1 APPENDIX A Environmental Fate and Transport Data2 (1) Laboratory degradation in soil systems Aerobic soil systems Degradation of sulfoxaflor was studied in 4 US and 4 EU soils. The results for the US soils are summarized in Figure 1 and those for EU soils in Figure 2

.

Figure 1 Fate of sulfoxaflor in Aerobic Soil systems (average for 4 US soils) 0% 2% 4% 6% 8% 10% 12% 14% 16% 18% 20%

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

0 100 200 300% of Applied (All others)% of Applied (Parent & X117194-74

Time (days) 

### Aerobic Soil System (4 US soils)

X11579457 X11719474 X11519540 Sulfoxaflor Others including CO2 Non

- extractable residue3 0% 2% 4% 6% 8% 10% 12% 14% 16% 18%

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

0 20 40 60 80 100 120% of Applied (All others)% of Applied (Parent & X117194-74

Time (days) 

### Aerobic Soil System (4 EU soils)

X11579457 X11719474 X11519540 Sulfoxaflor Others including CO2

Figure 2 Fate of sulfoxaflor in Aerobic Soil systems (average for 4 EU soils) Under aerobic conditions and 25 °C, sulfoxaflor parent degrade d rapidly to one major degradate (X

- 474) and was below the limit of detection (LOD= ) within 3

– 14 days after treatment (DAT). Calculated half

- life values ( t1⁄2) for the parent ranged from 0.3 to 0.6 days (MRID 478655

- 78). Similar results, with more rapid d egradation, were observed for sulfoxaflor parent in four EU soils (three from the UK and one from Germany; MRID 478320

- 13). In these EU soils, residues of the parent compound dropped below the LOD within 1

- 4 DAT. Calculated half lives, for the parent, r anged from 0.1 to 0.3 days. The overall degradation profiles in U.S. and European Union (EU) soil systems suggest that parent rapidly transforms into degradate X

- 474 which appears to transform into another two degradation products X

- 540 and X457, CO 2 and bound residues. Parent chemical is expected to be non

- persistent in the soil systems of the natural environment and important exposure, in these systems, is expected to be mainly associated with X

- 74; just after one to few day s following parent application

. Effect of low temperature and sterility were also studied using one EU soil “the UK Aberford soil” by incubating the samples at 10 °C for the temperature effects and by sterilizing the test soil for the sterilization effects. Data suggest that low tempe rature/ sterility reduces the bio

- transformation rate due to the reduction/elimination of biological activity. In addition sterility appears to inhibit transformation of the major degradate X474 into X457 and X540 ( Table 1 )

. Table 1 Summary of observed ef fects of temperature and sterilization on the degradation rate/profile of sulfoxaflor Non

- extractable residues4 Affected Parameters Characteristics of the Aberford soil Guideline Conditions (viable soil, incubation at 20 °C for 123 days Low Temperature Effects: (viable soil, incu bation at 10 °C for 120 days) Soil Sterility Effects (Sterilized soil incubation at 20 °C for 120 days) Profile for parent concentration decrease Reached “No detection” after 1 day Reached “No detection” after 3 days Decreased to 15% at study termination Parent half

- life 0.1 day 0.14 days 18

Profile for major degradate X117194

- 74 Reached a max. of 98% within only one day; then declined to 36% at at study termination Reached a max. of 97% within only one day; then declined to 68% at at study termination R eached a max. of 83% after 90 days; then declined to 77% at study termination

X117194

- 74 half

- life 85 184 Can not calculate (only two intervals) but appear to be Highly persistent
Profile for X115794

- 57 and X115795

- 40 degradates Max. observed 9% and 12%, respectively with no clear formation/decline profile Max. observed 8% for both with no clear formation/decline profile Non detected Evolved CO 2 32% max at 123 days 6% max at 120 days <1% max at 120 days Non

- extractable Residues 15% 9% 6%
Anaerobic so il systems Sulfoxaflor degradation was studied in one clay loam Texas soil (MRID 478322

- 79) under the following conditions:

• Aerobic incubation for 8 hours (which is equivalent to the half

- life estimated under aerobic conditions); followed by
• Anaerobic (fl ooding/purging with nitrogen) conditions for 113 days Examination of aerobicity data suggest that anaerobic conditions were met for the system as a whole although the soil was much more anaerobic compared to the water layer above. Data also show the follo wing:
• The presence of O 2 at detectable level at all intervals suggesting slightly aerobic conditions which appear to decrease with time (O 2 decreased from 5 to 0.2 ppm)
• Water pe+ pH decreased from 8.58 to 5.89 indicating sub

- oxic conditions (considered by EFED to be anaerobic), and
• Soil pe+ pH decreased from 4.50 to 3.00 (Oxic conditions= anaerobic) Similarly, sulfoxaflor degradation was studied in one EU soil “the UK Aberford soil” under the following conditions:

• Aerobic incubation for 2 hours (which is equivalent to the half

- life estimated under aerobic conditions). Followed by
• Anaerobic (flooding/purging with nitrogen) conditions for 120 days5 Examination of aerobicity data suggest that anaerobic conditions were met for the system as a whole and that th e soil reached true anaerobic conditions after 32 days. Data also show the following:
• The presence of O 2 at detectable level at all intervals suggesting higher level of aerobicity as compared to conditions for Texas soil above. However aerobicity appears t o decrease with time (O 2 decreased from 8 to 2 ppm)
• Water pe+ pH decreased from 11.00 to 8.83 indicating sub

- oxic conditions (considered by EFED to be anaerobic), and
• Soil pe+ pH decreased from 9.71 to 7.19 indicating sub

- oxic conditions (considered by EF ED to be anaerobic) from time zero to 14 days, then decreased further to a range from 4.27 to 3.25 suggesting oxic or anaerobic conditions.
The results for the US and EU soils are summarized in Figure 3

.

Figure 3 Sulfoxaflor degradation profile un der aerobic followed by anaerobic conditions In the US soil, more than half of sulfoxaflor transformed into its major degradate X

- 474 during the aerobic incubation period. Samples were analyzed at 1 day (i.e., few hours after the start of the anaerobic ph ase) and results indicated that 32% of the parent remained in the soil along with 62% of its major degradate X

- 474. Therefore, data for bio

- degradation under anaerobic conditions starts at 1 day (nearly the start of the anaerobic conditions) and ends at 12 0 days (study termination). During this anaerobic period, parent reached no detection at 20 DAT while the degradate X

- 474 continued to increase to a maximum of 95% at day 20 and then decrease to 75% by 113 days ( study termination). No other degradates we re identified and the un

- extracted residue reached nearly 25% at study termination with a maximum of <1% CO 2 evolved. Estimation of reliable half

- lives for Sulfoxaflor in aerobic and anaerobic phases is difficult because of the rapid degradation within on ly one interval. However, data suggest that degradation rate in both aerobic and anaerobic phases are relatively fast with a noticeable decrease in the rate for the anaerobic phase. In contrast, formation and decline data were available to Time (days) Aberford Soil, UK Time (days) Clay Loam Soil, TX6 estimate half

- li ves for main degradate (X

- 474) in anaerobic conditions. In the same soil, estimated anaerobic soil half

- life for X

- 474 were much shorter than that in aerobic conditions (t1⁄2= 320 days in anaerobic conditions compared >1000 days in aerobic conditions). Howev er, it is noted that estimated short anaerobic half

- life was a result of formation of relatively high bound residues (25% of the applied). In the EU soil, results indicated that, at the end of the aerobic phase, 29% of the parent remained in the soil al ong with 66% of its major degradate X

- 474. During the anaerobic phase of the study, residues of the parent compound dropped below the LOD by 1 DAT while the degradate X

- 474 increased to a maximum of 97

- 98% 4 to 7 DAT then decreased to 84% at study termin ation (120 DAT). No other degradates were identified and the un

- extracted residue reached nearly 12% at study termination with a maximum of <1% CO 2 evolved. Estimation of reliable half

- lives for sulfoxaflor in the aerobic and anaerobic phases is difficult to differentiate because of the rapid degradation within only two intervals. However, data suggest that degradation rate in both aerobic and anaerobic phases are relatively fast with a noticeable decrease in the rate for the anaerobic phase. In contrast, formation and decline data were available to estimate the half

- life of the main degradate X

- 474 under anaerobic conditions. Estimated anaerobic soil half

- life for X

- 474 was 532 days compared to a half

- life of 85 days estimated for the same soil under aerob ic conditions. Comparison of data from US and EU soils suggest similarity in reduction of parent degradation rate due to change from aerobic to anaerobic soil conditions. This observed reduction, in the rate, appeared to be more pronounced in US soil com pared to EU soil possibly due to the more stable anaerobic conditions in the former. Estimated anaerobic half

- life for the degradate X

- 474 in the US soil was much lower than the aerobic half

lives. In contrast, the results for the EU soil suggest an opposi te conclusion. Data do not suggest a clear conclusion for the effect of anaerobic soil conditions on the rate of degradation of the main degradate X

- 474. No an anaerobic soil study, in which the main degradate is used as a test substance, was executed a lthough such as study could have helped in drawing conclusions on the anaerobic degradation profile for this major degradate. (2) Laboratory degradation in water/sediment systems Aerobic water/sediment systems The aerobic degradation of 14 C radiolabel sulf oxaflor was studied in two pond water

sediment systems from England, one from Derbyshire (system

- 1) and the other from Staffordshire (system

- 2) for 103 days ( MRID 478320

- 14) in the dark at 20 °C. Parent, in the total pond system, declined to an average of 39 to 56% and 13 to 31% in systems 1 and 2, respectively (total system t1⁄2= 88 days and 37 days in systems 1 and 2, respectively). The decline occurred between 76 and 103 DAT. Parent transformed mainly7 into the one major degradate, X

- 474, with maximums ran ging from 25 to 71% in system

1 and 47 to 66% in system

- 2 occurring at 61

- 103 DAT with no apparent decline (system t1⁄2 cannot be determined). Mineralization to CO 2 and other degradates (maximums were low with a range: CO 2 : 6 to 1.5% and other degradates: <1 to 2.4%). At study termination (100 DAT), relatively high amounts of un - identified bound residues were observed only in system

- 2 (maximum of 26%) compared to lower amounts in system 1 (maximum of 6%). The observed high amounts of of un - identified bound r esidues in system

- 2 may be related to insufficient extraction and/or degradation. Examination of the aerobicity data for both water/sediment systems, suggest that they were outside guideline recommended values (E h of

- 80 to

- 190 mV in sediment layer and ox ygen concentration from 7 to 10 mg/L in water layer). Conditions were reducing to moderately reducing in the water layer and strongly reducing in the sediment. Anaerobic water/sediment systems A naerobic biotransformation of 14 C radiolabel sulfoxaflor parent and major degradate X117194

- 74 was studied separately in two pond water sediment systems from the United States. The first “sand” system (system

- 3) was obtained from Virginia and the second “sandy clay loam” system (system

- 4) was obtained from Iowa. The duration of the studies were up to 100 days and were incubated in the dark at 25 °C. Samples were treated with 14 C

- sulfoxaflor at the rate of 0.019 mg a.i. /L and 14 C

- X

- 4 74 at the rate of 0.015 mg/L. The sediment/water ratios used were approximately 1 :3 (MRID 478322

- 77). Data from p arent study show that radioactivity partitioned between water and sediment with a steady increase in the un

- identified bound residue (up to maximums ranging from 12 to 37%, in systems 3 and 4, respectively). Only very limit ed amounts of CO 2 evolved (maximums were <1% in systems 3 and 4). Parent, in the total pond systems, declined with a total system t1⁄2= 382 days and 103 days i n systems 3 and 4, respectively . The reason for parent decline may not be related to the formation of the degradate X

- 474 (max. 3% to 8%” in systems 3 and 4 ) but is related to the formation of the un - identified bound residue (maximum 12 and 37% in system

- 3 and 4, respectively). U n - identified bound residue may not be related to partitioning of the degra date X

- 474 as it has very low infinity to partition into the sediment (K oc = 25 L/Kg) . Also the reduced tendency of parent to partition into the sediment is inferred from its low K oc (K oc = 30 L/Kg) and the observed higher concentration of parent in the wa ter column compared to that in sediment layer. Degradate X

- 474 d ata show that the radioactivity partitioned between water and sediment and the steady increase in un

- identified bound residue reaching relatively low levels compared to parent study (maximum s of 2 to 5%, in systems 3 and 4, respectively). Only very limited amounts of CO 2 evolved (maximums were <1% in systems 3 and 4). Degradate X

- 474, shows relatively high, though variable persistence (total system t1⁄2= 1,090 days in system 4 and 5,270 days in system

- 3). Examination of data on actual study conditions suggests that the c onditions met EFED criteria for anaerobic studies in the two systems as a whole. However, the extent of anaerobic conditions appears to vary widely between the two systems and wi thin each system (water phase and sediment phase).8 Based on the observed parameters, anaerobic conditions were maintained much better in VA pond system (system

- 3) compared to IA pond system (system

- 4). In addition, anaerobic conditions appear to have been difficult to maintain in the overlying water column compared to the sediment for both systems. (3) Field Dissipation in Terrestrial Systems Extensive data were collected from the terrestrial field dissipation (TFD) studies for sulfoxaflor (MRID 47832282). T hese data are summarized hereunder. (1) Conceptual Design The terrestrial field dissipation ( TFD) study for sulfoxaflor was designed based on the results of laboratory studies. These studies showed that sulfoxaflor degraded rapidly in soil, forming a major d egradation product (X

- 474), and two minor degradation products (X

- 540 and X

- 457). Adsorption/desorption studies indicated that both parent sulfoxaflor and major/minor degradate (X

- 474, X

- 540 and X

- 457) are expected to be mobile. Additionally, sulfoxaflor a nd it degradate X

- 474 are systemic and were found to be stable to hydrolysis at pH 5, 7, or 9. Therefore, the TFD study design included leaching and plant uptake modules. Due to the low vapor pressure and Henry’s law constant of sulfoxaflor, volatility in the field was not measured. (2) Selection of sites Five sites were selected for conducting bare and cropped

- plots in California (CA), Florida (FL), North Dakota (ND), Ontario, Canada (ON), and Texas (TX). Sulfoxaflor soluble concentrate formulation ( 242 g act ive ingredient per litre of product or 22% w/w) was surface applied one to three times at nominal single rates ranging from 100g a.i./ha (equivalent to 0.089 lb a.i/A) to 200 g a.i./ha. Information about application and soils are as follows:

• The first a pplication rates in spinach and bell peppers were higher than proposed label rate ; • Label rates were not followed in the other crops (wheat the total rate was applied one time instead of two; soybeans received one application of 200 g a.i/ha instead of thr ee at 100 g a.i/ha; and cotton received only one application at 100 g a.i/ha instead of three at 100 g a.i/ha each). It is noted that terrestrial field dissipation studies guideline calls for application of the pesticide as per the label.
• The top soil of t he cropped plots show that soils chosen for conducting the studies represent a wide range of soil properties. Soil textural classes include two loamy sand soils from CA and FL; one loam to sandy loam soil from Ontario, Canada (ON), and two clay to clay loa m soils from ND and TX. Top soil horizons were acidic in CA, FL and ON (pH range from 5.3 to 6.4) and near neutral in ND and TX (pH range from 6.9 to 7.9); and9 • Characteristics of top soil for associated bare soil plots were the same for CA and TX soils, co ntains higher clay contents (by 7

- 10%) for FL and ON soils and contains lower clay content (by 10%) in ND soil. (3) Study design and sampling The study design consisted of two treated plots (one cropped and one bare soil) and an untreated control plot at eac h study location (located at least 30 m from the treated plot). Treated and rotational crops representative of the geographical location of each test site were planted on areas designated for cropped plots over the course of the study. The California and F lorida test sites were equipped with soil

- suction ly s ometers for the collection of soil

- pore water samples. As required, supplemental irrigation (type not specified) was supplied to maintain at least 110% of long term average rainfall. The monthly target moisture input was set at 400% of the local historical average monthly precipitation in California and 120% in other sites. Other normal agronomic practices were followed. Soil core samples were collected, for all sites, immediately after the first appli cation to a depth of 6”. Additionally, soil samples were collected from the soil profile to a depth of 36 inches at various sampling dates up to and including the end of the study (18 months in California, 15 months at other sites). The soil samples were e xtracted with 90:10 acetonitrile: 1.0 N hydrochloric acid (v: v) on a flat

- bed shaker and extracts were concentrated prior to analysis. Soil pore

- water samples were collected at depths of 3, 6, and 8 ft. in FL or 9 ft. in California at 1, 6, 13, 28 days a nd 2, 4, 6, 9, 12 and 15 months after the first treatment. Water samples were analyzed directly. Soil and water samples were analyzed for sulfoxaflor and its aerobic soil metabolite (X474, X540 and X457) using HPLC ) with positive

- ion electro

- spray (ESI) ta ndem mass spectrometry (HPLC/MS/MS). For at least one sampling event at each site, a set of transit stability samples were prepared to evaluate the stability of sulfoxaflor and its transformation products during shipment and storage. Soil samples were spi ked at 1x and 100x the limit of quantification. Pore water samples were spiked at 1x and 40x the LOQ. Spiked samples were subjected to the same procedures as the field samples. Average recovery in transit stability soil samples ranged between 82 and 97% fo r sulfoxaflor, 94 and 125% for X4

- 4, 77 and 101% for X457, and 81.0 and 111% for X540. Recovery in transit stability pore water samples was 88 and 88% for Sulfoxaflor, 95 and 88% for X117194

- 74, 85 and 84% for X5

- 0, and 99 and 93% for X457, in California and Florida, respectively. Crop samples were collected at various crop growth stages during the first and second growing seasons and analyzed for sulfoxaflor, X

- 474 (i.e., the major soil metabolite)and X

- 061 (i.e., the plant metabolite) using a reverse

- p hase polymeric solid

- phase extraction (SPE) cartridge on

- line system using HPLC/MS/MS. (4) Method of Analysis: Limits of Detection/Quantification LOD/ LOQ and Performance10 Data show that the method of analysis LODs and LOQs are reasonable when compared to the lowest expected concentrations in soils, plants and pore water samples. The range of sulfoxaflor, that may go un

- quantified in all media, is from <0.1 to 2.3%. The efficiency (or performance) of the analytical method was determined for:

• Soil, water, tank mix and saturation pads samples: Data suggest efficient performance over the concentration range of 0.001 to 0.2 ppm for spiked soils with a LOQ of 0.001 ppm and LOD of 0.0003 ppm; 0.05

- 2 ng/mL for spiked pore - water and the tank mix samples with LOQ of 0. 05 ng/mL and LOD of 0.015 ng/mL; and 2.00 to 100 μg/pad for the saturation pads with a LOQ of 2.00 μg/pad and LOD of 0.667 μg/pad;

• Freshly spiked and field spiked soils with parent sulfoxaflor, X

- 4 74, X

- 4 57 and X

- 5 40 degradate : Data suggest that the meth od’s recoveries for freshly spiked soils had a wide range of concentrations suggesting possible problems in preparation /analysis in at least some of the samples. Mean recovered concentrations for the freshly spiked soils were within a very narrow range fr om 100% for sulfoxaflor parent, X

- 474, and X

- 540 but wider ranges were obtained for X457 (85

- 105%: a wide range around 100%, mostly below 100%). Based on these data, it can be stated that the analytical method performed “well” for sulfoxaflor and its main degradate X

- 474 , may “slightly over

- estimate” or “under

estimate” X457, and may give a “good” or “under

- estimate” of X540.

• Field spiked reagents with parent sulfoxaflor, X

- 474, X

- 457 and X

- 540 degradates: with three exceptions, these data indicate that bo th the average and the range of concentrations found in field spiked reagents were within a very narrow margin of 100% which indicate very limited effects on concentrations of parent and it’s degradates as a result of transport and storage. The exceptions include X

- 440 concentrations found in reagents transported/stored with ND and TX samples and concentrations of X

- 4 57 found in reagents transported/stored with TX samples. It appears that concentrations found for X

- 40 in reagents transported/stored with ND were probably a result of errors in reagent preparation. In general, data suggest stability of parent sulfoxaflor and its degradates X

- 474, X

- 440, and X

- 457 during transport and storage; and

• Freshly spiked and field spiked pore

- water with parent sulfoxafl or and degradates X

- 474, X

- 457 and X

- 540: Data suggest that the method’s recoveries for freshly spiked pore

- water had a wide range of concentrations suggesting possible problems in preparation/analysis in at least some of the samples. Mean recovered concen trations for the freshly spiked pore

- water were within a narrow range from 100% for sulfoxaflor parent, X

- 4 74, and X

- 540 but wider ranges were obtained for X

- 457 in CA samples (over 115%). Based on these data, it can be stated that the analytical method pe rformed “well” for sulfoxaflor and its main degradates X

474 and X

- 54 0 but may “slightly over

- estimate” X

- 457 in CA samples.11 (5) Verification of application Application was verified by analysis of the tank mix, soil deposition trays/saturated pads, and tim e - zero data. The following is a summary of the results:  Tank

- mix data: The nominal application rates were verified by analyzing tank mix samples. A summary of the data is included in Figure 4

.

Figure 4 Tank

- mix data for the purpose of verification o f application rates Data in Figure 4 suggest that concentrations, found in most of the tank

- mix spray materials, were within reasonable limits of the target nominal concentrations (overall average 92%, range of averages 83

- 104%, and range of individual sam ples 80

- 147% of nominal). It is noted however that three sulfoxaflor degradates (X

- 474, X

- 540 and X

- 457) were present as impurities in the formulation with an average total of 3% and range of 3 to 4% of nominal. The suite of these degradates, in the tank m ix, consisted mainly of X

540 (overall average of 99% and range of 96

- 100% of the total degradates) with minor amounts of X

- 474 and X

- 457 (overall averages of 0.9% and 0.2% and ranges of 0.2

- 4% and 0.2

- 0.3% of the total degradates, respectively);  Soil dep osition trays/saturated pads: soil deposition trays were used to verify the application rates for all site including the Ontario cropped plots in which saturated pads were also used. The measured concentration of parent equivalents in the tank mix samples were between 86 and 108% of the nominal application rate. The average deposition tray recoveries (parent equivalents expressed as a percentage of nominal applied) ranged between 84 and 126% in California, 77 and 115% in 0% 20% 40% 60% 80% 100% 120% 140% 160%CA-1-MinMaxCA-2-MinMaxCA-3-MinMaxFL-1-MinMaxFL-2-MinMaxFL-3-MinMaxND-MinMaxON-MinMaxTX-MinMax Parent (78-147% ) X1175194-40 (2.4-4.1% ) X117194-74 (0.01-0.28% ) X115794-57 (0-0.01% )12 Florida, 85 and 98% in North Dakota, 33 and 114% in Ontario, and 93 and 97% in Texas. The low recovery in the deposition tray samples observed for the Ontario cropped plot (33%) was associated with crop canopy interception (soybean) because the deposition trays at this site were placed on th e ground below the soybean crop canopy. Saturation pads, placed over the soybean crop canopy during application, showed 75% recoveries; and  Day

- zero soil concentrations : For the first application, samples were taken from the top 6” of the soils at all sit es just after the first application to determine day

zero concentrations (i.e., the actual rate applied). TFD guidance emphasizes that “day zero concentration lays the foundation for all subsequent sampling and is used to build confidence that the pesticid e was applied uniformly and accurately”. Day

- zero data suggest that “average” concentrations of the pesticide residues (including the impurity of degradation products) are within the reasonable limits of 10

- 20% of nominal (i.e., 80

- 120% of nominal) of the expected at CA, FL, ND, and ON bare plots and at the FL cropped plot. In contrast, relatively high average found concentrations were observed at TX bare plot (154% of nominal) and CA and FL cropped plots (138 and 151% of nominal) with relatively low avera ge concentrations observed at ON and ND cropped plots (16

- 75% of nominal). This indicates that the pesticide was accurately and uniformly applied at CA, FL, ND, and ON bare plots and at the FL cropped plot. However, hot spots (areas receiving more pesticid e) appear to be present at TX bare plot and the CA and FL cropped plots and cold spots (areas receiving less pesticide) appear to be present at ON and ND cropped plots. No analysis can be performed for the multiple applications at CA and FL because day

- zer o samples were taken only just after the second and third applications with no samples taken just before these applications. The TFD guideline states that “For multiple applications, each application should be treated as time zero, and concentrations prior to and immediately after application should be determined”.

(6) TFD Half

- lives: Parent Sulfoxaflor parent, X

- 474, X

- 457 and X

- 540 (1) Parent Sulfoxaflor: Sulfoxaflor dissipation half

- lives (DT 50 ) were calculated for residues in the top 6” of the soil and the wh ole 0

- 36” soil profile. In all half

- life calculations, the highest observed residue value was used as the initial data point. Residue data for the 0

- 6 inch soil layer were plotted for all sites and data for the entire soil profile were plotted for ND, ON, and TX (data from deeper soil layers were not consistently available in CA and FL). To determine the DT 50 in the entire soil profile based on the total mass of parent sulfoxaflor throughout the soil profile was calculated using the bulk density and volume of each core segment at every sampling depth 1 . The data were analysed by using single first order (SFO), double first order in parallel (DFOP) and indeterminate order rate equation (IORE) models and best fit was chosen. When more than one application was m ade (i.e., for CA and FL), data collected after the first, second and third application were

1 Total chemical mass= concentration (mg/kg soil) x core volume (m 3 ) x mean bulk density (kg soil/m 3 )13 analysed separately. Furthermore, it is noted that the first data point below LOD was replaced with 1⁄2 the LOD and subsequent points less than the LOD were omitted from the curve fitting unless positive detections were determined at a later sampling points. Results are summarized in Table 2

. Table 2 A summary of field dissipation half

- lives (DT50 in days) for sulfoxaflor from the top 6” of the soil and the entire so il profile (0

- 36”)

Chemical Considered Depth CALIFORNIA* FLORIDA* NORTH DAKOTA* ONTARIO* TEXAS* Bare Cropd Bare Cropd Bare Cropd Bare Cropd Bare Cropd

Sulfoxaflor Parent 0

- 6” (top soil) 2.0 1.9 0.7 1.6 0.3 0.1 0.6 0.9 8.1 1.5 0

- 36” (entire profile) ND ND ND ND ND 0.2 0.6 ND 8.1 1.5 * Kinetic models used to fit data for dissipation half

- life: SFO (values in red)= Single First Order; DFOP (Values in blue)= Double First Order in Parallel; IEORE= Indeterminate Order Rate Equation (values in black) Bare= Bare soil plots; cropd= cropped plots; ND= Not determined due to lack of data
S ulfoxaflor rapidly dissipated in the field from the top 6”, the chemical dissipated in soil bare

- plots with half

- lives in the range of 0.3 to 2 .0 days in CA, FL, ND, ON. Rel atively longer dissipation half

- life of 8.1 days was observed in TX bare

soil plots. Calculated DT 50 for the same soil layer in the cropped plots ranged from 0.1 to 1.9 days.
These DT 50 results confirm data obtained from aerobic soil studies (t1⁄2= 0.3 to 0.6 days) although it appears that the chemical persists slightly longer in the field compared to the laboratory. The observed low amounts of the chemical that leached below 6” is probably a result of the slightly longer field half

- life and high mobility ( K oc = 12 to 71 mL/g). Sulfoxaflor was detected within 1 to 28 days after application at depths of 6

- 18” with concentrations ranging from 0.8 to 6% of the applied in CA bare/cropped plots and FL cropped plots. Lower concentrations of <1% of the applied were observed, at same depth, in ND, ON (Ontario, Canada), and TX bare/cropped plots and in FL bare

- plots. In CA only, the chemical reached concentrations ranging from <0.5% to 0.7% of the applied to depths of 18 to 36”. The relatively high leaching observed in CA soil was attributed to excessive irrigation. Therefore, leaching of sulfoxaflor parent is possible if heavy rain occurred just after application. The possibility of sulfoxaflor reaching very shallow ground water may not be discounted because sulfoxaflo r is mobile, less vulnerable to anaerobic degradation in lower soil horizons and is stable for hydrolysis. Field leaching was also tested using soil pore water suction lys o meters to collect soil

- pore water samples in two of terrestrial field dissipation studies: CA and FL.14 soil

- suction lys o meters were installed at sampling depths of 3, 6, and 8 (FL) or 9 (CA) feet below ground surface. Soil

- pore water samples were collected at

- 1, 6, 13, 28 days and 2, 4, 6, 9, 12 and 15 months after the first treatment. Although sulfoxaflor was not detected in pore water at any time/depth sampled in the high leaching profile in CA, it was concluded that non

- detection was related to time of sampling rather than absence of leaching (i.e., samples missed the leaching events) . In FL, the low leaching site, sulfoxaflor was detected, in only 6% of the samples, at low sporadic levels at all times/depths with maximum concentration of 0.0001 ppb (≈ 0.1% of applied) at a depth of 3 ft, 28 days after the 1 st treatment. It is noted th at SCIGROW predicts a very low ground water expected concentration for parent sulfoxaflor (EECs= 0.0001 ppb). (2) Major Degradate: Consistent with laboratory studies, X

- 474 was the major transformation product in the field dissipation studies. Data for the t op 6” of the soil indicate the rapid formation of X

- 474 as its concentration of 13

- 54% of the applied parent was observed immediately following the first application. This was the case also following the second and third applications in CA and FL sites. It is interesting to note that concentrations reached more than 100% of the applied parent after each of the single applications in bare/cropped plots in ND (112

- 185%), ON (101

- 350%), and FL (150

- 100%) and in bare plots in TX (129%). This may indicate mass b alance issues or may indicate that X4

- 74 is accumulating in hot spots possibly as a result of lateral movement if it can be assumed that parent was uniformly applied; however, X4

- 74 hot

- spots may also result from parent hot

- spots if parent was not distribu ted uniformly during application. Furthermore, data suggest that X

- 474 has the potential to carryover especially if leaching is limited (concentrations ranging from 1 to 18% of the applied parent were left in the soil after a year). Dissipation half

- lives (DT 50 ) for X

- 474 were calculated for residues in the top 6” of the soil and the whole 0

- 36” soil profile following the same procedure described for above for parent. Results are summarized in Table 3

. Table 3 A summary of field dissipation half

- lives (DT5 0) for major degradate X4

- 74 from the top 6” of the soil and the entire soil profile (0

- 36”)

Chemical Considered Depth CALIFORNIA* FLORIDA* NORTH DAKOTA* ONTARIO* TEXAS* Bare Cropd Bare Cropd Bare Cropd Bare Cropd Bare Cropd
X117194

- 74 Degradate 0

- 6” (top soil) 27.2 52.3 48.8 62.1 217 39.7 248 109 50.8 58.2 0

- 36” (entire profile) 5.9 9.9 49.4 59.9 200 36.4 114 58.5 45.1 51.9 * Kinetic models used to fit data for dissipation half

- life: SFO (values in red)= Single First Order; DFOP (Values in blue)= D ouble First Order in Parallel; IEORE= Indeterminate Order Rate Equation (values in black) Bare= Bare soil plots; cropd= cropped plots; ND= Not determined due to lack of data Bare= Bare soil plots; cropd= cropped plots; ND= Not determined due to lack of dat a15 Data summarized in Table 3 indicate that X

- 474 is much more persistent than its parent. Dissipation half

- lives ranged from 49 to 248 days and from 40 to 109 days in bare soil and cropped plots, respectively. Additionally, X

- 474 leached below the top 6 ” soil layers at all terrestrial field dissipation sites reaching 36, 30, 24, and 18” below the surface. At CA and FL sites, residues of X

- 474 reached a depth of 36” with maximum concentrations of 19.5 to 20.6 ppb (≈19

- 20% of the applied parent) at 28 day s after the 1 st application in CA and maximum concentrations of 1.7 to 2.5 ppb (≈2

- 4% of the applied parent) at 2

- 15 months after the 1 st application in FL. In ND, X474 reached a depth of 30” with maximum concentrations of 1.0 to 2.3 ppb (≈2

- 4% of the appl ied parent) at 2

- 11 months after the 1 st application. At ON (Canada) site, it reached a depth of 18” with maximum concentrations of 0.5

- 1.6 ppb (≈0.6

- 10% of the applied parent) at 9 months after the 1 st application. At TX site, it reached a depth of 12” b elow the soil surface with maximum concentrations of 14.7 to 17.5 ppb (≈18

- 22% of the applied parent) at 4

- 9 months after the 1 st application. Observed data confirm that field dissipation of X117194

- 74, from the top soil, is mainly related to transport (K o c = 7 to 74 mL/g) rather than degradation. Field leaching was also tested using soil pore water suction lys o meters to collect soil

- pore water samples in two of the terrestrial field dissipation studies: CA and FL. Soil

- suction lys o meters were installed at sampling depths of 3, 6, and 8/9 ft (FL/CA) below ground surface. Soil

- pore water samples were collected at

- 1, 6, 13, 28 days and 2, 4, 6, 9, 12 and 15 months after the first treatment. The range of X

- 474 concentrations, in pore water, was from 108 to 218 ppb (≈120

- 242% of the applied) at depths ranging from 3 to 9 ft in CA at 2

- 6 months after the 1 st application. Lower peak concentrations were observed in FL as they were in the range of 0.096 to 5.89 ppb (≈0.1

- 5.9% of the applied) after the 1 st applicatio n and at the same depths. Based on this field and laboratory data, high leaching is expected for X

- 47 4 and is expected to reach ground water at high concentrations. Other Degradates: X

- 540 and X

- 457: Degradates X

- 540 and X

- 457 were minor transformation p roducts in the field. In most field sites, both degradates dissipated from the 0

- 6 inch soil layer before the end of the study. The observed formation of minor quantities of degradates X

- 457 and X

- 540 is probably related to the relative high persistence of its most probable parent (the major degradate X

- 474 ). A kinetic analysis was not performed for X115195

- 40 and X115794

- 57. (7) Crop Residues: Target and rotational Crops Crop residue results for all five test sites were monitored for parent sulfoxaflor and i ts major transformation product X11719474, as well as X11721061 (a plant metabolite). Field plant data can be used to characterize foliage interception of applied parent and nature/concentration of residues in target and rotational crops (foliage uptake)

. Plant Interception16 Plant residue concentration data (in ppm) were collected but no data were collected for the total crop mass (g) / unit area (m 2 ). Therefore, data on the amount intercepted by foliage could not be related to the amount applied. In anothe r words, the amount of the pesticide intercepted by foliage could not be calculated as % of the applied parent. Additionally, for this systemic pesticide, found concentrations in plant samples may be interpreted as follows:

• Whole plant concentration, just after the first application represents the amount of sulfoxaflor intercepted by the plant foliage. Amounts intercepted at any other application may only be determined if plant samples are taken just before and just after each of these applications and the amount is equal to concentration just after the application minus concentration just after the application.
• For systemic pesticides, the observed change in whole plant concentration between applications is the result of many competing processes, namely: o D egradation that might occur on the surface of the foliage. This process is not expected to have a major e ffect on sulfoxaflor as it is stable for hydrolysis and photolysis; o Plant interaction with applied pesticide including how much of the pesticide enters the plant tissues and how much is affected by plant metabolism. o Wash

- off due to rainfall and/or irrigation which is expected to reduce concentrations that might remain on foliage (i.e., didn’t enter the plant). This process is expected to have minimum im pact on systemic sulfoxaflor which is expected to enter the plant tissues; and o Plant up

- take from sulfoxaflor reaching the soil. This process is not expected to impact sulfoxaflor due to its rapid soil degradation. (8) TFD: Nature and concentration of resid ues in target and rotational crops In California, spinach (treated crop), cantaloupe and wheat (rotational crops) were planted over the course of the stud y . Sulfoxaflor in spinach whole plant samples was detected at a maximum of 7.4 ppm immediately after the 2 nd application and then declined to non detectable levels by 46 days after the 1 st application (1 st order half

- life ranging from 1.1 to 2.8 days). X

- 474 and X

- 061 were detected at a maximum of 2.7 ppm (3 days after the 2 nd application) and 0.3 ppm (imm ediately after the 3 rd application), respectively. In Florida, peppers (treated crop), radishes and lettuce (rotational crops) were planted over the course of the study. In pepper whole plant samples, sulfoxaflor was detected at a maximum of 11.2 ppm imme diately following the 1 st application and then declined to non detectable levels by 63 days after the 1 st application (1 st order half

- life ranging from 1.5 to 4.7 days). The X

- 474 and X

- 061 degradates in whole plant samples were detected at a maximum of 2. 0 ppm and 0.8 ppm, respectively at 63 days after the first application. In pepper fruit only X474 was detected ( 0.1 ppm) at 63 days after the first application.17 In North Dakota, wheat (treated crop) and cabbage (rotational crop) were planted over the cour se of the study. In wheat whole plant samples, sulfoxaflor was detected at a maximum of 6.3 ppm immediately following application and then declined to nondetectable levels by 7 DAT (1 st order half

- life 0.6 day). Degradate X

- 474 was detected at a maximum of 0.03 ppm immediately following application and X

- 061 was detected at a maximum of 0.05 ppm at 3 DAT . Residues of sulfoxaflor, X

- 474, and X

061 were not detected in wheat grain and wheat straw. In Ontario, soybeans (treated crop) and corn (rotational cr op) were planted over the course of the study. In soybean whole plant samples, sulfoxaflor was detected at a maximum of 11ppm immediately following application and then declined to non detectable levels by 99 DAT (1 st order half

- life 7.9 days). X

- 474 and X

- 061 were found in the whole plant at a maximum of 0.53 ppm (14 DAT) and 0.28 ppm (1 DAT). Sulfoxaflor was not detected in the soy bean itself. In contrast, degradates X

- 474 and X

061 were found at 0.08 and 0.007 ppm, respectively. In Texas, cotton (treat ed) and melon (rotational crop) were planted over the course of the study. In cotton whole plant samples, sulfoxaflor was detected at a maximum of 7.1 ppm immediately following application and then declined to nondetectable levels by 14 DAT (1 st order half

- life 10.7 days). Degradates X

- 474 and X

- 061 were found in the whole plant at a maximum of 0.11 ppm immediately following application and 1 DAT, respectively. Parent, X

- 474 and X

- 061 were not detected in cotton seed proper. In summary, data indicate that sulfoxaflor parent is the most relevant residue observed in the whole plants (in terms of concentration) . The highest concentrations of the parent compound appear to occur just after applications. After reaching a maximum, parent sulfoxaflor appears to de cline rapidly in CA spinach, FL peppers, and ND wheat (1 st order half

- lives range from <1 to 5 days). In contrast, the parent compound declines much slower in ON soybeans and TX cotton (1 st order half

- life range from 8

- 11 days). The second relevant compoun d is X

- 474 ( plant and environmental metabolism product of parent sulfoxaflor ) with maximum concentrations ranging from 2.0 to 2.7 ppm in CA spinach and FL peppers, and 0.03 to 0.53 ppm in ND wheat, ON soybean and TX cotton. The plant only metabolism produ ct ( X

- 061) appears to form at low concentrations with peak residue levels ranging from 0.8 to 1.3 ppm in CA spinach and FL peppers and 0.05 to 0.28 ppm in ND wheat, ON soybean and TX cotton. R esidue profile s in spinach in CA and peppers in FL suggest that p eaks residues of sulfoxaflor parent appear to coincide with application (chemical source) which is followed by peaks in X

- 474. Both compounds appear to decline within two months following a multiple reapplication with two weeks intervals. (9) Nature and con centration of residues in rotational crops With only one exception, data indicate that parent sulfoxaflor was not detected in any sample from any of the rotational crops examined. Only the degradate X

- 474 and X

- 061 were detected. The degradate X

- 061 is ex pected to be present as it is a known plant18 metabolite, however, the presence of X474 in rotational crops suggests its uptake from soil (i.e., X

- 474 is systemic as parent)

. The following is a summary of the residues profile for the two degradates in rota tional crops:  In CA, cantaloupe was the first crop planted in rotation with spinach (77 days after the initial application to spinach). The degradate X

- 474 was found in whole plant samples at a maximum of 0.55 ppm at123 days after the 1 st application and remained at roughly similar levels until the end of the cantaloupe sampling period; X474 in melon samples was found at 0.07 ppm at 182 days after the 1 st sulfoxaflor application. The degradate X061 was detected at 0.17 ppm in the cantaloupe whole plant sa mples at 182 days after the 1 st sulfoxaflor application; no X061 residues were detected in the fruit itself. Additionally, wheat was the second crop planted in the rotation (planted 245 days after the initial application to spinach). The degradate X

- 474 wa s found in the wheat whole plant samples at 0.004 ppm (<LOQ of 0.01 ppm) at 368 days after the 1 st application and in the wheat straw at 0.007 ppm (<LOQ) at 425 days after the 1 st application ; X

- 474 was not detected in wheat grain itself. The degradate X06 1 was not detected in the wheat whole plant, wheat grain, and wheat straw samples.  In FL: radish was the first crop planted as a rotational crop (planting date was not reported) following an initial application to peppers. The degradate X

- 474 was found in whole plant samples at 0.01 ppm at 180 days after the 1 st application and was found in radish tops at 0.01 ppm (<LOQ) at 203 days after the 1 st application; X474 was not detected in radish root. No X061 residues were detected in the radish whole plant, roo t, and top samples. Additionally, leaf lettuce was the second rotational crop to be planted 315 days after the initial application to peppers. The degradate X

- 474 was found at a maximum of 0.01 ppm at 363 days after the 1 st application to wheat . The degrad ate X

- 061 was not detected in leaf lettuce.  In ND: Cabbage was planted 380 days after application to wheat. X

- 474 was found at a maximum of 0.01 ppm (<LOQ) at 426 DAT while X61 was not detected.  In ON: Corn was planted 327 days after an initial applicati on to soybeans. Degradates X

- 474 and X

- 061 were not detected in the corn whole plant, corn ears, or corn stover samples.  In TX: Melons were planted 309 days after an initial application to cotton. The degradate X

- 474 and X

- 061 were detected at 0.004 and 0 .005 ppm (both < LOQ), respectively, but were not detected in the melon fruit proper. (10) Dissipation Pathways for Parent and Degradates The major dissipation pathways for parent sulfoxaflor and transformation products were tracked and included degradation and leaching. Runoff and volatilization were not tracked as both are not expected to be factors in dissipation due to the study area (flat plots with limited possibility for runoff) and the low vapor pressure and Henry’s law19 constant for sulfoxaflor. Othe r minor pathways that were tracked include plant uptake and residue carryover. Two major properties of sulfoxaflor were the drivers for its dissipation in terrestrial systems, i.e., its ability to enter the plant through foliage (systemic distribution) fo llowing application and its high vulnerability to degradation in the soil system. Factors affecting dissipation for degradates were persistence and mobility.
(11) TFD: Residues Carryover In California, the DT 90 for sulfoxaflor was 6.6 and 6.1 days (from the 3 rd application to the end of the study; based on single first order kinetics) for the bare soil and cropped plot, respectively. Approximately one year after the 1 st application and including the two subsequent applications, sulfoxaflor was no longer detect ed and has a low potential for carryover into the next growing season. When considering the 0

- 6 inch soil layer, carryover of the transformation products at the beginning of the next growing season ranged from 0 to <1%of the Time 0 parent

- equivalent conce ntration for X

- 474, X

- 457 and X

- 540, respectively. When considering the entire soil profile, carryover of the transformation products at the beginning of the next growing season ranged from 0 to 2% of the Time 0 parent

- equivalent concentration for X

- 474, X

- 457 and X

- 540. In Florida, the DT 90 for sulfoxaflor was 22 days for the bare soil plot (from the 3 rd application to the end of the study; based on double first ord er (in parallel ) and 23 days for the cropped plot (from the 3 rd application to the end of t he study; based on an indeterminate order rate equation ) . Approximately one year after the 1 st application, sulfoxaflor was detected at 1% and less than 1% of the Time 0 parent

- equivalent concentration in the bare soil and cropped plots, respectively. Base d on these data, parent sulfoxaflor appears to have a low potential for carryover into the next growing season. When considering the 0

- 6 soil layer, carryover of the transformation products at the beginning of the next growing season was 14

- 15%, less than 1% and 1% of the Time 0 parent

- equivalent concentration for X

- 474, X

- 457 and X

- 540, respectively. When considering the entire soil profile, carryover of the transformation products at the beginning of the next growing season was 22

- 25%, less than 1% and 3 % of the time zero parent

- equivalent concentration for X

- 474, X

- 457 and X

- 540, respectively. In North Dakota, the DT 90 for sulfoxaflor was <1 day for bare soil and cropped plots. Parent sulfoxaflor was no longer detected well before the growing season had ended and thus is considered to have a low potential for carryover into the next growing season. When considering the 0

- 6 soil layer, carryover of the transformation products at the beginning of the next growing season was 28

- 39%, 1% and 3

- 4% of the Time 0 parent

equivalent concentration for X

- 474 , X

- 457 and X

- 540, respectively. When considering the entire soil profile, carryover of the transformation products at the beginning of the next growing season was 32

- 52%, 1

- 2% and 7% of the Time 0 parent

- equivalen t concentration for X

- 474, X

- 457 and X

- 540, respectively. The degradate X

- 474 is expected to carry over into the following season.20 In Ontario, the DT 90 for sulfoxaflor was approximately 1 day for the bare soil and cropped plots. Parent sulfoxaflor was no longer detected well before the growing season had ended and thus has a low potential of carryover into the next growing season. When considering the 0

- 6 inch soil layer, carryover of the transformation products at the beginning of the next growing season was 36

- 40%, <1% and 0

- 3% of the Time 0 parent equivalent concentration for X

- 474, X

- 457 and X

- 540, respectively. When considering the entire soil profile, carryover of the transformation products at the beginning of the next growing season was 50

- 131%, 0

- 1% and 4

- 6% of the Time 0 parent

- equivalent concentration for X

- 474, X

- 457 and X

- 540, respectively. The degradate X

- 474 is expected to carry over into the following season. In Texas, the DT 90 for parent sulfoxaflor was 8.1 and 1.5 days fo r the bare soil and cropped plots, respectively. Parent sulfoxaflor was no longer detected before the growing season had ended and thus has a low potential of carryover into the next growing season. When considering the 0

- 6 inch soil layer, carryover of th e transformation products at the beginning of the next growing season was 44

- 46%, <2% and 3

- 5% of the Time 0 parent equivalent concentration for X

- 474, X

- 457 and X

- 540, respectively. When considering the entire soil profile, carryover of the transformatio n products at the beginning of the next growing season was 65

- 76%, 1

- 3% and 4

- 8% of the Time 0 parent

- equivalent concentration for X

- 474, X

- 457 and X

- 540, respectively. The degradate X

- 474 is expected to carry over into the following season. In conclusion, top soil carryover is not expected for sulfoxaflor parent but is expected for X

- 474, X

- 457 and X

- 540. Estimated carryover for all of the three degradates were minimal (0

- <1%) for CA site while it was significantly higher for FL, ND, ON and TX sites. For X

- 474, the maximum top soil carryover is estimated to be 15% for FL, 39% for ND, 40% for ON and 46% for TX. This is a reflection of the high formation/persistence of the degradate X

- 474. For X

- 540, the maximum top soil carryover is estimated to be 1% for FL , 4% for ND, 3% for ON and 5% for TX. For X

- 457, the maximum top soil carryover is estimated to be <2% in FL, ND, ON and TX.