrated solutions in oil are still available. Pyrethrins offer a highly effective, organic alternative to synthetic insecticides, but they have two primary drawbacks: (1) they are short-lived in the environment; and (2) they are easily detoxified by many insect pests. While short-lived chemicals may be environmentally friendly, they also result in the need for frequent re-application in order to provide effective control of insect pests. This trait, along with the fact that many insect pests can detoxify pyrethrins faster than pyrethrins can neutralize the pests, has resulted in many pyrethrin-containing products being formulated with synergists. Synergists don t have any pesticidal properties in and of themselves (although they are regulated as pesticides), but they act to slow the degradation of pyrethrins in the environment and/or in target organisms, thereby increasing the efficacy of the pyrethrins with which they are formulated. Piperonyl butoxide (PBO) is an example of a synergist that is commonly mixed with pyrethrins. It should be noted that, while pyrethrins are organic, the synergists with which they are often mixed typically are not considered organic. Pyrethroids have overcome the primary drawbacks of pyrethrins listed above. Consequently, dozens of pyrethroids exist today, and it seems likely that more will continue to be developed. Modern pyrethroids even manage to provide fair residual insect control under certain conditions. While pyrethroids are considered to be broad spectrum insecticides with relatively low mammalian toxicity, the exact pests controlled and toxicity of these products vary from one to the next, so read the label carefully! Page 18 of 21 Content edited by Jeff Choate on 23 January Page 2 of 2

19 March 23, 2004 Vol. 53, No. 6 Telephone 503/ Emergencies 503/ Fax 503/ cd.summary@state.or.us AN EPIDEMIOLOGY PUBLICATION OF THE OREGON DEPARTMENT OF HUMAN SERVICES PESTICIDE POISONING FROM SYNTHETIC PYRETHROIDS WHEN HEALTH CARE providers think about pesticides, organophosphates (OPs) and their cholinergic symptoms come to mind. Welcome to a new generation of insecticides pyrethroids. Pyrethroids are a synthetic derivative of pyrethrins, a natural insecticide produced from chrysanthemums. Pyrethroids act as contact poisons, affecting the insect s nervous system. However, they are not cholinesterase inhibitors like OPs; they are, rather, dermal and respiratory allergens. Contact dermatitis, rhinitis and asthma have occurred following exposure. Pyrethroids are replacing OPs in insecticides in bugbombs, head lice treatments, and flea sprays for pets, and are commonly used in fruit orchards. Brand names include Nix, Elimite, Dragon, Drione, Pyrenon and Pyrocide. Suspected pesticide-related illness and injury have been reportable in Oregon since 1987 (OAR through ). For incidents reported to the Pesticide Poisoning Prevention Program in the years , the active pesticide ingredients associated with the largest number of likely pesticide illness were pyrethrins and their synthetic versions, pyrethroids. Reported Pesticide-Related Illness Associated with Pyrethrins/Pyrethroids, Oregon Year Total Cases Associated with Cases Pyrethrins/Pyrethroids Pesticide poisoning in general can be difficult to diagnose, and poisoning by pyrethroids is no exception. Symptoms may include headache, fatigue, peripheral neuropathy, and vomiting. A thorough history is generally necessary to identify pesticides as the cause. SYNTHETIC PYRETHROIDS AND PARESTHESIAS Scenario: A 58-year old adult male with a history of well-controlled insulindependent diabetes mellitus visits his physician, complaining of tingling and numbness on the fingers and dorsum of the hands. The symptoms began 12 hours before the office visit. The patient reports that the symptoms worsen when he washes his hands with warm water. He has no other symptoms. He has had similar episodes of tingling and numbness of the hands on 3 occasions in the past several months. On each occasion, the tingling and numbness occurred in different areas of the hands. In each case, the symptoms resolved after hours. On examination, the patient appears healthy. Inspection of the hands does not reveal rash, erythema, or edema. The hands are warm, with good peripheral pulses and capillary refill. Neurological examination reveals a slight decrease in sensation to light touch in the index finger of the right hand and on the dorsum of the thumb and index finger of the left hand. When testing for temperature sensation, the patient reports an exacerbation of symptoms after a warm stimulus. Neurological examination of the lower extremities and the remainder of the physical examination are unremarkable. Blood work reveals a hemoglobin A1c of 6.3% (indicating good control of blood sugar). A dipstick urinalysis is positive for trace levels of protein. The doc is concerned about peripheral neuropathy, and schedules the patient for nerveconduction studies and a follow-up appointment to reassess his current diabetes Chemical structure of lambda-cyhalothrin (nasty alpha-cyano group below bracket) treatment regimen. The patient cancels the follow-up appointment after his symptoms resolve within 24 hours of the office visit. DISCUSSION This case demonstrates the importance of an occupational and environmental exposure history, as the signs and symptoms of acute exposure to certain pesticides can be similar to those of other common medical conditions. This patient was a cabbage farmer whose skin had been exposed to the insecticide on several occasions throughout the growing season. When additional questions were asked about exposures during his farming activities, the patient related several instances of direct skin contact with a concentrated insecticide in which lambda-cyhalothrin was the active ingredient. The exposures occurred when he was mixing and transferring the liquid without the use of appropriate skin protection. An expanded occupational history led to the correct diagnosis and an opportunity to reduce exposure. Lambda-cyhalothrin is an insecticide registered for use in the US by the Environmental Protection Agency. It is a synthetic pyrethroid. Synthetic pyrethroids affect the nervous system of insects by prolonging the deactivation of voltage-gated sodium channels, which results in prolonged excitation of nerve fibers. 1 There is evidence that synthetic pyrethroids, which, like lambda-cyhalothrin, contain an alpha-cyano group are more potent in eliciting neurotoxic effects, compared to pyrethroids that lack this group, e.g., permethrin 1,2 (see figures). Chemical structure of permethrin Page 19 of 21