MRID 49090503 CDPR IMI Tomato (2011)

1 1. STUDY INFORMATION

Chemical: Imidacloprid PC Code 129099

Test Material: Admire Pro Percent Active Ingredient: 42.8 % A.I.

Study Type: Non

- Guideline field residue study on tomato to establish imidacloprid and

metabolite levels in anthers and leaves i n site locations that have been treated at least once per year for two successive years

.

Sponsor: Bayer CropScience

2T.W. Alexander Drive

Re search Triangle Park, NC

USA 27709 Experiment Start and

End Date: July 30, 2010

– January 14 , 2011

Sponsor Study

ID: EBNTL056

- 01

Study Locations: 9 Field Trials in Kern and Kings County

located in California. Study Completion

Date: March 31, 2011

GLP Status: Non

- GLP ; F inal protocol was submitted to CDPR for review

. [CDPR study ID 254887 , Data Volume 51950

- 0757 , Tracking ID# 241047 ]

2. REVIEWER INFORMATION

Study Reviewed by: California Department of Pesticide Regulation Richard Bireley, Sr. Environmental Scientist (Specialist) John Troiano, Ph.D., Research Scientist III Alexander Kolosovich, Environmental Scientist Brigitte Tafarella, Environmental Scientist Denise Alder, Sr. Environmental Scientist (Specialist)

Russel l Darling, Environmental Scientist

3. EXECUTIVE SUMMARY

Nine trials were conducted in clay or loam soils classified as fine ( “ heavy ” ) or “ medium ” to determine the residues of imidacloprid and its metabolites (5

- hydroxy imidacloprid and imidacloprid olefin) in anthers (pollen) and leaves collected from tomato plants grown at locations treated with imidacloprid at least once per year for two years. All soils had received pre vious chemigation applications of Admire Pro at total rates ranging from 0.18 t o 0.25 Ib

. a

. i

. /a cre (5.0 t o 7.0 fl oz formulated product/a cre ) in 2009.

Reference Freeseman, P.L.; Harbin, A. (2011) Determination of the Residues of Imidacloprid and its Metabolites

5

- Hydroxy Imidacloprid and Imidacloprid Olefin in Bee Relevant Matrices Collected from Tomato, a Fruiting Vegetable, Grown at Locations Treated with Imidacloprid at Least Once Per Year During Two

Successive Years : AMENDED. Project Number: EBNTL056/05/1/AMENDED. Unpublished study prepared by Bayer Cropscience and California Agr icultural Research, Inc. 144p. MRID 49090503 , CDPR Study I D 259130, Data Volume 51950

- 0786 , Tracking ID# 246252MRID 49090503 CDPR IMI Tomato (2011)

2 Ea ch trial received applications of Admire Pro in 2010 at the same rates as in 2009. The six sites located in Kings County received two applications of Admire Pro at 3.5 fI oz f ormu lated p roduct/ application (0.13

Ib . imidacloprid/ acre/ application) for a total seasonal rate of 7.0 fI oz f ormulated p roduct /acre (0.25 Ib

.

a

. i

. /a cre ). The first applications were made at or closely following transplant with the second application
occurring 52 to 57 days following the first applications. The three sites located in Kern County received a single application of Admire pro at 0.18 lb. imidacloprid/acre (5.0 fl oz formulated product/acre) 2 to 25 days following transplant

. Kern County is identified as North American Free Trade Agreement (NAFTA)
Region 10.

Plant growth stage was not documented at the time of application . However, the first application s likely occurred at growth stages of BBCH * 21 to 51 (first primary shoot to first inflor escence visible) and BBCH

61 to BBCH 69 (flowering but prior to fruiting) for the second applications. All applications were made through drip chemigation (buried lines). *BBCH = B iologische Bundesanstalt, B undessortenamt und

CH emische Industrie growth stage scale for tomato.

Composite samples of tomato anthers (pollen) and tomato leaves were collected from tomato plants 72 to 102 days following the last treatment (DALT) at indeterminate flowering an d fruiting growth stages (BBC H 61 to BBCH 79 ) and analyzed for residues of imidacloprid.

The residue(s) of imidacloprid, 5

- hydroxy imidacloprid, and imidacloprid olefin were quantitated by high performance liquid chromatography/triple stage quadrupole mass spectrometry (LC/MS/MS) us ing stable isotopically labeled internal standards. The individual analyte residues were summed to give a total imidacloprid residue.

4. STUDY VALIDITY

Guideline Followed: Non

- guideline study ( final protocol submitted by CDPR )

Guideline Deviations: N/A

Other Deviations: N/A

Classification: Supplemental

Rationale: N/A Reparability: N/A

5. MATERIALS AND METHODS

Test Material Characterization

Test item: Admire Pro Percent Active Ingredient: 42.8 % A.I.

Description: Suspension concentrate (SC) Density: 1.41

- 1.54 g/mL

Material Source: Bayer Corporation Solubility: 0.51 to 0.61 g/L

CAS #: 138261

- 41

- 3 pH (24°C) : 7.8

5A. S TUDY D ESIGN

The field and sampling phases of this study were not conducted under GLP. The experimental start date was July 30, 2010 (collection of the control anthers and leaves), and the experimental end date was January 14, 2011 (last analysis). The field sampling phase of the study was conducted by Califo rnia Agricultural Research, Inc.MRID 49090503 CDPR IMI Tomato (2011)

3 Data from nine tomato trials condu cted in fine (“ heavy ”) or “ medium ” soils are pr esented in the subject report. All sites were located in California, located in either Kings County (four heavy soil and two

medium soil t rials) or Kern County (three medium soil trials). All had received appl ications of imidacloprid (Admire Pro) in the preceding year (2009). Imidacloprid use in 2008 and prior years was

unknown. The application history/ pattern is shown in T able 1.

The analytical phase of this study was conducted under GLP and was initiated on December 3, 2010 (leaf sample homogenization). Homogenization of the leaves and analysis of all samples from the subject study were performed at the Bayer Research Park (BRP) located in Stilwell, KS. Report preparation was performed at BRP.

5B. A PPLICATI ON T IMING AND R ATES

The Admire Pro application rate used at the six sites located in Kings County was 3.5 fl oz formulated product/a cre/ appl ication (0.13 Ib. imidacloprid/a cre/ applicatio n) for a total seasonal rate of 7.0 fI oz formulated product/acre (0. 25 Ib

. a

. i

. / acre ). The first applications were made at or closely following transplanting (March 22 to 27, 2010) with the second applications 52 to 57 days following the first application (May 13 to 20, 2010).

S ingle applications of Admire Pro were made at the three sites located in Kern County at 5.0 fl oz formulated product/acre (0.18 Ib imidacloprid/A). A pplications were made 2 to 25 days following transplant. The growth stages of the plants at the times of applications were not documented but lik ely occurred at growth stages of BBCH 21 to 51 (first primary shoot to first inflorescence visible) for the first applications and BBCH61 to BBCH69 (flowering but prior to fruiting) for the second applications.

All applications were made through drip che migation (buried lines). The test substance use pattern for imidacloprid in 2010 for each site is described in Table 1 below

.

Table 1

. Study Use Pattern for 2010 Applica tion of Admire Pro on Tomatoes.Trial IdentificationLocation (City, State)End-UseProduct(Formulation)Plot NameMethodApplication NumberTiming/Growth Stage(BBCH)Rate lb a.i./A(oz FormulatedProduct/A)aInterval BetweenApplications (Days)bTotal Rate lb a.i./A(oz FormulatedProduct/A)

NT041 Kings County,

CA Admire

Pro Armona

Loam (Fine) Chemigation 1 BBCH

21

- 51 0.13 (3.5) NA 0.25 (7.0)

2 BBCH

61

- 69 0.13 (3.5) 52

NT043 Kings

Co unty,

CA Admire

Pro Westcamp

Loam ( Fine ) Chemigation 1 BBCH

21

- 51 0.13 (3.5) NA 0.25 (7.0)

2 BBCH

61

- 69 0.13 (3.5) 54MRID 49090503 CDPR IMI Tomato (2011)

4Trial IdentificationLocation (City, State)End-UseProduct(Formulation)Plot NameMethodApplication NumberTiming/Growth Stage(BBCH)Rate lb a.i./A(oz FormulatedProduct/A)aInterval BetweenApplications (Days)bTotal Rate lb a.i./A(oz FormulatedProduct/A)

NT044 Kings County,

CA Admire

Pro Houser Clay ( Fine ) Chemigation 1 BBCH

21

- 51 0.13 (3.5) NA 0.25 (7.0)

2 BBCH

61

- 69 0.13 (3.5) 54

NT045 Kings County,

CA Admire

Pro Tulare Clay (Heavy) Chemigation 1 BBCH

21

- 51 0.13 (3.5) NA 0.25 (7.0)

2 BBCH

61

- 69 0.13 (3.5) 57

NT046 Kings County,

CA Admire

Pro Boggs Sandy

Loam (Medium) Chemigation 1 BBCH

21

- 51 0.13 (3.5) NA 0.25 (7.0)

2 BBCH

61

- 69 0.13 (3.5) 52

NT047 Kings County,

CA Admire

Pro Lemoore Sandy Loam (Medium) Chemigation 1 BBCH

21

- 51 0.13 (3.5) NA 0.25 (7.0)

2 BBCH

61

- 69 0.13 (3.5) 52

NT048 Kern County,

CA Admire

Pro Wasco Sandy Loam (Medium) Chemigation 1 BBCH

61

- 69 0.18 (5.0) NA 0.18 (5.0)

NT049 Kern County,

CA Admire

Pro MacFarland

Loam (Medium) Chemigation 1 BBCH

61

- 69 0.18 (5.0) NA 0.18 (5.0)

NT050 Kern County,

CA Admire

Pro Milham Sandy Loam (Medium) Chemigation 1 BBCH

61

- 69 0.18 (5.0) NA 0.18 (7.0)

a Rates and spray volumes that were provided in the application order/recommendation.

b Interval between the first and second applications. NA = Not Applicable; only one application occurred.

5C. S TUDY S ITE L OCATION AND C HARACTERISTICS

All site locations were in Kern or Kings counties in California, NAFTA Region 10. The trial site conditions including soil types are listed in Table 2 . All sites used agronomic practices typical for commercial production of tomatoes.

Temperatures and rainfall recorded during the field phase of the study were similar to average historical records, with no significantly unusual weather conditions that would affect the conclusions of the study. Irrigation supplemented normal rainfall as needed for all trials. Temperature and precipitation data forMRID 49090503 CDPR IMI Tomato (2011)

5 each trial were obtained from the nearest California Irrigation Management Information Syste m (CIMIS)

weather station.

Table 2

. Trial Site Conditions for Imidacloprid on Tomatoes

Trial Identification Trial Location (County, State) Soil Type a Rainfall b (in) Temperature Range b (°F)

NT041 Kings County, CA Armona Loam ( Fine ) 1.51 40

- 77

NT043 Kings County, CA Westcamp Loam (Fine ) 1.51 40

- 77

NT044 Kings County, CA Houser Clay (Fine ) 1.51 40

- 77

NT045 Kings County, CA Tulare Clay ( Fine ) 1.50 42

- 79

NT046 Kings County, CA Boggs Sandy Loam (Medium) 1.51 40

- 77

NT047 Kings County, CA Lemoore Sandy Loam (Medium) 1.51 40

- 77

NT048 Kern County, CA Wasco Sandy Loam (Medium) 1.45 41

- 97

NT049 Kern County, CA MacFarland Loam (Medium) 1.45 41

- 97

NT050 Kern County, CA Milham Sandy Loam (Medium) 1.45 41

- 97

a A total of nine tomato trials were conducted; four in fine (“ heavy ”) soils and five in “ medium ” soils. Classification of the soils was obtained from the Soil Survey Geographic (SSURGO) Database provided by the Natural R esources Conservation Service. “ Heavy ” class represents soil with slow drainage capacity.

b Data is for the interval of the month of first application through the month of last sampling. Meteorological data were obtained from nearby government weather stations.

5D. S AMPLE C OLLECTION , H ANDLING , P ROCESSING

Quadruplicate samples of tomato anthers and leaves were collected from tomato plants at indeterminate flowering and fruiting growth stages as typical for solanaceous fruits (BBCH 61 to BBCH 79). The intervals from last imidacloprid application to sampling ranged from 72 to 102 days fo r the nine

trials.

Anthers and leaves were collected from the same plants. A sample weight of approximately 0.5 g anthers was collected from a minimum of 20 plants. For every anther collected, a leaf s ample was also collected. Leaf samples were a composite from high, low, inside, and outside areas of the plant. The person collecting the anther samples did not touch any leaves or other plant parts with their hands or any sampling equipment. All samples w ere protected from sunlight and placed on either dry ice or blue ice in coolers during field collection. Anther samples were collected in amber glassware and leaf samples were collected in bags. All samples were placed in frozen storage upon receipt at C al ifornia A gricultural Research, Inc . Samples were shipped frozen via Agricultural Chemicals Development Servi ces and remained frozen until receipt at BRP.MRID 49090503 CDPR IMI Tomato (2011)

6 Transit stability samples accompanied the field samples during all sample handling and preparation

s teps to ensure the validity of the sampling practices.

Sample Storage

.

Upon arrival at BRP, all samples were immediately transferred to frozen storage. The treated leaf samples were homogenized with dry ice using a Robot Coupe (Jackson, MS) chopper (control and field fortification samples were not homogenized prior to analysi s; the entire sample was blended during extraction). All samples were returned to frozen storage immediately following homogenization and the samples remained frozen at all times except during subsampling for analysis. A summary of collection, shipment, an d homogenization dates for the trials was recorded in a field report

.

5E. A NALYTICAL M ETHODS

The analytical method used in this study measured the residues of imidacloprid, 5

- hydroxy imidacloprid, and imidacloprid olefin in tomato anthers and leaves. 4

A ll neat analytical reference standards were stored frozen when not in use and all solutions were stored refrigerated. Analytical standard solutions used in this study were not stored for longer than approximately two ( 2 ) months and have been shown to be stable for this period of time. 5 All reference standard solutions were prepared in parent imidacloprid equivalents and corrected for purity during initial preparation.

For the determination of imidacloprid, 5

- hyd roxy imid acloprid (5

- O H) and im idacloprid olefin (olefin) in tomato anthers (pollen) or homogenized tomato leaves, an aliquot of tissue was extracted by blending the sample with water (H 2 0) first , then with acetonitrile . The sample was amended with stable, isotopic ally labeled internal standards, anhydrous magnesium sulfate (MgS O 4 ) and sodium chloride (NaCI). The sample was shaken vigorously followed by centrifugation. The organic supernatant was decanted or transferred to a centrifuge tube containing BONDESIL

- PSA ( solid

- phase extraction sorbent, primary and secondary amine) and MgS O 4 and mixed, followed again by centrifugation. An aliquot of the supernatant was subjected to a C

- 18 S olid P hase E xtraction bond elute cartridge and the eluate was evaporated. The solids were reconstituted with mob ile phase [(9: 1 v/v) water ( H 2 O )/methanol (MeOH)].

The sa mple was filtered with a 0.45 μ m nylon syringe filter and analyzed by high performance liquid chromatography/triple stage quadrupole mass spectrometry (LC/MS/MS).

Quantitation of each analyte was based on the daughter ion transitions of the analytes and the respective internal standard analogs. The responses of LC/MS/MS system to each analyte and its internal standard were measured in samples and in standards, and a relative response was calculated as the ratio of the analyte and the stable isotopically labeled internal standard responses. The relative response of the analyte in each sample was compared to the relative response of the analyte in the

standards.

The relative responses of imidacloprid, 5

- hydroxy imidacloprid, and imidacloprid olefin in solvent were measured over the range of 1 ppb to 1 000 pp b for each analyte. The coefficients of determination (r 2 ) were calculated using linear regression analysis ( LCQUAN 2.5 TM, Microsoft Excel ).MRID 49090503 CDPR IMI Tomato (2011)

7 The total imidacloprid residue is the sum of the individual measured residue values of imidacloprid, 5

- hydroxy imidacloprid, and imidacloprid olefin in parent equivalents. For the purpose of calculating total imidacloprid residues where individual analyte residue values were less than the limit of detection (LOD), the residues were assigned a finite value of 1⁄2 the value of the respective LOD. This value is only an estimate of potential residue in a sample, not a measured va lue. The method for determining imidacloprid, 5

- hydroxy imidacloprid, and imidacloprid olefin residues in/ on tomato anthers and leaves was validated by measuring the recovery of these analytes from

contr ol matrices fortified at the limit of quantitation ( LOQ ) (2 ppb ). Additional recoveries at higher fortification levels validated the method for the highest residues observed in individual matrices. Concurrent recoveries of imidacloprid, 5

- hydroxy imidacloprid, and imidacloprid olefin were measured

with each set of samples to verify method perform ance.

The control anther and leaf samples (approximately 0.5 g and 5 g, respectively) were not homogenized prior to extraction; the entire contents of the container were extracted by first blending the sample with

w ater, followed by blending with acetonitrile . Aliquots of the extracts (equivalent to approximately 0.5 g

contro l leaf) were further purified

.

5F. Q UALITY A SSURANCE R ESULTS

The responses of the LC/MS/MS system to imidacloprid, 5

- hydroxy imidacloprid, and imidacloprid olefin were linear in solvent over the range of 1.0 ppb to 1

, 000 ppb for each analyte. The coefficients of

determination were >0.992.

All control interferences for each analyte in tomato anthers a nd leaves were less than the LOQ (<2 ppb ). All control interferences for were also less than the respective LODs for each analyte in each matrix with the exception of 5

- hydroxy imidacloprid in one of the control leaf sam ples, where an apparent residue

of 0. 5 ppb was observed.

All recoveries were corrected for any interference in corresponding controls. The overall mean values of the recoveries for each matrix were within the acceptable range of 70% to 120%, and the relative

standard deviati on (RSD) values were below 20%.

The LOQ is defined as the lowest fortification level of an analyte at which acceptable recovery has been

achieved. The LOQ for total residue is the highest of the LOQ values assigned to the individu al analytes for a particular matrix.

The LOD is defined as the lowest concentration of an analyte that can be determined to be statistically

different from a blank. The LODs for individual analytes in the anthers and leaves are detailed in the

table below , along with the LODs for total imidacloprid residues (equal to the highest LOD of any of the analytes for each matrix). The LODs were determined from method validation data obtained from control samples fortified at the analyte LO D s. The LODs were calcula ted by multiplying the standard

deviation of recovery measurements at the LOD by t 0.99 [where t 0.99 is the one

- tailed t

- statistic at the 99% confidence level for the number of replicates (n)] 6 . The LODs determined in Bayer CropScience Study

EBNTL056

- 01 7 for cotton leaves were used as the LODs for tomato leaves since these are similar matrices. The LOD for the total imidacloprid residue in each matrix is the highest LOD value of any individual analyte for that particular matrix.MRID 49090503 CDPR IMI Tomato (2011)

8 The LO Q s and LODs are sum marized in T able 3 below.

Table 3

. Summary of LOQs and LODs

Matrix Analyte LOQ (ppb ) LOD (ppb )

Tomato Anthers (Pollen) Imidacloprid 2.0 0. 4

5

- hydroxy Imidacloprid 2 .0 0. 5

Imidacloprid Olefin 2 .0 0. 7 Total Imidacloprid 2 .0 0. 7

Tomato Leaves Imidacloprid 2.0 0. 6

5

- hydroxy Imidacloprid 2.0 0. 9

Imidacloprid Olefin 2.0 0. 6 Total Imidacloprid 2.0 0. 9

Any individual analyte or total residue measure d to be less than the Limit of Quantitation (LOQ ) was reported as < 2 ppb for anthers and leaves. A ny residue value that was below the LOD wa s reported as

less than the LOD and m easure d residue values between the LOQ and LOD are provided in Appendix 4 of the study report

.

6. RESULTS:

Summary results for concentration s of imidacloprid in anthers and leaves are summarized in Table 4 and

t he total imidacloprid residue data for tomato anthers and leaves are provided in Table 5

. The average total imidacloprid residue found in tomato anthers grown in fine

- textured soil was 2 1 pp b (n=8). The average total imidacloprid residue found in tomato anthers grown in medium

- textured soil was 34 pp b (n=10). The average total imidacloprid residue found in tomato leaves grown in fine

- textured soil was
93 pp b (n=8). The average total imid acloprid residue found in tomato leaves grown in medium

- textured

soil was 11 0 pp b (n=10).

The maximum total residues in tomato anthers were measured to be 30 ppb (mean ± SD, 21 ± 5) and 54 ppb (mean ± SD, 34 ± 12) in tomato anthers grown in fine and medium

- textured soil s , respectively

. Concentrations were similar between the two soil types.

Table 4 . Magnitude of total imidacloprid residues in tomato anthers and leaves.

Commodity Soil Texture
Category a Days After

Last

Treatment (DALT) b Total Imid acloprid Residue Levels (ppb) c

N Min Max Highest
Avg.

Site

Residue Median Mean Standard

Deviation

Tomato Anthers Fine 72

- 79 8 14 30 27 22 21 5

Tomato Anthers Medium 79

- 102 10 16 54 46 36 34 12

Tomato Leaves Fine 72

- 79 8 57 140 120 89 93 26

Tomato Leaves Medium 79

- 102 10 38 230 200 100 110 61

a Classification of the soils was obtained from the Soil Survey Geographic (SSURGO) Database provided by the Natural Resources Conservation Service and converted to soil texture categories.

b All trials received one or two applications of Admire Pro. DALT are the days following the last application when two applications were made.MRID 49090503 CDPR IMI Tomato (2011)

9 c Abbreviations used are as follows: Min is the lowest treated residue value; Max is the highest treated residue

v alue; Median is the geometric median of the treated residue values; Mean is the mathematical average of the treated residue values; Standard Deviation is the standard deviation for a small population of “N” samples.

Table 5

. Imidacloprid Residue Data in TomatoesTrial IdentificationLocation (City, State)Plot Name2009 Total Rate, lb a.i./A(oz FP/Acre)a2010 Total Rate, lb a.i./A(oz FP/Acre)aResidue SampleCollection DALTbImidacloprid Residue(ppb)5-Hydroxy ImidaclopridResidue (ppb)Imidacloprid OlefinResidue (ppb)Total ImidaclopridcResidue (ppb)

Anther s Residue (ppb)

NT041 Kings County, C A Armona Loam 0.25 (7.0) 0.25 (7.0) 78 14.3 <2.0 <2.0 17

18.2 <2.0 <2.0 21
Average

19

NT043 Kings County, C A Westcamp

Loam 0.25 (7.0) 0.25 (7.0) 71 16.6 <2.0 <2.0 19

19.7 2.1 <2.0 23
Average

21

NT044 Kings County, C A Houser Clay 0.25 (7.0) 0.25 (7.0) 71 20.9 <2.0 <2.0 24

26.7 <2.0 <2.0 30
Average

27

NT045 Kings County, C A Tulare Clay 0.25 (7.0) 0.25 (7.0) 71 20.9 <2.0 <2.0 24

12.3 <2.0 <2.0 14
Average

19

NT046 Kings County, C A Boggs Sandy

Loam 0.25 (7.0) 0.25 (7.0) 78 13.6 <2.0 <2.0 16

31.5 2.2 <2.0 36
Average

26

NT047 Kings County, C A Lemoore Sandy Loam 0.25 (7.0) 0.25 (7.0) 78 24.9 2.5 <2.0 28

33.0 2.3 <2.0 37
Average

33

NT048 Kern County,

C A Wasco Sandy

Loam 0.18 (5.0) 0.18 (5.0) 100 48.7 3.5 2.0 54

33.9 2.6 <2.0 38
Average

46

NT049 Kern County,

C A Macfarland Sandy Loam 0.18 (5.0) 0.18 (5.0) 92 33.3 2.8 <2.0 38

23.4 <2.0 <2.0 26
Average

32MRID 49090503 CDPR IMI Tomato (2011)

10Trial IdentificationLocation (City, State)Plot Name2009 Total Rate, lb a.i./A(oz FP/Acre)a2010 Total Rate, lb a.i./A(oz FP/Acre)aResidue SampleCollection DALTbImidacloprid Residue(ppb)5-Hydroxy ImidaclopridResidue (ppb)Imidacloprid OlefinResidue (ppb)Total ImidaclopridcResidue (ppb)

NT050 Kern County,

C A Milham Sandy

Loam 0.18 (5.0) 0.18 (5.0) 77 16.3 <2.0 <2.0 19

42.8 4.1 2.1 49
Average

34

Leaves Residue (ppb)

NT041 Kings County, C A Armona Loam 0.25 (7.0) 0.25 (7.0) 78 46.9 2.9 7.2 57

72.5 4.0 8.5 85
Average

71

NT043 Kings County, C A Westcamp

Loam 0.25 (7.0) 0.25 (7.0) 71 84.5 2.5 6.3 93

102 3.1 9.7 110
Average

100

NT044 Kings County, C A Houser Clay 0.25 (7.0) 0.25 (7.0) 71 101 3.6 7.6 110

121 3.5 10.4 140
Average

120

NT045 Kings County, C A Tulare Clay 0.25 (7.0) 0.25 (7.0) 71 71.0 2.0 6.1 79

59.2 2.6 7.7 70
Average

71

NT046 Kings County, C A Boggs Sandy

Loam 0.25 (7.0) 0.25 (7.0) 78 32.8 <2.0 5.1 38

109 2.6 10.3 120
Average

80

NT047 Kings County, C A Lemoore Sandy Loam 0.25 (7.0) 0.25 (7.0) 78 54.0 <2.0 7.1 63

57.3 <2.0 5.4 65
Average

64

NT048 Kern County,

C A Wasco Sandy

Loam 0.18 (5.0) 0.18 (5.0) 100 213 4.9 14.4 230

162 3.9 8.9 170
Average

200

NT049 Kern County,

C A Macfarland Sandy Loam 0.18 (5.0) 0.18 (5.0) 92 105 3.2 10.5 120

104 4.1 6.9 120
Average

120MRID 49090503 CDPR IMI Tomato (2011)

11Trial IdentificationLocation (City, State)Plot Name2009 Total Rate, lb a.i./A(oz FP/Acre)a2010 Total Rate, lb a.i./A(oz FP/Acre)aResidue SampleCollection DALTbImidacloprid Residue(ppb)5-Hydroxy ImidaclopridResidue (ppb)Imidacloprid OlefinResidue (ppb)Total ImidaclopridcResidue (ppb)

NT050 Kern County,

C A Milham Sandy

Loam 0.18 (5.0) 0.18 (5.0) 77 42.6 <2.0 4.2 48

77.0 <2.0 5.8 85
Average

66

a Applications during the 2009 and 2010 growing seasons; a.i. = imidacloprid; formulated product (FP) = Admire

Pro.

b DALT = Days After Last Treatment.

c Total imidacloprid is the sum of imidacloprid, 5

- hydroxy imidacloprid, and imidacloprid olefin.

7. STUDY VALIDITY/ CLASSIFICATION AND STUDY LIMITATIONS

Classification/Utility for Bee Risk Assessment. The study is considered to be SUPPLEMENTAL and

informative but does not represent the worst

- case application scenario due to the low test rates. The

tested rate of 0.18 lb

. a

. i

. /A cre (equivalent to 202 g a

. i

. /ha) is lower than the labeled maximum soil application rate for tomato in the U.S. (0.5 lb

. a

. i

. /A cre ) and Canada (559.9 g a

. i

. /ha). This study will be considered as an additional line of evidence for the estimation of exposure to bees.

Temporal Variability in Residues . The intervals from the last imidacloprid application to sampling ranged from 72 to 102 day s for the nine trials. This study was not designed to measure temporal variability in residues.

Spatial Variability in Residues. All sites were located in Kern or Kings County. The sites in Kern County typically had a higher average maximum temperature th an those located in Kings County; however, total rainfall was similar between all sites. There were no analyses of effects of soil type or location on imidacloprid residues in plant matrices in this study. However, it seems that imidacloprid residues in

bo th anthers and leaves are slightly higher in tomatoes grown in medium soil compared to heavy soil.

Pesticide Carryover. This study was not designed to measure pesticide carryover. All samples were

obtained in 2010, 72 to 102 days after the last applicatio n.

8. CONCLUSION

Studies were conducted to determine the residues of imidacloprid and its metabolites (5

- hydroxy imidacloprid and imidacloprid olefin) in anthers (pollen) and leaves collected from tomato plants grown at locations treated with imidacloprid at least once per year for two years. Nine trials were conducted in

fine

- textured clayey or medium

- textured loamy soils, classified as fine ( “heavy” ) or “medium” respectively, in the study report. All sites were locat ed in California, in either Kings County (four fine

textured soils and two medium

- textured soils) or Kern County (three medium

- textured soils). The sitesMRID 49090503 CDPR IMI Tomato (2011)

12 in Kern County typically had a higher average maximum temperature than those located in Kings
County, however total rainfall was similar between all sites. Each site was irrigated as needed.

Each trial received application(s) of Admire Pro in 2010 at the same rates as in 2009. The six sites located in Kings County received two applications of Admire Pro at 3.5 fl oz product/A cre /application (0.13 lb

.

a

. i

. /A cre /application) for a total seasonal rate of 7.0 fl oz product/A cre (0.25 lb

. a

. i

. /A cre ). The first applications were made at or closely following transplanting with the second applications 52 to 57 days following the first applications. The three sites located in Kern County received a single application of

Admire Pro at 0.18 lb

. a

. i

. /A cre (5.0 fl oz product/A cre ) 2 to 25 days following transplanting.

The average total imidacloprid residue found in tomato anthers grown in fine

- textured soil was 21 pp b (n=8). The average total imidacloprid residue found in tomato anthers grown in medium

- textured soil

was 34 pp b (n=10). The average total imidacloprid residue found in tomato leaves grown in fine

texture d soil was 93 pp b (n=8). The average total imidacloprid residue found in tomato leaves grown in

medium

- textured soil was 11 0 pp b (n=10).

The maximum total residues in tomato anthers were measured to be 30 ppb (mean ± SD, 21 ± 5) and 54 ppb (mean ± SD, 34 ± 12) in tomato anthers grown in fine and medium

- textured soil s , respectively

. Concentrations were similar between the two soil types.

9. REFERENCES

1. Hoelscher, A. 1998. Physical and chemical properties of the active ingredient imidacloprid. Bayer CropScience Report No. MO

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- 006885, M

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2. Talbott, T. D. 1991. Product Chemistry of BAY NTN 33893 Technical. Bayer CropScience Report No.

MRID M004227

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3. Krohn, J. 1993. Vapour Pressure Curve of lmidacloprid. Bayer CropScience Laboratory Project ID
142000804. Report No. M

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4. Brungardt, Jaime 2010. An Analytical Method for the Determination of Residues of lmidacloprid and its Metabolites lmidacloprid Olefin and 5

- Hydroxy Imidacloprid in Bee Relevant Matrices Using LC/MS/MS. Bayer Report No. NT

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5. Schoning, R. 1999. Residue Analytical Method for the Determination of Residues of lmidacloprid, Hydroxy

- lmidacloprid, Olefin

- lmidacloprid, YRC 2894, YRC 2894

- Amide, and 4

- Hydroxy

- YRC 2894

- Amide in Plant Material by HPLC with Electrospray MS/MSDetection. Method No. 0057 3. Report No. MR

853/98.

6. Office of Pesticide Programs, US EPA. 2000. Assigning values to non

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7. Beedle, Ellen C. and A. M. Harbin. 2011. Dete rmination of the Residues of Imidacloprid and its Metabolites 5 Hydroxy Imidacloprid and lmidacloprid Olefin in Bee Relevant Matrices Collected from Cotton, Grown at Locations Treated with Imidacloprid at Least Once Per Year During Two Successive

Years. Ba yer CropScience Report EBNTL056

- 01.