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

OFFICE OF

CHEMICAL SAFETY AND

POLLUTION PREVENTION



# Environmental Fate and Ecological Risk Assessment for the Proposed New Use of Spinosad

as a Commercial Seed Treatment

To control: seedcorn maggot and onion maggot in bulb vegetables, dried shelled pea and bean, cucurbit veg etables, and leaves of legume vegetables,

Date: 09/13/2010

United States Environmental Protection Agency Office of Pesticide Programs

Environmental Fate and Effects Division

Environmental Risk Branch V 1200 Pennsylvania Ave., NW

Mail Code 7507P Washington, DC 20460 Prepared by: Joseph DeCant, Ecologist/Team Leader Larry Liu, Chemist

Secondary Revision by: Mah

Shamim

Approved by:
Mah T. Shamim, Chief

Environmental Risk Branch V2 

## Table of Contents

1. Executive Summary

................................ ................................ ................................ ................ 4

1.1 Nature of Chemical Stressor

................................ ................................ ........................... 4

1.2 Potential Risk to Non

- Target Organisms

................................ ................................ ........ 4

1.3 Exposure Characterization

................................ ................................ .............................. 5

1.4 Effects Characterization

................................ ................................ ................................ .. 5

1.5 Da ta Gaps and Uncertainties

................................ ................................ ........................... 6

2 Problem Formulation

................................ ................................ ................................ .............. 7

2.1 Nature of Regulatory Action

................................ ................................ ........................... 7

2.2 Stressor Source and Distribution

................................ ................................ .................... 7

2.2.1 Nature of the Chemical Stressor

................................ ................................ ............. 7

2.2.2 Overview of Spino sad Usage

................................ ................................ ................ 10

2.3 Receptors

................................ ................................ ................................ ....................... 11

2.3.1 Aquatic and Terrestrial Receptors and Effects

................................ ..................... 11

2.3.2 Ecosystems Potentially at Risk

................................ ................................ ............. 12

2.4 Assessment Endpoints

................................ ................................ ................................ .. 12

2.5 Conceptual Model

................................ ................................ ................................ ......... 13

2.5.1 Risk Hypothesis

................................ ................................ ................................ .... 13

2.5.2 Conceptual Diagram

................................ ................................ ............................. 14

2.6 Analysis Plan

................................ ................................ ................................ ................ 15

2.6.1 Methods of Conducting Ecological Risk Assessment and Identification of Data Gaps 15

2.6.2 Measures of Effect and Exposure

................................ ................................ ......... 19

3 Exposure Assessment

................................ ................................ ................................ ............ 19

3.1 Aquatic Exposure Estimates

................................ ................................ ......................... 22

3.2 Terrestrial Exposure Estimates

................................ ................................ ..................... 23

4 Ecological Effects Assessment

................................ ................................ ............................. 24

4.1 Aquatic Effects Summary

................................ ................................ ............................. 24

4.2 Terrestrial Effects Summary

................................ ................................ ......................... 24

4.2.1 Toxicity Effects on Terrestrial animals

................................ ................................ . 24

4.2.2 Toxic ity Effects on Invertebrates

................................ ................................ .......... 25

4.3 Incident Database Review

................................ ................................ ............................. 26

5 Risk Characterization

................................ ................................ ................................ ............ 26

5.1 Risk Estimation

................................ ................................ ................................ ............. 27

5.1.1 Summary of Aquatic Risk Quotients

................................ ................................ .... 27

5.1.2 Summary of Terrestrial Risk Q uotients

................................ ................................ 27

5.2 Risk Description

................................ ................................ ................................ ............ 29

5.2.1 Risk to Aquatic Organisms

................................ ................................ ................... 29

5.2.2 Risk to Terrestrial Organisms

................................ ................................ ............... 29

5.3 Endangered Species Assessment

................................ ................................ .................. 31

5.3.1 Probit Slope Analysis

................................ ................................ ............................ 31

5.3.2 Direct and Indirect Effects

................................ ................................ .................... 32

5.4 Endocrine Disruption

................................ ................................ ................................ .... 32

5.5 Uncertain ties

................................ ................................ ................................ ................. 333 5.5.1 Exposure and Effects Assessment

................................ ................................ ........ 33

6 Bibliography

................................ ................................ ................................ ......................... 34



## List of Tables

Table 1. Summary of physicochemical properties of spinosad

. ................................ .................... 7 Table 2. Use information for the proposed use of spinosad on seeds as an insecticide.

............... 10 Table 3. Test Species Evaluated for Assessing Potential Ecological Effects of Spinosad.

......... 11 Table 4. Environmental Fate Data Requirements for Spinosad.

................................ .................. 15 Table 5. Ecological Effects Data Requirements for Spinosad.

................................ .................... 17 Table 6. Measures of Effect and Exposure for spinosad.

................................ ............................ 19

Table 7. EECs for the proposed use of spinosad as a seed treatment.

................................ .......... 22

Table 8. Toxic Effects in Terrestrial Animals D ue to Acute and Chronic Exposure to Spinosad.

................................ ................................ ................................ ................................ ....................... 25

Table 9. Toxic Effects in Terrestrial Invertebrates.

................................ ................................ ...... 25 Table 10. Toxic Effects in Terrestrial Invertebrates in the Rhizosphere Due to Acute Expos ure to Spinosad.

................................ ................................ ................................ ................................ ....... 26 Table 11. Ecological Incident Results as Listed by EIIS.

................................ ............................ 26 Table 12. Summary of Terrestrial Acute and Chronic Risk Quotients. Values in bold represent

an exceedence of the respective LOC.

................................ ................................ .......................... 28 Table 13. Listed Species Risks Associated with the Proposed New Uses of Spinosad.

.............. 32



## List of Figures

Figure 1. Conceptual Diagram Depicting Potential Risks to Terrestrial and Aquatic Animals from the Use of Spinosad as a Seed

- Treatment Insecticide.

................................ ......................... 14



## List of Appendices

Appendix A. TREX Methodology to Calculated Nagy Doses (EECs) and Risk Quotients for

Birds and Mammals

................................ ................................ ................................ ...................... 36 Appendix B. The Risk Quotient Method and Levels of Concern

................................ ................. 37 Appendix C. Ecological Effects Data

................................ ................................ ........................... 38 Appendix D: Modeling Results for Aquatic Exposure

................................ ................................ . 44 Appendix E. LOCATES Database Run for Endangered Species

. Error! Bookmark not defined.4 

## 1. Executive Summary

The Environmental Fate and Effects Division (EFED) has completed its ecological risk assessment in support of the proposed new use s of Entru st ® Naturalyte® (Spinosad as the active ingredient) to be used as a seed treatment to control seedcorn maggot and onion maggot in bulb vegetables, dried shelled pea and bean, cantaloupe, cucurbit vegetables (excluding cantaloupe, pumpkin, watermelon, winte r squash), leaves of legume vegetables, pumpkin, winter squash, and

watermelon

.



### 1.1 Nature of Chemical Stressor

Spinosad is a mixture of spinosad Factor A and Factor D. Factor A and D are very similar in chemical structure as well as in fate properties. The difference between A and D is that Factor D contains an extra methyl group at carbon 4 on the central ring. Although the ratio between Factors A and D in spinosad could vary (50

- 95% vs. 50

- 5%, respectively), Factor A is the major component in spinosad. Since Factors A and D are very similar in nature and the registrant had submitted more information on Factor A than Factor D, EFED selected Factor A to represent spinosad in the ecological risk assessment.



### 1.2 Potential Risk to Non

- Target Organisms

The resu lts of this screening

- level risk assessment suggest that the proposed use of spinosad can pose acute and chronic risk to non

- endangered, endangered, and threatened species of terrestrial organisms including birds and mammals , as well as to freshwater free

- swimming and benthic sediment organisms

.

Risk to other aquatic animals, as well as terrestrial and aquati c plants, is based on previous risk

assessment s for mint and green onion as well as turf. The aquatic EEC’s in the current

assessment were similar to or lower than the previous assessment for turf (DP279684+), but higher than those for mint and green onion (DP310860 + ). In both assessments, chronic ris k was

found for freshwater free

- swimming and benthic sediment dwelling invertebrates, but no risk

w as found for aquatic plants

. Therefore, the proposed spinosad seed treatment would also pose risk to these freshwater animals and not to aquatic plants. No risk is present for terrestrial plants due to the low toxicity of spinosad to these organisms.

A cute risk was found in this assessment for small birds and mammals. However, there is uncertainty regarding th e acute risk to birds due to the lack of definitive endpoints with avian species . For some crop uses, the lack of definitive endpoints means tha t the presumed risk is

low. However, for bulb vegetables (crop group 3), foliage of legume vegetables (excluding soybean) (subgroup 7A)

, cantaloupe, cucurbit vegetables (crop group 9), pumpkin, winter squash, and watermelon , the EECs are greater than the highest dose tested in the acute toxicity studies for avian wildlife. The hazard of the chemical has not been evaluated at exposure levels above the highest dose tested in the acute toxicity stud y

. While risk may be considered low for

those uses that res ult in EECs less than the highest dose tested in the toxicity studies, risk cannot be precluded for these other uses. Therefore, acute risk to listed and non

- listed birds cannot be precluded for bulb vegetables (crop group 3), foliage of legume vegetables (excluding soybean) (subgroup 7A)

, cantaloupe, cucurbit vegetables (crop group 9), pumpkin, winter squash, and

watermelon. Acute risk to non

- listed mammals was found for bulb vegetables (crop group 3)

,5 cantaloupe

, and cucurbit vegetables (crop group 9; e xcluding pumpkin, watermelon, winter squash), while acute risk to listed mammals was found for all uses except dried bean and shelled

pea. All of the proposed uses pose a chronic risk to both birds and mammals, for which definitive endpoints are available

.

The analysis shows that the proposed a.i./acre could be applied to a field at the maximum application rate per acre to pose a risk to e ndangered and threatened birds , so slightly lower application rates per acre would reduce the risk to these species. The application rate per seed, however, drives most of these risk conclusions and suggests that alternative rates could be explored to reduce the level of risk to birds and mammals on a n acute and chronic basis.



### 1.3 Exposure Characterization

Spinosad is prop osed for a variety of crops as a seed treatment

. Spinosad Factors A and D convert into transformation products that are very similar to the parent. in aerobic laboratory soil with

half

- lives of approximately 9

- 17 days. Under photoly tic conditions, the parent readily forms transformation products in water with a half life of <1 day (pH 7) and on soil with a half life of about 10 days. The fate of the transformation products could not be determined due to termination of the study in 4 8 hours. Spinosad Factor 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. Although no mobility data are available for Spinosad Factor D, it is 180x less soluble than F actor A and therefore would be expected to be less likely to leach in the soil. In terrestrial field dissipation studies with Spinosad Factor A on bareground plots, the half

- life was <1 day, no leaching was observed, and 3.1% of the applied was recovered in runoff. The study did not follow the formation and decline of the transformation products and the half life may reflect the conversion of parent to transformation products or distribution of the parent and its residues in

different environments.

Spin osad has a high affinity for sediment and moves rapidly from the water to the sediment phases where it is highly persistent. In anaerobic aquatic metabolism studies, spinosad had a

half

- life of 161

- 250 days. In an aquatic microcosm dissipation outdoor st udy, spinosad residues in the sediment peaked at 8 days and had an observed half

- life of >>25 days. Spinosad has a relatively low bio

- concentration factor (BCF’s of the parent 7.5X, 28.8X, and 21.1X 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 bio

- concentration of the material in

the food web.



### 1.4 Effects Characterization

Spinosad did not produce a definitive LC 50 or LD 50 in avian ac ute oral or dietary studies , with little mortality in the Bobwhite quail acute oral study and no mortality in the Mallard duck acute oral study

. However, avian chronic effects included reductions in reproductive parameters (eggs laid, live 3

- week embryos, normal hatchlings, 14 day

- old survivors). The mammalian acute

LD 50 is 3738 mg/kg. Effects in chronic mammalian studies included reduced litter size, offspring body weights and survival of F2 generation. Developmental studies with rats and

rabbits showe d no evidence of toxicity. There was also no toxicity to earthworms in soil. Acute contact toxicity tests showed that spinosad is highly toxic toward honey bees when exposed to the TGAI. Tier I studies were submitted for seedling emergence and vegetative vigor testing.6 The TGAI or formulated product caused no phytotoxic effects to terrestrial plants greater than 25%, thus no further plant testing is required.

Spinosad is slightly toxic to rainbow trout and moderately toxic to blue gill sunfish on an acute basis. Data were submitted for the freshwater fish early life

- stage test using rainbow trout

. Significant reductions occ urred in mean hatch, survival, and length and weight. Spinosad is categorized as moderately toxic to estuar ine fish on an acute basis. Spinosad reduced growth in estuarine fish early life

- stage testing. Spinosad is slightly toxic to freshwater invertebrates on an acute basis. Spinosad Factor B (the major transformation product of Factor A), is moderately

toxic to daphnids on an acute basis. Data were submitted for a chronic test with Daphnia magna

. Spinosad reduced daphnid growth and reproduction. Spinosad is categorized as highly toxic to mollusks on an acute basis. Spinosad reduced the number of young per f emale after 28 days of exposure in estuarine invertebrate life

- cycle testing. Spinosad reduced adult emergence in sediment testing to chironomid larvae. The freshwater diatom is the most sensitive nonvascular aquatic species and the duckweed the most sen sitive vascular species in aquatic plant tests.



### 1.5 Data Gaps and Uncertainties

850.1735: Whole Sediment Acute Toxicity Invertebrates, Freshwater . This test measures survival, growth and emergence of Chironomus riparius that have been exposed to pesticide

s piked sediment. EFED is not requesting this study at this time. Rather, EFED places this study

in reserve.

850.1740: Whole Sediment Acute Toxicity Invertebrates, Estuarine and Marine

- Testing with estuarine/marine invertebrates using the TGAI is requi red for spinosad because it is toxic to aquatic invertebrates, persistent in the environment, binds to sediment over time and the end

- use product is expected to reach the marine/estuarine environment because of it use in coastal counties. A study to fulfi ll this guideline has recently been submitted but was found to be supplemental because it did not establish a definitive LC 50

. Data on a definitive endpoint to estuarine and marine invertebrates in sediment therefore remains and uncertainty.

850.2100: Ac ute Toxicity for Birds

- For bulb vegetables (crop group 3), foliage of legume vegetables (excluding soybean) (subgroup 7A)

, cantaloupe, cucurbit vegetables (crop group 9), pumpkin, winter squash, and watermelon , the EECs are greater than the highest dose tested in the acute toxicity studies for avian wildlife. The hazard of the chemical has not been evaluated at exposure levels above the highest dose tested in the acute toxicity studies, which represents an uncertainty.

835.4200: Anaerobic Soil Metabolis m

- According to 40CFR Part 158 issued on 10/26/07, the registrant should submi t an anaerobic soil metabolism (835.4200) study to support the terrestrial

use.

Environmental C hemistry M ethod (ECM) and Independent L aboratory V alidation (ILV)

- According t o 40CFR Part 158 issued on 10/26/07, the registrant should submit these studies to support terrestrial and aquatic filed dissipation studies.7 

## 2 Problem Formulation

The purpose of this problem formulation is to provide the foundation for the environmental fa te
and ecological effects risk assessment being conducted for the seed treatment insecticide spinosad

. Additionally, this problem formulation is intended to identify data gaps, uncertainties, and potential assumptions to address those uncertainties relati ve to characterizing the risk associated with the registered uses of spinosad , which is a synthetic pyrethroid with current uses

as a foliar application

.



### 2.1 Nature of Regulatory Action

Under the authority of the Federal Insecticide, Fungicide, and Rodentici de Act (FIFRA), Dow AgroSciences is seeking registration for the new uses of Spinosad as a seed

- treatment insecticide in bulb vegetables, dried shelled pea and bean, cantaloupe, cucurbit vegetables (excluding cantaloupe, pumpkin, watermelon, winter squash ), leaves of legume vegetables, pumpkin, winter squash, and watermelon.



### 2.2 Stressor Source and Distribution

2.2.1 Nature of the Chemical Stressor

Spinosad belongs to the class of microbial insecticides. It is a secondary metabolite from the

aerobic fermentation of S. spinosa on nutrient media. Spinosad is a mixture of two active naturally occurring metabolites (Spinosad Factors A and D) produced by the actinomycetes Saccharopolyspora spinosa . The IUPAC chemical name of Spinosad Factor A is:
(2R,3aS,5aR,5bS,9S, 13S,14R,16aS,16bR)

- 2

- (6

- deoxy

- 2,3,4

- tri

- O

- methyl

- **∝**

- L

mannopyranosyloxy)

- 13

- (4

- dimethylamino

- 2,3,4,6

- te tradeoxy

- β

- D

- erythropyranosyloxy)

- 9

- ethyl

- 2,3,3a,5a,6,7,9,10,11,12,13,14,15,16a,16b

- hexadecahydro

- 14

- methyl

- 1H

- 8

- oxacyclododeca[b]as

- indacene

- 7,15

- dione. The IUPAC chemical name of Spinosad Factor D is:
(2R,3aS,5aR,5bS,9S,13S,14R,16aS,16bR)

- 2

- (6

- deoxy

- 2,3 ,4

- tri

- O

- methyl

- **∝**

- L

mannopyranosyloxy)

- 13

- (4

- dimethylamino

- 2,3,4,6

- tetradeoxy

- β

- D

- erythropyranosyloxy)

- 9

- ethyl

- 2,3,3a,5a,6,7,9,10,11,12,13,14,15,16a,16b

- hexadecahydro

- 4,14

- dimethyl

- 1H

- 8

- oxacyclododeca[b]as

- indacene

- 7,15

- dione. Trade names include Tracer, Naturalyte, and SpinTor.

Table 1 . Summary of physicochemical properties of spinosad

. Spinosad A Spinosad D

CAS Registry Number 131929

- 60

- 7 131929

- 63

- 0

Emperical Formula C 41 H 65 NO 10 C 42 H 67 NO 10

Molecular Weight 731.976 745.988

Odor Slightly stale water or earthy

Relative Density (20 **°** C) 0.5128 Melting Point 84

- 99.5 **°** C 161.5

- 170 **°** C

Vapor Pressure (25 **°** C) 2.4E

- 10 mmHg

3E

- 11 kPa 1.6E

- 10 mm Hg

2E

- 11 kPa

Octanol/Water Partition Coefficient (log K

ow ) pH 5 pH 7 pH 9

Distilled water 2.78

4.01

5.16

3.91 3.23

4.53

5.21

4.38

Dissociaton Constant (pK

a ) (20 **°** C) 8.10 7.87

Water Solubility (20 **°** C) 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

So lvent Solubility

Acetone

Acetonitrile

Dichloromethane

Methanol

Toluene 168.0 g/L 134.0 g/L 525.0 g/L 190.0 g/L 457 g/L 10.1 g/L 2.6 g/L 448.0 g/L 2.5 g/L 152 g/L

Spinosad is a mixture of spinosad Factor A and Factor D. The difference between A and D is that Factor D contains an extra methyl group at carbon 4 on the central ring. Although the ratio between spinosad A and D in spinosad varies (50

- 95% vs. 50

- 5%, respectively), the major component in spinosad is spinosad Factor A. Since spinosad Factor A and Factor D have very similar fate properties and the registrant had submitted more information on spinosad Factor A than spinosad Factor D, EFED selected spinosad Factor A to represent spinosad in the eco risk

assessment.

The primary mode of action of spinosad is the excitation of the neurons in the central nervous system (Salgado, 1998). Spinosad causes involuntary muscle contractions and tremors by widespread excitation of motor neurons. The prolonged hyperexcitation causes neuromuscular fatigue , resulting in paralysis. Within minutes of field application, insects are paralyzed and feeding ceases. Spinosad has limited translaminar movement in leaf tissue; however, the addition of a penetrating surfactant increases translaminar movement and activ ity on pests that forage leaves.

Aqueous photolysis (MRID 43507302) At the end of the study (i.e., two days), approximately 75% of the applied dose was identified as the parent compound and tr ansformation products 1, 2

, and 3. Although the decline of th e parent compound was established, the formation and decline of these three transformation9 products were not established because the study was terminated in two days. According to the report, transformation product 1 is the beta isomer of the 13,14

- dihydr o of the pseudoaglycone of the parent compound. Transformation product 2 is a rearrangement of the parent compound whereas transformation product 3 appears to be the parent compound with a water molecule

added. The material balance at the end of the stud y was nearly 100% and a volatile trap was not used, EFED estimated nearly 25% of the material in the test system was not characterized at the end of the study. Therefore, the half

- life for the total residues could not be calculated with

confidence.

Aero bic soil metabolism (MRID 43507305) The extractability of spinosad residues in soil by the acetone/methanol system used in the study became less during the duration of the study, with non

- extractable residues increasing to 43% after one year. At the end o f the study, only 27% of the applied was tentatively identified or characterized as the parent compound as well as eight transformation products. Although these transformation products were not fully characterized or identified, the report suggested that they are likely to be of a similar nature to the parent compound. Due to the concerns on the effectiveness of the solvent system used, EFED was unable to estimate the half

- life of the total residues based on their detections. However, based on the recove ry of the volatile radioactivity,

EFED estimated that the half

- live for the residues in the soil could range 2

- 3 years.

Anaerobic aquatic metabolism (MRID 43507304) Although the extractability of spinosad residues in soil by the acetone/methanol system u sed in the study became less during the duration of the study, the level of decrease is not as significant as that in the aerobic soil metabolism study mentioned above. The non

- extractable residues in the sediment increased to 17% after one year in the an aerobic aquatic metabolism study as compared to 43% at the same time in the aerobic soil metabolism study. No explanation was provided in the reports regarding the differences in the extractability between the aerobic soil and the anaerobic aquatic metabo lism studies. Four transformation products were tentatively identified or characterized whereas two were not identified in the anaerobic aquatic metabolism study. Since the report only provided information on the maximum concentrations found for

these t ransformation products during the duration of the study and no detailed information on their detections at each sampling was provided, EFED was unable to calculate the half

- life for the total residues. However, based on the residues recovered in the aqueo us phase and the extracts in the sediment, EFED believes that the half

- life for the total residues could be greater than three years.

Properties of Spinosad (Factor A and Factor D)

Below are the general fate properties of the parent compound only (spinos ad Factor A and spinosad Factor D). This part was described in the eco risk assessment completed in 2002. Spinosad Factors A and D convert into transformation products that are very similar to the parent in aerobic laboratory soil wi th half

- lives of approximately 9

- 17 days. Under photolytic conditions, the parent readily forms transformation products in water with a half life of <1 day (pH 7) and on soil with a half life of about 10 days. The fate of the transformation products

coul d not be determined due to termination of the study in 48 hours. Spinosad Factor 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. Although no mobility data are availab le for Spinosad Factor D, it10 is 180 times less soluble than Factor A and therefore would be expected to be less likely to leach in the soil. In terrestrial field dissipation studies with Spinosad Factor A on bareground plots, the

half

- life was <1 day, no leaching was observed, and 3.1% of the applied was recovered in runoff. The study did not follow the formation and decline of the transformation products and the half life may reflect the conversion of parent to transformation products or distribution of the parent

and its residues in different environments.

Spinosad has a high affinity for sediment and moves rapidly from the water to the sediment phases where it 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 >>25 days. Spinosad has a relatively low bio

- concentration factor (BCF’s of the parent 7.5X, 28.8X, and 21 .1X 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 bio

- concentration of the material in

the food web.



### 2.2.2 Overview of Spinosad Usage

This assessment is intended to address the proposed new use of spinosad as a seed treatment for various crops. Entrust is a Naturalyte insect product for control of seedcorn maggot and onion maggot. This product may be applied as a seed treatment at a r ate of 0.1

- 0.75 mg ai/seed or 0.0 2

- 8.82 lb ai/100 lb seed. The proposed new registration includes use on a number of different

crops.

The registrant is seeking a FIFRA Section 3 for the use of spinosad as a seed treatment. It serves

as an insecticide i n seed coating to protect the germinating seeds and seedlings. The crop, target pests, and relevant application information are summ arized in Table 2

.

Table 2 . Use information for the proposed use of spinosad on seeds as an inse cticide.

Crop (Seeds) Pests Entrust (mg ai/seed) Entrust (lb ai/100 lb seed) Maximum

Seasonal Application

Rate (lb ai/acre) 5

bulb vegetables (crop group

3) 1 onion maggot

seedcorn

maggot 0.2 6.82

– 8.82 0.45

dried shelled pea and bean

(except so ybean) (subgroup 6C) 2 (excluding cowpea, lentils) 0.1

– 0.5 0.03

– 0.2 0.19

cantaloupe 0.5

– 0.75 2.31

– 3.47 0.45 cucurbit vegetables (crop

group 9) 3 (excluding cantaloupe, pumpkin, watermelon, winter squash) 0.70

– 3.77

foliage of legume vegetabl es 0.17

– 0.4111 (excluding soybean) (subgroup 7A) 4

pumpkin 0.83

– 1.24 Winter squash 0.55

– 0.83

watermelon 1.10

– 1.65

1 Bulb vegetables (crop group 3) including dry bulb onion, garlic, great

- headed (elephant) garlic, green onion, leek,

sha llot, welch onion

2 Dried shelled pea and bean (except soybean) (subgroup 6C) including dried cultivars of bean Lupinus spp. (includes

grain lupin, sweet lupin, white lupin, white sweet lupin), Phaseolus spp. (includes field bean, kidney bean, lima bean (dr y), navy bean, pinto bean, tepary bean), bean Vigna spp. (includes adzuki bean, blackeyed pea, catjang, cowpea, crowder pea, moth bean, mung bean, rice bean, southern pea, urd bean), broad bean (dry), chickpea, guar, lablab bean, lentil, pea Pisum spp. (in cludes field pea), pigeon pea

3 Cucurbit vegetables (crop group 9) including cucumber, edible gourds, muskmelons (cantaloupe, honeydew, etc.),

pumpkin, summer squash, watermelon, winter squash

4 Foliage of legume vegetables (subgroup 7A) including any cultiv ar of bean and field pea (except soybean)

5 The maximum seasonal application rate is the total of all methods of application

– soil, foliar, and seed treatment.



### 2.3 Receptors

2.3.1 Aquatic and Terrestrial Receptors and Effects

The receptor is a biological entity tha t is exposed to the stressor (US Environmental Protection Agency, 1998). As described in the risk assessment Overview Document (US EPA, 2004), this risk assessment uses a surrogate species approach in its evaluation of spinosad . Toxicological data genera ted from surrogate test species, which are intended to be representative of broad taxonomic groups, are used to extrapolate the potential effects on a variety of species (receptors) included under these taxonomic groupings. For example, the mallard duck a nd bobwhite quail are the preferred species in avian toxicity tests (acute and chronic) to represent toxicity for the

entire class of bird species.

Acute and chronic toxicity data from studies submitted by the registrant along with the available

open lit erature are used to evaluate potential direct effects of pesticides to aquatic and terrestrial receptors. These data include toxicity studies on the technical grade active ingredien t (TGAI). The open literature are indentified through EPA’s ECOTOX databa se ( http://cfpub.epa.gov/ecotox/ ), which employ s a literature search engine for locating chemical toxicity data for aquatic and terrestrial floral and fauna. The evaluation of both sources of data provides ins ight into the direct and indirect effects of pesticides on biotic communities from the loss of species that are sensitive to the spinosad , and changes in structural and functional

characteristics of the affected communities. A search of the ECOTOX database did not yield any relevant studies additional to those submitted by the registrant that would support this action

.

Table 3 provides examples of taxonomic groups and the surrogate species tested to help understand potential ecological effects of spinos ad on these non

- target taxonomic groups.

Table 3 . Test Species Evaluated for Assessing Potential Ecological Effects of Spinosad

.

Taxonomic Group Example(s) of Surrogate Species Acute Toxicity Classification

Birds 1 Mallard duck ( Anas platyrhynchos ) Practically non

- toxic on a dietary basis to slightly toxic on a dose basis12 Taxonomic Group Example(s) of Surrogate Species Acute Toxicity Classification

Bobwhite quail ( Colinus virginianus )

Mammals Rat ( Rattus norvegicus ) Practically non

- toxic

Freshwater Fish 2 Bluegill sunfish ( Lepomis macrochirus)

Rainbow tro ut ( Oncorhynchus mykiss )

Fathead minnow ( Pimephales promelas ) Moderately toxic

Freshwater

Invertebrate Water flea ( Daphnia magna ) Slightly to moderately t oxic

Estuarine/marine fish Sheepshead minnow ( Cyprinodon variegates ) Moderately toxic

Estuarine/mar ine

invertebrates Mysid shrimp ( Mysidopsis

bahia ) Moderately toxic

Estuarine/marine

mollusks Eastern oyster ( Crassotrea virginica ) Very highly toxic

Terrestrial

invertebrates Honey bees ( Apis mellifera ) Highly toxic

1 Birds represent surrogates for terre strial

- phase amphibians and reptiles

2 Freshwater fish serve as surrogates for aquatic

- phase amphibians



### 2.3.2 Ecosystems Potentially at Risk

The ecosystems at risk from a stressor are often exclu sive in scope, and as a result it may not be possible to indentify s pecific ecosystems at the baseline level. However, in general terms, terrestrial ecosystems potentially at risk could include the treated field and areas immediately adjacent to the treated field that may receive drift or runoff. Areas adjacent to the tr eated field could include other cultivated fields, fencerows, hedgerows, meadows, fallow fields or grasslands, woodlands, riparian habitats, and other uncultivated areas.

Aquatic ecosystems potentially at risk from a stressor include water bodies adjace nt to, or down stream from the treated field and might include impounded bodies such as ponds, lakes, and reservoirs, or flowing waterways su ch as streams or rivers. For uses in coastal areas, aquatic habitat also includes marine ecosystems, including est uaries.

For spinosad , the terrestrial ecosystem primarily at risk is the rhizosphere zone in which treated seeds are planted o n the crop field or due to the seed left (accidental spillage or otherwise) on soil surface at the time of planting. Seed

- boun d spinosad may pose risk to aquatic ecosystems through leaching, runoff, o r erosion from the crop field. It is noted that for soil incorporated chemicals, or seed treatments, drift is usually a minor component.



### 2.4 Assessment Endpoints

Assessment endpoints re present the actual environmental value that is to be protected, defined by an ecological entity (species, community, or other entity) and its attribute or characteristics (US13 Environmental Protection Agency 1998 and 2005). For spinosad , the ecological ent ities include the following: birds, mammals, terrestrial plants, insects, freshwater fish and invertebrates, estuarine/marine fish and invertebrates, aquatic plants, and algae. The assessment endpoints for each of these entities include survival, growth, and/or reproduction. This assessment will use the most sensitive toxicity measures of effect from surrogate test species to estimate treatment

related direct effects on acute mortality and chronic reproductive, growth, and survival assessment endpoints.



### 2.5 Conceptual Model

For a pesticide to pose an ecological risk, it must reach ecological receptors in biologically significant concentrations. An exposure pathway is the means by which a pesticide moves in the environment from a source to an ecological rece ptor. For an ecological pathway to be complete, it must have a source, a release mechanism, an environmental transport medium, a point of exposure for ecological receptors, and a feasible route of exposure.

A conceptual model is intended to provide a w ritten description and visual representation of the predicted relationships between the stressor, potential routes of exposure, and the predicted effects for the assessment endpoint. A conceptual model consists of two major components: the risk hypothesis and the conceptual diagram (US Environmental Protection Agency 1998 and 2005).



### 2.5.1 Risk Hypothesis

Risk hypotheses are specific assumptions about potential adverse effects and may be based on theory and logic, empirical data, and mathematical models. For t his assessment, the risk is

stressor initiated where the stressor is the release of spinosad into the environment. The following risk hypothesis is presumed for this screening

- level assessment:

The proposed new use of spinosad on bulb vegetables

, dried s helled pea and bean, cantaloupe, cucurbit vegetables (excluding cantaloupe, pumpkin, watermelon, winter squash), leaves of legume vegetables, pumpkin, winter squash, and watermelon will likely involve situations where terrestrial and aquatic animals will be exposed to the chemical

and or its transformation products. Based on information on environmental fate, mode of action, direct toxicity, and potential indirect effects, EFED assumes that spi n osad may have the potential to cause reduced survival, growth , and reproduction to terrestrial and aquatic animal s as a result of the proposed uses of the pesticide.

The seedling emergence and vegetative vigor of non

- target terrestrial plants and growth with biomass accumulation of aquatic plants ad jacent to the site of spinosad application could be affected. The potential, however, is low as spinosad is not an herbicide and showed low toxicity to terrestrial plants

. The previous assessment on turf with a higher application rate (DP 279684+ )

also showed no risk c oncerns to aquatic and terrestrial plants

. Furthermore , this new use

addresses spinosad as a seed treatment, and therefore the risk to non

- target plants is further mitigated through a decrease in exposure ( i.e. reduction in drift and run

- off)

. Risk to no n

- target plants is therefore not evaluated in this assessment, which relies instead on the results of the previous assessment on turf (DP 279684+ ).14 

### 2.5.2 Conceptual Diagram

The potential exposure pa thways and effects of spinosad on terrestrial and aquatic envir onments are depicted in Figure 1 . Solid arrows represent the most likely routes of exposure and effects for spinosad

.

Figure 1 . Conceptual Diagram Depicting Potential Risks to Terrestrial and Aqua tic Animals from the Use of Spinosad as a Seed

- Treatment Insecticide

.

Since spinosad is a seed treatment insecticide, ingestion of treated seed placed in soil and seed dropped on soil surface at the time of planting is the primary pathway through which e xposure may occur for terrestrial wildlife (birds, mammals, and invertebrates). Other exposure routes such as dermal contact with treated seed and soil, inhalation of pesticide vapors, and ingestion of contaminated soil and drinking water are not evaluate d in this assessment. Potential pathways of exposure to aquatic animals include dermal contact, uptake though gills, and/or dermal uptake through integument due to the offsite movement of spinosad to near by water bodies. In view of

the high tendency for spinosad to persist and accumulate in aquatic sediments, potential does exist for prolonged exposures to both aquatic and terrestrial organisms.

Stressor

Source/ Transport Pathway

Source/ Exposure

Media

Exposure

Method

Receptors

Direct

Effects:

Non

Endangered Species

Indirect

Effects Food Web Dynamics Perturbed Forage or Prey Availability Habitat Alteration: impacts on nesting ability, ability to seek cover, etc. Individual Terrestrial

Animals

Reduced Survival

Reduced Growth Reduced Reproduction Individual Terrestrial

Plants Seedling Emergence

Vegetative Vigor Individual Aquatic

Vertebrates and

Inv ertebrates

Reduced Survival

Reduced Growth Reduced Reproduction Aquatic Plant Population

Reduced

Growth Rates

and Biomass Terrestrial Animals (Birds, Mammals, Reptiles, Terrestrial

phase Amphibians, Bees) Terrestrial Upland Plants Wetland/ Riparian

Plants Runoff and Erosion

Upland Foliage/

Soil Riparian/

Wetland Foliage/Soil Surface
Water,

Sediment

Direct Contact/

Root Uptake Gill/ Integument Uptake Direct Contact/

Root Uptake Ground

water

Direct Ingestion

Aquatic Invertebrates Aquatic Vertebrates

Aquatic Plants Leaching (Infiltration/

Percolati on)

Terrestrial Food

Residues ( foliage, fruit, insects)/Soil

Dietary uptake See d Treated with Spinosad and Planted in Soil or Left on Soil Surface15 This assessment to terrestrial animals considers environmental exposure resulting from treated seed only and i s not based on root uptake of spinosad by plants. Data on the movement and accumulation of spinosad in plants is not available. Even if spinosad translocates and accumulates in plants, its concentrations will be lower than those available on the seed.

F urthermore, spinosad is not classified as an herbicide so its toxic effects to plants are likely minimal. Therefore, the most conservative exposure estimate will result from ingestion of the treated seed rather than movement to foliage and within the plan t.



### 2.6 Analysis Plan

2.6.1 Methods of Conducting Ecological Risk Assessment and Identification of Data Gaps

This document characterizes the environmental fate and effects of spinosad to assess whether the proposed label new use of the compound results in risk to non

- target organisms at levels above the Agency’s LOCs. The primary method used to assess risk in this screening

- level assessment is the risk quotient (RQ). The RQ is the result of comparing measures of exposure to measures of effect. A commonly used m easure of exposure is the estimated exposure concentration (EEC) and commonly used measures of effect include toxicity values such as LD 50 or NOAEC. The resulting RQ is then compared to a specified level of concern (LOC), which represents a point of depar ture for concern, i.e. if the RQ exceeds the LOC, then risks are triggered. Although not necessarily a true estimate of risk since there is no estimated probability of effect, in general, the higher the RQ, the more certain the potential risks.

The regi strant has submitted additional information for terrestrial field dissipation, fish accumulation, aerobic aquatic metabolism, and aq uatic dissipation studies. The se data are under review. According to 40CFR Part 158 issued on 10/26/07, the registrant sho uld submit the following studies: (1) anaerobic soil metabolismat (835.4200) study; (2) Environmental chemistry method (ECM) for soil and water; and (3) Independent laboratory validation (ILV) to support the terrestrial and aquatic uses.

Whole sediment a cute toxicity testing for freshwater and estuarine/marine invertebrates is needed due to toxicity concerns for benthic organisms, persistence in aquatic environments, binding to sediment.

Table 4 summarizes the environmental fate data requirements for spi nosad according to 40 CFR Part 158 Subpart N. Studies that have been received or not yet received will be noted as such in

the table.

Table 4 . Environmental Fate Data Requirements for Spinosad.

Guideline Number Data Requirement M RID Study Classification Is more data needed?

161

- 1 835.2120 Hydrolysis 43507301 ACCEPTABLE No

161

- 2 835.2240 Photodegradation in

Water 43507302 ACCEPTABLE No

161

- 2 835.2240 Photodegradation in

Water 44597735 ACCEPTABLE No16 Guideline Number Data Requirement M RID Study Classification Is more data needed?

161

- 3 835.2410 Photodegradat ion on

Soil 43507302 ACCEPTABLE No

161

- 3 835.2410 Photodegradation on

Soil 43507303 ACCEPTABLE No

161

- 4 835.2370 Photodegradation in Air

--- WAIVED No

162

- 1 835.4100 Aerobic Soil

Metabolism 43507304 ACCEPTABLE No

162

- 2 835.4200 Anaerobic Soil

Metab olism --- No data Yes

162

- 3 835.4400 Anaerobic Aquatic

Metabolism 43507305 ACCEPTABLE No

162

- 4 835.4300 Aerobic Aquatic

Metabolism 46642701

47908501 Unacceptable

Under review Pending on the review

163

- 1 835.1240 Adsorption/Desorption 43507306 ACCEPTABL E No

163

- 1 835.1240 Adsorption/Desorption 43816602 ACCEPTABLE No

163

- 2 835.1410 Volatility (Lab)

--- Waived No

163

- 3 835.8100 Volatility (Field)

--- Waived No

164

- 1 835.6100 Terrestrial Field Dissipation 43714301 SUPPLEMENTAL

Additional data were

subm itted and they are

under review Pending on the review

164

- 2 835.6200 Aquatic Field Dissipation 47420102 Under review Pending on the review

164

- 3 835.6300 Forestry Dissipation

--- N/A No

164

- 4 835.6400 Combination and tank mixes Dissipation --- Waived No

165

- 4 850.1730 Fish BCF 43557601 SUPPLEMENTAL

Additional data were submitted and they are

under review Pending on the review

165

- 4 850.1730 Fish BCF 44537734 SUPPLEMENTAL

Additional data were submitted and they are

under review Pending on the rev iew

165

- 5 850.1950 Accumulation

- Aquatic Nontarget --- Waived No

166

- 1 835.7100 Ground Water Monitoring Prospective --- Waived No

201

- 1 840.1100 Droplet Size Spectrum

--- Waived No

202

- 1 840.1200 Drift Field Evaluation

--- Waived No

-- -- Environmen tal chemistry method (ECM) --- No data Yes

-- -- Independent laboratory validation (ILV) --- No data Yes17 Guideline Number Data Requirement M RID Study Classification Is more data needed?

Non

- guideline Aquatic microcosm dissipation 43848803 SUPPLEMENTAL Spinosad (480 g/L suspension concentrate, ratio of A:D about 85:15) was surface

ap plied at 100g/ha to surface to outdoor tanks containing pond water. Parent spinosad dissipated from the water with a half

- life of 1.5 days. Total spinosad residues dissipated

from the water with half

- life of 4 days. In the clay loam sediment, spinosad F actors A and B were maximum averages of 14.9 ppb (4 days) and 11.1 ppb (15 days), respectively; Spinosad Factor D was ≤4.2 ppb and Factor

B of D was not detected. Maximum total spinosad residues in sediment were 56.0 ppb (8 days).

Table 5 summarizes t he data requirements for spinosad according to 40 CFR Part 158 Subpart G. Studies that have been received or not yet received will be noted as such in the table.

Table 5 . Ecological Effects Data Requirements for Spinosad.

OPPTS

Guideline # Data Requirement MRID # Classification Is more data needed?

850.2100 Avian acute oral LD 50 (mallard duck)

(bobwhite quail) 434145

- 29

434145

- 28 Supplemental

Supplemental No

No

850.2200 Avian subacute dietary LC 50 (bobwhite quail)

(mal lard duck) 434145

- 31

434145

- 30 Acceptable

Acceptable No

No

850.2300 Avian reproduction (bobwhite quail)

(mallard duck) 434145

- 33

434145

- 32 Acceptable

Acceptable No

No

850.1075 Freshwater fish acute LC 500 (rainbow trout)

TGAI

DEG

(bluegill sunfish)

TGAI 434441

- 03

434145

- 34 Acceptable

Acceptable No

No

850.1010 Freshwater invertebrate acute EC 50 (daphnia)

TGAI

DEG 434145

- 37

445977

- 31

465053

- 12

465053

- 04

465053

- 07

465053

- 09 Acceptable Supplemental Acceptable Acceptable

Acc eptable Acceptable No

No

No

No

No

No

850.1735 Freshwater Invertebrate Sediment ToxicityTGAI N/A N/A Yes

850.1740 M arine Invertebrate Sediment ToxicityTGAI 47702901 Supplemental No

850.1075 Estuarine/marine fish acute LC 50 (sheepshead minnow) 434145

- 40 Acceptable No18 OPPTS

Guideline # Data Requirement MRID # Classification Is more data needed?

850.1025

850.1035 Estuarine/marine invertebrate acute EC 50 (eastern oyster)

(mysid)

(other) 434441

- 04/435712

- 03

434145

- 39 Acceptable

Supplemental No

No

850.1400 Freshwater fish early life stage 434145

- 41 Acceptable No

850 .1300 Freshwater invertebrate life cycle (daphnia)

DEG 465053

- 03

465053

- 06

465053

- 01

465053

- 11 Supplemental Supplemental

Invalid

Invalid No

No

No

No

850.1400 Estuarine/marine fish early life stage 444206

- 01 Acceptable No

850.1350 Estuarine/marine life cy cle (mysid) 444206

- 02 Acceptable No

850.1950 Aquatic Field Study N/A N/A N/A

870.1100 Acute mammalian oral LD 50 (rat) (rat) 437707

- 01

434145

- 15 Acceptable Acceptable No

No

870.4100 Mammalian Chronic (rat) 437015

- 06 Acceptable No

850.4100 Seedlin g Emergence

- Tier I 438488

- 02 Acceptable No

850.4150 Vegetative Vigor

- Tier I 445977

- 32 Acceptable No

850.5400 Aquatic plant algae

TGAI

434145

- 42

434145

- 43

434145

- 44

434145

- 45

434145

- 46 Acceptable Acceptable Acceptable Acceptable Acceptable No

No

No

No

No

850.4400 Aquatic plant acute EC 50 DEG 465053

- 10

465053

- 08

465053

- 05

465053

- 02 Supplemental Supplemental Supplemental Supplemental No

No

No

No

850.3020 Acute honey bee contact LD 50 434145

- 47

453408

- 01 Acceptable

Invalid No

No

850.3030 Hone y Bee Residue on Foliage 450077

- 01

450077

- 02

450077

- 03 Acceptable Supplemental

Invalid No

No

No

850.3040 Honey Bee Field Testing for Pollinators 457082

- 01

457088

- 01 Supplemental Supplemental No

No

Non

- guideline

Earthworm Chronic Midge Chronic 21 day tox to Rainbow trout (DEG) 28 day Midge Sediment Chronic (DEG) 28 day Midge Sediment Chronic (DEG) 28 day Midge Sediment Chronic (DEG) 28 day Midge Sediment Chronic (DEG) 434145

- 48

448284

- 02

465053

- 13

465053

- 14

465053

- 15

465053

- 16

465053

- 17 Supp lemental Supplemental Supplemental Supplemental Supplemental Supplemental Supplemental No

No

No

No

No

No

No19 

### 2.6.2 Measures of Effect and Exposure

Table 6 lists the measures of environmental exposure and ecological effects used to assess t he potential risks of spinosad to non

- target organisms in this assessment based on the concerns in the problem formulation . The methods used to assess the risk are consistent with those outlined

in the document “Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs.” (2004)

Table 6 . Measures of Effect and Exposure for spinosad.

Assessment Endpoint Surrogate Species and Measures of Ecological

Effect 1 Measures of Exposure

Birds 2 Survival - Mallard duck acute oral LD 50

- Bobwhite quail and mallard duck subacute dietary LC 50 Maximum residues on seed and

soil Reproduction

and growth Mallard duck and bobwhite quail chronic reproduction NOAEL

Mammals Survival Laboratory rat acute oral LD 50 Reproduction

and growth Lab oratory rat chronic reproduction NOAEL

1 If species listed in this table represent most commonly encountered species from registrant

- submitted studies, risk assessment guidance indicates most sensitive tested within taxonomic group are to be used for base line risk

assessments

2 Birds represent surrogates for terrestrial phase amphibians and reptiles



## 3 Exposure Assessment

Environmental fate data and modeling results indicate that spinosad residues can be expected to dissipate very slowly in the environment. A total residue method was used in estimating the water concentrations in the eco risk assessment. This is because the main ring structures in the transformation products which were tentatively identified or characterized in the fate studies remain unchange d (almost the same as the parent compound). In the modeling, EFED assumed spinosad and its transformation products are stable under the aqueous photolysis, aerobic soil metabolism, and anaerobic aquatic metabolism conditions. In conclusion, spinosad resid ues are expected to be very stable in the aquatic environment. Below are the general fate properties for spinosad Factor A and Factor D.

Spinosad Factors A and D converted in an aerobic soil metabolism study to transformation products very similar to the parent with half

- lives of approximately 9

- 17 days. Similar transformation products are formed under photolytic conditions with a half

- life of less than one day at pH 7 in sterile water and about 10 days in soil. The photodegradation half

- life is assumed

t o be stable because the study was not conducted long enough to provide formation and decline information on the transformation products. Spinosad Factor A has a low to moderate water solubility and a low to slight mobility in sandy soils, and is immobile i n silt loam and clay loam soils. Although no mobility data are available for Spinosad Factor D, it is 180x less soluble than Factor A and therefore would be expected to be less likely to leach in the soil. In terrestrial field dissipation studies with Spi nosad Factor A on bareground plots, the half

- life was <1 day, no leaching was observed, and 3.1% of the applied was recovered in runoff.20 Spinosad has a high affinity for sediment and moves rapidly from the water to the sediment phases where it is highly p ersistent. 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 >>25 days. Spinosad has a relatively low bio

- concentration factor (BCF’s of the parent 7.5X, 28.8X, and 21.1X 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 substant ial bio

- concentration of the material in

the food web.

Degradation and Metabolism

Spinosad Factors A and D were relatively stable in pH 5, 7, and 9 sterile aqueous buffer

solutions that were incubated in the dark at 25°C.

In ster ile buffered (pH 7) s olutions, spinosad F actors A and D phototransformed with half

- lives

of 0.8

- 0.9 days. The β

- isomers of the 13,14

- dihydro of the pseudoaglycone of Factor A and of

Factor D were detected at a maximum of 20.2

- 24.9% of the applied at 48 hours (study

terminatio n). In alkaline (pH 9.2) pond water, F actors A and D phototransformed rapidly with

half

- lives of 0.54

- 0.55 days. On soil, Factors A and D had photodegradation half

- life of 8.68

- 9.71 days. The only transformation present at >5 % of the applied was Factor B (N

– demethylated Factor A), which reached 14.8% of the applied at 18 days post

- treatment. These studies were not long enough to determined the fate of the transformation products

In aerobic silt loam soil, Spinosad Factors A and D converted to transformat ion products with

initial half

- lives of 17.3 and 14.5 days, respectively. Factor A converted to transformation products with a half

- life of 9.4 days in sandy loam soil incubated under similar conditions. Approximately 75

- 90% of the applied spinosad convert ed to transformation products by 28 days. The major degradate of Factor A was Factor B (N

- demethylated Factor 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% a t 1 year. The major transformation product of Factor D

was N

- demethylated Factor D (the Factor D analogue of Factor B), which accumulated to a maximum 68% of the applied at 28 days post

- treatment and approximately 50% at 6 months.

Several minor transforma tion products, each <10% of the applied, were isolated but not conclusively identified.

In anaerobic flooded clay sediment, Factors A and D converted to transformation products with

half

- lives of 161 and 250 days. By 7 days post

- treatment, >90% of the app lied radioactivity was associated with the sediment fraction. Three major transformation products of Factor A, each present at a maximum 8

- 12% of the applied chemical , were identified: Factor B (N

- demethylated Factor A), reversepseudoaglycone (806643), an d ketoreversepseudoaglycone (814426). One major transformation products of Factor D, N

- demethylated Factor D (the Factor D analogue of Factor B), 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 at21 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

s ystem. In addition, transformation products comprising **≥** 10% of the applied may have been present and not identified.

Soil sorption and mobility

The mobility of Factor A, at nominal concentrations of 0.04

- 5.0 μg/mL, was investigated in sand, loamy sand, sandy loam, silt loam, and clay loam soils. K

oc values were 2,862, 831, 4,237, 134,583, and 21,938, respectively. Freundlich K des 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, 28 8

- 357 and 292

- 296, respectively; corresponding 1/n values ranged from 0.826

- 0.921. The reviewer

- calculated coefficients of determination (r 2 ) for the relationships K ads vs . organic matter, K ads vs . pH and

K ads vs . clay content were 0.0647, 0.0498, and 0.8 114, respectively.

The mobility of Factor B, the major degradate of Factor A, was investigated at 0.05

- 5.0 μg/mL in sand, loamy sand, sandy loam, and silt loam soils. K

oc values were 2,138, 662, 2,881, and 74,583, respectively. Freundlich K des values fo r 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. The reviewer

- calculated coefficients of determination (r 2 ) for th e relationships K ads vs . organic matter, K ads vs . pH and K ads vs . clay content were 0.425, 0.235 and 0.957, respectively.

Factors A and D are not volatile; vapor pressures (25°C) are 2.0 to 3.0 x 10 - 11 kPa. CO 2 was the only volatile compound detected in metabolism studies.

Field dissipation

Factor 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. Approximately 2

- 3% remained aft er 3

- 5 days. No degradates were identified. Spinosad Factor 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

t he 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. Spinosad (Factors A + 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 t he water, the degradates Factors B and B of 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, Factor A was detected at a maximum average 14.9 ppb at 4 days and was 14.3 ppb at 35 days. Factor B was detected at a maximum average 11.1 at 15 days and was ≤9.4 ppb at 35 days. Factors D was ≤4.2 ppb and B of D was not detected (LOD 11.3 ppb) at any interval in the sediment. Total spinosad residues in22 the water had an observed ha lf

- life of <1 days. Total spinosad residues 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

tran sformation of the parent to other transformation products similar to the parent. Also the dissipation half

- lives reflect the movement of the parent and transformation products from one media to another and do not show degradation of the product.

Accumulat ion

[ 14 C]Factors A and D accumulated in rainbow trout held under laboratory flow

- through conditions for up to 28 days. In the high concentration experiments (19.0 ng/L for Factor A and 33.0 ng/L for Factor D), maximum BCFs for Factor 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 Factor 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 Factor 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 Factor 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 fi sh exposed to Factor 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 Sp inosad 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 Spinosad Factor B o f D was a maximum of 544 ng/g. All other metabolites were <50 ng/g.



### 3.1 Aquatic Exposure Estimates

An aquatic ex posure analysis was provided in previous risk assessment s for spinosad use on turf (DP 279684+ ) and bulb onion and mint ( DP 310860+ ) . The current ri sk assessment evaluated the

EECs (total residues) based on the proposed uses ( Table 7 ). PRZM/EX A MS output is given in Appendix D . The resulting EECs were less than or similar to the turf use but greater than the bulb onion and mint uses. Therefore, this assessment relies on the aq uatic analyse s performed in the previous assessment s due to lower use rates in the bulb onion and mint assessment and

similar or higher rates in the turf assessment

.

Table 7

. EECs for the proposed use of spinosad as a seed treatment.

PRIZM/EXAMS EECs for Spinosad Seed Treatment Use

Crop Portion Application

Rate

lb a.i./A Number of Application Acute

Conc.

ppm 21 Day

Conc.

ppm 60 Day

Conc.

ppm23 Onions

for Seed Water

Column 0.45 1 0.004 0.00 4 0.004

Pore

Water 0.45 1 0.004 0.004 0.004



### 3.2 Terrestrial Exposure Estimates

Consumption of spinosad

- treated seed is the most likely exposure route for terrestrial animals.

The Terrestrial Exposure Model (Version 1.4.1), was used to estimate the dietary exposure to terrestrial birds and mammals. Because of the differences in foliar application and seed treatment uses of pesticides, the seed treatment worksheet of TREX was used as a “stand

- alone” tool for estimating the avian and mammalian exposure conce ntrations for various crops.

The seed treatment worksheet of TREX assesses dietary exposure in two different ways. The first approach estimates the dietary dose assuming that an organism has been eating only treated seed. Using this assumption, the see d treatment worksheet calculates the food consumed by birds and mammals using Nagy’s allometric food consumption equations. Food consumption is calculated for the smallest avian (20

- gram weight) and mammalian (15

- gram weight) species ( Appendix A ). Using a scaling factor approach, which adjusts food intake and toxicity values to

account for the differences in the size of the animal assessed compared with the size of the animal used in the toxicity tests, daily doses or Nagy doses are calculated. Avian and

mam malian Nagy doses for spinosad were calculated using the equation

– (daily food intake g/day * 0.001 kg/g * maximum seed application rate mg/kg

- seed) / body weight of animal (kg).

The second method calculates the available concentration of pesticide on the basis of pesticide applied per square foot. Maximum spinosad application for each crop is converted to mg a.i./sq ft in order to derive an estimate of the pesticide exposure per square foot.

Typical input values (for foliar treatments) for TREX include applicati on rate, time interval

between two applications, total number of applications and foliar half

- life periods. Since spinosad is a seed

- treatment insecticide, terrestrial EECs were derived using 1 application for the maximum proposed use rat es for each crop. The default seeding rates contained in the TREX model were used when available for the various crops. When assessing the maximum application rate per acre, the default seeding rates provided in TREX were used for the following

crops: on ion

- bulb vegetables ( crop group 3 )

, dried beans

- dried shelled pea and bean (except soybean)(subgroup 6C)(excluding lentils, cowpea), field pea

– leaves of legume vegetables (subgroup 7A) (excluding cowpea, lentils)

. Seeding rates for Seeding rates for watermelon, pumpkin, cantaloupe, and cucumber (cucurbits crop group 9; excluding cantaloupe, pumpkin, watermelon, and winter squash) were obtained from Granberry et al. 2008. Seeding rates for winter squash were obtained from Kemble et al., 2000. When t he application rate per acre in TREX based on default seeding rates exceeded the maximum labeled seasonal amount, the seeding rates in TREX were adjusted to achieve the maximum labeled seasonal application rate.

T he TREX model assumes a default density of 8.33 lb/gal , and the spinosad label only indicates

that the formulated product contains 80% active ingredient by weight

. This density was24 therefore used in the TREX model. Also, as spinosad is a seed

- treatment, foliar half

- life periods

are irrelevant fo r this analysis.



## 4 Ecological Effects Assessment

The short

- term and long

- term exposure effects of spinosad on terrestrial organisms were characterized based on the studies submitted by the registrant only as the ECOTOX database review did not reveal any o pen l iterature studies for spinosad that were relevant. Toxicity studies

available for this risk

- assessment and the measurement endpoints selected for each taxonomic group are included in Appendix C of this document.



### 4.1 Aquatic Effects Summary

An aquatic e f fects analysis was provided in the previous risk assessment s for spinosad on bulb

onion and mint (DP310860+) as well as on turf ( DP 279684+ ) . The current risk assessme nt relies on the aquatic analyses performed in these assessment s

.



### 4.2 Terrestrial Effects Su mmary
The registrant submitted eight studies to document spinosad ’s effects on terrestrial birds and

mammals

. One study from the registrant examined the effects of spinosad on earthworms

. At this time the Agency does not have an established method to ass ess risk to beneficial terrestrial invertebrates. Therefore this study can only be qualitatively to characterize risk from spinosad to

terrestrial invertebrates.



### 4.2.1 Toxicity Effects on Terrestrial animals

Spinosad is categorized as slig htly toxic to avian species on an acute oral basis (Table 8 ) . Both the mallard duck and the bobwhite quail LD 50's are >1333 mg/kg (MRIDs 434145

- 28 and

434145

- 29). Spinosad is categorized as practically nontoxic to avian species on a subacute dietary basi s. Both the mallard duck and the bobwhite quail LC 50 are >5156 ppm (MRIDs

434145

- 28 and 434145

- 29). Reproductive parameters (eggs laid, live 3

- week embryos, normal hatchlings, 14 day

- old survivors, etc.) were significantly reduced in both mallard ducks a nd bobwhite quail at 1100 ppm (MRIDs 434145

- 32 and 434145

- 33). The NOAEC for both species is 550 ppm.

Based on mammalian data in the Hazard Evaluation Division’s toxicity database, the rat acute

oral LD 50 is 3738 mg/kg, categorizing spinosad as practical ly non

- toxic to small mammals. A reproductive study with rats identified a NOAEC of 10 mg/kg/day, based on reproductive toxicity ( in young: reduced litter size, offspring body weights, and surviv al of F2 generation)

.

Developmental studies with rats and r abbits showed no evidence of toxicity. The NOAEC in the rat study (MRID 435575

- 05) was ≥4000 ppm or ≥200 mg/kg/day, the highest dose tested. The NOAEC in the rabbit study (MRID 434145

- 21) was ≥1000 ppm or ≥50 mg/kg/day.25 Table 8 . Toxic Effects in Terrestrial Animals Due to Acute and Chronic Exposure to Spinosad.

Selection of Terrestrial Toxicological Endpoints Used to Calculate Risk Quotients for Spinosad

Type Of Toxicity Organism Species Toxicological Endpoint MRID #

Oral Acute

Bird Bobwhite/Mallard LD 50 > 1333 mg/kg 434145

- 29/ 434145

- 28

Dietary Bobwhite/Mallard LC 50 >5156 ppm 434145

- 31/ 434145

- 30

Chronic Bobwhite/Mallard NOAEC = 550 ppm 434145

- 33/ 434145

- 32

Oral Acute

Mammal R at LD 50 3738 ppm 437707

- 01/434145

- 15

Chronic Rat NOAEC > 1 0 ppm 437015

- 06



### 4.2.2 Toxicity Effects on I nvertebrates

Effects to terrestrial i nvertebrates are summarized below in Tables 9 and 10 . Only one study has

been submitted that examines the eff ects of spinosad on terrestrial invertebrates in the rhizosphere , which is based on effects to the earthworm. No toxicity was shown to earthworms in soil (based on reduction in biomass). The 14

- day LC 50 was >970 mg/kg (MRID 434145

- 48). However, the chem ical is highly toxic to the honey bee.

Table 9 . Toxic Effects in Terrestrial Invertebrates.

Non

- target insect toxicity

Species

% ai Results Toxicity Category/effects MRID Study

Classification

Honey bee (Apis mellifera ) 88% 0.0029 ug ai/b

ee Highly Toxic 434145

- 47 Acceptable

Honey bee (Apis mellifera) 0.02 N/A N/A 453408

- 01 Invalid

Honey bee (Apis mellifera) 22.8% N/A N/A 450077

- 04 Invalid

Honey bee (Apis mellifera) 24% RT 25 = 3hrs Mortality 450077

- 02 Supplemental

Honey bee (Apis mellifera) 22.8% N/A N/A 450077

- 03 Invalid

Honey bee (residue) (Apis mellifera) 23.5% RT 25 = 3hrs Mortality 450077

- 01 Acceptable26 Honey bee (field trail) (Apis mellifera) GF

- 120

Succes

s fruit fly No adverse

effects at use

rates N/A 457 082

- 01/457088

- 01 Supplemental

Table 10 . Toxic Effects in Terrestrial Invertebrates in the Rhizosphere Due to Acute Exposure to Spinosad.

Earthworm Toxicity

Species % ai LC50 (mg/kg) NOAEC (mg/kg) Endpoints

Affected MR ID Study

Classification

*Earthworm 88 >970 970 weight

decreases 434145

- 48 Supplemental



### 4.3 Incident Database Review

EPA maintains an incident database system called Ecological Incident Information System (EIIS), to track and evaluate accidental kills associated with pesticide use. Based on the information contained in the incident report, the likelihood of a particular pesticide causing the incident is listed as highly probable, probable, possible, or unlikely. If there are incident, this

infor mation will be reviewed and considered in conjunction with the degree to which the LOCs were exceeded, information on sales, local use practices, and monitored levels in the environment to determine whether the predicted effect based on labeled use of the product, is likely to occur or not.

A review of the Ecological Incident Information System (EIIS), maintained by the Agency’s Office of Pesticide Programs (OPP) indicates several reported ecological incidents rep orted with the use of spinosad ( Table 11 )

.

There were 4 incidents reported in the EIIS database. All incidents reported were plant related. No residue analysis was reported for any incidents.

Table 11 . Ecological Incident Results as Listed by EIIS

.

Incident # Date Crop State Certainty Legality Application Magnitude

IO13636

- 036 3.15.02 Orange CA 2

- possible RU Broadcast 21 acres

IO12366

- 001 9.10.01 Corn CA 2

- possible UN UN 9000 acres

IO13550

- 002 6.22.01 Potato DE 2

- possible RU Spray 65 acres

IO10927

- 029 4.15.00 Tobacco TN 1

- unlikely RU Spray 45 acres



## 5 Risk Characterization

Risk characterization is the integration of exposure and effects to determine the ecological risk

from the use of such stressors as spinosad . The risk characterization provides estimations and27 descriptions of the risk; articulates risk assessment assumptions, limitations, and uncertainties; synthesizes an overall conclusion; and provides the risk managers with information to make regulatory decisions.



### 5.1 Risk Estimation

The risk quotient (RQ) method was used to provide a metric for potential adverse ecological risks from the proposed uses of spinosad . The risk quotient, a comparison of exposure estimates and toxicity endpoints, is estimated by dividing ex posure concentrations by acute or chronic toxicity values ( Appendix B ). The resulting unitless RQs are compared to the Agency’s levels of concern (LOC) to determine the need for regulatory action.

These LOCs are criteria used by OPP to indicate potential risk to non

- target organisms and the need to consider regulatory action. The criteria indicate that a pesticide used as directed has the potential to cause adverse effects on non

- target organisms. LOCs currently address the following risk presumption ca tegories: (1) acute

– potential for acute risk is high, regulatory action may be warranted in addition to restricted use classification (2) acute restricted use

- potential for acute risk is high, but this may be mitigated through restricted use classific ation (3) acute endangered species

– the potential for acute risk to endangered species is high, regulatory action may be warranted, and (4) chronic risk

- the potential for chronic risk high, regulatory action may be warranted. Currently, EFED does not perform assessment for chronic risk to plants, acute or chronic risks to non

- target insects or chronic risks from granular/bait formulations to mammalian or avian species.

The ecotoxicity test values (i.e., measurement endpoints) used in the acute and c hronic risk quotients are derived from the results of required studies. Examples of ecotoxicity values

derived from results of short

- term laboratory studies that assess acute effects are (1) LC 50 (fish and birds), (2) LD 50 (birds and mammals), (3) EC 50 (a quatic plants and aquatic invertebrates, and (4) EC 25 (terrestrial plants). An example of a toxicity test effect level derived from the results of a long

- term laboratory study that assesses chronic effects is (1) NOAEC (birds, fish, and aquatic

invertebra tes). Risk presumptions, along with corresponding RQs and LOCs are tabulated in Appendix B

.



### 5.1.1 Summary of Aquatic Risk Quotients

An aquatic assessment was provided in previous risk assessment s for spinosad (DP310860+ and

DP 279684+ ). The current risk asses sme nt relies on the aquatic analyses performed in these

assessment s

.



### 5.1.2 Summary of Terrestrial Risk Quotients

Table 12 summarizes the acute and chronic avian and mammalian RQs. Due to the lack of a

definitive LD 50 for both mammalian and avian acute toxicity, all of the acute RQs are less than the number reported. T he acute RQs ra nged from < 0.02 to < 23 .2 4 for birds (20

- gram weight)

and 0. 0 0 to 4.25 for mammals (15

- gram weight), where many of the uses exceeded the endangered species LOC of 0.1.28 Table 12 . Summary of Terrestrial Acute and Chronic Risk Quotients . Values in bold represent an exceedence of the respective LOC

.

Crop Acute Dose

- Based RQs Chronic RQs 3

Avian RQs Mammalian RQs Avian RQs Mammalian RQs RQ1 1 RQ2 2 RQ1 1 RQ2 2

Onion : Bulb

vegetables < 23 .2 4 4 < 0. 2 4 5 2.27 4 0.0 4 160.36 441 .0 0

Watermelon < 4.35 4 < 0.02 0. 43 5 0.0 0 30.00 82.50

Pumpkin < 3.27 4 < 0.0 2 0. 32 5 0.0 0 22.55 62.00

Winter Squash < 2.19 4 < 0.0 2 0. 21 5 0.0 0 15.09 41.50

Cantaloupe < 9.14 4 <0.0 4 0

. 89 5 0.01 63.09 173. 50

Cucumber:

Cucurbit vegetables (crop group 9; excluding cantaloupe,

pumpkin, watermelon,

winter squash) < 9.94 4 < 0.0 6 0.97 4 0.0 1 68.55 188.50

Dried bean

and shelled

pea < 0.53 4 < 0. 07 0. 05 0.0 1 3.64 1 0 .00

Field pea:

Leaves of

legume vegetables (subgroup 7A) (excluding

cowpea, lentils) < 2.48 4 < 0. 56 5 0. 2 4 5 0.0 9 1 7. 09 47

. 00

1 Acute RQs for birds and mammals are determined by dividing the estimated dietary intakes (mg/kg

- bw/day) by a body weight adjusted avian LD 50 of 1333 mg/kg

- bw for Bobwhite quail

and a b ody weight adjusted mammalian LD 50 of 2 000 mg/kg

- bw for the rat.

2 Acute RQs were based on pesticide applied per square foot (mg a.i./ft 2 /LD 50 *bw)

3 Chronic RQs were based on spinosad seed application rate (mg a.i./kg seed) divi ded by a dietary

- based NOAEC (550 mg/kg

- di et for the mallard duck and a 200 mg/kg

- diet for the rat ).

4 RQ exceeds the LOCs of 0.5 and 0.1 for non

- listed and listed species, respectively.

5 RQ exceeds the LOC of 0.1 for listed species.

An analysis of the results shows that the acute av ian RQs exceeded the listed and non

- listed species LOC for the proposed use of spinosad on a dose basis (RQ1) for every crop use

. Acute mammalian RQ s also exceeded the listed species LOC on a dose basis (RQ1) for all of the uses29 except for dried bean and shelled pea and the non

- listed species LOC for the following crops: bulb vegetables (crop group 3 ), cantaloupe, and cucurbits (crop group 9, as listed in Table 12)

. Avian c hronic RQs exceeded the LOC for every crop group

. Mammalian chronic RQs exceeded

t he LOC for every crop group as well.

Currently, EFED does not assess risk to non

- target insects. R esults of acceptable studies are used for recommending appro priate label precautions. The study results show that spinosad is highly toxic to honeybees , bu t s hows low toxicity to earthworms.



### 5.2 Risk Description

The results of this baseline risk assessment indicate that the proposed uses for spinosad pose risk

to both non

- listed and listed mammalian and avian taxa. Therefore, the hypothesis that spinosad

has the potential to compromise survival and cause sub

- lethal effects in non

- target species is supported.



### 5.2.1 Risk to Aquatic Organisms

An aquatic ef fects analysis was provided in the previous risk assessment s for spinosad on bulb

onion and mint (DP310860+) as wel l as on turf ( DP 279684+ ) . The current risk assessme nt relies on the aquatic analyses performed in these assessment s

. The aquatic EEC’s in this assessment

were similar to or lower than the previous assessment for turf (DP279684+), but higher than

those fo r mint and green onion (DP310860 + ). In both assessments, chronic ris k was found for

freshwater free

- swimming and benthic sediment dwelling invertebrates, but no risk was found for aquatic plants

. Therefore, the proposed spinosad seed treatment would also pose risk to these freshwater animals and not to aquatic plants.



### 5.2.2 Risk to Terrestrial Organisms

Many of the crop uses pose acute and chronic risk to small birds and mammals ( Table 12 )

. Based on the application rate per acre per season (RQ2) , there are n o bird or mammal acute risks that appear for non

- listed species . However, there is acute risk based on this method (RQ2) to
listed birds for the following uses: bulb vegetables (crop group 3 ) and l eaves of legume vegetables (subgroup 7A; excluding cowpea, lentils) . T here is no acute risk to any listed or non

listed mammal species , however , based on the RQ2 method . The risk picture is very different based on the application rate per seed (RQ1) . There is acute risk to both listed and non

- listed

birds for every use. There is also acute risk to listed mammals for all of the crop uses except for dried bean and shelled pea , and acute risk to non

- listed mammals for the following crop uses: bulb vegetables (crop group 3), cantaloupe, and cucurbits (crop group 9 , as listed in Table 12). Similarly, the proposed applications for every crop use pose a chronic ris k concern to avian and

mammalian wildlife

.

The differences between the RQs based on an area basis ( RQ2, LD 50 /ft 2 ) versus the oral dose ( RQ1, ingestion of seeds) suggest that the application rate per seed drives most of the risk

conclusion s for this assessment. For example, the maximum application rate in lbs a.i. per 100 lbs of seed is 8.8 lbs for bulb onions. This rate is high enough to trigger a n acute and chronic

risk concern f or non

- listed and listed birds and mammals . Yet the risk based on application rate per acre results in only acute risk to listed species. The amount of a.i. per seed appears to be triggering most of the acute and chronic concern for risk, at least for non

- listed species. Note30 however, that three of the uses pose a risk concern to listed avian species

, even based on the application rate per acre. This suggests that enough a.i. could be applied to a field at the maximum applicati on rate per acre to pose a risk to e ndangered and threatened birds , so slightly lower application rates per acre would reduce the risk to these taxa

. However, t he maximum application rate for most of the crops per seed would need to be substantially reduc ed to
eliminate acute risk to listed and non

- listed birds and mammals

.

The non

- definitive endpoints derived from the acute toxicity studies to birds affect the risk conclusions in this assessment. Though this risk assessment shows that acute risk is pres ent for both birds and mammals based on the application rate per seed, the avian acute RQ’s are

undefined and there is uncertainty regarding this risk due to the lack of definitive endpoints. For

some crop uses, the lack of effects in the acute studies me ans that the presumed risk is low. However, for bulb vegetables (crop group 3), foliage of legume vegetables (excluding soybean) (subgroup 7A)

, cantaloupe, cucurbit vegetables (crop group 9), pumpkin, winter squash, and

watermelon , the EECs are greater th an the highest dose tested in the acute toxicity studies for

avian wildlife. The hazard of the chemical has not been evaluated at exposure levels above the highest dose tested in the acute toxicity studies. Therefore, while risk may be considered low for those uses that result in EECs less than the highest dose tested in the toxicity studies, risk cannot be precluded for the se other uses , considering that mortality was found in the acute avian study with Bobwhite quail . Based on the results of TREX, the maximum application rate per seed

would need to be ≤ 0. 38 lbs a.i./cwt to eliminate this uncertainty for b irds

.

TREX evaluates chronic risk based on the feeding rates of birds and mammals and incorporates the amount of a.i. per seed to establish exposure. For both birds and mammals, definitive NOAEC values have been derived from studies submitted by the registrant. All of the uses pose

a chronic risk to birds and mammals . The application rate per seed drives this risk conclusion and suggests that altern ative rates could be explored to reduce the level of risk to birds and

mammals on a chronic basis.

It is highly likely that the spinosad use period in the United States will coincide with the time when birds and mammals seek crop fields in which spinosa d

- treated seeds are planted for food and cover. The peak usage period could also overlap with the reproductive cycles of birds and mammals. Typically, peak spinosad

- seed treatment use would occur around planting time. Depending on the crop and the state in which it is planted, the planting time could span the entire

year.

The current assessment assumes that spinosad

- treated seed represents 100% of the dietary needs for birds and mammals. In reality, birds and mammals may not feed on spinosad

- treated seed for extended periods of time. While this assumption is conservative, the registrant submitted data are derived from a limited number of species that is then extrapolated to all mammalian and avian species. This extrapolation has uncertainty associat ed with it due to differences in species sensitivity. So at this screening level, the assumption of 100% of dietary needs being met through spinosad treated seed is used to be protective of all avian and mammalian species, and those species for which bird s serve as a surrogate.

In summary, acute risk to listed and non

- listed birds cannot be precluded for bulb vegetables (crop group 3), foliage of legume vegetables (excluding soybean) (subgroup 7A)

, cantaloupe,31 cucurbit vege tables (crop group 9 ), pumpkin, winter squash, and watermelon. Acute risk to non

listed mammals was found for bulb vegetables (crop group 3)

, cantaloupe

, and cucurbit vegetables (crop group 9; excluding pumpkin, watermelon, winter squash) , while acute risk to

listed mammals was found fo r all uses except dried bean and shelled pea . All of the proposed uses pose chronic risk to both birds and mammals. Based on previous assessments, chronic ris k

was found for freshwater free

- swimming and benthic sediment dwelling invertebrates, but no

ris k was found for aquatic plants

. Therefore, the proposed spinosad seed treatment would also pose risk to these freshwater animals and not to aquatic plants. No risk is present for terrestrial plants due to the low toxicity of spinosad to these organisms.



### 5.3 Endangered Species Assessment

For the purposes of this screening level assessment listed plants and wildlife are assumed to be located on or adjacent to the treated field and aquatic organisms are assumed to be located in a surface water body adjacent t o the treated field. This places the listed species within an assumed area of high potential exposure to the chemical.

If the assumptions associated with the screening

- level action area result in RQs that are below the listed species LOCs, a “no effect,” determination conclusion is made with respect to listed species in that taxa, and no further refinement of the action area is necessary. However, in situations where the screening assumptions lead to RQs in excess of the listed species LOCs for a given t axonomic group, there exists a potential for a “may affect,” conclusion that may be associated with direct effects on listed species or may extend to indirect effects upon listed species that depend on that taxonomic group as a resource.

Avian and mamma lian acute RQs exceeded the acute endangered species LOC 0.1. The chronic

LOC was also exceeded for birds and mammals. These taxa therefore are at risk for direct

effects under acute and chronic exposure to spinosad

.

To determine whether spinosad use sites are geographically associated with known locations of endangered species, a baseline level search of LOCATES (version 2. 10.4 ) database was

conducted. The database uses location information for endangered species at the state and county level and compares it to 2002 agricultural census data for crop production at the same

level of resolution. Preliminary LOCATES analysis indicated that the proposed new use patterns

for spinosad could potentially overlap with areas frequented by endangered avian a nd

mammalian wildlife. Appendix E lists the species on which indirect effects could potentially

occur due to new uses of spinosad

.



### 5.3.1 Probit Slope Analysis

The probit slope response relationship is evaluated to calculate the chance of an individual e vent corresponding to the listed species acute LOCs. If information is unavailable to estimate a slope for a particular study, a default slope assumption of 4.5 is used as per original Agency assumptions of a typical slope cited in Urban and Cook (1986).

A. Terrestrial Species32 Data from avian and mammalian terrestrial acute toxicity studies for spinosad did not provide an estimate of slope.



### 5.3.2 Direct and Indirect Effects

Based on acute and chronic exceedances for birds and mammals, potential does exis t for direct toxic effects to these endangered and threatened species, if exposure occurs. Given the potential

direct effects of spinosad on birds and mammals ( Table 13 ) , indirect effects to animals (e.g. terrestrial phase amphibians, larger mammals) that rely on them for resources critical to their life cycle is possible. For example, non

- listed and listed animals such as foxes, coyotes, and hawks feed on small animals such as mice, rabbits, and other rodents. Terrestrial phase amphibians

such as salama nders depend on mice and other small mammals for food. Predators that feed on birds may also be affected by food chain transfer. Overall, reduced food/prey availability could result if reductions in populations of small mammals or bird populations occur due to acute and chronic exposure to spinosad . Potential chronic impacts on birds could also lead to reduced plant pollination and dispersal. If that were to happen, the effects of spinosad may cascade through the entire food web affecting several taxa.

Table 13 . Listed Species Risks Associated with the Proposed New Uses of Spinosad

. Listed Taxa Potential Direct Effects Potential Indirect Effects

Terrestrial and semi

- aquatic plants

– monocots No Yes

Terrestrial and semi

- aquati c plants

– dicots No Yes

Insects * Yes No

Birds Yes Yes Terrestrial phase amphibians Yes Yes Reptiles Yes Yes

Mammals Yes Yes Aquatic phase amphibians No No Aquatic plants No No

Freshwater fish No No

Freshwater crustaceans No No

Mollusks No No

Ma rine/estuarine fish No No

Marine/estuarine crustaceans No No *Aquatic invertebrates only



### 5.4 Endocrine Disruption

As required under FFDCA section 408(p), EPA has developed the Endocrine Disruptor Screening Program (EDSP) to determine whether certain substa nces (including pesticide active and other ingredients) may have an effect in humans or wildlife similar to an effect produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator may33 designate.” The EDSP employs a two

- tiered approach to making the statutorily required determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal systems. Che micals that go through Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA will determine which, if any, of the Tier 2 tests are necessary based on the avail able data. Tier 2 testing is designed to identify any adverse endocrine related effects caused by the substance, and

establish a dose

- response relationship between the dose and the E, A, or T effect.

Between October 2009 and February 2010, EPA issued test orders/data call

- ins for the first group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. This list of chemicals was selected based on the potential for human exposure through pathways such as food and water, resid ential activity, and certain post

- application agricultural scenarios. This list should not be construed as a list of known or likely endocrine disruptors.

Possible endocrine mediated effects were found in a chronic freshwater invertebrate study with Daph nia magna , where a NOAEC of 0.62 ppb was established based on a statistically significant reduction in egg production at the highest concentration tested (2.19 ppb). Egg production is an

endocrine

- mediated process. Also, there were increases in thyroid wei ghts as well as increased thyroid, parathyroid and pituitary gland cell vacuolation in mammalian studies.

Spinosad is not among the group of 58 pesticide active ingredients on the initial list to be screened under the EDSP. Under FFDCA sec. 408(p) the Ag ency must screen all pesticide chemicals. Accordingly, EPA anticipates issuing future EDSP test orders/data call

- ins for all pesticide active ingredients.

For further information on the status of the EDSP, the policies and procedures, the list of 67

che micals, the test guidelines and the Tier 1 screening battery, please visit: http://www.epa.gov/endo/

.



### 5.5 Uncertainties

5.5.1 Exposure and Effects Assessment

- Variability in Species Sensitivity: Although the screening risk assessment relies on a selected toxicity endpoint from the most sensitive species tested, it does not necessarily mean that the selected toxicity endpoints reflect sensitivity of the most sensitive species existing in a given environment. The relative po sition of the most sensitive species tested in the distribution of all possible species is a function of overall variability among species to a particular chemical. For terrestrial animals, uncertainty associated with the limited quantification of intersp ecies variability in sensitivity to spinosad would probably not impact the risk assessment result substantially, given that spinosad is practically non

- toxic to slightly toxic to terrestrial animals.

- Effects of Pesticide Mixtures: This assessment consi dered only exposure to the active ingredient spinosad . However, simultaneous exposures to multiple chemical and physical stressors are likely to occur in the environment. No acceptable data was found that34 evaluated potential additive, synergistic, or ant agonistic interactions between spinosad and other chemical stressors. If such interactions occur, then risks could be under or over

estimated.

- Acute Toxicity for Birds: For bulb vegetables (crop group 3), foliage of legume vegetables (excluding soybean ) (subgroup 7A)

, cantaloupe, cucurbit vegetables (crop group 9), pumpkin, winter squash, and watermelon , the EECs are greater than the highest dose tested in the acute toxicity studies for avian wildlife. The hazard of the chemical has not been

evaluated at exposure levels above the highest dose tested in the acute toxicity studies, which represents an uncertainty given the mortality found in the Bobwhite quail acute oral toxicity study

.

- Data Gaps: The data gaps that were outlined in Section 2.6.1 were e ither required or conditionally required for spinosad and still have to be submitted. Acceptable data from these studies will aid in reducing some of the uncertainty associated with this assessment.



## 6 Bibliography

Granberry, D.M., T. Kelly, G. Boyhan. 2008. Seeding Rates for Vegetable Crops. University of Georgia Cooperative Extension. Bulletin 1128. Accessed from http://www.caes.uga.edu/publications/pubDetail.cfm?pk_id=6961

Kemble, J.M., E.J. Sikora, G.W. Zehnder, E. Bauske. 2000. Guide to Commerci al Pumpkin and Winter Squash Production. Alabama Cooperative Extension System. ANR

- 1041. Accessed from http://www.aces.edu/pubs/docs/A/ANR

- 1041/ANR

- 1041.pdf

Nagy, K. A. 1987. Field metabolic rate and food requirement scaling in mammals and birds. Ecologic al Monographs. 57:111

- 128.

U.S. Environmental Protection Agency. 1998. Guidelines for Ecological Risk Assessment. Risk Assessment Forum, Office of Research and Development, Washington, D.C. EPA/630/R

- 95/002F. April 1998.

U.S. Environmental Protection Agency. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs, U.S. Environmental Protection Agency. Endangered and Threatened Species Effects Determinations. Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Washington, D.C. January 23, 2004.

U.S. Environmental Protection Agency. 2005. Generic Format and Guidance for the Level I Screening Ecological Risk Assessments Conducted in the Environmental Fate

and Effects Division. Off ice of Pesticide Programs, Washington, D.C. January 24, 2005.

U.S. Environmental Protection Agency. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs. http://www.epa.gov/oppfead1/35 endanger/consultation/ecorisk

- overview.pdf

USDA

- NASS. Multiple years. Crop Production. Accessed from http://www.nass.usda . gov /Statistics_by_Subject/index.a sp36 

## Appendix A . TREX Methodology to Calculated Nagy Doses (EECs) and Risk Quotients for Birds and Mammals

The seed treatment worksheet of TREX calculates the avian and mammalian doses or exposure concentrations using t wo approaches: Nagy doses (mg a.i./kg

- bw day - 1 ) and pesticide available on unit soil surface area (mg a.i. ft 2 ). Nagy doses are used in the calculation of both acute and chronic RQs for birds and mammals. Only acute RQs are calculated using the pesticide available

on unit soil area.

Nagy doses for seed treatment applications are calculated using the scaling factor approach for a

20

- gram bird and 15

- gram mammal. The scaling factor approach adjusts the food intake and toxicity values to account for the di fferences in the size of the animal assessed compared with the size of the animal used in the toxicity tests. The Agency calculates the avian and mammalian Nagy doses using the equation below:

Avian and Mammalian Nagy Doses (mg a.i./kg

- bw) = ( daily food intake g / day *0.001 kg/g * maximum seed application (mg/kg

- seed) / (body weight of animal (kg)

In the second approach, the amount of pesticide available on unit soil surface area is calculated by converting the maximum application rate from lb acre - 1 to m g a.i./ft 2 . The equation used for this calculation is presented below:

Available a.i.(mg a.i./ft 2 ) = (Maximum application rate (lbs/Acre) * 10 6 mg/kg) / (43,560 square feet/acre * 2.2 lb/kg)

Calculation of Risk Quotients (RQs) for Seed Treatment Applica tions

Acute risk quotients are calculated using the adjusted LD 50 value for the smallest weight class of animal (20g for birds and 15g for mammals). Acute RQs are calculated using the two methods:

Method 1 or EEC/LD 50 method

Acute RQ = mg a.i./kg - 1 day - 1 /adjusted LD 50

Method 2 or EEC/LD 50 ft - 2 method

Acute RQ = mg/kg - 1 a.i. ft 2 / (adjusted LD 50 * body weight (kg)

Chronic RQs, which are not adjusted to different weight classes of birds or mammals, are calculated using the following equation:

Chronic RQ = mg a.i. kg - 1 seed / NOAEC (mg/kg

- diet)37 

## Appendix B

. The Risk Quotient Method and Levels of Concern

The Risk Quotient Method is the means by which the Environmental Fate and Effects Division (EFE D) integrates the results of exposure and ecotoxicity data. In this method, both acute and chronic risk quotients (RQs) are calculated by dividing exposure estimates by the most sensitive ecotoxicity values or toxicity endpoints derived from the studies. C alculated RQs are then compared to OPP's levels of concern (LOCs). The LOCs are the criteria used by OPP to indicate potential risk to non

- target organisms and the need to consider regulatory action. EFED has defined LOCs for acute risk, potential restrict ed use, and for endangered species. Risk presumptions, along with the corresponding RQs and LOCs are summarized in

the table below.

Risk Presumption RQ LOC

Birds

Acute Risk EEC/LC 50 or LD 50 /sqft or LD 50 /day 0.5

Acute Restricted Use EEC/LC 50 or LD 50 /s qft or LD 50 /day (or LD 50 < 50 mg/kg) 0.2

Acute Endangered Species EEC/LC 50 or LD 50 /sqft or LD 50 /day 0.1

Chronic Risk EEC/NOAEC 1

Mammals

Acute Risk EEC/LC 50 or LD 50 /sqft or LD 50 /day 0.5

Acute Restricted Use EEC/LC 50 or LD 50 /sqft or LD 50 /day (or LD 50 < 50 mg/kg) 0.2

Acute Endangered Species EEC/LC 50 or LD 50 /sqft or LD 50 /day 0.1

Chronic Risk EEC/NOAEC 1

Aquatic Animals

Acute Risk EEC/LC 50 or EC 50 0.5

Acute Restricted Use EEC/LC 50 or EC 50 0.1

Acute Endangered Species EEC/LC 50 or EC 50 0.05

Chronic Risk EEC/NOAEC 1

Terrestrial and Semi

- Aquatic Plants

Acute Risk EEC/EC 25 1

Acute Endangered Species EEC/EC 05 or NOAEC 1

Aquatic Plants

Acute Risk EEC/EC 50 1

Acute Endangered Species EEC/EC 05 or NOAEC 138 

## Appendix C

. 

## Ecological Effects Data

Summary: This insecticide was practically non

- toxic to avian species

- (subacutely) and mammals (acutely and chronically). However, Spinosad was slightly toxic to avian species

- (acutely), cold

- water fish, and freshwater aquatic invertebrates. Spinosad was moderately toxic to warm

- water fish, estuarine/marine fish(acutely) and estuarine shrimp. Furthermore, this insecticide was found to be highly toxic to estuarine/marine oysters and honey bees(acut e studies)

Toxicity to Terrestrial Animals The results of acute/subacute toxicity testing indicate that Spinosad is practically nontoxic to avian species on a subacute dietary basis and slightly toxic on an acute oral basis. Results of avian toxicity tes ting with spinosad are tabulated below.

Avian Acute/Subacute Toxicity

Species %

ai LC50 (ppm)/ LD50 (ppm) Toxicity Category MRID No.

Author/Year Study Classification

Northern bobwhite quail (Colinus virginianus) 88 LD50 >1333 slightly toxic 43414529 A.G. Murray

et al (1992) Supplemental 1

Mallard duck (Anas platyrhynchus) 88 LD50 >1333 slightly toxic 43414528 A.G. Murray

et al (1 992) Supplemental 1

Northern bobwhite quail (Colinus virginianus) 88 LC50 >5156 practically non

- toxic 43414531 A.G. Murray

et al (1992) Core

Mallard duck (Anas platyrhynchus) 88 LC50 >5156 practically non

- toxic 43414530 A.G. Murray

et al (1992) Core

1 Study is classified supplemental, but does not need to be repeated (refer to Data Evaluation for details). Study is adequate for risk assessment

purposes.

Avian Reproduction

Species % ai NOAEC/LOAEC (ppm) Endpoints Affected MRID No.

Author/Yea r Study

Classification

Northern bobwhite quail (Colinus virginianus) 88 550/1100 eggs laid, live 3

- wk embryos, normal hatchlings, 14

- day old survivors, hatchling weight 43414533

J. B. Beavers et al (1994) Core

Mallard duck (Anas platyrhynchus) 88 5 50/1100 eggs laid, eggshell thickness, viable embryos, live 3

- wk embryos, normal hatchlings, 14

- day old survivors, terminal female body weight 43414532

J. B. Beavers et al (1994) Core39 Mammals, Acute and Chronic Wild mammal testing is required on a case

- by

- case basis, depending on the results of lower tier laboratory mammalian studies, intended use pattern and pertinent environmental fate characteristics. In most cases, rat or mouse toxicity values obtained from the Agency's Health Effects Division (HED ) substitute for wild mammal testing. Based on a laboratory rat LD 50 value of >5000 mg/kg, spinosad is practically nontoxic to small mammals on an acute oral basis. These toxicity values are reported below.

Mammalian acute toxicity

Species % ai Test Type Toxicity

Value Affected Endpoints MRID

Rat (Rattus norvegicus) Tech oral LD50 3738 mg/kg Male mortality 437707

- 01

434145

- 15

Mammalian chronic toxicity

Species % ai Test Type Toxicity

Value Affected Endpoints MRID Laboratory rat (R attus norvegicus) 88 Rat Reproduction 10 mg/kg

- bw None 437015

- 06

Terrestrial Invertebrates

Earthworm Toxicity

Species % ai LC50 (mg/kg) NOAEC (mg/kg) Endpoints

Affected MRID Study

Classification

Earthworm 88 >970 970 weight

decreases 434 145

- 48 Supplemental

Insects Based on a honey bee acute contact test LD 50 of 0.0029 ug ai/bee, Spinosad is highly toxic to bees on an acute contact basis (43414547; K.A. Hoxter et al 1992). The results of spinosad testing using the honeybee are tabulated below:

Non

- target insect toxicity

Species

% ai Results Toxicity Category/effects MRID Study

Classification

Honey bee (Apis mellifera) 88% 0.0029 ug ai/bee Highly Toxic 434145

- 47 Core

Honey bee (Apis mellifera) 0.02 N/A N/A 453408

- 01 Inv alid

Honey bee (Apis mellifera) 22.8% N/A N/A 450077

- 04 Invalid

Honey bee (Apis mellifera) 24% RT 25 = 3hrs Mortality 450077

- 02 Supplemental

Honey bee (Apis mellifera) 22.8% N/A N/A 450077

- 03 Invalid

Honey bee (residue) (Apis mellifera) 23.5% RT 25 = 3 hrs Mortality 450077

- 01 Core

Honey bee (field trail) (Apis mellifera) GF

- 120

Success fruit fly No adverse

effects at use

rates N/A 457082

- 01/457088

- 01 Supplemental40 Toxicity to Aquatic Animals The results of acute testing show that Spinosad is categ orized as slightly toxic to cold

- water freshwater fish and freshwater invertebrates, and moderately toxic to warm

- water freshwater fish. Results of freshwater animal acute toxicity testing are tabulated below.

Freshwater Animal Acute Toxicity

Species % ai EC50/ LC50 (ppm) Toxicity Category MRID No.

Author/Year Study

Classification

Waterflea (Daphnia magna) 88 EC 50 = 14 Slope=N/A slightly toxic 434145

- 37

D.P. Milazzo et al (1994) Core

Waterflea (Daphnia magna) 100 Factor D

Static 66.8 Slightly toxi c 465053

- 04 Acceptable

Waterflea (Daphnia magna) 96 Factor D

static 3.8 Slope=1.62 moderately toxic 465053

- 09 Acceptable

Waterflea (Daphnia magna) 99 Factor A >197 practically non

- toxic 465053

- 07 Acceptable

Waterflea (Daphnia magna) 94 Factor B 6.5 mode rately toxic 465053

- 12 Acceptable

Waterflea (Daphnia magna) 94 Factor B 6.39/21.4 Slope=1.78 moderately toxic 445977

- 31 Supplemental

Rainbow trout (Oncorhynchus mykiss) 88 LC 50 = 30 Slope=4.39 slightly toxic 434441

- 03 J.T. Weinberg et al (1993) Core

B luegill sunfish (Lepomis macrochirus) 88 LC 50 = 5.94 Slope=N/A moderately toxic 434145

- 34

J.L. Newsted and D.E. Brock (1992) Core

Based on results above, technical Spinosad and its metabolites are considered slightly to moderately toxic to freshwater a quatic invertebrates on an acute toxicity basis. Studies with Spinosad Factors resulted in limited solubility.

Technical Spinosad impacted reproduction in fish at 0.49 ppm and in invertebrates at the 0.0006 ppm. The results of freshwater fish and inverteb rate chronic testing are tabulated below.

Freshwater Aquatic Invertebrate Life

- Cycle Toxicity and Fish Early Life

- Stage Toxicity

Species % ai NOAEC/LOAEC (ppm) MATC (ppm) Endpoints

Affected MRID No. Study

Classification

Waterflea (Daphnia magna) 8 8 0.0006/0.0012 0.0008 growth and reproductive capacity 43848801 Core

Waterflea (Daphnia magna) 96 Factor D

Flow

- through 1.0/1.7 ppb survival, reproduction and growth 465053

- 01 Invalid

Waterflea (Daphnia magna) 100 Factor D

Static renewal 4.85/9.32 l ength 465053

- 03 Supplemental

Waterflea (Daphnia magna) 99 Factor A 1.59/3.24 (21 da) length 465053

- 06 Supplemental

Waterflea (Daphnia magna) 93 Factor B

Flow

- through 0.95/2.1 ppb survival/growth 465053

- 11 Invalid41 Freshwater Aquatic Invertebrate Life

- Cycle Toxicity and Fish Early Life

- Stage Toxicity

Species % ai NOAEC/LOAEC (ppm) MATC (ppm) Endpoints

Affected MRID No. Study

Classification

Midge ( Chironomus riparius ) Factor A & D 0.622/1.328 ppb 0.909 ppb % emergence 448284

- 02 Supplemental

Midge ( Chironomus riparius ) Dihydropsuedoaglycon e of Spinosad 99% 0.252/>0.252

0.0734/>0.0734 (28 da) % emergence,

M & F developmental

rates 465053

- 14 Supplemental

Rainbow trout (Oncorhyn chus mykiss) Factor A & D

Flow

- through 1.2/2.1(21 da)

LC50=4.9 Signs of toxicity mortality 465053

- 13 Supplemental

Rainbow trout (Oncorhynchus mykiss) 88 0.498/0.962 0.692 growth, survival, day to

mean hatch 434145

- 41 J.T. Weinberg

et al (1993) Core

Th e results show that Spinosad is categorized as moderately toxic to estuarine/marine fish and moderately to very highly toxic to estuarine/marine invertebrates on an acute basis. The results of acute toxicity testing with estuarine/marine species are tabul ated below.

Estuarine/Marine Acute Toxicity

Species % ai. LC50/EC50 (ppm) Toxicity Category MRID No.

Author/Year Study

Classification

Sheepshead minnow ( Cypridon variegatus ) 87.9 LC50 =7.87 Slope=7.62 moderately toxic 434145

- 40 Core

Eastern oyste r (shell deposition or embryo

- larvae) (Crassostrea virginica) 87.9 EC50 = 0.3 Slope=2.2 very highly toxic 434441

- 04/435712

- 03 Core

Grass Shrimp (Palaemonetes pugio ) 87.9 LC50>9.76 Slope=N/A moderately toxic 434145

- 39 Supplemental

Mysid (Americamysis ba hia) 87.9 LC50 >7.87 moderately toxic 434145

- 39 Supplemental 1

1 Although the mysid shrimp study was classified as supplemental (organisms should have been fed during the study), the study does not have to be repeated because the oyster was found to be the most sensitive invertebrate species tested, and will be used for risk assessment purposes in lieu of the mysid shrimp.

Spinosad reduced growth of sheepshead minnow with a MATC of 1.65 ppm. Reproduction is impacted at concentrations as low as 0.17 p pm in mysid shrimp. The results of estuarine animal chronic testing are tabulated below.

Estuarine/ Marine Chronic Toxicity

Species % ai NOAEC/LOAEC (ppm) MATC (ppm) Endpoints

Affected MRID No.

Author/Year Study

Classification

Sheepshead Minnow, (Cy prinodon variegatus) 88 1.15/2.38 1.65 growth (length and weight) 444206

- 01

R.L. Boeri et al (1997) Core

Mysid ( Mysidopsis bahia) 88 0.0842/0.173 0.121 number of young.female after 28 days of

exposure 444206

- 02

R.L. Boeri et al (1997) Core42 Estuarine/ Marine Chronic Toxicity

Species % ai NOAEC/LOAEC (ppm) MATC (ppm) Endpoints

Affected MRID No.

Author/Year Study

Classification

Leptocheiru s plumulosus 88 Pore water: 1.38 mg TRR/L

Overlying water: 0.327 mg TRR/L N/A No effect on

survival 47702901

J. Aufderheide (2009) Supplemental

Toxicity to Terrestrial and Aquatic Plants

Radish was shown to be the most sensitive Dicot for the Tier I toxi city test. The results of Tier 1 toxicity tests are tabulated below.

Nontarget Terrestrial Plant Seedling Emergence/Vegetative Vigor Toxicity (Tier I)

Species % ai Dose (lb ai/A) % Response

and Endpoint

Affected MRID No.

Author/Year Stud y Classification

6 Dicots/4 monocots 44.2% 0.5 No phytotoxic or other effects 445977

- 32

D. Schwab (1997) Core

Monocots

- corn, oat, wheat, onion

Dicots

- carrot, cucumber, radish, soybean, sunflower, tomato 88% 200 grams

ai/Hectare (0.18 lb/ai/A) <25% 4384 88

- 02

D. Schwab (1994) Core

The Tier II results indicate that the freshwater diatom is the most sensitive non

- vascular aquatic plant. Aquatic plant testing (Tier II) results are tabulated below.

Nontarget Aquatic Plant Toxicity (Tier II)

Species % ai EC50 (ppm) NOAEC (ppm) MRID No.

Author/Year Study

Classification

Vascular Plants

Duckweed Lemna gibba 88 10.6 Slope=1.2 1.86 434145

- 46

D. P. Milazzo et
al (1994) Core

Nonvascular Plants

Green algae Kirchneria subcapitata 88.2 >105.5 Slope=N/ A 4.3 434145

- 42

D.E. Brock (1992) Core

Marine diatom

Skeletonema costatum 88 0.227 Slope=4.03 0.167 434145

- 45 J.S. Hughes and

M.M. Alexander (1993) Core

Freshwater diatom Navicula pelliculosa 88 0.09 Slope=2.59 0.05 434145

- 43 J.S. Hughes and

M.M. A lexander (1994) Core

Freshwater diatom Navicula pelliculosa 99 Spinosin

A 31 biomass 8.34 cell density 465053

- 05 Supplemental43 Nontarget Aquatic Plant Toxicity (Tier II)

Species % ai EC50 (ppm) NOAEC (ppm) MRID No.

Author/Year Study

Classification

Freshwater diatom Navicula pelliculosa 94 Factor B 0.16 cell density <0.019 465053

- 10 Supplemental

Freshwater diatom

Navi cula pelliculosa 96 Factor D 0.22 cell density 0.17 465053

- 08 Supplemental

Freshwater diatom Navicula pelliculosa 100 Spinosin

D 19 biomass 14.2 465053

- 02 Supplemental

Blue

- green algae Anabaena flos

- aquae 88 8.9 Slope=4.05 3.9 43414544 J.S. Hughe s and

M.M. Alexander (1993) Core44 

## Appendix D : Modeling Results for Aquatic Exposure

These exposure concentrations were calculated using PRIZM/EXAMS pe5. The assessment is conservative in that it assumes the maximum applic ation rate (0.45 lbs ai/A), no flow through the

field and no dilution from rainfall.

Spinosad Environmental Fate Input Parameters for PRIZM/EXAMS

Parameter Spinosad A Value Source

PC Code 110003 N/A Water Solubility (20 C, distilled water) 89.4 mg/L

Molecular Weight 732 g/mole Hydrolysis Half

- Life (pH 5,7,9) Stable MRID 43507301 Aerobic Soil Metabolism (days) Stable MRID 43507305

Anaerobic Aquatic Metabolism (days) Stable MRID 43507304

Aqueous Photolysis Half

- Life (days) Stable MRID 435073 02

Soil Water Partition Coefficient (Lowest non

- sand Koc) 4237 MRID 43507306

Vapor Pressure (torr) 2.4e - 10 Product Chemistry

Application Information Crop Label Rate (lbs/ac) Input Rate (lbs/ac) Max App /

Year Max lb

a.i./A/

season Min

Interval (day s)

Onions for

seed 0.45 0.45 1 0.45 0

Maximum Exposure Values

Water Column Concentration (ppm) Sediment Pore Water Concentration (ppm)

Peak Value 0.004 0.004 21 Day 0.004 0.004 60 Day 0.004 0.00445 stored as Onions.out Chemical: spinosad

PR ZM environment: WAonionsNMC.txt modified Thuday, 14 June 2007 at 11:18:44 EXAMS environment: pond298.exv modified Tueday, 26 August 2008 at 06:14:08

Metfile: w24243.dvf modified Tueday, 26 August 2008 at 06:15:56 Water segment concentrations (ppb)

Year Pe ak 96 hr 21 Day 60 Day 90 Day Yearly

1961 0.2474 0.2137 0.1316 0.09524 0.08153 0.04979

1962 0.6032 0.5363 0.3736 0.2655 0.2341 0.1432

1963 0.4746 0.4406 0.3722 0.3295 0.3133 0.2801

1964 2.115 1.89 0.9444 0.5422 0.4703 0.3588

1965 1.317 1.231 0.9476 0.8608 0.808 0.7619

1966 1.28 1.206 1.111 0.9645 0.941 0.9189

1967 1.175 1.141 1.059 1.004 0.9913 0.9627

1968 1.593 1.522 1.353 1.247 1.228 1.138

1969 1.44 1.406 1.324 1.269 1.257 1.23

1970 2.126 2.061 1.782 1.552 1.53 1.447

1971 1.955 1.883 1.709 1.606 1.603 1.5 78

1972 1.828 1.794 1.712 1.657 1.644 1.618

1973 2.264 2.194 2.05 1.911 1.835 1.715

1974 2.792 2.663 2.357 2.155 2.109 1.998

1975 2.877 2.767 2.5 2.33 2.291 2.161

1976 2.464 2.431 2.348 2.293 2.28 2.251

1977 3.719 3.508 2.961 2.524 2.447 2.329

1978 2.762 2 .729 2.647 2.591 2.579 2.56

1979 2.825 2.791 2.709 2.654 2.641 2.616

1980 3.111 3.047 2.901 2.782 2.754 2.712

1981 3.21 3.15 3.002 2.917 2.9 2.815

1982 3.47 3.395 3.227 3.118 3.085 3.007

1983 3.677 3.59 3.408 3.28 3.221 3.128

1984 3.482 3.443 3.361 3.289 3 .275 3.252

1985 3.524 3.491 3.409 3.353 3.341 3.314

1986 4.442 4.294 3.925 3.723 3.699 3.62

1987 5.086 4.873 4.354 3.942 3.86 3.735

1988 4.725 4.61 4.334 4.159 4.119 4.02

1989 4.304 4.27 4.19 4.135 4.123 4.096

1990 5.935 5.672 5.051 4.674 4.589 4.306

Sort ed results

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

0.032258064516129 5.935 5.672 5.051 4.674 4.589 4.306

0.0645161290322581 5.086 4.873 4.354 4.159 4.123 4.096

0.0967741935483871 4.725 4.61 4.334 4.135 4.119 4.02

0.129032258064516 4.442 4.294 4.19 3.9 42 3.86 3.735

0.161290322580645 4.304 4.27 3.925 3.723 3.699 3.62

0.193548387096774 3.719 3.59 3.409 3.353 3.341 3.31446 0.225806451612903 3.677 3.508 3.408 3.289 3.275 3.252

0.258064516129032 3.524 3.491 3.361 3.28 3.221 3.128

0.290322580645161 3.482 3.443 3.227 3.118 3.085 3.007

0.32258064516129 3.47 3.395 3.002 2.917 2.9 2.815

0.354838709677419 3.21 3.15 2.961 2.782 2.754 2.712

0.387096774193548 3.111 3.047 2.901 2.654 2.641 2.616

0.419354838709677 2.877 2.791 2.709 2.591 2.579 2.56

0.451612903225806 2.825 2.767 2.647 2.524 2.447 2.329

0.483870967741936 2.792 2.729 2.5 2.33 2.291 2.251

0.516129032258065 2.762 2.663 2.357 2.293 2.28 2.161

0.548387096774194 2.464 2.431 2.348 2.155 2.109 1.998

0.580645161290323 2.264 2.194 2.05 1.911 1.835 1.715

0.612903225806 452 2.126 2.061 1.782 1.657 1.644 1.618

0.645161290322581 2.115 1.89 1.712 1.606 1.603 1.578

0.67741935483871 1.955 1.883 1.709 1.552 1.53 1.447

0.709677419354839 1.828 1.794 1.353 1.269 1.257 1.23

0.741935483870968 1.593 1.522 1.324 1.247 1.228 1.138

0.77 4193548387097 1.44 1.406 1.111 1.004 0.9913 0.9627

0.806451612903226 1.317 1.231 1.059 0.9645 0.941 0.9189

0.838709677419355 1.28 1.206 0.9476 0.8608 0.808 0.7619

0.870967741935484 1.175 1.141 0.9444 0.5422 0.4703 0.3588

0.903225806451613 0.6032 0.5363 0.3 736 0.3295 0.3133 0.2801

0.935483870967742 0.4746 0.4406 0.3722 0.2655 0.2341 0.1432

0.967741935483871 0.2474 0.2137 0.1316 0.09524 0.08153 0.04979

0.1 4.6967 4.5784 4.3196 4.1157 4.0931 3.9915 Average of yearly averages: 2.13737966666667

Inputs gen erated by pe5.pl

- Novemeber 2006

Data used for this run: Output File: Onions

Metfile: w24243.dvf

PRZM scenario: WAonionsNMC.txt

EXAMS environment file: pond298.exv

Chemical Name: spinosad Description Variable Name Value Units Comments Molecular weight mw t 732 g/mol Henry's Law Const. henry atm

- m^3/mol Vapor Pressure vapr 2.4e

- 10 torr Solubility sol 89.4 mg/L

Kd Kd mg/L

Koc Koc 4237 mg/L Photolysis half

- life kdp 0 days Half

- life Aerobic Aquatic Metabolism kbacw 0 days Halfife Anaerobic Aquatic Metabolism kbacs 0 days Halfife

Aerobic Soil Metabolism asm 0 days Halfife47 Hydrolysis: pH 7 0 days Half

- life

Method: CAM 4 integer See PRZM manual Incorporation Depth: DEPI 2.5 cm Application Rate: TAPP 0.5 kg/ha Application Efficiency: APPEFF .99 fraction Spray Dri ft DRFT 0.01 fraction of application rate applied to pond Application Date Date 01

- 04 dd/mm or dd/mmm or dd

- mm or dd

- mmm Record 17: FILTRA

IPSCND 1

UPTKF

Record 18: PLVKRT

PLDKRT

FEXTRC 0.5 Flag for Index Res. Run IR EPA Pond Flag for runoff calc. RUNOFF none, monthly or total(average of entire run)

****************************************************************************

stored as Onionsben.out Chemical: spinosad

PRZM environment: WAonionsNMC.txt modified Thuday, 14 June 2007 at 11:18:44

EXAMS environment: pond298.exv modified Tueday, 26 August 2008 at 06:14:08

Metfile: w24243.dvf modified Tueday, 26 August 2008 at 06:15:56 Benthic segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 0.06461 0.06375 0.05513 0.0517 0.051 08 0.03531

1962 0.1841 0.1841 0.184 0.1822 0.1682 0.1148

1963 0.2778 0.2778 0.2775 0.275 0.2735 0.2516

1964 0.4665 0.4535 0.3568 0.3294 0.3245 0.3069

1965 0.7206 0.7205 0.7197 0.7131 0.7109 0.6868

1966 0.8931 0.893 0.8921 0.881 0.8754 0.8518

1967 0.9306 0. 9306 0.9306 0.9306 0.9306 0.9204

1968 1.137 1.137 1.135 1.133 1.13 1.056

1969 1.193 1.193 1.189 1.187 1.187 1.175

1970 1.395 1.395 1.387 1.381 1.38 1.355

1971 1.521 1.521 1.518 1.516 1.516 1.496

1972 1.567 1.566 1.562 1.561 1.561 1.55

1973 1.734 1.734 1.73 2 1.704 1.675 1.62

1974 1.943 1.943 1.943 1.943 1.943 1.886

1975 2.133 2.133 2.133 2.133 2.133 2.046

1976 2.173 2.173 2.173 2.173 2.173 2.162

1977 2.367 2.364 2.304 2.243 2.233 2.206

1978 2.465 2.465 2.464 2.462 2.461 2.448

1979 2.53 2.53 2.529 2.525 2.523 2.508

1980 2.651 2.651 2.646 2.619 2.612 2.59

1981 2.757 2.757 2.754 2.749 2.741 2.692

1982 2.959 2.958 2.954 2.946 2.934 2.859

1983 3.083 3.083 3.08 3.049 3.029 2.9948 1984 3.156 3.156 3.153 3.139 3.136 3.119

1985 3.199 3.199 3.199 3.199 3.198 3.185

1986 3 .518 3.518 3.518 3.518 3.516 3.427

1987 3.723 3.722 3.687 3.607 3.592 3.559

1988 3.891 3.891 3.891 3.891 3.891 3.842

1989 3.95 3.95 3.95 3.949 3.949 3.936

1990 4.257 4.257 4.257 4.257 4.256 4.089

Sorted results

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

0.032258064516129 4.257 4.257 4.257 4.257 4.256 4.089

0.0645161290322581 3.95 3.95 3.95 3.949 3.949 3.936

0.0967741935483871 3.891 3.891 3.891 3.891 3.891 3.842

0.129032258064516 3.723 3.722 3.687 3.607 3.592 3.559

0.161290322580645 3.518 3.518 3.518 3.51 8 3.516 3.427

0.193548387096774 3.199 3.199 3.199 3.199 3.198 3.185

0.225806451612903 3.156 3.156 3.153 3.139 3.136 3.119

0.258064516129032 3.083 3.083 3.08 3.049 3.029 2.99

0.290322580645161 2.959 2.958 2.954 2.946 2.934 2.859

0.32258064516129 2.757 2.757 2.754 2.749 2.741 2.692

0.354838709677419 2.651 2.651 2.646 2.619 2.612 2.59

0.387096774193548 2.53 2.53 2.529 2.525 2.523 2.508

0.419354838709677 2.465 2.465 2.464 2.462 2.461 2.448

0.451612903225806 2.367 2.364 2.304 2.243 2.233 2.206

0.483870967741936 2.173 2.173 2.173 2.173 2.173 2.162

0.516129032258065 2.133 2.133 2.133 2.133 2.133 2.046

0.548387096774194 1.943 1.943 1.943 1.943 1.943 1.886

0.580645161290323 1.734 1.734 1.732 1.704 1.675 1.62

0.612903225806452 1.567 1.566 1.562 1.561 1.561 1.55

0.6451 61290322581 1.521 1.521 1.518 1.516 1.516 1.496

0.67741935483871 1.395 1.395 1.387 1.381 1.38 1.355

0.709677419354839 1.193 1.193 1.189 1.187 1.187 1.175

0.741935483870968 1.137 1.137 1.135 1.133 1.13 1.056

0.774193548387097 0.9306 0.9306 0.9306 0.9306 0.9 306 0.9204

0.806451612903226 0.8931 0.893 0.8921 0.881 0.8754 0.8518

0.838709677419355 0.7206 0.7205 0.7197 0.7131 0.7109 0.6868

0.870967741935484 0.4665 0.4535 0.3568 0.3294 0.3245 0.3069

0.903225806451613 0.2778 0.2778 0.2775 0.275 0.2735 0.2516

0.935483 870967742 0.1841 0.1841 0.184 0.1822 0.1682 0.1148

0.967741935483871 0.06461 0.06375 0.05513 0.0517 0.05108

0.03531

0.1 3.8742 3.8741 3.8706 3.8626 3.8611 3.8137 Average of yearly averages: 2.03212033333333

Inputs generated by pe5.pl

- Novemeber 200 649 Data used for this run: Output File: Onions

Metfile: w24243.dvf

PRZM scenario: WAonionsNMC.txt

EXAMS environment file: pond298.exv

Chemical Name: spinosad Description Variable Name Value Units Comments Molecular weight mwt 732 g/mol Henry's Law Const. h enry atm

- m^3/mol Vapor Pressure vapr 2.4e

- 10 torr Solubility sol 89.4 mg/L

Kd Kd mg/L

Koc Koc 4237 mg/L Photolysis half

- life kdp 0 days Half

- life Aerobic Aquatic Metabolism kbacw 0 days Halfife Anaerobic Aquatic Metabolism kbacs 0 days Halfife

Aerobic So il Metabolism asm 0 days Halfife Hydrolysis: pH 7 0 days Half

- life

Method: CAM 4 integer See PRZM manual Incorporation Depth: DEPI 2.5 cm Application Rate: TAPP 0.5 kg/ha Application Efficiency: APPEFF .99 fraction Spray Drift DRFT 0.01 fraction of applica tion rate applied to pond Application Date Date 01

- 04 dd/mm or dd/mmm or dd

- mm or dd

- mmm Record 17: FILTRA

IPSCND 1

UPTKF

Record 18: PLVKRT

PLDKRT

FEXTRC 0.5 Flag for Index Res. Run IR EPA Pond Flag for runoff calc. RUNOFF none, monthly or total(a verage of entire run)