Document ID: EPA-HQ-OPP-2013-0730-0012
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2015-12-31T05:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                            WASHINGTON, D.C.  20460
                 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                            WASHINGTON, D.C.  20460

              OFFICE OF CHEMICAL SAFETY
AND POLLUTION PREVENTION
              OFFICE OF CHEMICAL SAFETY
AND POLLUTION PREVENTION

										February 19, 2015

MEMORANDUM

SUBJECT:	Drinking Water Assessment for IR4 New Uses of Spinosad and Spinetoram on Coffee, Berry/Low Growing Berry (Subgroup 13-07G), Berry/Small Fruit/Vine Climbing (Subgroup 07-07F), Bulb Vegetables (Subgroup 3-07B), Cottonseed (Subgroup 20C),  and Dow New Proposed Uses on the Control of Root Maggot on Cabbage Plant (Brassica (Cole) Leafy Vegetables, Subgroup 5). 
		(PC 110003 - Spinosad, 110008/110009 - Spinetoram; DP Barcodes D415813, 415815)

FROM:	Larry Liu, Chemist, Ph.D.
		Environmental Risk Branch 5
		Environmental Fate and Effects Division (7507P)

THROUGH:	Mah T. Shamim, Ph.D., Branch Chief
		Environmental Risk Branch 5
		Environmental Fate and Effects Division (7509P)
									
TO:		Tom Bloem
		Health Effects Division (7509P)

		Barbara Madden; RM 05
      Registration Division (7505P)

Summary

Currently proposed section 3 uses and the previously-modeled turf use of spinosad and spinetoram were modeled using the currently-released EFED models (SWCC for surface water and PRZM-GW for ground water).  The results of the modeling exercise indicate that turf use results in higher EDWCs than all the proposed new uses. Therefore, the revised EDWCs are as follows:

(a)	For spinosad concentrations in surface water: the acute 1-in-10 years peak EDWC is 25.0 ppb, the non-cancer/chronic 1-in-10 years annual mean EDWC is 21.7 and the 1-10-years overall mean cancer/chronic is 14.2 ppb.  For spinetoram concentrations in surface water: the acute 1-in-10 years peak EDWC is 8.6 ppb, the non-cancer/chronic 1-in-10 years annual mean EDWC is 5.9 and the 1-10-years overall mean cancer/chronic is 3.8 ppb.  

(b)	Due to the extremely high adsorption of spinosad and spinetoram with soil, even using 100-year weather records and all available scenario (DELMARVA_STD.SCN, FLCITRUS_STD.SCN, FLPOTATO_STD.SCN, GACOASTAL_STD.SCN, NCCOASTAL_STD.SCN, WISANDS_STD.SCN) in PRZM-GW simulation, Post-Breakthrough Mean Concentration (PBT) and Simulation Average Breakthrough Time (BT) were not achieved (See Appendix E for further details).  Although the use on coffee resulted in the highest groundwater EDWCs in all proposed uses, these values are below detection limits 

Introduction

The Environmental Fate and Effects Division (EFED) has completed its review of an IR-4 petition for the new uses of Spinosad (Reg. numbers 62719-266, 62719-497, and 62719-621) and Spinetoram (Reg. no. 62719-539, 62719-545, 62719-541) on coffee, berry/low growing berry (subgroup 13-07G), berry/small fruit/vine climbing (subgroup 07-07F), and bulb vegetables (subgroup 3-07B), and cottonseed (subgroup 20C).  The other actions associated with the subject data package codes are conversions of crop groups, which do not include new uses for evaluation, for berry subgroups 13-07A and B, citrus fruit group 10-10, pome fruit group 11-10, stone fruit group 12-12, tree nut group 14-12, onion subgroup 3-07A, and fruiting vegetable subgroup 8-10. Furthermore, Dow AgroSciences has requested the addition of new proposed use for the control of root maggot (Brassica (Cole) Leafy Vegetables, Subgroup 5) at the base of cabbage plants and adjacent soils by utilizing banded applications. 

Uses of Characterization 

Spinosad is an insecticide and currently registered on a variety of crops and non-crops in the US.  It controls many foliage feeding pests such as lepidopterous larvae (worms or caterpillars), leafminers, thrips, and red imported fire ants. This product's active ingredient, Spinosad, is biologically derived from the fermentation of Saccharopolyspora spinosa, and it is formulated as an SC (suspension concentrate). Table 1 summarizes the application rates from the product label for all proposed new uses of spinosad. 

Table 1. Proposed New Uses of Spinosad
Products
Crop
Single Appl. Rate (lb ai/A)
Max # Appl./Year
Minimum Appl. Interval (days)
Max Appl. Rate/Year (lb ai/A)
Appl. Methods
Entrust SC(R) Insecticide

Coffee

0.064-0.164

6

5
0.45
Spray/ground, chemigation and aerial

Berry, Low Growing Berry (Subgroup 13-07G) except cranberry and lowbush berry

Berry, Small Fruit, Vine Climbing (Subgroup-13-07F) except fuzzy kiwifruit
0.064-0.096

0.064-0.120
5

5
3-7

5
0.45

0.45
Spray/ground, chemigation and aerial

Spray/ground, chemigation and aerial

Bulb Vegetables (Subgroup 3-07B)
0.040-0.120
5
4
0.45
Spray/ground, chemigation and aerial

Cottonseed (Subgroup 20C)
0.046-0.096
unspecified
5
0.45
Spray/ground, chemigation and aerial

Brassica (Cole) Leafy Vegetables, (Subgroup 5) for Control of Root Maggot on Cabbage Plant
0.078-0.156
6
4
0.45
Spray/ground

Spinetoram is an insecticide and currently registered on a variety of crops in the US. It controls or suppresses many foliage feeding pests such as lepidopterous larvae (worms, caterpillars), dipterous leafminers, thrips, and certain psyllids. This product's active ingredient, Spinetoram, is derived from the fermentation of Saccharopolyspora spinosa, and it is formulated as SC (suspension concentrate) and WG (dispersible granules). Table 2 summarizes the application rates from the various product labels for all proposed new uses of spinetoram. 

Table 2.  Proposed New Uses of Spinetoram
Products
Crop
Single Appl. Rate (lb ai/A)
Max # Appl./Year
Minimum Appl. Interval (days)
Max Appl. Rate/Year (lb ai/A)
Appl. Methods
Delegate WG(R) Insecticide

Radiant SC(R) Insecticide

Coffee

0.032-0.080

6

5
0.305
Spray/ground, chemigation and aerial

Berry, Low Growing Berry (Subgroup 13-07G) except cranberry and lowbush berry

Berry, Small Fruit, Vine Climbing (Subgroup-13-07F) except fuzzy kiwifruit
0.048-0.080
5
3-4
0.305
Spray/ground, chemigation and aerial

Bulb Vegetables (Subgroup 3-07B)
0.040-0.080
5
4
0.234
Spray/ground, chemigation and aerial

Cottonseed (Subgroup 20C)
0.011-0.064
6
4
0.266
Spray/ground, chemigation and aerial

Brassica (Cole) Leafy Vegetables, (Subgroup 5) for Control of Root Maggot on Cabbage Plant
0.039-0.078
6
4
0.266
Spray/ground

General Physical-Chemical and Fate Properties 

Spinosad 

Spinosad (XDE-105) is a mixture of two active naturally occurring secondary degradates (Spinosad A and Spinosad D). Even though the two degradates have analogous fate properties (i.e., similar half-lives in hydrolysis, aqueous photolysis, soil photolysis, aerobic soil metabolism, etc), the key distinction between the two spinosad components is that Factor D consists of an extra methyl group at carbon 4 on the central ring. In addition, spinosad A is the major component in parent spinosad is at approximately an 85:15 ratio. Both spinosad A and D have similar molecular weight (732 vs 746 g/mol respectively). Spinosad A has a greater water solubility than spinosad D and as pH increases water solubility decreases. Table 3 presents a summary of physicochemical properties of the two spinosad components.

Table 3. Summary of Physicochemical Properties of Spinosad 

Physical Property

Spinosad A

Spinosad D
Structure

CAS Registry Number

131929-60-7

131929-63-0

Empirical Formula

C41H65NO10

C42H67NO10

Molecular Weight

731.976

745.988

Odor

Slightly stale water or earthy

Relative Density (20C)

0.512

Melting Point

84-99.5C

161.5-170C

Vapor Pressure (25C)

2.4E-10 mmHg
3E-11 kPa

1.6E-10 mm Hg
2E-11 kPa

Octanol/Water Partition Coefficient (log Kow)
      pH 5
      pH 7
      pH 9
      Distilled water

2.78
4.01
5.16
3.91

3.23
4.53
5.21
4.38

Dissociation Constant (pKa) (20C)

8.10

7.87

Water Solubility (20C)
      pH 5
      pH 7
      pH 9
      Distilled water

290 mg/L
235 mg/L
16 mg/L
89.4 mg/L

28.7 mg/l
0.332 mg/L
0.053 mg/L
0.495 mg/L

Spinosad A and spinosad D converted in an aerobic soil metabolism study to degradates that are very identical to the parent with half-lives of approximately 9-17 days. Similar degradates are formed under photolytic settings with a half-life of <1 day at pH 7 in sterile water and about 10 days in soil. Spinosad A has a low to moderate water solubility and a low to slight mobility in sandy soils, and is immobile in silt loam and clay loam soils. In terrestrial field dissipation studies with Spinosad A on bare ground plots, the half-life was <1 day, no leaching was observed, and 3.1% of the applied was recovered in runoff.

Spinosad has a high affinity for sediment and moves rapidly from the water to the sediment phases where it, together with its major degradates, is highly persistent. In anaerobic aquatic metabolism studies, spinosad had a half-life of 161-250 days. In an aquatic microcosm dissipation outdoor study, spinosad residues in the sediment peaked at 8 days and had an observed half-life of greater than 25 days (See Appendix A for details). 

Spinetoram 

Spinetoram (XDE-175) is a new second generation spinosyn insecticide consisting of a mixture of spinetoram J and spinetoram L at roughly 3:1 ratio. These two components are not isomers.  Furthermore, spinetoram J is the major component in the spinetoram mixture, and the distinction between both components is that spinetoram L contains an extra methyl group at carbon 4 on the central ring. Spinetoram L is slightly heavier (760 g/mol) than spinetoram J (748 g/mol), and spinetoram J has a lower water solubility than spinetoram L, that is, spinetoram L is more soluble in water at pH 5 and 7 (See Table 4). 

Based on laboratory studies, both components of spinetoram dissipate rapidly by photolysis in pH 7 buffer solution, with half-lives of <1 day. Other major routes of dissipation are aerobic soil metabolism, with non-linear half-lives of 3-31 days, and photolysis in soil, with environmental half-lives of 19-88 days. In aerobic and anaerobic water/sediment systems, spinetoram rapidly associates with the sediment phase where dissipation proceeds more slowly. Half-lives in total aerobic water/sediment systems were 116-124 days, and in total anaerobic water/sediment systems were 385-1,386 days. In laboratory soil, spinetoram was generally immobile (Kd = 84 and Koc =8,570). Under terrestrial and aquatic field conditions, spinetoram dissipated rapidly, with observed half-lives of <=1 day. Leaching was not significant under terrestrial field conditions, and migration into sediments was not significant under aquatic field conditions.  

The octanol/water partitioning coefficients for spinetoram J and spinetoram L are 12,303 and 30,903, respectively. Spinetoram (both components), does accumulate in fish. In rainbow trout exposed to spinetoram J, the bioconcentration factors (BCFs) for edible tissue, nonedible tissue, and whole fish were 11, 53, and 46 mL/g, respectively. In rainbow trout exposed to spinetoram L, the BCFs for edible tissue, nonedible tissue, and whole fish were 104, 330, and 344 mL/g, respectively (See Appendix B for details).
  
Table 4. Physical/Chemical and Fate Properties of Spinetoram  

Spinetoram J
Spinetoram L
Chemical Structure

Molecular Weight (g/mol)
748
760
Water Solubility -pH 5
423 ppm
1630 ppm
                            pH 7
11.3 ppm
46.7 ppm
                            pH 9
8 ppm
2 ppm
                           pH 10
6.3 ppm
0.7 ppm
Log Kow
4.09
4.38
Vapor Pressure
5.3x10-5 Pa
2.1x10-5 PA
Hydrolysis, pH 5 (half-life)
Stable
stable
Hydrolysis, pH 7 (half-life)
Stable
stable
Hydrolysis, pH 9 (half-life)
Stable
158 days
Aqueous Photolysis (pH 7) (half-life of parent)
0.5 day
0.2 day
Soil Photolysis (half-life)
27.4 days
9.4 days
Aerobic Soil Metabolism (half-life)
26.5 days (CA)
17.9 days (CA)

8.6 days (VA)
3.2 days (VA)

22.7 days (MS)
19.1 days (MS)

30.8 days (IA)
15.3 days (IA)
Anaerobic Aquatic Metabolism (half-life)
385 days (total system)
1,386 days (total system)
Aquatic Aerobic Metabolism (half-life)
116 days (total system)
124 days (total system)
Kd/Koc (loamy sand)
14/1800
31/3936
Kd/Koc (silt loam)
271/24648
483/43873
Kd/Koc (sandy loam)
38/5490
92/13185
Kd/Koc (loam)
12/2344
24/4816
Terrestrial Field Dissipation (half-life)
23.7 days (CA)

6.1 days (VA)

< 1 day (ID)

< 1 day (Ontario, Canada)

< 1 day (Prince Edward Island, Canada)
Aquatic Field Dissipation(half-life)
< 1 day (GA)

1.3 days (IN)
BCF (non-edible)
53/103 (low dose/high dose)
330/430 (low dose/high dose)
BCF (edible)
11/43 (low dose/high dose)
104/214 (low dose/high dose)
BCF (whole fish)
46/86 (low dose/high dose)
344/348 (low dose/high dose)

 Four major degradates were identified in spinetoram fate studies: N-demethyl-J, N-demethyl-L, O-demethyl-175-J, and O-demethyl-175-L (see Appendix C for details). The registrant has submitted absorption studies for two major degradates (N-demethyl-J and N-demethyl-L) detected in spinetoram assessments. Results suggest that N-demethyl-J and N-demethyl-L are classified as slightly mobile and hardy mobile, respectively (Table 5). 
 
Table 5. Physical, chemical, and fate properties for two major degradates (N-demethyl-J and N-demethyl-L) detected in the fate studies for spinetoram J and spinetoram L

N-demethyl-J
N-demethyl-L
Chemical Structure

Molecular Weight (g/mol)
734
746
Kd/Koc (loamy sand)
16/2062
34/4270
Kd/Koc (silt loam)
133/12127
340/30918
Kd/Koc (sandy loam)
32/4642
81/11559
Kd/Koc (loam)
8/1631
19/3718
Average Kd/Koc
47/5116 
119/12616 

Drinking Water Assessment 

Tier II models (SWCC and PRZM/GW) were used to estimate surface water and groundwater EDWCs, respectively, for the proposed uses of spinosad and spinetoram. A total residue method was used in estimating EDWCs. This is because the main ring structures in the transformation products which were tentatively characterized in the fate studies remain unchanged.  For example, spinetoram-J has a molecular weight (MW) of 748g/mol whereas as its degradate (N-demethyl-J) has a MW of 734, due to the loss of a small methyl group.  In the modeling, EFED assumed all the total spinosad and spinetoram residues (fully or partially identified) are stable under the aqueous photolysis, aerobic soil metabolism, aerobic aquatic metabolism, and anaerobic aquatic metabolism settings. Table 6 lists the input parameters used in modeling. Due to the high adsorption of spinosad and spinetoram with soil, EDWCs in groundwater are negligible.
Table 6.  Summary of Input Parameters for Spinosad and Spinetoram in SWCC and PRZM/GW
Input Parameter
Spinosad
Spinetoram
Hydrolysis
Stable
Stable
Aqueous Photolysis
Stable
Stable
Aerobic Soil Metabolism
Stable
Stable
Aerobic Aquatic Metabolism
Stable
Stable
Anaerobic Aquatic Metabolism
Stable
Stable
Koc
11,543 L/kg
12,511 L/kg
Vapor Pressure
2.4x 10 -10 torr
1.6x 10 -7 torr
Water Solubility
87.4 ppm
11.3 ppm
Molecular Weight (g/mol)
734
760
Application Method
Aerial
Aerial

The use of spinosad and spinetoram on coffee resulted in the highest surface water EDWCs in all the proposed uses, results are presented in Table 7 (see Appendix D).   However, since much highest application rate on turf (i.e., 1.6 lb ai/A) in all proposed uses was modeled using FIRST in the 2002 spinosad DWA and the highest application rate on turf (i.e., 0.454 lb ai/A) was modeled using FIRST in the 2007 spinetoram DWA, in addition to the proposed new uses, EFED decided to use the recently released SWCC to generate EDWCs on the registered turf use.  Although the peak EDWC for coffee is slightly higher than that for turf, since the only available scenario for coffee is from Puerto Rico, EFED decided not to consider that those values and recommended to use EDWCs from turf use in the current DWA.  

Due to the extremely high adsorption of spinosad and spinetoram with soil, even using 100-year weather records and all six available scenario (DELMARVA_STD.SCN, FLCITRUS_STD.SCN, FLPOTATO_STD.SCN, GACOASTAL_STD.SCN, NCCOASTAL_STD.SCN, WISANDS_STD.SCN) in PRZM-GW simulation, Post-Breakthrough Mean Concentration (PBT) and Simulation Average Breakthrough Time (BT) were not achieved (See Appendix E for further details).  Although the use on coffee resulted in the highest groundwater EDWCs in all proposed uses, these values are below detection limits (Table 8).  

Table 7.  Surface Water EDWCs from the Proposed Crop Uses and the Registered Turf Use of Spinosad and Spinetoram.
Crop (Registration Status)
Estimated Environmental Concentrations (ppb)
Spinosad 
Spinetoram  
Coffee (proposed)
Peak (1-in-10 yr)
13.8
9.4

365-day Avg  (1-in-10 yr)
7.7
5.9

Entire Simulation Mean
5.7
4.6
Berry (proposed)
Peak (1-in-10 yr)
6.9
4.4

365-day Avg  (1-in-10 yr)
5.7
3.6

Entire Simulation Mean
3.4
2.0
Bulb Vegetables (proposed)
Peak (1-in-10 yr)
9.1
4.0

365-day Avg  (1-in-10 yr)
8.0
3.5

Entire Simulation Mean
4.6
2.0
Cottonseed (proposed)
Peak (1-in-10 yr)
7.0
2.8

365-day Avg  (1-in-10 yr)
3.5
2.3

Entire Simulation Mean
2.6
1.7
Cabbage (proposed)
Peak (1-in-10 yr)
13.0
7.3

365-day Avg  (1-in-10 yr)
6.1
3.4

Entire Simulation Mean
5.1
2.8
Turf (registered)
Peak (1-in-10 yr)
25.0
8.6

365-day Avg  (1-in-10 yr)
21.7
5.9

Entire Simulation Mean
14.2
3.8

Table 8.  Groundwater EDWCs from the Proposed Crop Uses of Spinosad and Spinetoram.

Coffee

ChemicalID
Scenario ID
Peak(ppb)
PBT
Avg(ppb)
SimAvg
BT(d)
spinosad
DELMARVA_STD.SCN
1.42E-11
Incomplete
7.24E-13
Incomplete
0.0801
spinosad
FLCITRUS_STD.SCN
0.000996
Incomplete
0.000117
Incomplete
0.0938
spinosad
FLPOTATO_STD.SCN
1.37E-12
Incomplete
1.13E-13
Incomplete
0.0431
spinosad
GACOASTAL_STD.SCN
0
Incomplete
0
Incomplete
0.0569
spinosad
NCCOASTAL_STD.SCN
7.83E-09
Incomplete
4.66E-10
Incomplete
0.1008
spinosad
WISANDS_STD.SCN
3.84E-18
Incomplete
1.65E-19
Incomplete
0.0698

Berry

ChemicalID
Scenario ID
Peak(ppb)
PBT
Avg(ppb)
SimAvg
BT(d)
spinosad
DELMARVA_STD.SCN
1.35E-11
Incomplete
6.90E-13
Incomplete
0.0801
spinosad
FLCITRUS_STD.SCN
0.00094
Incomplete
0.000111
Incomplete
0.0938
spinosad
FLPOTATO_STD.SCN
1.29E-12
Incomplete
1.06E-13
Incomplete
0.0431
spinosad
GACOASTAL_STD.SCN
0
Incomplete
0
Incomplete
0.0569
spinosad
NCCOASTAL_STD.SCN
7.32E-09
Incomplete
4.35E-10
Incomplete
0.1008
spinosad
WISANDS_STD.SCN
3.60E-18
Incomplete
1.55E-19
Incomplete
0.0698

Bulb Vegetables

ChemicalID
Scenario ID
Peak(ppb)
PBT
Avg(ppb)
SimAvg
BT(d)
spinosad
DELMARVA_STD.SCN
1.35E-11
Incomplete
6.90E-13
Incomplete
0.0801
spinosad
FLCITRUS_STD.SCN
9.40E-04
Incomplete
1.11E-04
Incomplete
0.0938
spinosad
FLPOTATO_STD.SCN
1.29E-12
Incomplete
1.06E-13
Incomplete
0.0431
spinosad
GACOASTAL_STD.SCN
0.00E+00
Incomplete
0.00E+00
Incomplete
0.0569
spinosad
NCCOASTAL_STD.SCN
7.32E-09
Incomplete
4.35E-10
Incomplete
0.1008
spinosad
WISANDS_STD.SCN
3.60E-18
Incomplete
1.55E-19
Incomplete
0.0698

Cottonseed

ChemicalID
Scenario ID
Peak(ppb)
PBT
Avg(ppb)
SimAvg
BT(d)
spinosad
DELMARVA_STD.SCN
1.32E-11
Incomplete
6.74E-13
Incomplete
0.0801
spinosad
FLCITRUS_STD.SCN
0.000944
Incomplete
0.000111
Incomplete
0.0938
spinosad
FLPOTATO_STD.SCN
1.30E-12
Incomplete
1.07E-13
Incomplete
0.0431
spinosad
GACOASTAL_STD.SCN
0
Incomplete
0
Incomplete
0.0569
spinosad
NCCOASTAL_STD.SCN
7.52E-09
Incomplete
4.48E-10
Incomplete
0.1008
spinosad
WISANDS_STD.SCN
3.71E-18
Incomplete
1.60E-19
Incomplete
0.0698

Cabbage

ChemicalID
Scenario ID
Peak(ppb)
PBT
Avg(ppb)
SimAvg
BT(d)
spinosad
DELMARVA_STD.SCN
1.39E-11
Incomplete
7.10E-13
Incomplete
0.0801
spinosad
FLCITRUS_STD.SCN
0.000998
Incomplete
0.000118
Incomplete
0.0938
spinosad
FLPOTATO_STD.SCN
1.38E-12
Incomplete
1.14E-13
Incomplete
0.0431
spinosad
GACOASTAL_STD.SCN
0
Incomplete
0
Incomplete
0.0569
spinosad
NCCOASTAL_STD.SCN
7.94E-09
Incomplete
4.73E-10
Incomplete
0.1008
spinosad
WISANDS_STD.SCN
3.91E-18
Incomplete
1.68E-19
Incomplete
0.0698

Coffee

ChemicalID
Scenario ID
Peak(ppb)
PBT
Avg(ppb)
SimAvg
BT(d)
spinetoram
DELMARVA_STD.SCN
2.17E-12
Incomplete
1.09E-13
Incomplete
0.0739
spinetoram
FLCITRUS_STD.SCN
0.000328
Incomplete
3.81E-05
Incomplete
0.0865
spinetoram
FLPOTATO_STD.SCN
2.34E-13
Incomplete
1.92E-14
Incomplete
0.0398
spinetoram
GACOASTAL_STD.SCN
0
Incomplete
0
Incomplete
0.0525
spinetoram
NCCOASTAL_STD.SCN
1.21E-09
Incomplete
7.11E-11
Incomplete
0.0931
spinetoram
WISANDS_STD.SCN
3.12E-19
Incomplete
1.30E-20
Incomplete
0.0645

Berry

ChemicalID
Scenario ID
Peak(ppb)
PBT
Avg(ppb)
SimAvg
BT(d)
spinetoram
DELMARVA_STD.SCN
2.06E-12
Incomplete
1.03E-13
Incomplete
0.0739
spinetoram
FLCITRUS_STD.SCN
0.000327
Incomplete
3.80E-05
Incomplete
0.0865
spinetoram
FLPOTATO_STD.SCN
2.35E-13
Incomplete
1.93E-14
Incomplete
0.0398
spinetoram
GACOASTAL_STD.SCN
0
Incomplete
0
Incomplete
0.0525
spinetoram
NCCOASTAL_STD.SCN
1.24E-09
Incomplete
7.28E-11
Incomplete
0.0931
spinetoram
WISANDS_STD.SCN
3.20E-19
Incomplete
1.34E-20
Incomplete
0.0645

Bulb Vegetables

ChemicalID
Scenario ID
Peak(ppb)
PBT
Avg(ppb)
SimAvg
BT(d)
spinetoram
DELMARVA_STD.SCN
1.43E-12
Incomplete
7.14E-14
Incomplete
0.0739
spinetoram
FLCITRUS_STD.SCN
2.26E-04
Incomplete
2.63E-05
Incomplete
0.0865
spinetoram
FLPOTATO_STD.SCN
1.62E-13
Incomplete
1.33E-14
Incomplete
0.0398
spinetoram
GACOASTAL_STD.SCN
0.00E+00
Incomplete
0.00E+00
Incomplete
0.0525
spinetoram
NCCOASTAL_STD.SCN
8.54E-10
Incomplete
5.03E-11
Incomplete
0.0931
spinetoram
WISANDS_STD.SCN
2.11E-19
Incomplete
7.90E-21
Incomplete
0.0645

Cottonseed

ChemicalID
Scenario ID
Peak(ppb)
PBT
Avg(ppb)
SimAvg
BT(d)
spinetoram
DELMARVA_STD.SCN
1.86E-12
Incomplete
9.36E-14
Incomplete
0.0739
spinetoram
FLCITRUS_STD.SCN
0.000288
Incomplete
3.35E-05
Incomplete
0.0865
spinetoram
FLPOTATO_STD.SCN
2.06E-13
Incomplete
1.69E-14
Incomplete
0.0398
spinetoram
GACOASTAL_STD.SCN
0
Incomplete
0
Incomplete
0.0525
spinetoram
NCCOASTAL_STD.SCN
1.08E-09
Incomplete
6.34E-11
Incomplete
0.0931
spinetoram
WISANDS_STD.SCN
2.71E-19
Incomplete
1.06E-20
Incomplete
0.0645

Cabbage

ChemicalID
Scenario
ID
Peak(ppb)
PBT
Avg(ppb)
SimAvg
spinetoram
DELMARVA_STD.SCN
1.86E-12
Incomplete
9.36E-14
Incomplete
0.0739
spinetoram
FLCITRUS_STD.SCN
0.000288
Incomplete
3.35E-05
Incomplete
0.0865
spinetoram
FLPOTATO_STD.SCN
2.06E-13
Incomplete
1.69E-14
Incomplete
0.0398
spinetoram
GACOASTAL_STD.SCN
0
Incomplete
0
Incomplete
0.0525
spinetoram
NCCOASTAL_STD.SCN
1.08E-09
Incomplete
6.34E-11
Incomplete
0.0931
spinetoram
WISANDS_STD.SCN
2.71E-19
Incomplete
1.06E-20
Incomplete
0.0645

Appendix A: Environmental Fate Properties of Spinosad 

Degradation and Metabolism

Spinosad and Spinosad A and spinosad D were relatively stable in pH 5, 7, and 9 sterile aqueous buffer solutions that were incubated in the dark at 25°C (MRID 43507301). 

In sterile buffered (pH 7) solutions, spinosad A and spinosad D phototransformed with half-lives of 0.8-0.9 days (MRID 43507302). The β-isomers of the 13,14-dihydro of the pseudoaglycone of spinosad A and of spinosad D were detected at a maximum of 20.2-24.9% of the applied at 48 hours (study termination). In alkaline (pH 9.2) pond water, spinosad A and spinosad D phototransformed rapidly with half-lives of 0.54-0.55 days. On soil, spinosad A and spinosad D had photodegradation half-life of 8.68-9.71 days (MRIDs 44597733 and 43507303). The only transformation present at >5 % of the applied was N-demethyl-A, which reached 14.8% of the applied at 18 days post-treatment. These studies were not long enough to determine the fate of the degradates.

In aerobic silt loam soil, spinosad A and spinosad D converted to degradates with initial half-lives of 17.3 and 14.5 days, respectively (MRIDs 44597733 and 43507303). Spinosad A converted to degradates with a half-life of 9.4 days in sandy loam soil incubated under similar conditions. Approximately 75-90% of the applied spinosad converted to degradates by 28 days. The major degradate of spinosad A was N-demethyl-A, which accumulated to a maximum 51-61% of the applied at 14-28 days post-treatment, then decreased to 12.27-21.72% at 9 months and 2.77-5.96% at 1 year. The major degradate of spinosad D was N-demethyl - D, which accumulated to a maximum 68% of the applied at 28 days post-treatment and approximately 50% at 6 months. Several minor degradates, each less than 10% of the applied, were isolated but not conclusively identified. The anaerobic soil metabolism of spinosad could not be evaluated because no studies were submitted.

In anaerobic flooded clay sediment, spinosad A and spinosad D converted to degradates with half-lives of 161 and 250 days (MRID 43507305). By 7 days post-treatment, >90% of the applied radioactivity was associated with the sediment fraction.  Three major degradates of spinosad A, each present at a maximum 8-12% of the applied were identified: N-demethyl-A, reversepseudoaglycone (806643), and ketoreversepseudoaglycone (814426). One major degradate of spinosad D, N-demethyl-D, was present at a maximum 6.5% of the applied. 

The fate of spinosad under the aerobic aquatic environment is unknown. This is because the submitted study (MRID 46642701) is classified as unacceptable and is scientifically invalid because significant variability in the results between sampling intervals and between systems at the same sampling interval prevents any confident interpretation of the study results.  Because of poor results in the initial experiment, the data presented in this MRID are a compilation of analyses of selected test systems from four separate experimental sets for each test substance and system.  In addition, degradates comprising 10% of the applied may have been present and not identified.

Soil sorption and mobility

The mobility of spinosad A, at nominal concentrations of 0.04-5.0 ug/mL, was investigated in sand, loamy sand, sandy loam, silt loam, and clay loam soils (MRID 43507306).  Koc values were 2,862, 831, 4,237, 134,583, and 21,938, respectively.  Freundlich Kdes values for both desorption phases for the sand, loamy sand, sandy loam, and silt loam soils were 8.4-9.2, 6.6-8.2, 27-30, 288-357 and 292-296, respectively; corresponding 1/n values ranged from 0.826-0.921. Adsorption coefficients for spinosad A were used in modeling.

The mobility of N-demethyl-A, the major degradate of spinosad A, was investigated at 0.05-5.0 ug/mL in sand, loamy sand, sandy loam, and silt loam soils (MRID 43816602).  Koc values were 2,138, 662, 2,881, and 74,583, respectively.  Freundlich Kdes values for both desorption phases for the sand, loamy sand, sandy loam, and silt loam soils were 6.3-6.5, 5.3-6.3, 19-20, and 171-179, respectively; corresponding 1/n values ranged from 0.775-0.880.  

Spinosad A and D are not volatile; vapor pressures (25°C) are 2.0 to 3.0 x 10[-11] kPa.  CO2 was the only volatile compound detected in metabolism studies.

Field dissipation

Radioactive spinosad A, formulated as an emulsifiable concentrate, degraded with half-lives of 0.5 days in bareground plots of silt loam soil in Mississippi and 0.3 days in loam soil in California (MRID 43714301).  Approximately 2-3% remained after 3-5 days.  The study did not include those major degradates detected in the laboratory fate studies as analytes. Spinosad A and its degradates were not detected below the 6-inch soil depth. Unextracted [[14]C] residues increased to a maximum of 34-58% by 38-40 days. At the Mississippi site, total radioactivity in the runoff accounted for 3.1% of the applied radioactivity. 

Pond water (pH 7.6, ca. surface area 2.2 m[2], depth 47.5-50 cm) and clay loam sediment (ca. depth 5.5-6 cm) maintained in outdoor tanks were treated once with a broadcast-spray application of the suspension concentrate at 100 g/ha to the water surface (MRID 43848803). Spinosad (including spinosad A and D) dissipated rapidly from the water with a calculated half-life of 1.5 days, and total spinosad residues dissipated from the water with a calculated half-life of 4 days. In the water, the degradates N-demethyl-A and N-demethyl-D were detected at maximums of 2.3 ppb (8 hours) and 3.6 ppb (0 hour), respectively, and were <0.5 ppb at 15 days.  In the sediment, spinosad A was detected at a maximum average 14.9 ppb at 4 days and was 14.3 ppb at 35 days. N-demethyl-A was detected at a maximum average 11.1 at 15 days and was <=9.4 ppb at 35 days. Spinosad D was <=4.2 ppb and N-demethyl-D was not detected (LOD 11.3 ppb) at any interval in the sediment. Total spinosad residues in the water had an observed half-life of <1 days. Spinosad residues (parent and its degradates) in the sediment reached a maximum concentration at 8 days post-treatment and had decreased by approximately 25% by 35 days. These field studies need to be re-evaluated because the half-lives may reflect the transformation of the parent to other degradates similar to the parent. Also the dissipation half-lives reflect the movement of the parent and degradates from one media to another and do not show degradation of the product.

Accumulation

[[14]C]Spinosad A and D accumulated in rainbow trout held under laboratory flow-through conditions for up to 28 days (MRIDs 44537734 and 43557601). In the high concentration experiments (19.0 ng/L for spinosad A and 33.0 ng/L for spinosad D), maximum BCFs for spinosad A were 28.8 mL/g (at Day 28) for the nonedible tissue, 7.5 mL/g (at Day 25) for the edible tissue, and 21.1 mL/g (at Day 7) for the whole fish tissue; and for spinosad D were 42 mL/g (at Day 11) for the nonedible tissue, 20.5 mL/g (at Day 11) for the edible tissue, and 41.9 mL/g (at Day 7) for the whole fish tissue.  Registrant-calculated BCFs for total [[14]C]residues were 103-152, 16-47, and 84-115 mL/g for the nonedible, edible, and whole fish tissues, respectively. 

In fish exposed to spinosad A, parent accounted for 68.34% of the HPLC distribution in whole fish extracts on exposure day 1, and <=29.74% at later sampling intervals. Spinosad J was present at 125 ng/g in day 25 nonedible extracts and day 28 whole fish extracts; all other degradates were each <50 ng/g.  In fish exposed to spinosad D, parent accounted for 83.43% of the HPLC distribution in whole fish tissue on exposure day 1, 48.80% on day 7, 42.19% on day 14, and 35.44% on day 28.  In the whole fish tissues, 15-Pk4 and 20-Pk4 [N-monomethylated, O-demethylated Spinosad Factor D] was a maximum of 134 ng/g; 15-Pk6 and 20-Pk6 [N-monomethylated, O-demethylated Spinosad Factor D]  was a maximum of 230 ng/g; Spinosad Factor L was a maximum of 229 ng/g; Spinosad Factor O was a maximum of 173 ng/g; and N-demethyl-D was a maximum of 544 ng/g.  All other degradates were <50 ng/g.

Spinosad (i.e., spinosad A and D) has a relatively low bioconcentration factor (BCF's of the parent ranged from 8-20,X, 29-42X, and 21-42X for muscle, viscera, and whole fish, respectively), and a relatively rapid rate of depuration (half-life of about one day). These factors generally would prevent substantial bioconcentration of the material in the food web.

Appendix B: Environmental Fate Properties of Spinetoram

Degradation and Metabolism

 The total residue method was used in estimating EECs in the ecological risk assessment. This is because the main ring structures in the degradates, which were tentatively identified or partially characterized in the fate studies, are essentially the same as the parent. In the modeling of spinetoram, EFED used the same toxicity for spinetoram J and spinetoram L and the persistence of the spinetoram residues (including parent and its degradates) under the aqueous photolysis, soil photolysis, aerobic soil metabolism, and anaerobic aquatic metabolism conditions.  

Spinetoram is expected to dissipate relatively rapidly under most environmentally relevant conditions with the apparent primary route of dissipation being via photolysis in water and soil, and aerobic metabolism in soil.  However, it should be noted that most of the degradates detected in the laboratory studies  still contain the major complicated ring structures. Parent spinetoram is stable to hydrolysis and persistent under aerobic and anaerobic aquatic environments in the laboratory, but dissipates rapidly in terrestrial and aquatic field environments. Also, leaching and migration into sediments under field conditions was not significant.  

Spinetoram was stable to hydrolysis at pH 5, and 7, and had <10% decline over 30 days at pH 9 (MRID 46695023).  The photodegradation half-life in pH 7 buffer solutions for spinetoram J and spinetoram L was 12 and 5 hours, respectively (MRID 46695022). In moist loam soil, the photodegradation half-life for spinetoram J and spinetoram L was 27.4 and 9.4 days, respectively (MRID 46695024).  In VA loam, MS loam, sandy loam and silt loam soils, spinetoram J dissipated with nonlinear half-lives of 9, 23, 27 and 31, respectively; spinetoram L dissipated with nonlinear half-lives of 3, 19, 18 and 15 days, respectively (MRID 46695025).  

In aerobic aquatic conditions, the half-life in water could not be determined as dissipation from the water phase was very rapid, with both test substances rapidly associating with the sediment; spinetoram J and spinetoram L degraded in the sediment with nonlinear half-lives of 126 and 114 days, respectively; and from the total system with half-lives of 116 and 124 days, respectively (MRID 46695027).  In anaerobic aquatic conditions, both test substances again associated rapidly with the sediment; spinetoram J and spinetoram L degraded in the sediment with half-lives of 408 and 1,386 days, respectively; and in the total system with half-lives of 385 and 1,386 days, respectively (MRID 46695026).    

The proposed transformation pathway involves spinetoram J and spinetoram L degrading due to photolysis and/or microbial metabolism by de-methylation to yield N-demethyl-J and N-demethyl-L, respectively (O-demethyl-J and O-demethyl-L, respectively, under anaerobic aquatic conditions), and several minor unidentified compounds. Further degradation occurs to form numerous increasingly polar compounds over time, and ultimately mineralization to CO2.  

Soil Sorption and Mobility

Spinetoram is expected to be generally immobile in soil (MRID 46695028). Spinetoram J and spinetoram-L were classified as having low mobility to being immobile according to McCall's Relative Mobility classification system in loamy sand, silt loam, sandy loam and loam soils from the U.S., with a Koc of 1800 to 43873 mL/g.  

Field Dissipation

Under terrestrial field conditions, the half-life for spinetoram (-J + -L) in loam and sandy loam soil was 23.7 days and 6.1 days, respectively, while the observed half-life was <=1 day in each soil (MRIDs 46695029 and 47072901).  Spinetoram was not detected below the 0-15 cm soil depth at any sampling intervals. Under aquatic field conditions, spinetoram dissipated very quickly in water (MRID 46695030), with no partitioning of residues into the sediment. Total spinetoram residues (spinetoram J + spinetoram L) dissipated in the water with half-lives of 18.1 to 20.4 hours.  No residues of spinetoram J or spinetoram L were detected in any pre- or post-application sediment samples.

Accumulation

Since the octanol/water partitioning coefficients for spinetoram J and spinetoram L are high (12,303 and 30,903, respectively), these two components are expected to bioconcentrate in fish.  In rainbow trout exposed to spinetoram J at 17.3 ng/mL, the bioconcentration factors (BCFs) for edible tissue, nonedible tissue, and whole fish were 11, 53, and 46 mL/g, respectively (MRID 46695128). After 1 day of depuration, total [[14]C] residues in the whole fish had decreased by 28.2%.  After 21 days of depuration, total [[14]C] residues had decreased by 88.7%. The elimination half-lives for [[14]C] residues in edible tissue, nonedible tissue, and whole fish were 2.3, and 4.1, and 4.6 days, respectively. In rainbow trout exposed to spinetoram L at 22.3 ng/mL, the BCFs for edible tissue, nonedible tissue, and whole fish were 104, 330, and 344 mL/g, respectively (MRID 46695129). After 1 day of depuration, total [[14]C] residues in the whole fish had steadily decreased by 9.5%. After 14 days of depuration, total [[14]C] residues had decreased by 87.4%. The elimination half-lives for [[14]C] residues in whole fish, edible tissue, and nonedible tissue were 4.5, 3.9, and 4.1 days, respectively. Spinetoram J and spinetoram L rapidly metabolized, yielding 2-4 more polar degradates; correspondingly, N-demethyl-J and N-demethyl-L were positively identified, along with 3'-O-deethyl-XDE-175-L.

Appendix C: Summary of Degradates in the Environmental Fate Studies for Spinetoram 

Degradate (Name)
Maximum Degradate Concentration (% of applied) and Time (days) to Maximum Concentration in Study:
Degradates Analyzed in Study:

Hydrolysis
(161-1)
Aqueous
Photo.
(161-2)
Soil Photo.
(161-3)
Aerobic Soil
(162-1)
Anaerobic
Aquatic
(162-3)
Aerobic Aquatic
(162-4)
Field Diss.
(164-1)
Aquatic Diss.
 (164-2)
Fish Study (165-4)
N-demethyl-J
6.7% @ 30 d
6.6% @ 0.33 d
Not Analyzed
68.1% @ 125 d
Not Analyzed
8.9% @ 16 d
0.0590 mg/kg @ 26 d
0.373 ug/L @ 1 h
7.141 mg/kg @ 21 d 
N-demethyl-L
11.9% @ 30 d
12.2% @ 0.17 d
Not Analyzed
41.0% @ 32 d 
Not Analyzed
9.6% @ 21 d
(0.0039 mg/kg @ 0 d) [2]
0.060 ug/L @ 0.5 h 
Not Reported[1]
N-demethyl-J +
N-demethyl-L
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
0.410 ug/L @ 6 h[1]
Not Analyzed
O-demethyl-175-J
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
26.7% @ 365 d
2.8% @ 30 d
Not Analyzed
Not Analyzed
Not Analyzed
O-demethyl-175-L
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
10.4% @ 365 d
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
3'-O-deethyl-175-J
Not Analyzed
Not Detected
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Detected
3'-O-deethyl-175-L
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Reported[1]
N-demethyl-175-L + 
3'-O-deethyl-175-L
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
16.034 mg/kg @ 28 d
N-formyl-175-J
Not Analyzed
Not Detected
Not Analyzed
Not Detected
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Detected
Aglycone-175-J
Not Analyzed
Not Detected
Not Analyzed
Not Detected
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Detected
C9-pseudoaglycone-175-J
Not Analyzed
Not Detected
Not Analyzed
Not Detected
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Detected
C9-pseudoaglycone-175-L
Not Analyzed
Not Detected
Not Analyzed
Not Detected
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Detected
C9-ketopseudoaglycone-175-J
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Detected
C9-ketopseudoaglycone-175-L
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Detected
C17-pseudoaglycone-175-J
Not Analyzed
Not Detected
Not Analyzed
Not Detected
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Detected
C17-pseudoaglycone-175-L
Not Analyzed
Not Detected
Not Analyzed
Not Detected
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Detected
Carbon dioxide
Not Analyzed
Not Analyzed
3.5% @ 18 d 
spinetoram J:
from 5.0% @ 366 d (CA) to 
35.2% @ 276 d (VA)

spinetoram-L:
From 12.50% @ 276 d (CA) to 
36.2% @ 365 d (VA)
0.2% @ 90 d
0.7% @ 2 d
Not Analyzed
Not Analyzed
Not Analyzed
Nonextractable residues
Not Analyzed
Not Analyzed
15.6% @ 18 d
37.9% @ 276 d
12.1% @ 365 d
11.0% @ 21 d
Not Analyzed
Not Analyzed
Not Analyzed
1 Data from identified degradates reported as a combined number.
2 Maximum concentration was <LOQ.

Appendix D: Surface Water Modeling of Spinosad and USEPA Standard Reservoir 

Estimated Environmental Concentrations for spinosad are presented in Table 1 for the USEPA standard reservoir with the FLturfSTD field scenario. A graphical presentation of the year-to-year peaks is presented in Figure 1. These values were generated with the Surface Water Concentration Calculator (SWCC Version 1.106). Critical input values for the model are summarized in Tables 2 and 3.
This model estimates that about 0.77% of spinosad applied to the field eventually reaches the water body. The main mechanism of transport from the field to the water body is by spray drift (63.7% of the total transport), followed by runoff (30.3%) and erosion (6.05%).
In the water body, pesticide dissipates with an effective water column half-life of 551.8 days. (This value does not include dissipation by transport to the benthic region; it includes only processes that result in removal of pesticide from the complete system.) The main source of dissipation in the water column is washout (effective average half-life = 551.9 days) followed by volatilization (4767521 days).
In the benthic region, pesticide is stable.  The vast majority of the pesticide in the benthic region (99.92%) is sorbed to sediment rather than in the pore water.

Table 1. Estimated Environmental Concentrations (ppb) for spinosad.
Peak (1-in-10 yr)
25.0
4-day Avg (1-in-10 yr)
24.0
21-day Avg (1-in-10 yr)
23.3
60-day Avg (1-in-10 yr)
22.5
365-day Avg (1-in-10 yr)
21.7
Entire Simulation Mean
14.2

Table 2. Summary of Model Inputs for spinosad.
Scenario
FLturfSTD
Cropped Area Fraction
1.0
Koc (ml/g)
11543
Water Half-Life (days) @ 25 °C
0
Benthic Half-Life (days) @ 25 °C
0
Photolysis Half-Life (days) @ 25 °Lat
0
Hydrolysis Half-Life (days)
0
Soil Half-Life (days) @ 25 °C
0
Foliar Half-Life (days)
35
Molecular Wt
734
Vapor Pressure (torr)
0.00000001
Solubility (mg/l)
87.4

Table 3. Application Schedule for spinosad.
Date (Mon/Day)
Type
Amount (kg/ha)
Eff.
Drift
6/1
Foliar
0.448
0.95
0.16
6/8
Foliar
0.448
0.95
0.16
6/15
Foliar
0.448
0.95
0.16
6/22
Foliar
0.448
0.95
0.16

Figure 1. Yearly Peak Concentrations

Appendix E.  Groundwater Analysis for spinosad and the Wisconsin Corn - WI Central Sands Scenario
Estimated groundwater concentrations and breakthrough times for spinosad are presented in Table 1 for the Wisconsin Corn - WI Central Sands groundwater scenario. A graphical presentation of the daily concentrations in the aquifer is presented in Figure 1. These values were generated with the PRZM-GW (Version 1.07). Critical input values for the model are summarized in Tables 2 and 3.

Table 1. Groundwater Results for spinosad and the Wisconsin Corn - WI Central Sands Scenario.
Peak Concentration (ppb)
3.84E-18
Post-Breakthrough Mean Concentration (ppb)
Incomplete
Entire Simulation Mean Concentration (ppb)
1.65E-19
Average Breakthrough Time (days)
Incomplete
Throughputs
0.06983208

Table 2. Chemical Properties for Groundwater Modeling of spinosad.
Koc (ml/g)
11543
Surface Soil Half Life (days)
0
Hydrolysis Half Life (days)
0
Diffusion Coefficint Air (cm2/day)
0.0
Henry's Constant
0.0
Enthalpy (kcal/mol)
0.0

Table 3. Pesticide application scheme used for spinosad.  This application scheme was applied every year of the simulation.
Application Date
(Month/Day)
Application Method
Application Rate
(kg/ha)
6/1
Above canopy application
0.089
6/6
Above canopy application
0.089
6/11
Above canopy application
0.089
6/16
Above canopy application
0.089
6/21
Above canopy application
0.089
6/26
Above canopy application
0.089

Figure 1. Aquifer Breakthrough Curve for spinosad and the Wisconsin Corn - WI Central Sands Scenario