UNITED STATES ENVIRONMENTAL PROTECTION AWNCY 

WASHINGTON, D.C. 20460 

OFFICE OF 

PREVENTION, PESTICIDES, 

AND TOXIC SUBSTANCES 

PC Code: 029841 

DB Barcode 377095 

Date: May 24,2010 

MEMORANDUM 

Subject: EFED Response to a FIFRA Section 18 Emergency Exemption for i 

Dicamba co-formulated with 2,4-D (LatigoTM) Use on Teff grown for 

grain, seed, and hay to control broadleaf weeds. Requested by the Oregon 

Department of Agriculture. I 

To: 

From: 

Thru: 

Marcel Howard, Risk Manager 

Risk Integration, Minor Use & Emergency Response Branch 

Registration Division (7505P) 

USEPA Office of Pesticide Programs 

Tiffany Mason, Environmental Engineer 

Michael Wagman, Biologist 

Environmental Risk Branch I1 

Environmental Fate and Effects Division (7507P) 

USEPA Office of Pesticide Programs 

William P. Eckel, Acting Branch Chief 

Environmental Risk Branch I1 

Environmental Fate and Effects Division (7507P) 

USEPA Office of Pesticide Programs 

The Oregon State Department of Agriculture has requested a FIFRA Section 18 

emergency exemption for ground application of 2,4-D formulated with dicamba (batigo, 

EPA Reg # 5905-564) to control broadleaf weeds in teff grown for hay, seed and grain. 

In the case of the product formulations of active ingredients, each active ingredie t is 

subject to an individual risk assessment for regulatory decision regarding the acti 3 e 

ingredient on a particular use site. This assessment analyzes the risk associated dith 

dicamba use. EFED has reviewed the risk to non-listed and listed species in Ore& 

based on the proposed application method and rate, and the availability of viable 

exposure pathway and toxicological data. EFED concludes that there may be an 

adverse risk from dicamba application to teff for amphibians, reptiles, birds, 

insects and non-target plants (especially dicots). Dicamba use 

adverse risk from acute dietary-based exposure and chronic exposure to 

is no chronic freshwater or saltwater fish and invertebrate data. In the 

data, EFED assumes that there is potential chronic risk to these 

TEXT SEARCHABLE DOCUMENT - 2010
analysis of endangered species was run and is attached in Appendix E. A buffer analysis 

was conducted for dicamba using AgDrift. This analysis concluded that a buffer of 76 

feet was necessary to reduce effective exposure concentrations below the Agency's level 

of concern (LOC). 

Application Method and Timing 

The Oregon Department of Agriculture (ODA) is requesting the use of Dicamba 

formulated with 2,4-D (Latigo) to control broadleaf weeds in teff (Erogrostis teJ) grown 

for hay, seed and grain. Specifically, the pest species to be controlled are kochia (Kochia 

scoparia), redroot pigweed (Amaranthus retrofexus), common lambsquarters 

(Chenopodium album), common purslane (Portulaca oleracea), hairy nightshade 

(Solanum sarrachoides), field bindweed (Convolvulus arvensis). The ODA claims that 

there are no selective broadleaf herbicides registered for use on teff, which significantly 

decreases the quality and yield of hay, grain and seed. The emergency condition has 

been created by a sharp increase in the weed seed bank of broadleaf weeds, especially 

due to herbicide resistance in kochia and redroot pigweed, the latter of which emerges at 

the same time as teff which is planted in June. 

Hay from teff does not dry properly when slow-drying broadleaf weeds are interspersed 

with the slender teff grass blades. Excessive moisture results in moldy hay, which is 

unhealthy for animals to consume. Teff seed or grain contaminated with redroot pigweed 

seed is particularly difficult to clean out, resulting in significant seed cleaning costs. 

Latigo is an emulsifiable concentrate of 24.62% 2,4-D acid (2,4-Dichlorophenoxyacetic 

acid) and 18.28% dicamba acid (3,6-dichloromethoxybenzoic acid). LatigoTM (EPA Reg 

# 5905-564) is used to control broadleaf weeds in pastures, rangeland, grass (hay, silage), 

sugarcane, wheat, conservation reserve program land, and certain noncrop sites. The 

Oregon Department of Agriculture estimates that a maximum of 3,830 acres of teff would 

be treated from May 21, through August 21,2010 for a total maximum amount of 598.43 

gallons (1,436.22 lb a.i. 2,4-D acid and 1,077.17 lb a.i. dicamba acid) used. The 

proposed use counties are Benton, Crook, Deschutes, Douglas, Jefferson, Klamath, Lake, 

Lane, Malheur, Marion, Polk, Tillamook, Washington, and Yamhill. 

According to the proposed label, Latigo can be applied at the maximum rate of 20 fl.oz 

per acre (0.38 lb 2,4-D acidacre and 0.28 lb dicamba acidacre), and can be applied once 

per growing season by ground spray technologies. 

The emergency exemption label states that all applicable directions, restrictions, and 

precautions on the Latigo label must be followed. The "Environmental Hazards" 

statements relevant on the Latigo label include1: 

1 Note that the section 18 label, at this time, does not show these statements on the label; however, these 

statements are on the proposed section 3 label, and the documentation that came with the section 18 label. 

These environmental hazard statements must be placed on the section 18 label as stated in the proposed 

package for the section 18 label. 
This pesticide is toxic to aquatic invertebrates. Do not apply directly to watkr, 

areas where surface water is present, or to intertidal areas below the mean high 

water mark. 

Drift or runoff may adversely affect aquatic invertebrates and non-target plpts. 

Do not apply when weather conditions favor drift from target area. 

Do not contaminate water by cleaning of equipment or disposing of equipl+ent 

washwaters or rinsate. 

Caution should be exercised when handling 2,4-D pesticides to prevent 

contamination of groundwater supplies. Use of a closed system for mixing lor 

transferring this pesticide will reduce probability of spills. ~ 

Mixinglloading equipment placed on impervious pads to contain spills will help 

prevent groundwater contamination. 

Exposure - Pathways of Concern and Fate Properties - of Latigo 

The new proposed use of dicamba and 2,4-D may result in drift onto plants, soil, 

adjacent to a treated field. Foliar application of the dicamba and 2,4-D mixture, 

ground application, will result in residues on dietary items for birds and 

on the use pattern for the mixture, the main exposure pathways for 

are direct exposure via consumption of food items and from direct 

invertebrateslinsects such as honeybees. Aquatic organisms may 

dicamba and 2,4-D mixture as a result of runoff and/or spray drift. 

Aerobic soil metabolism is the main degradative process for dicamba. A single obkerved 

half-life for dicamba was six days, with formation of the intermediate non-persist&nt 

degradate dichlorosalicylic acid (DCSA) at a maximum concentration of 17.5%. ~CSA 

degraded at roughly the same rate as dicamba; the final metabolites were carbon 

and microbial biomass. Dicamba is stable to abiotic hydrolysis at all pH's and , photodegrades slowly in water and on soil. 

Dicamba is more persistent under anaerobic soil :water systems in the laboratory, 

half-life of 141 days. The major degradate under anaerobic conditions was DCS$:kh 

was persistent, comprising > 60% of the applied after 365 days of anaerobic 

No other anaerobic degradates were present at > 10% during the incubation. 

acceptable data for the aerobic aquatic metabolism of dicamba; 

indicates that dicamba degades more rapidly in aquatic systems 

Dicamba is very soluble (6,100 ppm) and very mobile (&, = 13.4) in the 

Because dicamba is not persistent under aerobic conditions, very little is 

leach to groundwater. Any dicamba reaching anaerobic ground water would be 

somewhat persistent (due to its anaerobic half-life of 141 days); any 

ground water would be expected to persist as well. 

Results from two acceptable field dissipation studies conducted with 

of dicamba, indicated that dicamba dissipated with a half-life range 

The DCSA was the major degadate in both studies. Both, dicamba 
(DCSA) were found in soil segments deeper than 10 cm. 

Dicamba is not expected to bioaccumulate in aquatic organisms because it is an anion at 

environmental pHs (pKa = 1.9). 

Surface Water: PRZM-EXAMS simulations were conducted for the use on teff grown 

for seed, grain, and hay to calculate peak, 21 -day average, and 60-day average EECs for 

parent dicarnbia and its degradate dichlorosalicylic acid (DCSA). A total toxic residues 

approach was used to determine the exposure. Dicamba and DCSA were run separately 

using PRZWEXAMS and then their daily EECs spanning over a 30 year period were 

combined using a residue summation approach. Then the goth percentile was taken to 

determine the peak, 21 -day, and 60 day EECs. Selected PRZMIEXAMS modeling inputs 

are shown in. The input and output files for these runs are in Appendix A. 

Table 1. Surface water exposure inputs for PRZMEXAMS for Dicamba 

(application date 05/15/2010) 

MODEL INPUT 

VARIABLE 

Application rate (kg 

ailhectare) 

Number of appl./season 

Interval between appl. (d) 

Application Method 

Scenario modeled 

Henry's Law Constant 

(atm m3/mol) 

Molecular Weight (g/mol) 

Solubility @ 25°C (mg/L) 

Vapor Pressure (torr) 

%C (mL/g) 

Aerobic Soil Metabolic 

Half-life (days) 

Anaerobic Soil Metabolic 

Half-life (days) 

Is the pesticide wetted-in? 

Spray Drift Fraction 

Application Efficiency 

Aerobic Aquatic 

Metabolic Half-life (days) 

Anaerobic Aquatic 

Metabolic Half-life (days) 

Hydrolysis (pH 7) half-life 

(days) 

INPUT VALUE 

0.3 1 

1 

Not Applicable 

Ground 

ORgrassseedSTD 

1.6 x lo-' 

22 1 

6100 

3.41 x 

13.4 (average) 

18 

18 

No 

0.01 

0.99 

12 

423 

0 

SOURCE and COMMENTS 

Proposed Emergency Exemption (0.28 lb a.i./A) 

Proposed Emergency Exemption 

Proposed Emergency Exemption 

Proposed Emergency Exemption 

Closest scenario available 

Estimated 

(VP x MW)/(760 todl atm * solubility) 

SANDOZE Safety Data Sheet (Nov, 1989). 

SANDOZE Safety Data Sheet (Nov, 1989). 

SANDOZE Safety Data Sheet (Nov, 1989). 

MRID# 427741 01 ; Input parameters guideline 

(1 0/22/2009). 

MRID # 43245207; (6d x 3) lnput parameters guideline 

(10/22/2009). 

MRID # 43245207; (6d x 3) lnput parameters guideline 

(1 0/22/2009). 

EPA Reg. No. 5905-564 

Input guideline, 2009 

Input guideline, 2009 

No acceptable aerobic aquatic metabolism data were 

available, therefore 2x the aerobic soil metabolism half-life 

(identified above) was used per guidance (Input guideline, 

2009). 

MRID# 43245208. Input Parameter Guidance 2009. (141 x 

3 = 423) 

Stable. IvlRID# 40547902 
MRID 42774102. Input Parameter Guidance 2009; 

Adjusted half-life to represent sun intensity and 12 hours 

of sunlight per day. 3 8.1 day value represented co~tinuous 

sun exposure at an intensity of 1.38 times natural sbnlight. 

Degradate not present. 

Aquatic Photolysis Halflife (days) 

I 

Table 2. Surface water exposure inputs for PRZMEXAMS for DCSA (application 

date 05/15/2010) I 

105 

I 

SOURCE and COMMENTS I 

Proposed Emergency Exemption (0.26 lb a.i./A) ~ 

I 

I 

I Proposed Emergency Exemption I , 

I 

Proposed Emergency Exemption , 

Closest scenario available I 

MODEL INPUT 

VARIABLE 

Application rate (kg 

ailhectare) 

Number of appl./season 

Interval between appl. (d) 

Scenario modeled 

INPUT VALUE 

0.29 

1 

Not Applicable 

P 

ORgrassseedSTD 

Henry's Law Constant 

(atm m3/mol) 

Molecular Weight (gmol) 

Solubility @ 25OC (m@) 

Vapor Pressure (torr) - 

KO, (mL/g) 

Aerobic Sail Metabolic 

Half-life (days) 

Anaerobic Soil Metabolic 

Half-life (days) 

Is the pesticide wetted-in? 

Spray Drift Fraction 

Application Efficiency 

Aerobic Aquatic 

Metabolic Half-life (days) 

Anaerobic Aquatic 

Metabolic Half-life (days) 

Hydrolysis (pH 7) half-life 

(days) 

Aquatic Photolysis Halflife (days) 

*(degradate molecular I 

Effect Characterization 

1.6 x 

207 

21 12 

3.4 1 x 

1208 (average) 

24.6 

24.6 

No 

0.01 

0.99 

16.4 

0 

0 

105 

weight)/(parent 

Estimated for dicamba and used for DCSA 

(VP x MW)/(760 torrll atm * solubility) I 

Product Chemistry I 

I 

MRID 4309530 1 I 

For Dicamba. SANDOZE Safety Data Sheet (NO+, 1989). 

MRID# 4309530; Input parameters guideline (10/~2/2009). 

MRID # 43245207; (8.2 d x 3) lnput parameters +idelhe 

(10/22/2009). 

MRID # 43245207; (8.2 d x 3) lnput parameters 

(1 0/22/2009). 

EPA Reg. No. 5905-564 

Input guideline, 2009 

Input guideline, 2009 

No acceptable aerobic aquatic metabolism data 

available, therefore 2x the aerobic soil metabolisni 

(identified above) was used per guidance (Input 

2009). 

Stable. MRID# 43245208. Input Parameter Guidance 

2009. 

glideline 

were 

half-life 

glideline, 

Stable. MRID# 43245208 

No information for the degradate; therefore, used 

dicamba: MRID 42774102. Input Parameter Guidance 

value for 

2009. Adjusted half-life to represent sun intensity and 12 

hours of sunlight per day. 38.1 day value represe ted 

continuous sun exposure at an intensity of 1.38 t' es 

natural sunlight. 

molecular weight) x application rate 

1 
The Agency does not routinely include, in its risk assessments, an evaluation of mixtures 

of active ingredients, either those mixtures of multiple active ingredients in product 

formulations or those in the applicator's tank. In the case of the product formulations of 

active ingredients (that is, a registered product containing more than one active 

ingredient), each active ingredient is subject to an individual risk assessment for 

regulatory decision regarding the active ingredient on a particular use site. If effects data 

are available for a formulated product containing more than one active ingredient, they 

may be used qualitatively or quantitatively in accordance with the Agency's Overview 

Document and the Services' Evaluation Memorandum (U.S., EPA 2004; USFWS/NMFS 

2004). 

Latigo is a registered product that contains multiple active ingredients. Analysis of the 

available acute oral mammalian LD50 data (and available open literature for dicamba) 

for multiple active ingredient products relative to the single active ingredient is provided 

below. The results of this analysis show that an assessment based on the toxicity of the 

single active ingredients of Latigo is appropriate 

The toxicity of the mixture of 2,4-D and dicamba as compared to the technical grade 

active ingredient (TGAI) toxicity was evaluated to determine whether the formulated 

products are more toxic than the TGAI. Limited information has been submitted 

regarding the toxicity of the Latigo formulation or of other mixtures of 2,4-D and 

dicamba. However, mammalian rat acute oral toxicity data is available on a mixture of 

12.4% dicamba with 35.7% 2,4-D salt. This product had LD50 formulation values 

(MRID 44948003) of 1889 mglkg for males and 1 180 mglkg-bw for females which is of 

intermediate toxicity compared to the two technical active ingredients alone. The 

dicamba technical LD50 value exhibits lower toxicity (MRID 00078444) with an LD50 of 

2740 mglkg-bw. The 2,4-D technical LDSo has greater toxicity to rats (MRID 001 01 605) 

with an LD50 of 639 mgkg. No confidence intervals were able to be calculated for any of 

these studies. When the mixture formulation is adjusted for toxicity of the active 

ingredient, the toxicity for 2,4-D to female rats in that formulation is 421.26 mg a.i.kgbw which is relatively close to the reported 2,4-D technical LD50 toxicity indicating that 

these products do not appear to be synergists. 2,4-D acid and dicamba acid have the 

same molecular weight, so no conversion from a mass-based toxicity to a molar based 

toxicity is necessary. The rest of this assessment will focus solely on the dicamba acid 

part of the mixture. 

Acute and chronic risk was based on the most sensitive species for terrestrial and aquatic 

organisms. The acute and chronic toxicity values for the most sensitive terrestrial and 

aquatic organisms are presented in 

Table 3. No chronic toxicity data is available for any fish or aquatic invertebrate taxa. 

Toxicity of the major degradate, DCSA, is unknown. However, DCSA does appear to 

have comparatively similar chemical structure to dicarnba. Therefore, for this 

assessment, EFED will assume that DCSA residues have equal toxicity to parent 

dicamba. 
Table 3. Toxicity values for most-sensitive aquatic and terrestrial species to 

dicamba 

AQUATIC ORGANISMS I 

Rainbow trout (Oncorhynchur 

mykiss) 1 000253!/l0l/N~ (TGAI 

$6.6%) 

Chronic Endpoints 

(mg afi) Species 

Sheepshead Minnow 

(Cyprinodon variegatus) 

Acute Endpoints 

(mg afil 

96 hr LC50 =28 

96 hr LC5, >I80 

Water Flea (Daphnia magna) 

Grass Shrimp (Palaemonetes 

pugio) 

ND 

Duckweed (Lemna gibba) 

I 

TERRESTRIAL ORGANISMS I 

48 hr EC50 > 100 

96 hr EC50 > 

Blue-green algae (Anabaena 

ji'os-aquae.) 

40098001/N~ (TGAI 88%) 

I 

14-d IC50 > 3.25 

, 

ND 

ND 

5-d IC50 = 0.061 

40094602)FJD (TGAI 88%) 

00034q02m (TGAI 

f46.2%) 

I 

14-d NOAEC = 0.20 

Number 

(ac~.te/chronic) 

Bobwhite (Colinus virginianus) 

Mallard duck (Anas 

platyrhynchos) --chronic endpoint 

only 

Rat 

5-d NOAEC = 0.005 

MRD 

Honeybee (Apis rnellijera) 

Terrestrial Plants 

Monocot (Onion) I ECz5/NOAEC = 0.0041 I ECz5/NOAEC = 0.062 / I i 

427741 1 

42774 109 (TGAI 89.5%) 1 

Chronic Endpoints Species 

Acute Oral LD50 = 188 

mg ailkg-bw 

Acute Dietary LC5, > 

10,000 mg aikg-diet 

Acute Oral LDS0 = 2740 

mg/kg Acute Dietary LOAEL = 

3111) 

Dicot (Soybean) 

NA = Not Applicable 

1 (TGAI 89.5%) 

Acute Endpoints 

--- I 

LD50 > 90.65 pghee I NA 

Non-1istedIListed species 

' Based on reduction in hatchability at 1600 mg/kg 

'~ecreased pup weight was seen at the LOAEL of 136 mg/kg/day 

= mdkgl 

NOAEL = 45 mg 

/kg/da? 

Seedling Emergence 

Ec25m0AEC = 0.0027 

1<0.002 lb/A 

Seedling Emergence 

0003 

I 

42918d01,000253911 

438 1400b (TGAI 86.9%) I 

5935 (TGAI) 

vegetative Vigor 

EC~~~OAEC = 0.00651 

< 0.004 1bIA 

Vegetative Vigor 

0 

I 

I 

I 

3078444, 

42774104143 137101 

(TGAI) 
Risk Summary 

Aquatic Organisms: 

EECs and RQs for aquatic organisms are presented in Table 4. No acute RQ values 

exceeded any LOCs for freshwater and estuarinelmarine fish and invertebrates or LOCs 

for aquatic plants. No chronic data for fish or invertebrates was available, therefore 

EFED will assume that there is potential for chronic risk to aquatic organisms. 

1 I I Invertebrate . 1 0.0000044 ( NA 1 

Table 4. EECs and RQs for Ground Applications of Dicamba to Teff. 

EEC (PP~) 

(Palaemonetes pugio) 

Plant - vascular (duckweed) 

Invertebrate chronic RQ = 21 -d EECIchronic NOAEC 

0.441 1 0.3 19 1 NA I Estuarinelmarine I I I 

Taxa 

Freshwater Fish 

Estuarinelmarine Fish 

(Sheepshead minnow) 

Freshwater Invertebrate 

(Daphnia magna) 

Peak 

0.441 

0.441 

0.44 1 

0.441 

Terrestrial organisms: 

0.002 

RQs and EECs for birds and mammals are provided in the TREX tables in Table 5 and 

Appendix B. Maximum dietary-based EECs on potential food items range from 4.2 ppm 

to 67.2 ppm. The acute Level of Concern (LOC of 0.5) for potential effects to non-listed 

animals from acute exposures is exceeded for small birds on short grasses. The acute 

listed species dose-based LOC (0.1) is exceeded for small birds consuming tall grasses, 

broadleaf plants and small insects and medium birds consuming short grasses, tall 

grasses, broadleaf plants and small insects. As toxicity information is not available for 

land-phase amphibians and reptiles, birds are used as surrogates for these taxa, therefore 

acute dose-based risk is also expected for these organisms. Avian dietary based RQ 

values did not exceed any LOCs. 

2 1 -day avg. 

NA 

--- 

NA 

0.3 19 

RQ 

NA 

Acute RQ = Peak EECIacute toxicity value; Fish chronic RQ = 60-d EECIchronic NOAEC; 

NA 

Mammalian dietary based RQ values exceeded the acute listed LOC (0.1) for short grass, 

tall grass, broadleaf plants and small insects. Small and medium sized mammals had 

chronic dose-based RQ values that exceeded the chronic LOC (1 .O) for potential effects 

to non-listed and listed animals from chronic dietary exposure to short grass. 

60-day avg. 

0.222 

0.222 

NA 

acute 

-- 

0.000016 

0.0000024 

0.0000044 

chronic 

NA 

NA 

NA 

NA Plant - nonvascular 

(AnabaenaJlos-aquae) 0.087 NA 
1 Acute: I 

Table 5. LOCs Exceeded For Acute and Chronic Risk to Birds and Mammals from 

Dicamba Ground Application to Teff in Oregon 

Taxa food 

RQ 

0.57 

I insects 

- 100 g I Short grasses, tall grasses, broadleaf 1 0.12-0.25 

weight Dose-based 

Birds Short grasses 

1 

I 

I I 

Mammals 

Dicamba is practically non-toxic to beneficial insects (honeybee acute contact LDSo > 

90.65 yg aihee). This acute contact LDS0 value was converted to a body weight vblue 

using 0.128 g as the body weight of a bee. The extrapolated acute contact toxicity alue 

for terrestrial invertebrates is 708 ppm.2 Risk to insects were evaluated by comp ing 

dicamba toxicity, as determined in the submitted honeybee acute contact study, 'th the 

residue levels horn dicamba use on small and large insects generated as dietary-b sed 

EECs for birds and mammals using T-REX. Comparisons of the EECs for dicam a uses 

and the extrapolated acute toxicity are presented in Table 6. Although the Agenc does 

listed species of terrestrial insects will be assumed. 

not have an official LOC for terrestrial invertebrates, an interim acute endangered 

i 

species 

LOC of 0.05 is used for terrestrial invertebrates in endangered species assessment The 

small insects value calculated hom T-REX barely exceeds this value, therefore ris 1 to 

I 

Table 6. Comparisons of Small and Large Insect EECs from Ground ~~~lic~tion of 

Dicamba to the Extrapolated Acute Contact Honeybee Concentration I 

~ 

Dietary 

20 g 

Chronic: 

Mammals 1 15-35 g I Short grass 1 1.11-1.30 1 

- 

Application Rate Dietary Item EEC (mg/kg-diet) 

- Teff 

0.28 lb aUAJ 

.Tall grasses, Broadleaf plants & small 

I plants, & small insects 

Short grass, tall grass, broadleaf plants 

5-1000g / & small insects 

Al110.15 

I I I I I 

*based on extrapolated acute contact value of 708 ppm. I 

0.26-0.32 

Acute LOC = 0.1 (listed species) and 0.5 (non-listed species); chronic LOC = 1.0 

TerrPlant (Version 1.2.2) is used to calculate EECs for non-target plant species i 

dry and semi-aquatic areas. Parameter values for application rate, drift 

found in Appendix C. 

incorporation depth are based upon the use and related application method and c$ be 

RQs were exceeded for listed and non-listed monocots and dicots on both dry and semiaquatic land as well as through spray-drift except that non-listed monocot RQ values did 

, 

- LD50honeybee - 90.65 ~g - 708 ppm 2 Ex@a~olated LD50 temza, In sect - whomy bee 0.128 g 

All O.O1 

I 

0.110-0.22 
not exceed LOCs (1 .O) on dry land. As a broadleaf herbicide, dicamba would be 

expected to have greatest risk to dicots, which greatly exceeded the LOC. Because the 

NOAEC values are inequalities (less than the lowest treatment level tested) and no ECoj 

values were generated, risk to listed species may actually be higher than these values 

indicate. 

When there are exceedances for any of the taxa, a buffer is determined using AgDRIFT. 

AgDrift is a peer-reviewed model that predicts the amount of residue deposition at 

distances from the edge of the treated field. It is EFED policy for AgDrift model inputs 

that for pesticides that contain spray application labeling that do not use specific language 

on nozzle size, analysts will use the very fine to fine nozzle spray size as input for the 

model. Fine to medium/coarse size was used for input into the AgDrift model and 

ground application was modeled. 

Table 7. RQ values for plants in dry and semi-aquatic areas exposed to Dicamba through runoff 

andlor spray drift.* 

The most sensitive endpoint of all of the species assessed was for the dicot plant 

(soybean). Therefore, the EC25 for the terrestrial seedling emergence soybean study 

(0.0027 lb a.i./A) was used in AgDRIFT to determine the buffer. The maximum 

application rate of 0.3 1 lb ai/A was used. A fraction of applied was determined using the 

EC2j divided by the application rate in order to model the distance necessary from the 

edge of the field before the concentration of dicamba on the surface would be at the EC2j 

concentration for the most sensitive terrestrial plant (soybean). For ground application 

from a point source, a distance of 76 feet off site is required before the concentration is at 

the EC25 for the terrestrial plant seedling emergence soybean study. 

Plant Type 

Monocot 

Monocot 

Dicot 

Dicot 

The 2006 RED recorded thirty-five ecological incidents attributed to dicamba use having 

been recorded in the Ecological Incident Information System (EIIS) as of Junel, 2005. Since 

the RED, two additional incidents have been reported. In 2006, in St. Landry County, LA, 

1500 acres of soybean were damaged by a combination of glyphosate, dicamba and 2,4-D. 

The type of injury was not reported. This incident was classified as probable for dicamba 

and 2,4-D and possible for glyphosate and the incident was considered as an intentional 

misuse. In 2007, in Lancaster County, PA, 4 rabbits were killed after a homeowner applied 

product with MCPP, Dicamba, and 2-4 D ingredients to the house lawn. This incident was 

classified as possible for all three active ingredients and the legality was undetermined. 

The earlier incidents reported include terrestrial, plant, and aquatic impacts. 19 of the 

incidents involve 2,4-D in addition to dicamba and sometimes other active ingredients. 

Although the database lists a terrestrial mammalian incident in Utah where dicamba was 

*If RQ > 1 .O, the LOC is exceeded, resulting in potential for risk to that plant group. 

Listed Status 

non-listed 

listed 

non-listed 

listed 

Dry 

0.97 

1 .OO 

22.22 

30.00 

Semi-Aquatic 

8.23 

8.50 

188.89 

255.00 

Spray Drift 

6.25 

6.67 

3.70 

5.00 
applied, the database states that dicarnba is "unlikely" to have caused the incident. Impacts to 

plants included a wide range of crops (soybeans, corn, wheat) as well as non-agricultural 

applications. The specific impacts varied from browning and plant damage to mortality of all 

plants within the treated area. Aquatic impacts consist of two fish kill incidents associated 

with agricultural and residential turf application. 

Therefore, acute adverse risk from dicarnba application to teff is expected for reptiles, 

amphibians, birds, and non-target plants (especially dicots). Adverse risk from acyte 

dietary-based exposure to mammals may also occur. Chronic exposure to marnmdls may 

also result in adverse risk from dicamba use on teff. Due to a lack of chronic toxidity 

data, potential risk exists for chronic effects to fish and aquatic invertebrates. A li$t of 

Federal endangered and threatened species is shown in E. 
Appendix A. Surface Water EECs from PRZMIEXAMS 

Output from Dicamba run: 

stored as Dicamba Teff.out 

Chemical: Dicamba 

PRZM environment: 0RgrassseedSTD.txt modified Tueday, 26 August 

2008 at 06:16:42 

EXAMS environment: pond298.exv modified Tueday, 26 August 2008 at 

06:14:08 

Metfile: w24232.dvf modified Tueday, 26 August 2008 at 06:15:54 

Water segment concentrations (ppb) 

Year 

1961 

1962 

Peak 96 hr 21 Day 60 Day 90 Day Yearly 

0.155 0.1478 0.1213 0.07595 0.05662 0.01481 

0.1551 0.1484 0.123 9 0.07937 0.05852 

0.01542 

0.1551 0.1467 0.1174 0.07417 0.05505 

0.01452 

0.1551 0.1477 0.1209 0.07618 0.0557 

0.0146 

0.1551 0.1482 0.1229 0.09117 0.0685 

0.01807 

0.1551 0.1475 0.12 0.07458 0.05453 0.01424 

0.1551 0.1476 0.1206 0.07321 0.05282 

0.01356 

0.1926 0.1834 0.1596 0.1062 0.07803 

0.02033 

0.3189 0.2965 0.2295 0.139 0.1255 0.03631 

0.1553 0.1477 0.1202 0.07261 0.05238 

0.01402 

0.1551 0.1479 0.1219 0.08424 0.06345 

0.01679 

0.7646 0.7254 0.5832 0.364 0.2653 0.0687 

0.1553 0.1473 0.1188 0.07396 0.05386 

0.01447 

0.155 0.1481 0.1224 0.07647 0.05596 0.01456 

0.1551 0.1476 0.1205 0.07655 0.05616 

0.01475 

0.1551 0.1479 0.1217 0.07922 0.05864 

0.01547 

0.3004 0.2873 0.2388 0.1491 0.1092 

0.02844 

0.1551 0.1472 0.1187 0.07097 0.06062 

0.01695 

0.1551 0.1468 0.1173 0.07186 0.05202 

0.01378 

0.1551 0.1478 0.1213 0.09132 0.06909 

0.01836 

0.1919 0.1848 0.1466 0.1207 0.09271 

0.02462 

0.1551 0.1474 0.1195 0.07184 0.05212 

0.01365 

0.155 0.1467 0.1172 0.076 0.05709 0.01502 
Sorted results 

Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly 

0.032258064516129 1.492 1.419 1.091 0.6227 0.4552 0.122 

0.0645161290322581 0.7646 0.7254 0.5832 0.364 

0.2653 0.0687 

0.0967741935483871 0.3189 0.2965 0.2388 0 .I49 

0.1255 0.03631 

0.129032258064516 0.3004 0.2873 0.2295 0.139 0.109 

0.03111 

0.161290322580645 0.2568 0.2383 0.1766 0.1207 

0.09704 0.02916 

0.193548387096774 0.2165 0.2022 0.1596 0.1062 

0.09452 0.02844 

0.225806451612903 0.1926 0.1848 0.1538 0.1025 

0.09271 0.02462 

0.258064516129032 0.1919 0.1834 0.1466 0.09944 

0.07803 0.02059 

0.290322580645161 0.1553 0.1484 0.1271 0.0986 

0.07793 0.02033 

0.32258064516129 0.1553 0.1482 0.123 9 0.09132 

0.06909 0.01836 

0.354838709677419 0.1553 0.1481 0.1229 0.09117 

0.0685 0.01807 I 

0.387096774193548 0.1551 0.148 0.1224 0.08424 

0.01695 

0.419354838709677 0.1551 0.1479 0.1221 0.08005 

0.06062 0.01679 

0.451612903225806 0.1551 0.1479 0.1219 0.07937 

0.05864 0.01547 

0.483870967741936 0.1551 0.1478 0.1219 0.07922 

0.05852 0.01542 

0.516129032258065 0.1551 0.1478 0.1217 0.07829 

0.05784 0.01524 

0.548387096774194 0.1551 0.1478 0.1213 0.07655 

0.05723 0.01502 

0.580645161290323 0.1551 0.1477 0.1213 0.07647 

0.05709 0.0149 

0.612903225806452 0.1551 0.1477 0.1209 0.07618 

0.05662 0.01481 

0.645161290322581 0.1551 0.1476 0.1206 

0.01475 

0.67741935483871 0.1551 0.1476 0.1205 0.07595 

0.05596 0.0146 

0.709677419354839 0.1551 0.1475 0.1202 0.07458 

0.0557 0.01456 
0.1 0.31705 0.29558 0.23787 0.14809 0.12387 

0.03579 

Average of yearly averages: 0.023303 

Inputs generated by pe5.pl - Novemeber 2006 

Data used for this run: 

Output File: Dicamba Teff 

Metf ile: w24232.dvf 

PRZM scenario: 0RgrassseedSTD.txt 

EXAMS environment file: pond298.exv 

Chemical Name: Dicamba 

Description Variable Name Value Units Comments 

Molecular weight mwt 221 g/mol 

Henry's Law Const. henry 1.6E-9 atm-mA3/mol 

Vapor Pressure vapr 3.413-5 torr 

Solubility sol 6100 mg/L 

Kd Kd m9/L 

Koc Koc 13.4 mg/L 

Photolysis half-life kdp 105 days Half-life 

Aerobic Aquatic Metabolism kbacw 12 days Halfife 

Anaerobic Aquatic Metabolism kbacs 423 days Halfife 

Aerobic Soil Metabolism asm 18 days Halfife 

Hydrolysis: pH 5 0 days Half-life 

Hydrolysis: pH 7 0 days Half-life 

Hydrolysis: pH 9 0 days Half-life 

Met hod : CAM 2 integer See PRZM manual 

Incorporation Depth: DEPI cm 

Application Rate: TAPP 0.32 kg/ha 

Application Efficiency: APPEFF 0.99 fraction 

Spray Drift DRFT 0.01 fraction of application rate applied to pond 

Application Date Date 15-5 dd/mm or dd/mmm or dd-mm or dd-mmm 

Record 17: FILTRA 

IPSCND 1 

UPTKF 

Record 18: PLVKRT 

PLDKRT 

FEXTRC 0.5 

Flag for Index Res. Run IR EPA Pond 

Flag for runoff calc. RUNOFF 

total(average of entire run) 

none, monthly or 
Output from DCSA run: 

stored as DCSA Teff-out 

Chemical: DCSA 

PRZM environment: 0RgrassseedSTD.txt modified Tueday, 26 August 

2008 at 06:16:42 

EXAMS environment: pond298.exv modified Tueday, 26 August 200b at 

06:14:08 1 

Metfile: w24232.dvf modified Tueday, 26 August 2008 at 06:15:5k 

Water segment concentrations (ppb) I 

Year 

1961 

Peak 96 hr 21 Day 60 Day 90 Day Yearly 

0.1446 0.1337 0.09963 0.05928 0.0454 

0.01542 I 

0.1498 0.1392 0.106 0.06565 0.05104 0. 021015 

0.151 0.1391 0.1028 0.06347 0.04976 0. 021812 

0.1517 0.1407 0.106 0.06552 0.05084 0. 021613 

0.1508 0.1401 0.1064 0.06751 0.05238 

0.02157 

0.1509 0.1397 0.1048 0.06407 0.0497 

0.02088 

0.151 0.14 0.1052 0.06336 0.04866 0.0201 

0.1503 0.1392 0.1107 0.07087 0.05498 

0.02425 

0.1523 0.1403 0.1033 0.07926 0.06698 

0.03092 

0.1554 0.1441 0.1089 0.06636 0.05141 

0.02406 

0.1518 0.1409 0.1067 0.07014 0.05524 

0.02602 

0.2245 0.2077 0.1571 0.09743 0.07538 

0.0308 

0.1538 0.1423 0.1067 0.06595 0.05126 

0.02345 

0.151 0.1402 0.1062 0.06514 0.05054 

0.1512 0.1401 0.1053 0.06528 0.05071 

0.02175 

0.1515 0.1406 0.1064 0.06694 0.05228 

0.02203 

0.1619 0.1506 0.1146 0.07022 0.05451 

0.0227 

0.151 0.1395 0.1038 0.06199 0.04922 

0.1513 0.13 97 0.1036 0.06289 0.04849 

0.02504 

0.1539 0.1429 0.1084 0.07285 0.05743 

0.02538 I 

0.1517 0.1407 0.1063 0.08363 0.06645 

0.02792 

0.1535 0.1422 0.1068 0.06454 0.05012 

0.02229 I 

0.1503 0.1386 0.1025 0.06438 0.05302 I 

0.02331 

0.1521 0.1411 0.1068 0.08218 0.06578 

0.02769 1 

0.295 0.2796 0.2065 0.1407 0.1129 0.04652 

0.1603 0.1488 0.1129 0.07373 0.06107 

0.03083 
d'w 

w w 0 0 

rl rl 

in N rlmom 

wmwm 

In 

N 

TI' 

N 

0 

0 

rl 

In 

TI' 

In 

0 

0 
0.1 0.18008 0.165 0.11973 0.083485 0.074324 

Average of yearly averages: 

Inputs generated by pe5.pl - Novemeber 2006 

Data used for this run: 

Output File: DCSA Teff 

Metf ile: w24232.dvf 

PRZM scenario: 0RgrassseedSTD.txt 

EXAMS environment file: pond298.exv 

Chemical Name: DCSA 

Description Variable Name Value Units Comments 

Molecular weight mwt 207 g/mol 

Henry's Law Const. henry 1.6E-9 atm-mA3/mol 

Vapor Pressure vapr 3.413-5 torr 

Solubility sol 2112 mg/L 

Kd Kd mg/L 

Koc Koc 1208 mg/L 

Photolysis half-life kdp 105 days Half-life 

Aerobic Aquatic Metabolism kbacw 16.4 days Halfife 

Anaerobic Aquatic Metabolism kbacs 0 days Halfife 

Aerobic Soil Metabolism asm 24.6 days Halfife 

Hydrolysis: pH 5 0 days Half-life 

Hydrolysis: pH 7 0 days Half-life 

Hydrolysis: pH 9 0 days Half-life 

Method : CAM 2 integer See PRZM manual 

Incorporation Depth: DEPI cm 

Application Rate: TAPP 0.29 kg/ha 

Application Efficiency: APPEFF 0.99 fraction 

Spray Drift DRFT 0.01 fraction of application rate applied to 

Application Date Date 15-5 dd/mm or dd/mmm or dd-mm or dd-mmm 

Record 17: FILTRA 

IPSCND 1 

UPTKF 

Record 18: PLVKRT 

PLDKRT 

FEXTRC 0:5 

Flag for Index Res. Run IR EPA Pond 

Flag for runoff calc. RUNOFF none, monthly or 

total(average of entire run) 

Example of a portion of the Residue Summation to determine Total Toxic ~dsidues 

for Dicamba and DCSA 

Year MaxPeak 4-day Max 14 day Max 21 day Max 30 day Max 60 day Max 90 day Annual 

17 
90th % (ppm) 

90th % (ppb) 

1 

0.4413 0.34853286 0.31943048 

vlax Peak 4-day Max14day Max21day 

0.28322933 0.22169233 

Max 30 day Max 60 day 

0.175049889 

Max 90 day 

Average Annual 

0.09314 

Annual 

0.00006 
Appendix B. T-REX Input and Output 

TREX MODEL INPUTS These values mll be used m thecakulatton of exposureestmates for follar,granula-, llquld andlor 

seed appliations of pestic~des. 

Use: 

Produd name and form: 

X A.I. (leading zero must be entered fol 

formulations 4% a.i.) 

Application Rate (IbslA): 

Half-life (days): 

Application Interval (days)' 

What bodyweight range is assessed 

(grams)? 

LC50 (mglkgdiet 

Reported Chronic Endpoin 

Medium 

Laqe 

Summary of Risk Quotient Calculations Based on Upper Bound Kenaga EETs I 

I I 

Birds Mammals 

Note: Sounes of wildllfe d~et are assumed to be available for less than one vear forthls model. 

Endpoints 

100 I 35 

1000 

Table X. Upper Bound Kenaga, Acute Avian Dose-Based Risk Quotients I 

I000 

Size Class 

(grams) 

Adjusted 

LD50 

EECs and RQs 

Short Grass Tall Grass 

~ 

Granivore 

I 

Broadleaf Plants1 

Insects 

Fruits/Pods/ 

Large Insects 
Table X. Upper Bound Kenaga, Subacute Avian Dietary Based Risk Quotients 

20 

100 

1000 

RQ 

0.57 

0.25 

0.08 

I 

135.44 

172.42 

243.55 

EECs and RQs I I I 1 

Short Grass 

Size class not used for dietary risk quotients 

EEC 

76.53 

43.64 

19.54 

EEC 

35.08 

20.00 

8.96 

LC50 

10000 

Table X. Upper Bound Kenaga, Chronic Avian Dietary Based Risk Quotients 

Tall Grass 

RQ 

0.26 

0.12 

0.04 

EEC 

67.20 

Table X. Upper Bound Kenaga, Acute Mammalian Dose-Based Risk Quotients 

EECs and RQs I I I I 

Broadleaf 

Plants/ 

Small Insects 

NOAEC 

(PP~) 

800 

EEC 

43.05 

24.55 

10.99 

Fruits/Pods/ 

Seeds/ 

Large Insects 

RQ 

0.01 

Size class not used for dietary risk quotients 

EECs and RQs 

Size Class djusted 

(grams) IDSO 

RQ 

0.32 

0.14 

0.05 

EEC 

30.80 

Short Grass 

Short Grass 

RQ 

0.00 

EEC 

67.20 

EEC 

4.78 

2.73 

1.22 

RQ 

0.08 

Tall Grass 

Tall Grass 

RQ 

0.04 

0.02 

0.01 

EEC 

1.06 

0.61 

0.27 

EEC 

37.80 

EEC 

30.80 

RQ 

0.01 

0.00 

0.00 

RQ 

0.04 

Broadleaf 

Plants/ 

Small Insects 

Broadleaf Plants1 

Small Insects 

RQ 

0.00 

EEC 

37.80 

FruitsIPodsl 

Seeds/ 

Large Insects 

RQ 

0.05 

EEC 

4.20 

FruitsIPodsl 

Seeds, 

Large Insects 

EEC 

4.20 

RQ 

0.01 

Granivore 

RQ 

0.00 
Size class not used for dietary risk quotients 

Table X. Upper Bound Kenaga, Chronic Mammalian Dietary Based Risk 

Size class not used for dietary risk quotients 

Quotients 

NOAEC 

(PPm) 

450 

Table X. Upper Bound Kenaga, Chronic Mammalian Dose-Based Risk Quotients 

EECs and RQs 

I I I 

EECs and RQs 

1- 

Size 

(grams) 

Adjusted 

NOAEL 

FruitsIPodsl 

Seeds1 

Large Insects 

EEC 

4.20 

Broadleaf 

Plants1 

Small Insects 

Short Grass 

Short Grass 

RQ 

0.01 

,EEC 

37.80 

Tall Grass 

EEC 

67.20 

RQ 

0.08 

EEC 

30.80 

RQ 

0.15 

Tall Grass 

RQ 

0.07 

Broadleaf Plants1 

Insects 

Fruits/Pods/ 

Large Insects 

Cjranivore 

, 
Appendix C. TerrPlant Input and Output 

TerrPlant v. 1.2.2 

Green values signify user inputs (Tables 1,2 and 4). 

lnput and output guidance is in popups indicated by red arrows. 

Tab& 3 ,tEberntcza3 gdentfty. 

Chemical Name 

PC code 

Use 

Application Method 

Application Form 

Solubility in Water 

(PP~) 

TaMe 2- 1npT.rt p;lr;ur~efeas, mdt6 derive 'EECs. , , , 

Dicamba 

29801 

TeR 

Foliar 

Liquid 

6100 

Input Parameter 

Application Rate 

Incorporation 

Runoff Fraction 

Drift Fraction 

Table 3, EEGS frpk~immba, W@ in-, 

Description 

Runoff to dry areas 

Runoff to semi-aquatic areas 

Spray drift 

Total for dry areas 

Total for semi-aquatic areas 

Ta4lW. Plapfsuwival and graWkk@&a used for RQJlefJveticfa. Wits are in . 

Symbol 

A 

I 

R 

D 

Plant type 

Monocot 

TaMe 5. RQgaltce. for plan& in dryaed semiaaq~atic ~e~~x~~~edko~i~brr~run^@ 

andrur $pray d&W 

Equation 

(A/I)*R 

(A.I)*R*I 0 

A* D 

((AH)*R)+(A*D) 

((AII)*R*I O)+(A*D) 

Plant Type 

Monocot 

Monocot 

Dicot 

Dicot 

Value 

1 

I 

0.05 

0.01 

EEC 

0.05 

0.5 

0.01 

0.06 

0.51 

Dicot 0.0027 

Units 

none 

none 

none 

Seedling Emergence 

*If RQ > 1.0, the LOC is exceeded, resulting in potential for risk to that plant group. 

Listed Status 

non-listed 

listed 

non-listed 

listed 

EC25 

0.062 

Vegetative Vigor 

NOAEC 

0.06 

EC25 

0.0016 

Dry 

0.97 

1 .OO 

22.22 

30.00 

NOAEC 

0.0015 

Semi-Aquatic 

8.23 

8.50 

188.89 

255.00 

Spray Drift 

6.25 

6.67 

3.70 

5.00 
Appendix D. AGDRIFT Output 

Ground; fine to medium coarse droplet; High Boom 
Appendix E. LOCATES Output 

Species in Counties by State and Taxa 

No species were excluded 

Minimum of 1 Acre 

All Medium Types Reported 

Mammal, Marine mml, Bird, Amphibian, Reptile, Fish, Crustacean, Bivalve, Gastropod, Arachnid, Insect, 

Dicot, Monocot, Ferns, ConYcycds, Coral, Lichen 

seed crops - other field and grass, hay, other tame, grains - other (PR), haylage/grass 

silage/greenchop all 

Oregon 

- Bird Dicot 

Murrelet, Marbled 

Brachyramphus marmoratus 

manoratus 

Douglas 

Lane 

Polk 

Tillamook 

Owl, Northern Spotted 

Strix occidentalis caurina ssp. 

Benton 

Douglas 

Klamath 

Lake 

Lane 

Linn 

Marion 

Polk 

Tillamook 

Washington 

Yamhill 

Plover, Western Snowy 

Charadrius alexandrinus nivosus 

Douglas 

Lane 

Tillamook 

Milk-vetch, Applegate's 

Astragalus applegatei 

Klamath 

Popcornflower, Rough 

Plagiobothrys hirfus 

Douglas 

Checker-mallow, Nelson's 

Sidalcea nelsoniana 

Benton 

Linn 

Marion 

Polk 

Tillamook 

Washington 

Yamhill 

Daisy, Willamette 

Erigeron decumbens 

var. decumbens 

Benton 

Lane 

Linn 

Marion 

Polk 

Lomatium, Bradshaw's 

Lomatium bradshawii 

Dicot 

Lupine, Kincaid's 

Lupinus sulphureus (=oreganus ) 

Benton 

Douglas 

Lane 

Linn 

Polk 

Yamhill 

Chub, Hutton Tui 

Gila bicolor ssp. 

Lake 

Chub, Oregon 

Oregonichfhys crameri 

Benton 

Lane 

Linn 

Marion 

Polk 

Dace, Foskett Speckled 

Rhinichthys osculus ssp. 

Lake 

Benton 

Lane 

Linn 

Marion 

Polk 
- Fish 

Salmon, Chinook (Upper 

Willamette River) 

Oncorhynchus (=Salmo) tshawytscha 

Benton 

Douglas 

Lane 

Linn 

Marion 

Polk 

Tillamook 

Washington 

Sucker, Shortnose 

Chasmistes brevirostris 

Sucker, Warner 

Catostomus wamerensis 

Lake 

Trout, Bull 

Salvelinus confluentus 

Yamhill 

Crook 

Salmon, Chum (Columbia 

River population) 

Oncorhynchus (=Salmo) keta 

Washington 

Salmon, Coho (Southern 

ORlSouthern CA Coast) 

Oncorhynchus (=Salmo) kisutch 

Douglas 

Klamath 

Steelhead, (Lower 

Columbia population) 

Oncorhynchus (=Salmo) mykiss 

Marion 

Washington 

Steelhead, (Middle 

Columbia population) 

Oncorhynchus (=Salmo) mykiss 

Crook 

Jefferson 

Steelhead, (Upper 

Willamette River population) 

Oncorhynchus (=Salmo) mykiss 

Benton 

Lane 

Linn 

Marion 

Polk 

Tillamook 

Washington 

Yamhill , 

Deschutes 

Jefferson 

Klamath 

Lake 

Lane 

Linn 

Malheur 

Polk 

Yamhill 

Trout, Bull (Columbia 

River Population) 

Crook 

Deschutes 

Jefferson 

Klamath 

Lake 

Lane 

Linn , 

Malheur 

Trout, Bull (Klamath 

River Population) 

Salvelinus confluentus 

Crook 

Deschutes 

Jefferson 

Klamath 

Lake 

Lane 

Linn 

Malheur 

Sucker, Lost River 

Deltistes luxatus 

Klamath 

Mammal I 

Deer, Columbian I 

White-tailed 

Odocoileus virginiknus 

leucurus I 

Douglas 

Insect 

Butterfly, Fenderk Blue 

lcaricia icarioides fenderi 

Benton 

Lane 

Polk 

Yamhill 

Butterfly, Oregop 

Silverspot 

Speyeria zerene hippolyta 

Lane 

Tillamook 

Yamhill