# EPA Data Call

- In Discussion Concerning Exposure and Toxicity of Clothianidin to Bees September 23, 2013

Richard Allen Dan Dyer David Fischer Allen Olmsted Sue Shen

## Addressing EPA’s questions following our presentations in May and submission of protocols in August

- EXPOSURE

• What do Valent/Bayer propose EPA use as exposure values when crop specific data are unavailable?

• What do Valent/Bayer propose EPA use as exposure values when application methods at different use sites differ from the available studies’ application methods?

• What confidence do Valent/Bayer have that proposed crops will be inclusive of the range of clothianidin residues expected from currently registered uses?

• What do Valent/Bayer propose as an approach to ensure that residues in tomato and other fruiting vegetables are protectively represented? 2

## Objective of Tier II exposure studies : Refine the upper bound residue levels in pollen and nectar, with measurements under actual use conditions to support pollinator risk assessments

• Seed treatment

• Soil applications

• Foliar applications to annual crops

• Applications to perennial crops 

# Use Patterns

• Crops that receive pollination services

• Crops that are attractive to bees*

• Major crops

• Major clothianidin uses 

# Relevance

• Pollen and nectar collection

• Extent of crop acreage

• Surrogates for crops of similar morphology, application timings and rates

• Label mitigation as an alternative to data generation 

# Practicality

3 EPA White paper: “Tier II exposure assessments rely upon field measurements of the assessed pesticide in pollen and nectar of crops that are relevant to the use of the pesticide and the exposure of bees ( e.g. , crops that are attractive to bees).”

# Seed Treatments

Use patterns (mg/seed)



### • Corn: 1.25

• Canola: 0.016

• Soybeans: 0.13

• Cotton: 0.42

• Sugar beet: 0.6

• Potato: 12.5 g/100 kg seed

• Vegetables: 0.07

– 1.19 Relevance



### • Major use

• Major use; pollination services for hybrid seed

• Major use

• Attractiveness varies by region

• Not relevant for ag production

• Not attractive

• Minor use/ pollination services used for seed production Practicality



### • Studies ongoing. Highest use rate

• Studies ongoing. Surrogate for brassicae

• Studies ongoing

• Indeterminate flowering

– sampling challenge



### •

•

• Canola as surrogate for brassicae . Label mitigation for seed production possible
4

# Soil Application to annual crops

Use patterns (g/ha)

• Cucurbits @ planting: 224

• Fruiting Vegetables

@ planting: 224

• Leafy Vegetables

@ planting : 224

• Root and tuber vegetables @

planting: 224

• Brassica Vegetables @

planting: 224 

# Relevance

• Pollination services

• Some use pollination services.

Not a source of nectar

• Ag production not relevant for

bees

• Ag production not relevant for

bees

• Ag production not relevant for

bees 

# Practicality

• Sampling challenge except

pumpkins. Study ongoing.

• Sampling challenge

(bumblebees or toothbrush)

• Label mitigation possible for

seed production

• Label mitigation possible for

seed production

• Label mitigation possible for

seed production

5

# Foliar Application to Annual Crops

Use patterns (g/ha)

• Cotton: 2 x 112

• Cucurbits: 2 x 112

• Fruiting Vegetables: 2 x 112

• Leafy Vegetables: 2 x 112

• Root and tuber vegetables: 4 x 56

• Brassica: 2 x 112

• Rice 1 x 84

• Soybean: 2 x 112

• Tobacco: 3 x 75 Relevance

• Attractiveness varies by region.

Major use

• Requires pollination services

• Some use services but no apps

during flowering

• Ag production not relevant for bees

• Ag production not relevant for bees

• Ag production not relevant for bees

• Not relevant for bees

•

• Not relevant for bees Practicality

• Study ongoing

• Study ongoing

• Sampling challenge (bumblebees or

toothbrush)

• Label mitigation possible for seed

production

• Label mitigation possible for seed

production

• Label mitigation possible for seed

production

•

• Label mitigation possible for post

bloom use only

•

6

# Soil & Post Bloom Foliar Application to Perennial Crops

Use patterns (g/ha)

• Tree nuts (post bloom foliar): 2 x 112

• Pome fruits (post bloom foliar): 1 x 224

• Peach (post bloom foliar): 2 x 112

• Cranberry (post bloom, soil): 224

• Grapes (up to harvest): 224 

# Relevance

• Almonds require pollination services

• Pollination services provided in some areas

• Pollination services provided in some area

• Pollinated by bumble bees but post

- bloom use

• Not relevant for bees; use pattern targeted at late season pests 

# Practicality

• Study proposed

• Study proposed

• Study proposed

• Label mitigation in place (post

- bloom only)

•

7

# Cucurbit protocols as surrogate for fruiting vegetables

Parameters Cucurbits Fruiting vegetable

Use Patterns Ongoing protocols: Soil: 1 x 224 g/ha at planting Soil: 1 x 224 g/ha to soil at BBCH 21

- 23 Foliar: 2 x 105 g/ha at BBCH 21

- 23 and 51 (before bloom) Soil: 1 x 224 g/ha at planting

Foliar: 4 x 56 or 3 x 75 g/ha (before bloom) 

### Water demand CA: About 6

- 7 inches between planting and flowering CA: About 6

- 7 inches between planting and flowering 

### Comparison of data for imidacloprid Bee collected nectar 1

– 8 ppb Bee collected pollen < 10

– 32 ppb Hand collected anthers: 14

– 54 ppb

8 

### Anthers vs pollen & nectar Hand collection vs bee collection Different fields and application rates

## Addressing EPA’s questions following our presentations in May and submission of protocols in August

- EFFECTS

• Have Valent/Bayer considered conducting semi

- field tunnel studies and/or feeding studies that develop colony level dose

- response relationships that can be compared to the residue data being generated?

– Aware of proposal from other registrants; Many studies have already been conducted by BCS. Plan to evaluate all existing data (lab and field) to determine if additional studies are needed to further inform the risk assessment.

• How does Valent/Bayer suggest using currently available data as well as additional data to be generated to be protective of non

- Apis bees?

– ‘ A reasonable surrogate’ (SAP Panel response). Further testing should be held in reserve pending development of test methods and risk assessment scenarios for non

- Apis species. 9

# Summary of Program

• Completed and ongoing seed treatment studies allow for an upper bound exposure relevant for all seed treatment uses

• Data for soil treatments and foliar treatments are representative and focused on major crops, relevant for bees. Other crops not relevant because they either:

– do not flower in agricultural production

– not attractive to bees

– applications are made post

- blooms

• We consider the range of use patterns covered by these studies allow definition of an upper

- bound exposure level for a specific crop group (e.g. investigating foliar and soil applications to cucurbits)

10

# Back Up Slides

11

# Accumulation and Bioavailability in Corn / Canola

• 2012

– 20 corn sites (US); 5 canola sites (Canada)

• Corn pollen; canola pollen and nectar

-- hand collected

• Soil cores (0

- 12 inch); composite of 8 cores

• Corn pollen samples limited due to drought

• No accumulation of residues in soil from multiple years of use (see graph)

• Pollen/nectar residues low, and not correlated with years of use (e.g. 1.1 ppb from site with 9 years of use)

12 

### 2013: additional 30 corn and 10 canola sites

– samples collected

# Imidacloprid

– tomato vs melon

• Tomato

– 2 x 0.125 lb a.i./acre; drip chemigation

– App. 1: closely following transplanting; App 2: 52

- 57 days following App. 1

– 0.18 to 0.38 lb ai/A applied in previous year

– Anthers and leaves sampled

• Melon

– 0.23

- 0.38 (typically 0.30) lb a.i./acre; soil application at transplant

– Bee collected pollen and nectar (tented bees); and leaves

13

# Imidacloprid

– tomato vs melon

14 TomatoCommodityPlotTypea Total Im i dacloprid R e sidue Le v e ls (ppm) dnMinMaxHighestAverageSiteResidueMedianMeanStandardDeviation

Tomato

– Anthers Heavy Soil 8 0.014 0.030 0.027 0.022 0.021 0.005

Tomato

– Anthers Medium Soil 10 0.016 0.054 0.046 0.036 0.034 0.012

Tomato

– Leav e s Heavy Soil 8 0.057 0.14 0.12 0.089 0.093 0.026

Tomato

- Leav e s Medium Soil 10 0.038 0.23 0.20 0.10 0.11 0.061

Melon