BIOPESTICIDES REGISTRATION ACTION DOCUMENT



## Optimum® AcreMaxTM B.t. Corn Seed Blends

U.S. Environmental Protection Agency (EPA) Office of Pesticide Programs Biopesticides and Pollution Prevention Division (BPPD)

Updated August, 2011Optimum AcreMax B.t. Corn S eed Blends Page 2 of 54 Biopesticides Registration Action Document



### TABLE OF CONTENTS

I. OVERVI EW ................................................................................................................. 3

A. BACKGROUND ................................................................................................................. ..... 3

B. USE PROF ILE ......................................................................................................... 3

II. INSECT RESISTANCE MANAGEMENT ................................................................. 6

III. BENEFITS - CORN ROOTWORM SEED BLEND ................................................. 15

IV. REGULATORY RATIONAL E .............................................................................. 17

V. TERMS AND CONDITIONS FOR NEW ECB SEED BLENDS.............................. 23

OAM; EPA REGISTRATION NUMBER 29964-12....................................................... 23

OAM XTRA; EPA REGIST RATION NUMBER 29964-11 ............................................ 35

VI. REFERENCES ....................................................................................................... 50Optimum AcreMax B.t. Corn S eed Blends Page 3 of 54 Biopesticides Registration Action Document

I. OVERVIEW

A. BACKGROUND

On April 30, 2010, EPA conditionally registered th e plant-incorporated protectant products, Optimum® AcreMaxTM 1 (OAM1), a seed bl end of 90% HERCULEX® XTRA and 10% HERCULEX® I, and OAM RW, a seed bl end of 90% HERCULEX® RW and 10% Non- B.t. Corn. These registrations were originally se t to expire on September 30, 2010. The registrant for both products is Pioneer Hi-Bre d International, Inc. (Pioneer). OAM1 is the first registered B.t. corn product to incorpor ate a "blended" refuge; i.e., th e OAM1 product requires a 10% refuge for corn rootworm, and the corn rootworm refuge seed is sold within the same seed bag as the B.t. corn rootworm product. (OAM1 also re quires a separate 20% re fuge for lepidopteran pests, and that refuge is in the form of a structured refuge that is sold separately).

EPA considered amending the OAM products at the same time as other expiring Bt corn registrations. Consistent with th e policy of making re gistration actions more transparent, the proposed amendments to the expiring OAM1 and OAM RW corn products were subject to a 30- day comment period, along with other Bt corn PIPs, expressing differe nt proteins effective in controlling various lepidopteran and coleopteran pests, that were set to expire in 2010 (Docket Number EPA-HQ-OPP-2010- 0607). Based on all data submitte d in support of the expiring OAM1 and OAM RW corn registrations and in c onsideration of the public comments received, the Agency concluded that it is in the best interest of the pub lic and the environment to amend the currently existing OAM1 and OAM RW regi strations by extending the current expiration dates to September 30, 2012. These amendments were granted on September 29, 2010. The basis for this decision can be found within this Biope sticides Registration Ac tion Document (BRAD).

On April 19, 2010, Pioneer applied to register two new seed blends that incorporate the lepidopteran refuge within the seed blend in the bag. Optimum® AcreMaxTM Xtra Insect

Protection contains a seed blend w ith 90% 1507xMON810x59122 (Cry1Ab x Cry34/35Ab1 x Cry1F) and 10% Non- B.t. Corn. Optimum® AcreMaxTM Insect Pr otection contains a seed blend with 95% Optimum® IntrasectTM (Cry1Ab x Cry1F) and 5% Non- B.t. Corn.

B. USE PROFILE

Active Ingredients:

Bacillus thuringiensis Cry34Ab1 and Cry35Ab1 proteins and the genetic material necessary for their production (P HP17662 T-DNA) in event DAS-59122-7 corn (OECD Unique Identifier: DAS-59122-7)

Bacillus thuringiensis Cry1F protein and the genetic mate rial (plasmid insert PHI8999A) necessary for its production in corn event DAS-Ø15Ø7-1

Bacillus thuringiensis Cry1Ab delta-endotoxin and the genetic material necessary for its production (Vestor PV-ZMCT01) in event MO N 810 corn (OECD Unique Identifier: MONØØ81Ø-6)Optimum AcreMax B.t. Corn S eed Blends Page 4 of 54 Biopesticides Registration Action Document

Trade & Other Names:

HERCULEX® I => Cry1F Corn

HERCULEX® RW (Rootworm) => Cry34/35Ab1 Corn

HERCULEX® XTRA => Cry1F + Cry34/35Ab1 Corn

MON810 => Cry1Ab Corn

Optimum® AcreMaxTM 1 (OAM1) => Seed Blend of 90% HERCULEX® XTRA

and 10% HERCULEX® I

OAM RW => Seed Blend of 90% HERCULEX® RW and 10% Non- B.t. Corn

Optimum® AcreMaxTM Xtra Insect Protection => Seed Blend of 90% Cry1Ab x Cry1F x Cry34/35Ab1 and 10% Non- B.t. Corn

Optimum® AcreMaxTM Insect Protection => Seed Blend of 95% Cry1Ab x Cry1F

and 5% Non- B.t. Corn

OPP Chemical Codes: 006490 (Cry34/35Ab1 corn), 006481 (Cry 1F corn), and 006430 (Cry1Ab corn)

Type of Pesticide: Plant-Incorporated Protectants (PIPs)

Product Profile:

HERCULEX® I The registration for Cry1F Event TC1507 (Event DAS-01507-1), also known as HERCULEX® I, was first granted by the Agency on Ma y 18, 2001. HERCULEX® I expresses the Cry1F insecticidal crystal protein as well as the PAT (phosphinothrin acetyl transferase) protein, which

confers tolerance to the herbicid al active ingredient glufosinate- ammonium. Cry1F is efficacious against lepidopteran pests, and the primary targ et pest of HERCULEX® I is the European corn borer (ECB, Ostrinia nubilalis ); other target pests are corn earworm (CEW, Helicoverpa zea ), southwestern cornborer (SWCB, Diatrea grandiosella ), fall armyworm (FAW, Spodoptera frugiperda ), western bean cutworm (WBCW, Richia albicosta ), and black cutworm (BCW, Agrotis ipsilon ). The main target pests for which insect resistance management (IRM) requirements apply are ECB, CEW, and SWCB.

HERCULEX® RW The registration for Event DAS-59122-7, also kn own as HERCULEX® RW, was granted by the Agency in August, 2005. HERCULEX® RW expresses B.t. toxins Cry34Ab1 and Cry35Ab1, which are efficacious against coleopteran pests. The primary target pests of HERCULEX® RW

are western corn rootworm and northern corn rootworm (CRW, Diabrotica species). Maize containing Event 59122-7 has been modified to expr ess the PAT protein, wh ich confers tolerance to gluphosinate-alum inum herbicide.Optimum AcreMax B.t. Corn S eed Blends Page 5 of 54 Biopesticides Registration Action Document

HERCULEX® XTRA The registration for HERCULEX® XTRA (E vent TC1507 x DAS59122-7) was granted in

October 2005. HERCULEX® XTRA is the resu lt of a conventional breeding cross between

HERCULEX® I and HERCULEX® RW and is consider ed a stacked PIP because it targets two different kinds of pests (Lepi doptera and Coleoptera) and cont ains two separate PIP active ingredients.

OAM1: EPA Registration Number 29964-6 Optimum® AcreMaxTM 1 Insect Prot ection, a blended seed product th at contains two different kinds of seeds of the already registered products HERCULEX® XT RA and HERCULEX® I was registered on April 30, 2010. The product incorpor ates the CRW refuge into the seed bag. The seed blend percentage was amended to 90% HERCULEX® XTRA and 10% HERCULEX®

I.

OAM RW: EPA Registration Number 29964-10 Optimum® AcreMaxTM RW Insect Protection, a seed blend consisting of 90% HERCULEX®

RW and 10% non- B.t. corn was registered on April 30, 2010. The product incorporates the CRW refuge into the seed bag and also can serv e as a refuge for the Cry1F portion of OAM1.

Optimum ® Intrasect TM : EPA Registration Number 29964-7 Optimum® IntrasectTM is a Bt corn with Cry1Ab and Cry1F both targeting European corn borer

and southwestern corn borer and wa s registered on February 24, 2010.

1507x MON810x59122: EPA Registration Number 29964-8 1507x MON810x59122 is a Bt corn with Cry1Ab and Cr y1F targeting European corn borer and southwestern corn borer and Cry34/35Ab1 targe ting corn rootworm. It was registered on February 24, 2010.

OAM: EPA Registration Number 29964-12 OAM is a blended seed product th at contains two di fferent kinds of seeds of the already registered product Optimum® In trasectTM (95%) and 5% Non- B.t. Corn.

OAM Xtra: EPA Registration Number 29964-11 OAM Xtra is a blended seed produc t that contains two different kinds of seeds of the already registered product 1507x M ON810x59122 (90%) and10% Non- B.t. Corn.

Pioneer’s Projected Use in 2010, 2011, and 2012

Pioneer’s forecast for OAM1 U.S. acreage in the 2010, 2011, and 2012 growing seasons is listed below. Pioneer states that “[t]hese estimates ha ve been divided into high-pressure areas for corn rootworm (i.e., the Red Zone) and non-Red Zone acres (i.e., the remaining U.S. corn acreage outside the Red Zone). The Red Zone is defi ned by Pioneer as 90 coun ties that have a 100% chance of corn rootworm infestation in any give n year. These counties ar e primarily located in northeastern Illinois, no rthwestern Indiana and, to a lesser extent, southeastern Wisconsin and southwestern Michigan. Because of the strong selection pressure present in the Red Zone, it is considered a potential area for corn rootworm re sistance to develop. Th e percentages are based on general USDA acreage projections, which project a total of 90 million corn acres in the U.S. in 2010, 2011, and 2012.”Optimum AcreMax B.t. Corn S eed Blends Page 6 of 54 Biopesticides Registration Action Document

Growing season Red Zone geogr aphy Non-Red Zone geography

2010 ~0.077% ~0.042%

2011 ~5.8% ~8.2%

2012 ~8% ~12%

Pioneer provided information to EPA indicatin g that the total OAM1 acres planted in 2010 was 34,804, which is less than originally projected. (Rood 2010). Pioneer has not changed the initial projections for 2011 and 2012.

II. INSECT RESISTANCE MANAGEMENT

A. Corn Rootworm

FIFRA Scientific Advisory Panel (SAP)

Pioneer/Dupont's initial registra tion application for OAM1 consis ted of a seed blend of 95% HERCULEX® XTRA and 5% [3.5% (±1.5) ] HERCULEX® I. The HERCULEX® I was intended to serve as the IRM refuge for the corn rootworm active co mponent of HERCULEX® XTRA. The proposed seed blend strategy and re duction in refuge from 20% to 2% to 5% represented a significant paradigm shift for the B.t. IRM strategy that has been employed for over 15 years. BPPD conducted a risk assessment and presented preliminary conclusions to the Scientific Advisory Panel for peer review on February 23 to 24, 2009.

The SAP (2009) expressed concer n about the proposed refuge reduction. The Panel concluded that there was no compelling eviden ce, either in the data provid ed by Pioneer or in the public literature, to support a 5% blende d refuge for this particular pr oduct. The Panel noted, however, that the biology of the corn rootworm makes it su sceptible to successful control and mitigation by a seed blend methodology, if the refuge is of sufficient size.

Ad hoc members of the SAP commented on EP A's grant of the OAM1 registration for 2010.

These members noted that the 2009 SAP had voi ced concerns on the simultaneous approval of a blended and reduced refuge for corn rootworm , and stated that EPA "ignored" the 2009 SAP's general conclusion to retain a 20% refuge while research continues. In granting a registration for sale and distribution of OAM1 for the 2010 growi ng season, EPA did consider and rely upon the

advice of the SAP. Pioneer's in itial application sought approval for a 2.5 % blended refuge and

that is what EPA took before the SAP. Concerns raised by the SAP were a major factor in why the Agency did not approve the 2.5% blended refuge proposal. Moreover, the concerns raised by the SAP, and other commenters, are a significant factor in certain of the unique terms and conditions that EPA is placing on the OAM1 re gistration for 2011 – 2012. The ad hoc members also commented that the SAP's concerns rega rding Pioneer's hypothesi s concerning mode of

action were not addressed. EPA did not specifically address the SAP's recommendation on the mode of action hypothesis because that hypothesis did not play a role in our decision. EPA similarly has concerns as to the validity of th e mode of action hypothesis and did not in any way factor this hypothesis in our decision.

OAM1 is a blended seed product that cont ains 90% HERCULEX® XTRA seeds (Cry34/35Ab1 x Cry1F) and 10% HERCULEX® I seeds (Cry1F).

OAM RW is a blended seed product that contains 90% HERCULEX® RW seeds (Cry34/35Ab1) and 10% non- B.t. Corn.Optimum AcreMax B.t. Corn S eed Blends Page 7 of 54 Biopesticides Registration Action Document

Seed Blending

Pioneer submitted information and analyses suppor ting their claim that refuge plants will be randomly distributed throughout th e field, including information i ndicating that the expected error of mixing the refuge seed is ±1.5% (usi ng the seed mixing technology described in their submission) and that the standard deviation for planting the correct pe rcentage of refuge is ±1%.

IRM Modeling

EPA Model Description

EPA'S POPGEN (Population Genetics ) simulation models are a series of generalized, flexible population genetics modeling systems modeling th e evolution of resistance to conventional pesticides and transgenic crops. The programs are capable of simulating complex landscapes that vary spatially as well as temporally over the course of a growing season.

POPGEN-D

The deterministic model POPGEN-D is a relatively simple frequency-based model that incorporates non-compliance estimates, non-rand om mating in refuge fields, and larval movement. The model permits modeling of bot h block refuges and blended seed-mixture refuges.

POPGEN-S2

The stochastic model POPGEN-S2 is a modification of an earlier stochastic, spatially explicit, dual locus, simulation model designed to evaluate the development of resistance in crop pests to insecticides. (Caprio et al 2006).

POPGEN-SM

The stochastic model POPGEN-SM is a modification of an earlier stochas tic, spatially explicit, dual locus, simulation model designed to evaluate development of resistance in crop pests to insecticides and incorporating multi loci. (Caprio et al 2006).

To incorporate uncertainty in the parameters used in the deterministic model, distributions, based

on data for the lowest and maxi mum possible values, were devel oped as well as a most likely

value. These values were used in PERT distribu tions based on a beta distribution with the most likely value weighted by 4 (Vose 2001).

Dr. David Onstad of the University of Illinoi s commented that it was difficult to understand EPA's modeling because insufficient detail on th e design and inputs was included in the docket for the initial registrati on. We recognized that it would have been useful to place more information on the modeling in the docket. Unfo rtunately, this information was not ready for release at the start of the comment period. We supplemented the docket with additional information on the model and model inputs dur ing the comment period. Dr. Onstad also suggested that EPA's modeling efforts should be more transp arent and should include more explicit explanation of how the modeling wa s conducted. We hope that the additionalOptimum AcreMax B.t. Corn S eed Blends Page 8 of 54 Biopesticides Registration Action Document

information provided to the docket addressed the concerns regarding tran sparency. Also, EPA will convene a public meeting of the SAP to evalua te these models in early December. We urge all interested parties to partic ipate and submit comments at that time. Additional information on this meeting of the SAP will be availa ble within the normal time frame.

5% Seed Blend

Subsequent to the February 2009, FIFRA Scientif ic Advisory Panel meeting, Pioneer submitted revised modeling that incorporat ed new corn rootworm movement data. EPA fully evaluated this modeling, including assessing the new corn rootworm movement data. In addition, using the

POPGEN model deve loped by EPA ORD, EPA conducted an independent modeling analysis of Pioneer's proposed seed blend using both determin istic and stochastic models. EPA concluded that a number of critical input parameters to the Pioneer modeling were not supported by data or were inadequate to support a rational basis fo r regulatory decisionmaking. Therefore, BPPD

concluded that the results of the Pioneer modeli ng indicating that the propos ed 5% seed blend is superior to a 20% block refuge deployment strategy for OAM1 and corn rootworm were not scientifically supported.

EPA had concerns regarding Pioneer's assumptions about short range insect dispersal because the data (Nowatzki et al. 2003) were limited, a nd were derived from only one location in the

cornbelt. This was a critical factor because the adult insect dispersal input is a sensitive parameter for modeling the durability of block ref uges. Parameter inputs representing a shorter dispersal range lowered the resulting effectiv eness of a block refuge. Using a range of representative parameter values and assumptions to predict the durability of a 20% block refuge versus Pioneer's proposed 5% blended refuge, EPA's deterministic modeling showed that the predicted durability for the 20% block refuge wa s superior to a 5% seed blend strategy (11.95 years vs. 8.1 years).

In addition to the 5% seed blend, EPA modeled other blend percentages for comparison. A 10% seed blend was predicted to have a durability of 11.3 years, which was slightly less durable (5.4%) relative to a 20% block refuge based on EPA's assumptions. EPA concluded, however,

that these results were of lim ited actual utility because a numbe r of parameter inputs to the original Pioneer model did not reflect actual vari ability and/or uncertainty. Therefore, to assess the current application for a 10% blended refuge, EPA conducte d modeling using a range of representative input parameters.

10% Seed Blend

In the latest modeling, EPA incorporated uncer tainty by using probabilis tic distributions of

critical data that we determined to be variable and/or uncerta in. The analysis was based on a PERT-Beta distribution (minimum value, most li kely, and maximum value) for parameters of uncertainty. Each simulation was run1,000 times, a nd each run utilized input parameters drawn

from the PERT distributions. "Resistance" was defined as the resistance allele exceeding 50%, and EPA measured the mean, 25 th, and 75 th percentiles of the time to "resistance." EPA also determined the proportion of simulations where th e time to resistance exceeded 11 years. (The SAP has advised that 15 years with no resist ance is a reasonable goal for an IRM program applicable to a single-gene toxin. The Cry34/35 transgenic toxin has been in use for four years. Therefore, we believe it relevant to assess how many of the simula tions indicate that either the 20% block or the 10% blend will delay development of resistance for 11 or more years.) TheOptimum AcreMax B.t. Corn S eed Blends Page 9 of 54 Biopesticides Registration Action Document

data analysis indicated comparative durability values of 11.3 years for the 10% blended refuge, yet 20.2 years of durability for the 20% block ref uge. Thus, the 10% blend was 45% less durable than the 20% block refuge currentl y required for single trait CRW PIPs.

IRM Refuge Compliance

Critical to an assessment of the likely efficacy of an IRM mitigation program is the level of compliance with that program. Data receiv ed by EPA from the Agri cultural Biotechnology Stewardship Technical Committee (ABSTC) indicat e that compliance with the paradigmatic 20% block refuge requirement for most B.t. corn crops has been stead ily decreasing. As noted by a number of commenters, this decreased co mpliance increases the risk of resistance development (see, e.g., Complacency on the Farm , CSPI 2009, and Impact of Genetically Engineered Crops on Farm Sustain ability in the United States, NAS 2010 )

.

For the 2002 to 2008 planting seasons, ABSTC reported refuge compliance either as ‘all compliant' (i.e., always planting a 20% refuge, with in the proper distance) or 'out-of-compliance’ (i.e., not having either a 20% ref uge, or having the refuge not lo cated exactly where required, or neither). In 2007 and 2008, ABSTC be gan to also report if growers at least planted a 15% refuge or/and if most of a grower's B.t. fields met the refuge distance requirement. (Reporting these

additional data reflects that ther e may be degrees of noncompliance, for example, a grower may be inadvertently out of compliance with di stance requirements by a degree that does not materially affect the efficacy of the refuge. Also, while, admittedly, a 15% refuge is not compliant with a 20% refuge requi rement, it has a much different field impact than does a 0% refuge.)

The graphs and chart below compare complian ce data from the ABSTC telephone and online

surveys.Optimum AcreMax B.t. Corn S eed Blends Page 10 of 54 Biopesticides Registration Action DocumentOptimum AcreMax B.t. Corn S eed Blends Page 11 of 54 Biopesticides Registration Action Document

Telephone and Online Survey for Bt Protected Corn

2002-2010 Refuge Compliance Refuge Distance

year Refuge Size CRW PIPs Stacks year ECB PIP CRW

PIPs Stacks

'02 86 '02 89

'03 92 '03 93

'04 91 '04 96

'05 92 93 '05 96 87

'06 89 89 78 '06 96 82 92

'07 80 80 70 '07 88 79 66

'08 78 74 72 '08 88 63 66

'09 74 79 71 '09 78 71 67

'10 76 73 69 '10 87 67 63

B. European Corn Borer and Southwestern Corn Borer

An SAP meeting (December 2010), convened to evaluate a similar seed blend product, concluded (based on modeling analysis) that a dual gene, high efficacy product with a seed blend approach targeting ECB and SWCB was less durable than a block refuge of equivalent non-Bt proportion (SAP 2011).

BPPD reviewed biological data and simulation modeling for lepidopt era pest of corn that was submitted by Pioneer/DuPont to support a registration request for a 5% Optimum AcreMax (expressing Cry1F and Cry1Ab) and 10% Opt imum AcreMax Xtra RI B (expressing Cry1F, Cry1Ab, and Cry34/35) (BPPD 2011a). BPPD identifie d a number of concerns and deficiencies with the proposed refuge strategies and was unable to quantify the re lative durability of the proposed seed blends at that time (BPPD 2011a), ye t concluded that a 5% block refuge was more durable than a 5% RIB (SAP 2011). Pioneer/DuP ont responded to the Agency’s review by resubmitting additional explanations and modeling (MRID 485219-01) to address the

uncertainties and deficiencies .

Pioneer’s Results:

Pioneer/DuPont reported that infl ating the fecundity of ECB and SWCB to avoid extinction and effects of genetic drift, as recommended by BP PD, lead to unrealistically small durability estimates as was evident for the single toxin si mulations. For single PIPs deployed with a 20% structured refuge, estimated durab ilities were less than the actual time the products had been commercialized. The applicant recommended that re sults be considered relative to each other rather than viewed as absolute predictions.

The applicant concluded that a 5% Optimum Ac reMax RIB was more durable against ECB and SWCB than either single gene PIP deployed with a 20% structured refuge irrespective of the fact whether the refuge was kept in the same loca tion each year or randomly assigned between two possible locations. When benchmark and worst-cas e assumptions were considered, the 5% RIB

scenarios were estimated to be between 7-36 fo ld and 4-6 fold more durable than the single toxins MON810 (Cry1Ab) and 1507 (Cry1F), resp ectively, deployed with a 20% block refuge. When the same comparisons were made for SWCB under the same benchmark and worst-caseOptimum AcreMax B.t. Corn S eed Blends Page 12 of 54 Biopesticides Registration Action Document

assumptions, then the durabilities for a 5% RIB were 18-58 and five-fold more durable than the single toxins MON810 and 1507, respectively

.

Furthermore, Pioneer/DuPont reported that a 5% MON810 x 1507 RIB was more durable than a 10% RIB using the same pyramided toxins. The a pplicant reasoned that this was not unexpected based on the inflated fecundity levels chosen an d the resulting increase in density dependent mortality on refuge plants in scenarios with a hi gher blend percentage compared to a lower blend percentage and cited to discussions in Ives et al. (2011) and SAP (2011) for support. A 5% RIB targeting ECB was only moderately more durab le than the 10% RIB, while for SWCB the durability decreased nearly by half when the bl end percentage increased from 5% to 10%. The applicant had set the (per-plant) carrying capacity at 18 larvae (G en1) and 22 larvae (Gen2) for ECB and 1 larva (both generations) for SWCB an d noted that if was difficult to determine whether the differences in durability seen betw een the two species was only a function of the different carrying capacities chosen (and DD-mo rtality) or whether differences in mating

behavior could have also influenced the results.

The applicant stated that increasing the dom inance value for the “pre-dispersal tasting mortality”1 value from 0.02 to 0.50 created a survival differential between SS and RS individuals that was not supported by the late st research (manuscr ipt in process).

The 5% block refuge scenario ha d the greatest dura bility of all simulated refuge options. But the applicant noted that compliance was modeled at 100% and that any compliance less than that would decrease the durability of the block refuge. The differen ce in durability between the 5%

block and 5% RIB scenario would therefore be reduced if non-compliance was considered.

BPPD Conclusions:

Pioneer/DuPont addressed the recommendations pr eviously made by BPPD (2011): the applicant artificially inflated the fecund ity for European and southwestern corn borers to avoid population extinction in their modeling analyses, included some worst-case values for several sensitive parameters in their new simulations, conducted a pr obability analysis to be able to report a risk profile to the Agency, and addressed the most germane uncertainties described by the SAP (2011) for seed blends with pyramided PIPs targeti ng Lepidoptera. Pioneer/DuP ont did not include nonuniform oviposition by Lepidoptera in their main m odeling analyses and explore greater female (southwestern corn borer) dispersal out of seed blends.

After careful review of the applicant’s ne w modeling submission, BPPD concludes that:

 The 20% single toxin block refuges had the lowest durability estimates of all options

tested in Pioneer/DuPont’s model. Those dur ability results were, however, artificially reduced by higher fecundity assumptions. Pi oneer/DuPont estimated blends to be

between 6 and 60-fold more durable th an 20% blocks for single toxin PIPs.

 The proposed seed blends (5% and 10%) will li kely be substantially less durable than a 5% block refuge for the same product (100% compliance assumed). This was also concluded by the SAP (2011). With real istic assumptions of non-compliance the estimated durability for the block scenario w ould likely be somewhat lower but still more

durable than the blends. Pioneer/DuPont’s mode l estimated that a 5% block had close to

1 The proportion of CRW larvae that die upon initial feeding before movement.Optimum AcreMax B.t. Corn S eed Blends Page 13 of 54 Biopesticides Registration Action Document

double the durability of blends for both pests (benchmark assumptions). The durability of the pyramided blends is highly likely to fa ll in between the two block options. They can be expected to be more durable than the single toxins (especially under assumptions of low cross-resistance). The uncer tainties described below (eff ects of increased fecundity, no modeling of non-uniform oviposition and great er dispersal out of blends) can be expected to further erode the durability of blends.

 A 10% blend is likely to be more durable than a 5% seed blend for the same product. Pioneer/DuPont reported, however , that the lower blend percen tage had slightly greater durability than the higher blend percentage. Possible explanations for this unexpected

outcome are discussed in the uncertainties section below.

 These conclusions are based on all availa ble information, including Pioneer/DuPont’s modeling, the 2011 SAP report, a nd EPA/ORD modeling analyses created for other seed blend products. Quantification of the risk (i.e. level of durabil ity) for Optimum AcreMax and Optimum AcreMax Xtra is complicated by uncertainties in some biological parameters including uniform/non-uniform ovi position, effects of inflated fecundity, degree of female pre-ovipositional dispersal as well as aspects of the probability analysis. All these uncertainties together could functi onally lower the durability of seed blends relative to block refuges.

 In consideration of the cumulative effect of the uncertainties and without additional modeling, BPPD is unable to completely quantif y the relative durabi lities of the various refuge options. BPPD expects, however, the relative durabil ity relationship to hold true: 5% pyramid block > 10% pyramid seed blend > 5% pyramid seed blend > 20% single toxin block.

 The 10% Optimum AcreMax 1 seed ble nd (expressing Cry34/35) targeting corn rootworm was approved in 2009. The applicant seeks to combine this single CRW gene with the pyramid PIP for Lepidoptera into a new 10% seed blend product (Optimum AcreMax Xtra). As stated above, the risk of resistance development and relative durability cannot be quantifie d for any of the proposed blends; however, BPPD expects

the risk of resistance evolution to be lo wer for a 10% seed blend expressing two pyramided PIPs than a 5% blend as proposed for the Optimum AcreMax product targeting Lepidoptera only.

BPPD has identified the following uncerta inties in Pioneer/DuPont’s analysis:

1) Non-uniform oviposition behavior was not in cluded into Pioneer/DuPont’s benchmark simulations although a sensitivity analysis for this parameter showed a trend of greater durability for the 10% seed blend over the 5% blend when conservative, yet realistic, assumptions of non-uniform oviposition favoring Bt plants were included. Based on the advice received by the SAP (2011) as well as information published in Hellmich et al. (1999), BPPD concludes that any durability anal ysis of a seed blend application targeting lepidoptera should conservati vely incorporate non-uniform oviposition in order to address situations where greater insect damage to refuge pl ants in a seed mixture could result in greater oviposition onto Bt plants. One of Pioneer /DuPont’s proposed products (Optimum AcreMax Xtra) contains a corn root worm protectant gene; for PIP plants that receive additional below ground protection, early crowding out of refuge plants by Bt plants is another reason why non-uniform ovi position needs to be addressed in modeling analyses.

2) Pioneer/DuPont’s durability estim ates for the 5% seed blend were greater than for theOptimum AcreMax B.t. Corn S eed Blends Page 14 of 54 Biopesticides Registration Action Document

10% seed blend strategy. BPPD determined that this non-intuitive result may have been a consequence of having inflated the fecundity of the target pests by 6- and 4-fold for ECB and SWCB. This unexpected outcome of greater durability for a blend containing a lower non-Bt proportion was also the t opic of discussion in the SA P report (2011) and Ives et al. (2011). It was demonstrated there that by inflating fecundity greatly that a two-toxinpyramid in a seed blend with low non-Bt propor tions could be driven to have increased durability over a blend with gr eater non-Bt proportions when target pests were mobile. In fact, the SAP demonstrated that at first th e durability of seed bl ends increased with increasing proportion of non-Bt plants. Then a precipice was reached where durability began to decrease for blends with greater pr oportions of non-Bt plants. As fecundity was successively inflated, the precipice moved towa rds lower values of blends with non-Bt proportions. In other words, when fecundity was greatly increased, the effect was that there was greater mortality of susceptible ge notypes as a result of density-dependence; this led to greater selection of resistant ge notypes (Ives et al. 2011). “Because all sorts of variability are not considered in deterministic simulations, it is po ssible to push the model over the precipice, which marks the point on the graph where populations begin to head towards extinction and the density-depende nt model becomes density-independent;

accelerated resistance evolution can be observed at this point; the precautionary advice is to stay away from this precipice or boundary” (Ives, personal communication).

Since the applicant’s du rability estimates appear to be derived from beyond this boundary (precipice), BPPD concluded th at it might be more meaningful to look at the sensitivity analysis conducted for non- uniform oviposition: when Bt plants were favored as oviposition sites, the fecundity of suscep tible genotypes may have been indirectly reduced (for ECB but not so for SWCB) and density-dependence moved

Pioneer/DuPont’s model back into the real m where durability estim ates conformed to expectations under resistance evolution models and where seed blends with greater nonBt proportions had greater durability than those with fewer non- Bt plants. Modeling analyses conducted in the past by EPA/ORD also predicted that a greater percentage (i.e., 10%) of refuge plants in a seed blend will be more durable than a lower percentage (i.e., 5%) of refuge plants (BPPD 2010a and BPPD 2010b). BPPD also considered Carriere et
al. (2004) who reported that differences in Bt durability predicted by block and seed blends of equal refuge plant proportions (cau sed by a reduction in ref uge insects in seed blends) could be overcome by increasing th e proportion of non-Bt plants in seed

mixtures.

3) Pioneer/DuPont conducted a sensitivity analys is for the “number of eggs produced in natal fields” by SWCB in block refuges (sin gle and pyramided PIPs) but not for seed blend scenarios. The applicant reported that durability results for blocks were not very sensitive to changes in this parameter although a slightly decreasing trend in durability was noted for single PIPs as pre-ovipositional dispersal increased. For a 5% block refuge with a pyramided PIP (where no resistance evolved for the duration of the simulation – 400 yrs), the applicant reported that the fina l resistance allele fr equency was slightly higher when there was more dispersal out of th e fields. This result agrees with what the SAP (2011) reported, namely, that with high fe male dispersal, resi stance would evolve faster. Pioneer/DuPont did not compare the durab ility of blends to blocks when varying this parameter. This would have been an im portant relative comparison, since dispersal in blends requires adults to onl y move short distances away from the refuge plant before having dispersed from their “n atal field”. Hence the effect s of female pre-ovipositionalOptimum AcreMax B.t. Corn S eed Blends Page 15 of 54 Biopesticides Registration Action Document

dispersal out of seed blends can be expect ed to have a greater effect on resistance

evolution in seed blends th an block refuges. The SAP (2011) stated that “for seed mixtures dispersal rates will be 100%, and greater than between field refuges. The main consequence [of greater dispersal rates] is that seed mixtures will have faster resistance evolution than between field refuges”.

Additional Data and Analysis Required:

In order to improve the streng th of modeling, Pioneer/DuPont ha s been required to incorporate the following into their model and to clarify certain assumptions utilized:

a) Non-uniform oviposition for both generations of lepidoptera in a 10% seed blend (OAM Xtra); b) Non-uniform oviposition for the second generati on of lepidoptera in a 5% seed blend without a corn rootworm trait; and c) Increased female (SWCB) pre-ovipositional dispersal out of seed blends. d) How was fecundity increased in seed blends? Does the 6-fold (and 4-fold) increase refer to the fecundity of susceptible insects on refuge plants relative to fecundity on Bt plants? e) How was uniform oviposition d ealt with in the model code? The methodology should be explained. Do adults form one big random mating pool in seed blends, and eggs are uniformly applied across the field (or else)? f) How was non-uniform oviposition dealt with in the model code of the sensitivity analysis? Pioneer/DuPont shoul d explain the methodology used.

The following seed blend related IRM data is bei ng required to support a l onger term analysis of the potential for insect resistance developing from th e use of two toxin based Bt corn seed blends targeting European corn borer and southwestern corn borer.

a) Ovipositional behavior in seed blends unde r, for example, increased pest pressure; b) The potential and degree of crowding out refuge plan ts by Bt protected plants in blends expressing corn rootworm traits under different environmental conditions and higher pest pressure; c) Adult movement (related to mating and move ment from refuges), larval movement, larval feeding (i.e., selective feeding with in corn ears or on pollen), survival of heterozygote genotypes on OAM (markers may need to be determined for heterozygotes), and the potential for epistatic mechanisms of resistance (particularly with older instars).

III. BENEFITS - CORN ROOTWORM SEED BLEND

We expect OAM1 to have the following benefits: (1) Reduced pesticide use in the refuge. Currently, the 20% block refuge may be sprayed with pesticide to mitigate pest damage. The blended in-field refuge will not be sprayable. (2) Significantly less complicated refuge deployment for the corn rootworm active ingredient. Currently, to be fully compliant with the refuge requirements, growers must accurately ca lculate 20% of the field, accurately determine the proper distance for th e refuge field, and properly plant th e required acreage in the correct location. Moreover, there are temporal concerns , as the refuge field must be planted at, essentially, the same time as the yield field so that emergence of refuge rootworms is contemporaneous with emergence of field root worms. Anecdotal reports from growers make clear that meeting each of thes e requirements can be challenging in the actual on-farmOptimum AcreMax B.t. Corn S eed Blends Page 16 of 54 Biopesticides Registration Action Document

environment. A product with the refuge blende d with the field seed will significantly ease deployment of the rootworm refuge. (3) Increas ed grower compliance with IRM requirements for the corn rootworm active ingredient. A seed blend product that inco rporates an effective refuge in the seed bag necessarily leads to 100% compliance with refuge requirements for those growers planting that product.

In addition, indirect benefits of introducing Optimum® Ac reMaxTM 1 may include reduced energy consumption for manufacture, transport, and application of ch emical insecticides; reduced waste streams arising from pesticide ma nufacture; reduced dispos al of pesticide waste containers; and reduced residues fr om pesticide applications.

Efficacy and Yield Benefits

Pioneer conducted a two year study (2006 to 2007) to assess efficacy and yield benefits of a blended seed refuge. The purpose of the study was to determine the effects of a blended refuge approach on field standability, root ratings, and yield (three effects measured at each treatment level). The 2006 experiment was replicated at eight different locations in a randomized block design with four replicates for all five treatmen ts. The treatments were: (1) untreated control; (2) conventional seed treated with P1250; (3) 100% HXRW (HERCULEX® RW) seed treated with P250; (4) 10% seed mix of conventiona l seed treated with P250 and 90% HXRW seed treated with P250; and (5) 20% seed mix of conventional seed treated with P1250 and 80% HXRW seed treated with P250. During July 2006, five roots per plot we re randomly selected, root damaged scored using the Iowa State 0-3 no de injury scoring, and yield determined at end of the growing season. Under low insect pressure, Pioneer reports little difference in node injury or yields between treatments (no data provi ded). Under high ins ect pressure, all HXRW treatments had approximately equal grain yiel d and node injury and the 10% and 20% seed blends were equivalent to th e control of 100% HXRW maize.

The Center for Science in the Publ ic Interest (CSPI) commented that our analysis of the benefits

of OAM1 should consider overall IR M compliance, including that in the lepidopteran refuge. In addition, CSPI stated that EPA should require ad ditional conditions related to the lepidopteran refuge, such as requiring that refuge requirements be placed on seed bags, requiring that on-farm assessments be conducted by third parties, requir ing growers to certify compliance annually, and separating compliance data into geographic regi ons. EPA agrees with and is implementing a number of these suggestions. Pioneer has comm itted to including labe ling on OAM1 seed bags indicating the size of the required refuge for lepidoptera, and this is being made a specific term of the registration. (We note that this is also bei ng made a term of all B.t. corn registrations and that all B.t. corn registrants ar e required to make best efforts to implement this change on as many bags of seed as possible for the 2011 grow ing season, on 50% of seed bags for the 2012 growing season, and on 100% of seed bags for th e 2013 growing season). EPA is also requiring that on-farm assessments for all B.t. corn regi strations must be conducted by independent, thirdparties. Also, compliance data will be require d to be submitted in a form that will permit evaluation by geographic region. We are not, at th is time, requiring that gr owers annually certify ex post facto that they complied with the IRM requiremen ts; but, that is a requirement that we will consider in the future, should the compliance picture not improve. Dow AgroSciences commented that the requirement for a separate structured lepidopteran refuge would create confusion among growers. We agr ee that there is the possibility of grower

confusion related to the fact th at there must be two separate refuges for OAM1. Pioneer is required to conduct enhanced grower education to ensure that purchasers of OAM1 understandOptimum AcreMax B.t. Corn S eed Blends Page 17 of 54 Biopesticides Registration Action Document

the lepidopteran refuge requirements. Pioneer also is responsible for 2000 independent, thirdparty on-farm assessments to address compliance with the lepidopteran refuge requirements. Significant non-compliance with the OAM1 lepidopteran refuge requirements, if verified, could have implications for continued availability of OAM1 in 2011 and beyond .

In 2007, the study was repeated with the additi on of HX1 (HERCULEX® I) as refuge seed (treated with P250 and P1250). BPPD did not se e statistically significan t differences between node injury, % root lodging, a nd grain yields between any of the HXX (HERCULEX® XTRA) treatments except with respect to no de for the 20% refuge with P250.

IV. REGULATORY RATIONALE

A. 2010 Corn Rootworm Refuge in the Bag Registration Decision

Section 3(c)(7)(A) of FIFRA provides for the regist ration or amendment of a pesticide when the pesticide and proposed use “...are identical or substantially simila r to any currently registered pesticide and use thereof, or differ only in ways that would not significantly increase the risk of

unreasonable adverse effects on the environmen t, and (ii) approving the registration or amendment in the manner proposed by the applicant would not significantly increase the risk of any unreasonable adverse effect on the environment.” Unreasonable adverse effects on the environment are defined under Section 2(bb) of FI FRA as “... any unreasonable risk to man or the environment, taking into account the economic, social, and environmental costs and benefits of the use of any pesticide...” Thus, pursuant to Section 3(c)(7)(A), EPA may conditionally register a pesticide if (1) the pesticide and its proposed use are identical or substantially similar to a currently registered pesticide; or (2) the pesticide and its proposed use differ only in ways that would not significantly increa se the risk of unreasonable a dverse effects; and (3) approving the registration would not significantly increase the risk of any unreasona ble adverse effect.

In our registration decision for the 2010 grow ing season, we found that OAM1 and OAM RW met criteria (2) and (3) of Section 3(c)(7)(A) fo r a time-limited registration to expire September 30, 2010. Optimum Acre Max (OAM) 1 is a seed bl end consisting of two currently registered products, 90% Herculex Xtra and 10% Herculex I. Optimum Acre Max (OAM) RW is a seed blend consisting of an already registered produ ct and non-PIP corn, 90% Herculex RW and 10% non-B.t. corn. Thus, both products were found to be substantially similar to already registered PIPs in composition and use site (field corn). These products did not meet criteria (1), however, because the proposed use of OAM1 and OAM RW that achieves the insect resistance management refuge via a seed mix rather than a block refuge is not substantially similar to any currently registered pesticide. Having the re fuge in the bag of seeds is a novel approach.

We determined, however, that each of these pr oducts met criteria (2) as, when used in

accordance with the terms and conditions of the tim e-limited registration set to expire September 30, 2010, neither would significantly increase the risk of unreas onable adverse effects on the

environment. Since OAM1 and OAM RW are substant ially similar to already registered PIPs in composition and use site, EPA’s considerati on of whether these new products would significantly increase the risk of any unreasonable adverse effect on the environment was limited to the change in insect resistance management refuge deployment and percentage, i.e., a 10% seed blend in the bag versus a 20% block refuge . The unreasonable adverse effect of concern was the development of resistance to Cry34/35Ab1 in corn. Thus, we considered: (1) how does the registration of OAM1 and OAM RW contribut e to the development of corn rootwormOptimum AcreMax B.t. Corn S eed Blends Page 18 of 54 Biopesticides Registration Action Document

resistance to Cry34/35Ab1 corn; (2) should this re sistance develop, what risk does it pose to man or the environment; and (3) taking into account the economic, social, and environmental costs and benefits, does this risk constitu te an unreasonable adverse effect?

The Risk of OAM1 and OAM RW Registrati ons Causing CRW Resistance to Cry34/35Ab1

The modeling used by EPA to assess IRM strategi es utilizes comparative simulation models. The model durability output, years to resistance, is intended to be used for comparative purposes to evaluate different refuge options on a relative basis. The durability outputs that EPA determined for the proposed 90% CRW protected seed/10% non-CRW protected seed blend, and a 20% block refuge are 11.3 years to resistance, and 20.2 years to resistance, resp ectively. Thus, our analysis indicated that, as modeled, the proposed seed blend is 45% less durable on a comparative basis than the 20% block refuge cu rrently required for si ngle trait CRW PIPs .

Besides the currently registered Pioneer PIPs, Cry34/35Ab1 corn is registered in a number of

other B.t. corn PIPs, including multi-CRW B.t. toxin products, by Monsanto and Dow AgroSciences. Should resistance develop to Cry34/35 in a OAM1 seed blend, these other products could be adversely affected including potential loss of efficacy and viability as CRW control tools. We note, in particular, the re cent statement of the National Research Council to

the effect that “.

. . results from simulation models and small-scale laboratory experiments

indicate that the evolu tion of resistance to two- toxin cultivars is accelerated when plants that produce two B.t. toxins are grown near plan ts that produce just one to xin.” National Academy of Sciences, Impact of Genetically Engineer ed Crops on Farm Sustainability in the United States, 2-37 (2010). Based on our assessment, we concl uded that significant acreage of a 10% seed blend with a single, non-high dose mode of actio n such as Cry 34/35Ab1 likely increases the risk

of resistance for all B.t. corn products containing Cry34/ 35Ab1. But, the time-limited registration expiring September 30, 2010, likely would not increase the risk of resistance to Cry34/35Ab1.

Pioneer projected that the tim e-limited registrations granted for the 2010 growing season would result in planting on only approximately 0.042% of acres of non-Red Zone geography corn acres; and only on approximately 0.077% of Red-Zone ge ography corn acres. In the context of 90 million acres of corn planted in the United States annually, we concluded that plantings on such limited acreage would not have effects on CRW resistance development.

The ad hoc members of the SAP commented that the evolution of resistance that occurs as a result of OAM1 presence in the field will speed resistance to Cry34/35 pyramided products. Comments from Dow Agrosciences and Syngent a also expressed concern that OAM1 would impact other PIP products and speed resistance evolution. CSPI commented that if the registration decision was based in part on sales projections, then ac reage caps should be a term of the registration. We appreciat e the concerns of the ad hoc members of the SAP, Dow Agrosciences, and Syngenta regarding the poten tial of OAM1 to accele rate evolution of resistance to Cry 34/35. This is a concern that we share. We took steps and imposed terms on the OAM1 registration for the 2010 growing season to address these concerns. Pioneer was required to implement an enhanced resistan ce monitoring plan for OAM1 that included benchmark studies showing susceptibility of th e western corn rootworm populations (WCRW) in the Sublethal Seedling Assay. These studies must be submitted by December 1, 2010. Pioneer must attempt to obtain benchmark susceptibility data using the Subletha l Seedling Assay for the northern corn rootworm as well, and submit such studies by December 1, 2011. Pioneer mustOptimum AcreMax B.t. Corn S eed Blends Page 19 of 54 Biopesticides Registration Action Document

also submit by December 1, 2010, a detailed OAM1-sp ecific resistance monitoring and remedial action plan, including an analysis to determine the expected fi eld performance criteria for OAM1 products so that unexpected damage can be benchmarked. This plan will be updated by December 1, 2012, if needed, based on continue d field evaluation of OAM1 performance. Pioneer was also required to develop programs to evaluate whether there are statistically significant and biologically releva nt changes in target insect susceptibility to Cry1F and Cry34Ab1/Cry35Ab1 proteins in the targ et insects; and a remedial ac tion plan that must set forth the specific measures Pioneer will take in the event that any field-relevant insect resistance is

detected. While we are not re quiring specific acreage caps as part of the registration for 2011 and 2012, we will closely monitor the extent of sales and plantings of OAM1, as well as all insect monitoring data. In the event there is a ny indication of resistance evolution, Pioneer must report that to EPA immediately. We will assess all data and information relevant to the indication of resistance evolution and, if we de termine that such action is appropriate, will use our authority under Section 6(c) of FIFRA to suspend the registration.

Should Resistance Develop, What Risk Does it Pose to Man or the Environment, and What Economic and Social Costs?

Should Cry34/35Ab1 resistance develop, there would be an increase in conventional chemical insecticide use for U.S. corn production. Although there are other CRW controlling PIPs in the marketplace and under development, Cry34/35Ab1 resistance would not only impact OAM1 and OAM RW, but also HERCULEX® RW, HERCU LEX® XTRA, and GenuityTM SmartStaxTM.

Increased use of conventional insecticides woul d increase impacts on the environment and man. There would also be indirect impacts in in creased energy consumption for manufacture, transport, and application of chemical insect icides; increased waste streams arising from pesticide manufacture; and increase d disposal of pesticide waste containers and residues from pesticide applications.

What are the Economic, Social, and Environmental Benefits of OAM1 and OAM RW?

Both OAM1 and OAM RW have been determined by EPA to be efficacious in their control of

corn rootworm.

OAM1 and OAM RW should increase grower co mpliance with CRW refuge requirements by providing a novel and effective way of simplifying the refuge deployment process for growers as the corn rootworm refuge is deployed as a seed bl end rather than a separate block in the field.

OAM1 and OAM RW should also reduce the insect icide use in the CRW refuge and in the CRW-PIP fields. Currently, corn rootworm PIP products require in secticide treatment of the PIP acreage, even if economic thresholds are not reache d. This use of insectic ides solely to support the management of resistance has b een required if aerial insecticides are applied to the refuge for control of CRW adults or if pests other than a dult corn rootworms are treated with CRW-labeled insecticide on the refuge acres when adult corn rootworms are present. OAM1 and OAM RW

would reduce this IRM based use of insecticides. Indirect benef its of decreased insecticide use include reduced energy consumption for manufactu re, transport, and application of chemical insecticides; reduced waste streams arising from pesticide manufacture; reduced disposal of pesticide waste containers and residues from pesticide applications. OAM1 and OAM RW should benefit growers by simplif ying the planting process.

Corn Rootworm Refuge in the Bag Registration Decision for 2010 Growing SeasonOptimum AcreMax B.t. Corn S eed Blends Page 20 of 54 Biopesticides Registration Action Document

We concluded that OAM1 and OAM RW met the cr iteria for registration under FIFRA Section 3(c)(7)(A). Our assessment suppor ted the determination that th ese products are not likely to contribute towards the development of resist ance of CRW to Cry34/35A b1 during the period of the time-limited registration in effect for the 2010 growing season. Our assessment of the likely impacts concerning ease of use, increased grower compliance, efficacy, and reduced insecticide use coupled with our determination that OAM1 and OAM RW are not likely to increase the risk

of resistance of CRW to Cr y34/35Ab1 developing during the 2010 growing season supported the

conclusion that the criteria under FIFRA Section 3(c)(7)(A) were met such that registration of OAM1 and OAM RW would not pose a risk of unr easonable adverse effects on the environment during this period.

On October 1, 2009, EPA announced a new policy to provide a more meani ngful opportunity for the public to participate on major registration decisi ons before they occur. According to this new policy, EPA intends to provide a public comment period prior to making a registration decision for, at minimum, the following types of applicati ons: new active ingredient s; first food use; first outdoor use; first residential use; and other actions for which the Agency anticipates that there will be significant publ ic interest.

Notwithstanding that the current actions on OAM1 and OAM RW qualify as "actions for which the Agency anticipates that there will be signif icant public interest," EPA believed that it was in the best interests of the public and the envir onment to issue the registrations for OAM1 and OAM RW without delay. The PRIA (Pesticide Registration Im provement Act) deadline date of May 1, 2010, was sufficiently late in the grow ing season that a 30-day delay would have lessened the likelihood that sign ificant acreage of these product s could be planted in 2010. Given the potential benefits attendant to the bl ended refuge concept, EP A concluded that it was in the best interests of the public and the envi ronment to issue the registrations for OAM1 and OAM RW without delay for 2010 gr owing season. The registration is only effective for the current growing season. Therefore, consistent with the Agency’s policy for making certain registration actions more transparent, EPA issued these time-limited registrations with an initial period to expire September 30, 2010, and, concu rrent with their issu ance, provided a 30-day public comment period on the time-limited registrati ons. EPA registered this product as a timelimited registration, with the unde rstanding that public comment s could bring to light new

information or concerns that co uld inform EPA’s initial decisi on. Any subsequent action taken on these registrations will be informed by any information received during the public comment period.

CSPI commented that the public participation process for th e OAM1 registration for the 2010 growing season was inadequate. CSPI believed that the opportunity for public comment should have occurred prior to the registration decision. We do not disagree with the comment. All things being equal, however, we felt that it was important to meet the PRIA due date for this action, and that taking public comment concurre nt with the registra tion would not unfairly deprive the public of the opportuni ty for meaningful comment, nor deprive us of the benefit of public input. The OAM1 2010 regi stration was a very short, approximately five-month, time limited registration that was only good for one grow ing season. Moreover, as noted in the April 30, 2010, BRAD, the timing of the registration wa s so late in the growing season that it precluded significant sale and planting of the pr oduct. As it happened, data submitted by Pioneer (Rood, 2010), verified that OAM1 acres for 2010 am ounted to only 39,000 acres, which is less than projected in the earlier BRAD. We are pleased that we di d receive meaningful comment onOptimum AcreMax B.t. Corn S eed Blends Page 21 of 54 Biopesticides Registration Action Document

the April 30, 2010, registration action, and that th at comment has been useful in informing the preliminary decision that we are announcing today. The OAM1 registration that we are proposing today contains a number of enhanced requirements for corn rootworm resistance management that we believe will have a propitio us impact not only on this registration, but on other B.t. corn registrations as well. Fi nally, comments received on the OAM1 registration played a significant role in EPA's delibera tions on the concept of tiered time-limited registrations. As discussed below, we believe that it makes sense to make a specific connection between the risk of resistance evolving that a particular product presents and the time permitted for the registration of that product to be in eff ect. Products that we de termine through scientific evaluation to meet a stringent sta ndard for protecting against the ri sk of resistance evolving will be eligible for a registration of up to fifteen y ears. CSPI also commented that EPA "stealthily" released the OAM1 BRAD, and did not announce the comment period either in the Federal Register or by press release. We can assure all concerne d that the intent was not to be "stealthy." EPA opened the public comment period for this acti on as it has done for all other actions subject to the new public participa tion initiative, i.e., by announc ing the comment period on the Agency's public participation webpage. This co mment points out to us, however, that there are instances where more extensive efforts to publicize the initiation of a comment period and the availability of BRADs, etc., may be warranted. We undertook such efforts in conjunction with the B.t. corn registrations comment period.

B. Corn Rootworm Refuge in the Bag Registration Decision for 2011 and 2012 Growing Seasons

In the April 30, 2010 BRAD, we preliminarily conc luded that our modeling analysis combined with the Pioneer sales projections for the 2011 and 2012 growing seasons supported continued registration of OAM1 and OAM RW for 2011 and 2012. We noted that Pioneer predicts OAM1 and OAM RW acreage to increase up to 8% of the Red Zone and 12% of the non-Red Zone. EPA invited comments during the 30-day comment period on the preliminary decision to register OAM1 and OAM RW for the 2011-2012 growing seas ons. Important to this preliminary

decision was the fact that Pioneer committed to additional elements that would enhance the IRM plan applicable to OAM1 and OAM RW regardi ng insect resistance monitoring and remedial

action should resistance be detect ed, and the refuge assurance pr ogram. These were listed in

detail in the terms and conditions of th e April 30, 2010, OAM1 and OAM RW registrations.

Section 3(c)(7)(A) of FIFRA provides for the regi stration or amendment of a pesticide when the pesticide and proposed use “...are id entical or substantially simila r to any currently registered pesticide and use thereof, or differ only in ways that would not significantly increase the risk of

unreasonable adverse effects on the environmen t, and (ii) approving the registration or amendment in the manner proposed by the applicant would not significantly increase the risk of any unreasonable adverse effect on the environment.” Unreasonable adverse effects on the environment are defined under section 2(bb) of FI FRA as “... any unreasonable risk to man or the environment, taking into account the economic, social, and environmental costs and benefits of the use of any pesticide...” Thus, pursuant to section 3(c)(7)(A), EPA may conditionally register a pesticide if (1) the pesticide and its proposed use are identical or substantially similar to a currently registered pesticide; or (2) the pesticide and its proposed use differ only in ways that would not significantly increa se the risk of unreasonable a dverse effects; and (3) approving the registration would not significantly increase the risk of any unreasona ble adverse effect.

The Agency concludes that the following Cry34/ 35Ab1 corn product registrations, set to expireOptimum AcreMax B.t. Corn S eed Blends Page 22 of 54 Biopesticides Registration Action Document

September 30, 2010, and described in-depth throu ghout this BRAD, meet both criteria (1) and (2):

(1) Optimum® AcreMaxTM 1 (OAM1) => Seed Blend of 90% HERCULEX® XTRA

and 10% HERCULEX® I

(2) OAM RW => Seed Blend of 90% HERCULEX® RW and 10% Non- B.t. Corn

Each of these Cry34/35Ab1 corn products are identical in both composition and use (field corn) to plant-incorporated protectants that are curre ntly registered. Thus, criterion (1) has been fulfilled. With regard to criterion (2), the Agen cy maintains, as was previously determined for the original registration of thes e particular products, that cu ltivation of Cry34/35Ab1-containing

corn will not cause unreasonable adverse effects on the environment. The conditional environmental effects data, submitted in respons e to terms and conditions of registration and summarized in section II(C)(2)(b) of this BRAD, strengthen the Agency ’s initial position and also confirm that long-term effects on non-targ et organisms are not anticipated. Lastly, the continued use of these products will likely still pr ovide many of the benefits as were evaluated to support the OAM1 registration for the 2010 gr owing season (e.g., reduction in use of conventional insecticides that are highly toxi c to both humans and the environment; increased compliance with CRW refuge requirements).

In conclusion, as the expiring Cry34/35A b1 products (Optimum® AcreMaxTM 1 (OAM1) =>

Seed Blend of 90% HERCULEX® XTRA and 10% HERCULEX® I; and OAM RW => Seed

Blend of 90% HERCULEX® RW and 10% Non- B.t. Corn) have met the required criteria under section 3(c)(7)(A) of FIFRA, the Agency has amended these registrations to extend their respective expiration dates as follows:

Product Name (EPA Reg. No.) Proposed Expiration Date

OAM1 (29964-6) September 30, 2012

OAM1 RW (29964-10) September 30, 2012

Although data provided were satisfactory to make the determinations required by section 3(c)(7)(A) of FIFRA, they we re not sufficient to support an unconditional registration under FIFRA section 3(c)(5). Additional data, specifically in relation to insect resistance management are necessary for a finding of registrability under FIFRA section 3(c)(5) and remain as terms or conditions for the purposes of the proposed amendments.

C. European Corn Borer and Southwestern Corn Borer Refuge in the Bag Registration Decision for the 2011 Growing Season

Section 3(c)(7)(A) of FIFRA provides for the regi stration or amendment of a pesticide when the pesticide and proposed use “...are id entical or substantially simila r to any currently registered pesticide and use thereof, or differ only in ways that would not significantly increase the risk of

unreasonable adverse effects on the environmen t, and (ii) approving the registration or amendment in the manner proposed by the applicant would not significantly increase the risk of any unreasonable adverse effect on the environment.” Unreasonable adverse effects on the environment are defined under section 2(bb) of FI FRA as “... any unreasonable risk to man or the environment, taking into account the economic, social, and environmental costs and benefitsOptimum AcreMax B.t. Corn S eed Blends Page 23 of 54 Biopesticides Registration Action Document

of the use of any pesticide...” Thus, pursuant to section 3(c)(7)(A), EPA may conditionally register a pesticide if (1) the pesticide and its proposed use are identical or substantially similar to a currently registered pesticide; or (2) the pesticide and its proposed use differ only in ways that would not significantly increa se the risk of unreasonable a dverse effects; and (3) approving the registration would not significantly increase the risk of any unreasona ble adverse effect.

The Agency concludes that the following Bt corn seed blend product registrations, set to expire September 1, 2011, and described in-depth throughout this BRAD, meet both criteria (1) and (2):

Optimum® AcreMaxTM Xtra Insect Protecti on contains a seed blend with 90% 1507xMON810x59122 (Cry1Ab x Cry34/35Ab1 x Cry1F) and 10% Non- B.t. Corn.

Optimum® AcreMaxTM Insect Protection cont ains a seed blend with 95% Optimum® IntrasectTM (Cry1Ab x Cry1F) and 5% Non- B.t. Corn.

Each of these corn products are identical in both composition and use (field corn) to plantincorporated protectants that are currently registered. Thus, criteri on (1) has been fulfilled. With regard to criterion (2), the Agen cy maintains that cultivation of the two toxin lepidopteran seed

blend corn will not cause unreasonable adverse effects on the environment. In regards to criterion (3), although the Agency has determined that a seed ble nd refuge for lepidopteran pests may present a greater risk of resistance than a comparable block ref uge, this risk is not unreasonable under FIFRA. This is because the durability of seed blends for AOM (pyramided products) are expected to be higher than a 20% block refuge for single toxin Bt corn PIPs. Lastly, the use of these products will provide benefits by increasing compliance with refuge requirements and possibly further reducing conv entional pesticide use (block refuges are frequently treated to economically manage pests whereas seed blend refuges are not independently treated).

Product Name (EPA Reg. No.) Expiration Date

OAM (29964-12) September 1, 2011

OAM Xtra (29964-11) September 1, 2011

Although data provided were satisfactory to make the determinations required by section 3(c)(7)(A) of FIFRA, they we re not sufficient to support an unconditional registration under FIFRA section 3(c)(5). Additional data, specifically in relation to insect resistance management are necessary for a finding of registrability under FIFRA section 3(c)(5) and remain as terms or conditions for the purposes of the proposed amendments.

V. TERMS and CONDITIONS for NEW ECB SEED BLENDS

OAM; EPA Registration Number 29964-12

This product is conditionally registered in accordan ce with FIFRA Section 3(c)(7)(A) of the Federal Insecticide, Fungicide, and Rodenticid e Act (FIFRA), as amended, provided that you do the following terms and conditions.Optimum AcreMax B.t. Corn S eed Blends Page 24 of 54 Biopesticides Registration Action Document

1] The subject registration will automa tically expire on midnight September 1, 2011.

2] The subject registration w ill be limited to a seed mix of TC1507 (Cry1F) x Cry1Ab corn seed

blended with not less than 5% non-Bt corn seed.

3] Submit/cite all data required for registrati on of your product under FIFRA § 3(c)(5) when the Agency requires registrants of si milar products to submit such data.

4] This plant-incorporated prot ectant may be combined through conventional breeding with other registered plant-incorporated protectants that are similarly approved for use in combination, through conventional breeding, with other register ed plant-incorporated protectants to produce inbred corn lines and hybrid corn varie ties with combined pesticidal traits.

5] Submit or cite all data required to suppor t Optimum® IntrasectTM within the timeframes required by the terms and conditions of EPA Registration Number 29964-7.

6] The following seed blend related IRM data is being required to support a longer term analysis of the potential for insect resistance developi ng from the use of two toxin based Bt corn seed blends targeting European corn borer and sout hwestern corn borer. Provided the registration expiration date is extended, submit an interim re port on the following data within one year and a final report within two years.

d) Ovipositional behavior in seed blends unde r, for example, increased pest pressure; e) The potential and degree of crowding out refuge plan ts by Bt protected plants in blends expressing corn rootworm traits under different environmental conditions and higher pest pressure; f) Adult movement (related to mating and move ment from refuges), larval movement, larval feeding (i.e., selective feeding with in corn ears or on pollen), survival of heterozygote genotypes on OAM (markers may need to be determined for heterozygotes), and the potential for epistatic mechanisms of resistance (particularly with older instars).

7] In order to improve the strength of mode ling, you must incorporat e the following into your model and clarify certain assumptions utilized with in 120 days of the date of this registration:

g) Non-uniform oviposition for both generations of lepidoptera in a 10% seed blend (OAM ); h) Non-uniform oviposition for the second generati on of lepidoptera in a 5% seed blend without a corn rootworm trait; and i) Increased female (SWCB) pre-ovipositional dispersal out of seed blends. j) How was fecundity increased in seed blends? Does the 6-fold (and 4-fold) increase refer to the fecundity of susceptible insects on refuge plants relative to fecundity on Bt plants? k) How was uniform oviposition d ealt with in the model code? The methodology should be explained. Do adults form one big random mating pool in seed blends, and eggs are uniformly applied across the field (or else)? l) How was non-uniform oviposition dealt with in the model code of the sensitivity analysis? Pioneer/DuPont shoul d explain the methodology used.

8] Pioneer must implement the following Insect Resistance Management Program:Optimum AcreMax B.t. Corn S eed Blends Page 25 of 54 Biopesticides Registration Action Document

The required IRM program for OAM corn must have the following elements:

Requirements relating to creation of a lepidopteran refuge (consis ting of corn that does not contain any Bt trait for lepidopteran contro l) in cotton growing regions in conjunction with the planting of any acreage of OAM corn;

Requirements for Pioneer to prep are and require OAM users to sign “grower agreements,” that impose binding contractual obligatio n on the grower to comply with the refuge requirements;

Requirements regarding programs to edu cate growers about IRM requirements;

Requirements regarding programs to evaluate and promote growers’ compliance with IRM requirements;

Requirements regarding programs to evaluate wh ether there are statistically significant and biologically relevant changes in target insect su sceptibility to Cry1Ab and Cry1F proteins in the target insects;

Requirements regarding a “remedial action plan,” th at contains measures Pioneer would take in the event that any field-relevant insect resistance was detected as well as to report on activity under the plan to EPA;

Annual reports on units sold by state (units sold by county level will be made available to the Agency upon request), IRM grower agreements re sults, and the compliance assurance program including the educational program on or before January 31 st of each year, beginning in 2011.

a) Refuge requirements for OAM

Corn-Belt/Non-Cotton Growing Areas

Optimum ® AcreMax TM Xtra Insect Protection contains a Lepidopteran and corn rootworm refuge that is “in the bag” and is automatically implem ented when the grower plants the product. No additional refuge is required when planting this product.

Foliar insecticide treatments for control of Eur opean corn borer, corn earworm, southwestern corn borer, fall armyworm, black cutworm, west ern bean cutworm, lesser corn stalk borer, southern corn stalk borer, and sugarcane borer may be applied only if economic thresholds are reached for one or more of these target pests. Foliar insecticide treatments are also permitted for

control of corn rootworm adults if economic thresholds are reached. Economic thresholds will be determined using methods recommended by lo cal or regional profe ssionals (e.g., Extension Service agents, crop consultants).

Cotton-Growing Region Refuge Requirements

In cotton-growing regions where corn earworm is a significant pest:

 The 20% refuge must be planted with non- Bt corn hybrids.

 Optimum ® AcreMax TM and the 20% non- Bt refuge should be sown on the same day, or with the shortest window possibl e between planting datesOptimum AcreMax B.t. Corn S eed Blends Page 26 of 54 Biopesticides Registration Action Document

 External refuges may be planted as an in-field or adjacent (e.g., across the road) refuge or as a separate block within 1/2 mile of the Optimum ® AcreMax TM corn field.

 In field refuge options include : blocks, perimeter strips (i.e ., along the edges or headlands), or in-field strips.

 When planting the refuge in strips across the field, refuges must be at one (1) row wide.

 Insecticide treatments for control of European corn borer, corn earworm, southwestern corn borer, fall armyworm, black cutworm, wester n bean cutworm, lesser corn stalk borer, southern corn stalk borer, and sugarcane borer may be applied only if economic thresholds are reached for one or more of these target pe sts. In addition, the re fuge can be protected from CRW damage by an appropriate seed treatment or soil insecticide; however,

insecticides labeled for adult CRW control must be avoided in the ref uge during the period of CRW adult emergence. Economic thresholds will be determined using methods recommended by local or regional professi onals (e.g., Extension Service agents, crop consultants). Microbial Bt insecticides must not be applied to non- Bt corn refuge plants.

 Cotton-growing areas include the following stat es: Alabama, Arkansas, Georgia, Florida, Louisiana, North Carolina, Mississippi, Sout h Carolina, Oklahoma (only the counties of Beckham, Caddo, Comanche, Custer, Greer , Harmon, Jackson, Kay, Kiowa, Tillman, Washita), Tennessee (only the coun ties of Carroll, Chester, Crocke tt, Dyer, Fayette, Franklin, Gibson, Hardeman, Hardin, Haywood, Lake, Lauderdale, Lincoln, Madison, Obion, Rutherford, Shelby, and Tipton), Texas (excep t the counties of Carson, Dallam, Hansford, Hartley, Hutchinson, Lipscomb, Moore, Ochiltree, Roberts, and Sherman), Virginia (only the counties of Dinwiddie, Franklin City, Greensville, Isle of Wight, Northampton, Southampton, Suffolk City, Surrey, Sussex) a nd Missouri (only the c ounties of Dunklin, New Madrid, Pemiscot, Scott, Stoddard).

These refuge requirements do not apply to seed pr opagation of inbred and hybrid corn seed corn up to a total of 20,000 acres per c ounty and up to a combined U.S. total of 250,000 acres per PIP active ingredient per registrant per year.

When on-farm assessments identify non-compliance with refuge requirements for one or more Bt corn products, additional educational material an d assistance are provided by the registrant to help these growers meet the refuge re quirements across their farming operations.

b) Grower Agreement for OAM Corn

1. Persons purchasing OAM corn must sign a grower agreement. The term “grower agreement” refers to any grower purchase contract, license agreement, or similar legal document.

2. The grower agreement and/or specific st ewardship documents referenced in the grower agreement must clea rly set forth the terms of the current IRM program. By signing the grower agreement, a gr ower must be contractually bound to comply with the requirements of the IRM program.

3. Pioneer must implement a system equiva lent to what is already approved for previously registered Pioneer Bt corn products, which is reasonably likely to assure that persons purchasing OAM corn will affirm annually that they are contractually bound to comply with the requirements of the IRM program. A description of the system must be submitte d to EPA within 90 days from the dateOptimum AcreMax B.t. Corn S eed Blends Page 27 of 54 Biopesticides Registration Action Document

of registration. (This information has b een submitted and is being evaluated by the Agency.)

4. Pioneer must use a grower agreement and must submit to EPA, within 90 days from the date of registration, a copy of that agreement and any specific stewardship documents referenced in the grower agreement. (This information has been submitted and is being evaluated by the Agency.)If Pioneer wishes to change any part of the grower agreemen t or any specific stewardship documents referenced in the grower agreement that would affect either the content of the IRM program or the legal enforceability of the provisions of the agreement relating to the IRM program , 30 days prior to implementing a proposed change, Pioneer must submit to EPA the text of such changes to ensure it is consistent

with the terms and conditions of this registration.

5. Pioneer shall maintain records of all OAM corn grower agreements for a period of three years from December 31 st of the year in which the agreement was signed.

6. Beginning on January 31, 2012, and annually thereafter, Pioneer shall provide EPA with a report on the number of units of OAM corn seed shipped and not returned, and the number of such units that were sold to persons who have signed grower agreements. The report shall cover the time frame of a twelve-month period. Note: The first report shall cont ain the specified information from the time frame starting with the date of registration and extending through the 2011 growing season.

7. Pioneer must allow a review of the grower agreements and grower agreement records by EPA or by a State pesticide regul atory agency if the State agency can

demonstrate that confidential business information, including names, personal information, and grower license number, will be protected.

c) IRM Education and IRM Compliance Mo nitoring Program for OAM Corn

1. Pioneer must design and implement a comprehensive, ongoing IRM education program designed to convey to OAM corn users the importance of complying with the IRM program. The program must also address unexpected pest damage and guidance for growers in this area. The education program shall involve the use of multiple media, e.g. face-to-face meetings, maili ng written materials, EPAreviewed language on IRM requirements on the bag or bag tag, and electronic communications such as by internet, radio, or television commercials. Copies of the materials will be provided to EPA for their records. The program shall

involve at least one written communica tion annually to each OAM corn user separate from the grower technical guid e. The communication shall inform the user of the current IRM requirements and specifically the need to plant a lepidopteran refuge in co tton growing regions. Pion eer shall coordinate its education program with the educational efforts of other registrants and other organizations, such as the National Corn Growers Association and state extension

programs.

2. Pioneer must design and im mediately implement a “bag tag” that will be attachedOptimum AcreMax B.t. Corn S eed Blends Page 28 of 54 Biopesticides Registration Action Document

to all bags of OAM seed sold and delivered for the 2011 growing season and annually thereafter. The purpose of this bag tag is to remind growers that OAM products require a separate 20% lepidopteran refuge in co tton-growing areas. The PIP product label accepted by EPA must include how this information will be conveyed to growers via text and graphics. A revi sed PIP product label must be submitted by January 31, 2011.

3. Pioneer must conduct targeted, on-farm compliance assessments for growers who purchase OAM seed to ensure growers are compliant with the requirement of a 20% refuge for lepidopteran pests in cotton growing areas. For the 2011 growing season and thereafter, Pioneer must conduct on-farm assessments or roughly half the number

of assessments that Pioneer will cont ribute to the 2011 Agri cultural Biotechnology Stewardship Technical Committee (ABS TC) compliance assurance program assessment for corn borer and stacked produc ts. Pioneer must contract with an independent third party to conduct these co mpliance assessments. The table below

reflects the relative number of on-farm a ssessments for OAM based on Pioneer’s contribution to the ABSTC compliance assu rance program report and is subject to change with time as appropriate.

i. A third party is classified as a party ot her than the registrant, the grower, or anyone else with a direct interest in IRM compliance for Bt corn.

Pioneer must provide a report to EPA su mmarizing the OAM compliance assurance program activities and results for the prio r year and plans for the OAM compliance assurance program for the current year, by January 31, 2012, and annually thereafter. Within one month of submitting this report to EP A, the registrant shall meet with EPA to discuss its findings. The report must inform EPA of the number of growers deemed ineligible to purchase Bt corn seed on th e basis of continued non-compliance with the insect resistance management refuge requirements.

4. Annually, Pioneer shall revise, and expand as necessary, its education program to take

into account the information collected th rough the compliance survey and from other sources. The changes shall address aspects of grower compliance that are not sufficiently high.

5. Beginning January 31, 2012, Pioneer must provide a report to EPA summarizing the

activities it carried out under its educa tion program for the prior year. Annually thereafter, Pioneer must provide EPA any s ubstantive changes to its grower education activities as part of the overall IRM complia nce assurance program report. Pioneer must either submit a separate report or contribut e to the report from the industry working group, ABSTC.

6. The registrant shall revise and expand its existing Compliance Assurance Program to include the following elements. The registra nt must prepare and submit by January 31, 2012, a written description of its revised Co mpliance Assurance Program. The registrant may coordinate with other registrants in designing and implementing its Compliance Assurance Program.Optimum AcreMax B.t. Corn S eed Blends Page 29 of 54 Biopesticides Registration Action Document

7. The registrant will enhance the refuge e ducation program throughout the seed delivery

channel:

i. Ensure sales representatives, licensees, seed dealers, and growers recognize the importance of correct refuge implementation and potential consequences of failure to plant the required refuge;

ii. Pioneer must design and immedi ately implement a “bag tag” that will be attached to all bags of OAM seed sold and delivered for the 2011 growing season and annually thereafter. The purpose of this bag tag is to remind growers that OAM products require a separate 20% lepidopteran refuge in cotton growing areas. The PIP product label accepted by EPA must include how this informa tion will be conveyed to growers via text and graphics. A revised PIP product labe l must be submitted by January 31, 2011.

8. The registrant will focus the majority of on-farm assessments on regions with the greatest risks for resistance:

i. Use Bt corn adoption, pest pressure informa tion, and other available information to identify regions where the risk of resistance is greatest;

ii. Focus approximately two-thirds of on-fa rm assessments on these regions, with the remaining assessments conducted across othe r regions where the product is used.

9. The registrant will use its available Bt sales records and other information to refine grower lists for on-farm assessments of th eir compliance with re fuge requirement:

i. Identify for potential on-farm assessment growers whose sales information indicates they have purchased the Bt corn product but may have purch ased little or no refuge seed from the registrant, licensee, or affiliated company.

10. The registrant will contra ct with third parties to pe rform on-farm assessments of compliance with refuge requirements:

i. The third-party assessors will conduct all first-time on-farm assessments as well as second-year on-farm assessments of those growers found out of compliance in a firsttime assessment

11. The registrant will annually refine the on-farm assessment program for the Bt corn product to reflect the adoption rate and leve l of refuge complian ce for the product.

12. The registrant will follow up with grower s who have been found significantly out of compliance under the on-farm assessment pr ogram and are found to be back in compliance the following year:

i. All growers found to be significantly out of compliance in a prior year will annually be sent additional refuge assistance information for a minimum of two years by the registrant, seed supplier, or th ird party assessor, after comple ting the assessment process;Optimum AcreMax B.t. Corn S eed Blends Page 30 of 54 Biopesticides Registration Action Document

ii. The registrant will conduct follow-up check s on growers found to be significantly out of compliance within three y ears after they are found to be back in compliance;

iii. A grower found with a second incident of sign ificant non-compliance with refuge requirements for the Bt corn product within a five-year period will be denied access to

Pioneer Hi-Bred’s Bt corn products the next year. Si milarly, seed dealers who are not fulfilling their obligations to inform/educate grow ers of their IRM obligations will lose their opportunity to sell Bt corn.

d) Insect Resistance Monitoring and Remedial Action Plan for OAM Corn

The Agency is imposing the following cond itions for this lepidopteran toxin:

The registrant will monitor for resi stance to its lepidopteran-resistant Bt corn. The monitoring program shall consist of two a pproaches: (1) focused population sampling and laboratory testing; and (2) investigation of reports of less-than ex pected control of labeled insects. Should fieldrelevant resistance be confirmed, an appropriate resistance management action plan will be implemented.

(1) Focused Population Sampling

The registrant shall annually sample and bioassay populations of the key target pests Ostrinia

nubilalis (European corn borer; ECB), Diatraea grandiosella (Southwestern corn borer; S WCB), and Helicoverpa zea (corn earworm; CEW). Sampling for th e target pests will be focused

in areas identified as those w ith the highest risk of resistance development (e.g., where lepidopteran-active Bt hybrids are planted on a high proportion of the corn acres, and where the insect species are regarded as key pests of corn ). Bioassay methods must be appropriate for the goal of detecting field-relevant shifts in population response to lepidopteran resistant Bt corn and/or changes in resist ance allele frequency in response to the use of Bt corn and, as far as possible, should be consistent ac ross sampling years to enable co mparisons with historical data.

The number of populations to be collected shall reflect the regional importance of the insect species as a pest, and specific collection regions will be identified for each pest. For ECB, a minimum of 12 populations across the sampling regi on will be targeted fo r collection at each annual sampling. For SWCB, the target will be a minimum of six populations. For CEW, the target will be a minimum of 10 populations. Pe st populations should be collected from multiple corn-growing states reflective of different ge ographies and agronomic conditions. To obtain sufficient sensitivity to detect resistance alle les before they become common enough to cause measurable field damage, each population collection shall attempt to target 400 insect genomes (egg masses, larvae, mated females, and/or mixed-sex adults), but a successful population collection will contain a minimum of 100 genomes. It is recognized that it may not be possible to collect the target number of in sect populations or genomes du e to factors such as natural fluctuations in pest density, environmental conditions, and area-wid e pest suppression.

The sampling program and geographic range of co llections may be modified as appropriate based on changes in pest importance and for th e adoption levels of lepidopteran-resistant Bt corn. The Agency shall be consulted prior to the implementation of such modifications.Optimum AcreMax B.t. Corn S eed Blends Page 31 of 54 Biopesticides Registration Action Document

The registrant will report to the Agency before August 31 each year the results of the population sampling and bioassay monitoring program.

Any incidence of unusually low sensitivity to the Bt protein in bioassays sh all be investigated as soon as possible to understand any field relevance of such a finding. Such investigations shall proceed in a stepwise manner until the field rele vance can be either confirmed or refuted, and results of these shall be reported to the Agen cy annually before Augus t 31. The investigative steps will include:

1. Re-test progeny of the collect ed population to determine wh ether the unusual bioassay response is reproducible and herita ble. If it is not reproducible a nd heritable, no further action is required.

2. If the unusual response is repr oducible and heritable, progeny of insects that survive the diagnostic concentration will be tested using me thods that are representative of exposure to Bt corn hybrids under field conditi ons. If progeny do not survive to adulthood, any suspected

resistance is not fiel d relevant and no furthe r action is required.

3. If insects survive steps 1 and 2, resistance is confirmed, and further steps will be taken to evaluate the resistance. These steps may include:

 determining the nature of the resistance ( i.e., recessive or dominant, and the level of functional dominance);

 estimating the resistance-allele freq uency in the original population;

 determining whether the resistance-allele Frequency is increasing by analyzing field collections in subsequent years sampled from the same site where the resistance allele(s) was originally collected;

 determining the geographic distribution of the resistance allele by analyzing field collections in subsequent years from site s surrounding the site where the resistance allele(s) was originally collected.

Should field-relevant resistance be confirmed, and the resistance appears to be increasing or spreading, the registrant will consult with the Ag ency to develop and implement a case-specific resistance management action plan.

(2) Investigation of Reports of Unexpect ed Levels of Damage by the Target

Pests:

The registrant will follow up on grower, extension specialist or consultant reports of unexpected levels of damage by the lepidopteran pests listed on the pesticide label. The registrant will

instruct its customers to contact them if such in cidents occur. The registrant will investigate all legitimate reports submitted to the comp any or the company's representatives.

If reports of unexpected levels of damage lead to the suspicion of resistance in any of the key target pests (ECB, SWCB, and CEW) , the registrant will implemen t the actions described below, based on the following definitions of suspected resistance and confirmed resistance.Optimum AcreMax B.t. Corn S eed Blends Page 32 of 54 Biopesticides Registration Action Document

Suspected resistance

EPA defines suspected resistance to mean field reports of unexpe cted levels of insect feeding damage for which:

 the corn in question has been c onfirmed to be lepidopteran-active Bt corn;

 the seed used had the proper percentage of corn expressing Bt protein;

 the relevant plant tissues are ex pressing the expected level of Bt protein; and

 it has been ruled out that speci es not susceptible to the prot ein could be responsible for the damage, that no climatic or cultural reas ons could be responsible for the damage, and

that that there could be no othe r reasonable causes for the damage.

The Agency does not interpret suspected resistance to mean grower reports of possible control failures or suspicious results from annual ins ect monitoring assays, nor does the Agency intend

that extensive field studies and testing be undertaken to confirm scientifically the presence of

insects resistant to Bt corn in commercial production fields before responsive measures are

undertaken.

If resistance is suspected, the registrant will instruct growers to do the following:

 Use alternative control measures in the Bt corn fields in the affect ed region to control the target pest during the immediate growing season.

 Destroy Bt corn crop residues in the affected region within one month after harvest with a technique appropriate for local production practices to minimize the possibility of

resistant insects over-winteri ng and contributing to the next season's target pest population.

Additionally, if possible, and pr ior to the application of alte rnative control measures or destruction of crop residue, the registrant will collect samples of the insect population in the affected fields for laboratory re aring and testing. Such rearing a nd testing shall be conducted as expeditiously as practical.

Confirmed resistance

EPA defines confirmed resistance to mean, in the case of field re ports of unexpected levels of damage from the key target pests, th at all the following criteria are met:

 There is > 30% insect survival and commensurate inse ct feeding in a bioassay, initiated with neonate larvae, that uses methods that are representati ve of exposure to Bt corn hybrids under field conditions (ECB and SWCB only).

 In standardized laboratory bioassays using diagnostic concentrations of the Bt protein suited to the target pest in question, the pest exhibits resistance that has a genetic basis and the level of survivorship indicates that there may be a resistance allele frequency of ≥ 0.1 in the sampled population.Optimum AcreMax B.t. Corn S eed Blends Page 33 of 54 Biopesticides Registration Action Document

 In standardized labora tory bioassays, the LC 50 exceeds the upper limit of the 95%

confidence interval of the LC 50 for susceptible populations su rveyed both in the original baselines developed for this pest species a nd in previous years of field monitoring.

(3) Response to Confirmed Resistance in a Key Target Pest as the Cause of Unexpected Levels of Damage in the Field

When field resistance is confirmed (as defined above), the following steps will be taken by the registrant:

 EPA will receive notification within 30 days of resistance confirmation;

 Affected customers and extension agents will be notified about confirmed resistance within 30 days;

 Monitoring will be increased in the affected ar ea and local target pest populations will be sampled annually to determine the ex tent and impact of resistance;

 If appropriate (depending on the resistant pest species, the extent of resistance, the timing of resistance, and the nature of resistance, and the availabi lity of suitable alternative control measures), alternative control measures will be employed to reduce or control target pest populations in the affected ar ea. Alternative control measures may include advising customers and extension agents in th e affected area to incorporate crop residues into the soil following harvest to minimize th e possibility of over-wintering insects, and/or applications of chemical insecticides;

 Unless otherwise agreed with EPA, stop sale and distribution of the relevant lepidopteran-active Bt corn hybrids in the affected area immediat ely until an effective local mitigation plan approved by EPA has been implemented;

 The registrant will develop a case-specific resistance management action plan within 90 days according to the characte ristics of the resistance even t and local agronomic needs. The registrant will consult with appropriate st akeholders in the development of the action plan, and the details of such a plan shall be approved by EPA prior to implementation;

 Notify affected parties (e.g. growers, consulta nts, extension agents , seed distributors, university cooperators a nd state/federal authorities as a ppropriate) in the region of the

resistance situation and approved action plan; and

 In subsequent growing seasons, maintain sales suspension and a lternative resistance management strategies in th e affected region(s) for the Bt corn hybrids that are affected by the resistant population until an EPA-approved local resistance management plan is in place to mitigate the resistance.

A report on results of resistance monitoring and investigations of damage reports must be submitted to the Agency annually by August 31 st each year for the duration of the conditional registration.Optimum AcreMax B.t. Corn S eed Blends Page 34 of 54 Biopesticides Registration Action Document

e) Remedial Action Plan for lepidopteran pests and OAM Corn

When field resistance is confirmed (as previously defined), the following steps will be taken by the registrant:

• EPA will receive notification within 30 days of resistance confirmation;

• Affected customers and extension agents will be notified about confirmed resistance within 30 days;

• Monitoring will be increased in the affected area and local target pest populations will be sampled annually to determine the ex tent and impact of resistance;

• If appropriate (depending on the resistant pest species, the extent of resistance, the timing of resistance, and the nature of re sistance, and the availability of suitable alternative control measures) , alternative control measures will be employed to reduce or control target pest populations in the affected area. Alternative control measures may include advising customers and extension agents in the affected area to incorporate crop residues into the soil following harvest to minimize the possibility of over-wintering insects, and/ or applications of chemical insecticides;

• Unless otherwise agreed with EPA, stop sale and distribution of the relevant lepidopteranactive Bt corn hybrids in the affected area immediatel y until an effective local mitigation plan approved by EPA has been implemented; • The registrant will develop a case-specific resistance manageme nt action plan within 90 days according to the characteristics of the resistance event and local agronomic needs. The registrant will consult with appropriate stak eholders in the development of the action plan. and the details of such a plan shall be approved by EPA prior to implementation;

• Notify affected parties (e .g. growers, consul tants, extension agents , seed distributors, university cooperators and state/ fe deral authorities as appropriate) in the region of the resistance situation and approved action plan; and

• In subsequent growing seasons, maintain sales suspension and a lternative resistance management strategies in th e affected region(s) for the Bt corn hybrids that are affected by the resistant population until an EP A-approved local resistance management plan is in place to mitigate the resistance.

A report on results of resistance monitoring and investigations of damage reports must be submitted to the Agency annually by August 31st each year for the duration of the conditional registration.

f) Refuge Assurance Program for OAM Corn

Pioneer must implement a Blended Seed Refuge Assurance Program designed to ensure OAM products are formulated with the ap propriate rate of refuge seeds. The program must include the following four elements:

1. Trait purity check on seed lots prior to blending;Optimum AcreMax B.t. Corn S eed Blends Page 35 of 54 Biopesticides Registration Action Document

2. ISO 9000 Standard Operating Proced ures for the blending process;

3. Calibration of blending equipment; and

4. Records and data retention records for seed blend products.

 Calibration records - Pioneer will retain documentation for a specified period of time on the equipment calibration including the procedure, when it was conducted

and the results.

 Blend proportion records (weight and ke rnel based) - Pioneer will retain documentation for a specified period of time on the kernel per pound data of the components, the calculations to determ ine the proportions based on weight and the actual weights that are blended toge ther to make up an OAM product by seed

lot.

All records must be maintained at the Pioneer blending facility and must be available for the EPA review upon request.

g) Annual Reporting Requirements for OAM Corn

1. Annual Sales: reported and summed by state (county level data available by request) January 31 st each year, beginning in 2012;

2. Grower Agreements: number of units of OAM corn seed shipped or sold and not returned, and the number of such units that were sold to persons who have signed grower agreements, January 31 st each year, beginning in 2012;

3. Grower Education: substantive chan ges to education program completed previous year, January 31 st each year, beginning in 2011;

4. Compliance Assurance Program: compliance assurance program activities and results for the prior year and plans for the compliance assurance program for the current year, January 31 st each year, beginning in 2012;

5. Compliance Survey Results: results of annual surveys for the prior year and survey plans for the current year; full report January 31 st each year, beginning in 2012;

6. Insect Resistance Monitoring Result s: results of monitoring and investigations of da mage reports, August 31 st each year, beginning in 2012 for

western corn rootworm and northern corn rootworm.

OAM XTRA; EPA Registration Number 29964-11

This product is conditionally registered in acco rdance with FIFRA Section 3(c)(7)(A) of the Federal Insecticide, Fungicide, and Rodenticid e Act (FIFRA), as amended, provided that you do the following terms and conditions.

1] The subject registration will automa tically expire on midnight September 1, 2011.

2] The subject registration will be limited to a seed mix of TC1507 (Cry1F) xDAS-59122-7 (Cry34Ab1/Cry35Ab1) x Cry1Ab corn seed blended with not less than 10% non-Bt corn seed.

3] Submit/cite all data required for registrati on of your product under FIFRA § 3(c)(5) when the Agency requires registrants of si milar products to submit such data.Optimum AcreMax B.t. Corn S eed Blends Page 36 of 54 Biopesticides Registration Action Document

4] This plant-incorporated prot ectant may be combined through conventional breeding with other registered plant-incorporated protectants that are similarly approved for use in combination, through conventional breeding, with other register ed plant-incorporated protectants to produce inbred corn lines and hybrid corn varie ties with combined pesticidal traits.

5] Submit or cite all data required to support 1507x MON810x59122 within the timeframes required by the terms and conditions of EPA Registration Number 29964-8.

6] The following seed blend related IRM data is being required to support a longer term analysis of the potential for insect resistance developi ng from the use of two toxin based Bt corn seed blends targeting European corn borer and sout hwestern corn borer. Provided the registration expiration date is extended, submit an interim re port on the following data within one year and a final report within two years.

g) Ovipositional behavior in seed blends unde r, for example, increased pest pressure; h) The potential and degree of crowding out refuge plan ts by Bt protected plants in blends expressing corn rootworm traits under different environmental conditions and higher pest pressure; i) Adult movement (related to mating and move ment from refuges), larval movement, larval feeding (i.e., selective feeding with in corn ears or on pollen), survival of heterozygote genotypes on OAM (markers may need to be determined for heterozygotes), and the potential for epistatic mechanisms of resistance (particularly with older instars).

7] In order to improve the strength of mode ling, you must incorporat e the following into your model and clarify certain assumptions utilized with in 120 days of the date of this registration:

m) Non-uniform oviposition for both generations of lepidoptera in a 10% seed blend (OAM Xtra); n) Non-uniform oviposition for the second generati on of lepidoptera in a 5% seed blend without a corn rootworm trait; and o) Increased female (SWCB) pre-ovipositional dispersal out of seed blends. p) How was fecundity increased in seed blends? Does the 6-fold (and 4-fold) increase refer to the fecundity of susceptible insects on refuge plants relative to fecundity on Bt plants? q) How was uniform oviposition d ealt with in the model code? The methodology should be explained. Do adults form one big random mating pool in seed blends, and eggs are uniformly applied across the field (or else)? r) How was non-uniform oviposition dealt with in the model code of the sensitivity analysis? Pioneer/DuPont shoul d explain the methodology used.

8] Pioneer must implement the following Insect Resistance Management Program:

The required IRM program for OAM Xtra co rn must have the following elements:

Requirements relating to creation of a lepidopteran refuge (consis ting of corn that does not contain any Bt trait for lepidopteran contro l) in cotton growing regions in conjunction with the planting of any acreage of OAM Xtra corn;

Requirements for Pioneer to prepare and require OAM XTRA users to sign “grower agreements,” that impose binding contractual obliga tion on the grower to comply with the refugeOptimum AcreMax B.t. Corn S eed Blends Page 37 of 54 Biopesticides Registration Action Document

requirements;

Requirements regarding programs to edu cate growers about IRM requirements;

Requirements regarding programs to evaluate and promote growers’ compliance with IRM requirements;

Requirements regarding programs to evaluate wh ether there are statistically significant and biologically relevant changes in target inse ct susceptibility to Cry1F and Cry34Ab1/Cry35Ab1 proteins in the target insects;

Requirements regarding a “remedial action plan,” th at contains measures Pioneer would take in the event that any field-relevant insect resistance was detected as well as to report on activity under the plan to EPA;

Annual reports on units sold by state (units sold by county level will be made available to the Agency upon request), IRM grower agreements re sults, and the compliance assurance program including the educational program on or before January 31 st of each year, beginning in 2011.

e) Refuge requirements for OAM XTRA

Corn-Belt/Non-Cotton Growing Areas

Optimum ® AcreMax TM Xtra Insect Protection contains a Lepidopteran and corn rootworm refuge that is “in the bag” and is automatically implem ented when the grower plants the product. No additional refuge is required when planting this product.

Foliar insecticide treatments for control of Eur opean corn borer, corn earworm, southwestern corn borer, fall armyworm, black cutworm, west ern bean cutworm, lesser corn stalk borer, southern corn stalk borer, and sugarcane borer may be applied only if economic thresholds are reached for one or more of these target pests. Foliar insecticide treatments are also permitted for

control of corn rootworm adults if economic thresholds are reached. Economic thresholds will be determined using methods recommended by lo cal or regional profe ssionals (e.g., Extension Service agents, crop consultants).

Cotton-Growing Region Refuge Requirements

In cotton-growing regions where corn earworm is a significant pest:

 The 20% refuge must be planted with non- Bt corn hybrids.

 Optimum ® AcreMax TM Xtra and the 20% non- Bt refuge should be sown on the same day, or with the shortest window po ssible between planting dates

 External refuges may be planted as an in-field or adjacent (e.g., across the road) refuge or as a separate block within 1/2 mile of the Optimum ® AcreMax TM Xtra corn field.

 In field refuge options include : blocks, perimeter strips (i.e ., along the edges or headlands), or in-field strips.

 When planting the refuge in strips across the field, refuges must be at one (1) row wide.

 Insecticide treatments for control of European corn borer, corn earworm, southwestern corn borer, fall armyworm, black cutworm, wester n bean cutworm, lesser corn stalk borer,Optimum AcreMax B.t. Corn S eed Blends Page 38 of 54 Biopesticides Registration Action Document

southern corn stalk borer, and sugarcane borer may be applied only if economic thresholds are reached for one or more of these target pe sts. In addition, the re fuge can be protected from CRW damage by an appropriate seed treatment or soil insecticide; however,

insecticides labeled for adult CRW control must be avoided in the ref uge during the period of CRW adult emergence. Economic thresholds will be determined using methods recommended by local or regional professi onals (e.g., Extension Service agents, crop consultants). Microbial Bt insecticides must not be applied to non- Bt corn refuge plants.

 Cotton-growing areas include the following stat es: Alabama, Arkansas, Georgia, Florida, Louisiana, North Carolina, Mississippi, Sout h Carolina, Oklahoma (only the counties of Beckham, Caddo, Comanche, Custer, Greer , Harmon, Jackson, Kay, Kiowa, Tillman, Washita), Tennessee (only the coun ties of Carroll, Chester, Crocke tt, Dyer, Fayette, Franklin, Gibson, Hardeman, Hardin, Haywood, Lake, Lauderdale, Lincoln, Madison, Obion, Rutherford, Shelby, and Tipton), Texas (excep t the counties of Carson, Dallam, Hansford, Hartley, Hutchinson, Lipscomb, Moore, Ochiltree, Roberts, and Sherman), Virginia (only the counties of Dinwiddie, Franklin City, Greensville, Isle of Wight, Northampton, Southampton, Suffolk City, Surrey, Sussex) a nd Missouri (only the c ounties of Dunklin, New Madrid, Pemiscot, Scott, Stoddard).

These refuge requirements do not apply to seed pr opagation of inbred and hybrid corn seed corn up to a total of 20,000 acres per c ounty and up to a combined U.S. total of 250,000 acres per PIP active ingredient per registrant per year.

When on-farm assessments identify non-compliance with refuge requirements for one or more Bt corn products, additional educational material an d assistance are provided by the registrant to help these growers meet the refuge re quirements across their farming operations.

f) Grower Agreement for OAM XTRA Corn

8. Persons purchasing OAM XTRA corn must sign a grower agreement. The term “grower agreement” refers to any grower purchase contract, license agreement, or similar legal document.

9. The grower agreement and/or specific st ewardship documents referenced in the grower agreement must clea rly set forth the terms of the current IRM program. By signing the grower agreement, a gr ower must be contractually bound to comply with the requirements of the IRM program.

10. Pioneer must implement a system equiva lent to what is already approved for previously registered Pioneer Bt corn products, which is reasonably likely to assure that persons purchasing OAM XTRA corn will affirm annually that they are contractually bound to comply with the requirements of the IRM program. A description of the system must be submitte d to EPA within 90 days from the date of registration. (This information has b een submitted and is being evaluated by the Agency.)

11. Pioneer must use a grower agreement and must submit to EPA, within 90 days from the date of registration, a copy of that agreement and any specific stewardship documents referenced in the grower agreement. (This information has been submitted and is being evaluated by the Agency.)If Pioneer wishes toOptimum AcreMax B.t. Corn S eed Blends Page 39 of 54 Biopesticides Registration Action Document

change any part of the grower agreemen t or any specific stewardship documents referenced in the grower agreement that would affect either the content of the IRM program or the legal enforceability of the provisions of the agreement relating to the IRM program , 30 days prior to implementing a proposed change, Pioneer must submit to EPA the text of such changes to ensure it is consistent

with the terms and conditions of this registration.

12. Pioneer shall maintain records of all OAM XTRA corn grower agreements for a period of three years from December 31 st of the year in which the agreement was signed.

13. Beginning on January 31, 2012, and annually thereafter, Pioneer shall provide EPA with a report on the number of units of OAM XTRA corn seed shipped and not returned, and the number of such units that were sold to persons who have signed grower agreements. The report shall cover the time frame of a twelvemonth period. Note: The first report sha ll contain the specified information from the time frame starting with the date of registration and extending through the 2011 growing season.

14. Pioneer must allow a review of the grower agreements and grower agreement records by EPA or by a State pesticide regul atory agency if the State agency can

demonstrate that confidential business information, including names, personal information, and grower license number, will be protected.

g) IRM Education and IRM Compliance Moni toring Program for OAM XTRA Corn

2. Pioneer must design and implement a comprehensive, ongoing IRM education program designed to convey to OAM XTRA corn users the importance of complying with the IRM program. The program must also address unexpected pest damage and guidance for growers in this area. The education program shall involve the use of multiple media, e.g. face-to-face meetings, mailing written materials, EPA-reviewed language on IRM requirements on the bag or bag tag,

and electronic communications such as by internet, radio, or television commercials. Copies of the materials will be provided to EPA for their records. The program shall involve at least on e written communication annually to each OAM XTRA corn user separate from the grower technical guide. The

communication shall inform the user of the current IRM requirements and specifically the need to plant a lepidopt eran refuge in cotton growing regions. Pioneer shall coordinate its education pr ogram with the educational efforts of other registrants and othe r organizations, such as the National Corn Growers Association and state extension programs.

2. Pioneer must design and im mediately implement a “bag tag” that will be attached to all bags of OAM XTRA seed sold a nd delivered for the 2011 growing season and annually thereafter. The purpose of this bag tag is to remind growers that OAM XTRA products require a separate 20% le pidopteran refuge in cotton-growing areas. The PIP product label accepted by EPA must include how this information will be conveyed to growers via text and graphics. A revised PI P product label must be submitted by January 31, 2011.Optimum AcreMax B.t. Corn S eed Blends Page 40 of 54 Biopesticides Registration Action Document

3. Pioneer must conduct targeted, on-farm compliance assessments for growers who purchase OAM XTRA seed to ensure grower s are compliant with the requirement of a 20% refuge for lepidopteran pests in co tton growing areas. For the 2011 growing season and thereafter, Pioneer must conduct on-farm assessments or roughly half the

number of assessments that Pioneer w ill contribute to the 2011 Agricultural Biotechnology Stewardship Technical Co mmittee (ABSTC) compliance assurance program assessment for corn borer and stacked products. Pioneer must contract with an independent third party to conduct these compliance asse ssments. The table below

reflects the relative number of on-farm assessments for OAM XTRA based on

Pioneer’s contribution to the ABSTC compliance assurance program report and is subject to change with time as appropriate.

i. A third party is classified as a party ot her than the registrant, the grower, or anyone else with a direct interest in IRM compliance for Bt corn.

Pioneer must provide a report to EPA summarizing the OAM XTRA compliance assurance program activities a nd results for the prior year and plans for the OAM XTRA compliance assurance program for the cu rrent year, by January 31, 2012, and annually thereafter. Within one month of submitting this report to EPA, the registrant shall meet with EPA to discuss its findings. The report must inform EPA of the number of growers deemed ineligible to purchase Bt corn s eed on the basis of continued non-compliance

with the insect resistance ma nagement refuge requirements.

4. Annually, Pioneer shall revise, and expand as necessary, its education program to take

into account the information collected th rough the compliance survey and from other sources. The changes shall address aspects of grower compliance that are not sufficiently high.

5. Beginning January 31, 2012, Pioneer must provide a report to EPA summarizing the

activities it carried out under its educa tion program for the prior year. Annually thereafter, Pioneer must provide EPA any s ubstantive changes to its grower education activities as part of the overall IRM complia nce assurance program report. Pioneer must either submit a separate report or contribut e to the report from the industry working group, ABSTC.

6. The registrant shall revise and expand its existing Compliance Assurance Program to include the following elements. The registra nt must prepare and submit by January 31, 2012, a written description of its revised Co mpliance Assurance Program. The registrant may coordinate with other registrants in designing and implementing its Compliance Assurance Program.

7. The registrant will enhance the refuge e ducation program throughout the seed delivery

channel:

i. Ensure sales representatives, licensees , seed dealers, and growers recognize the importance of correct refuge implementation and potential consequences of failure to plant the required refuge;Optimum AcreMax B.t. Corn S eed Blends Page 41 of 54 Biopesticides Registration Action Document

ii. Pioneer must design and immedi ately implement a “bag tag” that will be attached to all bags of OAM XTRA seed sold and delivered for the 2011 growing season and annually thereafter. The purpose of this bag tag is to remind growers that OAM XTRA products require a separate 20% lepidopteran refuge in cotton growing areas. The PIP product label accepted by EPA must include how this information will be conveyed to growers via text and graphics. A revised PIP pr oduct label must be submitted by January 31,

2011.

8. The registrant will focus the majority of on-farm assessments on regions with the greatest risks for resistance:

i. Use Bt corn adoption, pest pressure informa tion, and other available information to identify regions where the risk of resistance is greatest;

ii. Focus approximately two-thirds of on-fa rm assessments on these regions, with the remaining assessments conducted across othe r regions where the product is used.

9. The registrant will use its available Bt sales records and other information to refine grower lists for on-farm assessments of th eir compliance with re fuge requirement:

i. Identify for potential on-farm assessment growers whose sales information indicates they have purchased the Bt corn product but may have purch ased little or no refuge seed from the registrant, licensee, or affiliated company.

10. The registrant will contra ct with third parties to pe rform on-farm assessments of compliance with refuge requirements:

i. The third-party assessors will conduct all first-time on-farm assessments as well as second-year on-farm assessments of those growers found out of compliance in a firsttime assessment

11. The registrant will annually refine the on-farm assessment program for the Bt corn product to reflect the adoption rate and leve l of refuge complian ce for the product.

12. The registrant will follow up with grower s who have been found significantly out of compliance under the on-farm assessment pr ogram and are found to be back in compliance the following year:

i. All growers found to be significantly out of compliance in a prior year will annually be sent additional refuge assistance information for a minimum of two years by the registrant, seed supplier, or th ird party assessor, after comple ting the assessment process;

ii. The registrant will conduct follow-up check s on growers found to be significantly out of compliance within three y ears after they are found to be back in compliance;

iii. A grower found with a second incident of sign ificant non-compliance with refuge requirements for the Bt corn product within a five-year period will be denied access toOptimum AcreMax B.t. Corn S eed Blends Page 42 of 54 Biopesticides Registration Action Document

Pioneer Hi-Bred’s Bt corn products the next year. Si milarly, seed dealers who are not fulfilling their obligations to inform/educate grow ers of their IRM obligations will lose their opportunity to sell Bt corn.

h) Insect Resistance Monitoring and Reme dial Action Plan for OAM XTRA Corn

The Agency is imposing the following cond itions for this lepidopteran toxin:

The registrant will monitor for resi stance to its lepidopteran-resistant Bt corn. The monitoring program shall consist of two a pproaches: (1) focused population sampling and laboratory testing; and (2) investigation of reports of less-than ex pected control of labeled insects. Should fieldrelevant resistance be confirmed, an appropriate resistance management action plan will be implemented.

(2) Focused Population Sampling

The registrant shall annually sample and bioassay populations of the key target pests Ostrinia

nubilalis (European corn borer; ECB), Diatraea grandiosella (Southwestern corn borer; S WCB), and Helicoverpa zea (corn earworm; CEW). Sampling for th e target pests will be focused

in areas identified as those w ith the highest risk of resistance development (e.g., where lepidopteran-active Bt hybrids are planted on a high proportion of the corn acres, and where the insect species are regarded as key pests of corn ). Bioassay methods must be appropriate for the goal of detecting field-relevant shifts in population response to lepidopteran resistant Bt corn and/or changes in resist ance allele frequency in response to the use of Bt corn and, as far as possible, should be consistent ac ross sampling years to enable co mparisons with historical data.

The number of populations to be collected shall reflect the regional importance of the insect species as a pest, and specific collection regions will be identified for each pest. For ECB, a minimum of 12 populations across the sampling regi on will be targeted for collection at each annual sampling. For SWCB, the target will be a minimum of six populations. For CEW, the target will be a minimum of 10 populations. Pe st populations should be collected from multiple corn-growing states reflective of different ge ographies and agronomic conditions. To obtain sufficient sensitivity to detect resistance alle les before they become common enough to cause measurable field damage, each population collection shall attempt to target 400 insect genomes (egg masses, larvae, mated females, and/or mixed-sex adults), but a successful population collection will contain a minimum of 100 genomes. It is recognized that it may not be possible to collect the target number of in sect populations or genomes du e to factors such as natural fluctuations in pest density, environmental conditions, and area-wid e pest suppression.

The sampling program and geographic range of co llections may be modified as appropriate based on changes in pest importance and for th e adoption levels of lepidopteran-resistant Bt corn. The Agency shall be consulted prior to the implementation of such modifications.

The registrant will report to the Agency before August 31 each year the results of the population sampling and bioassay monitoring program.

Any incidence of unusually low sensitivity to the Bt protein in bioassays sh all be investigated as soon as possible to understand any field relevance of such a finding. Such investigations shallOptimum AcreMax B.t. Corn S eed Blends Page 43 of 54 Biopesticides Registration Action Document

proceed in a stepwise manner until the field rele vance can be either confirmed or refuted, and results of these shall be reported to the Agen cy annually before Augus t 31. The investigative steps will include:

1. Re-test progeny of the collect ed population to determine wh ether the unusual bioassay response is reproducible and herita ble. If it is not reproducible a nd heritable, no further action is required.

2. If the unusual response is repr oducible and heritable, progeny of insects that survive the diagnostic concentration will be tested using me thods that are representative of exposure to Bt corn hybrids under field conditi ons. If progeny do not survive to adulthood, any suspected

resistance is not fiel d relevant and no furthe r action is required.

3. If insects survive steps 1 and 2, resistance is confirmed, and further steps will be taken to evaluate the resistance. These steps may include:

 determining the nature of the resistance ( i.e., recessive or dominant, and the level of functional dominance);

 estimating the resistance-allele freq uency in the original population;

 determining whether the resistance-allele Frequency is increasing by analyzing field collections in subsequent years sampled from the same site where the resistance allele(s) was originally collected;

 determining the geographic distribution of the resistance allele by analyzing field collections in subsequent years from site s surrounding the site where the resistance allele(s) was originally collected.

Should field-relevant resistance be confirmed, and the resistance appears to be increasing or spreading, the registrant will consult with the Ag ency to develop and implement a case-specific resistance management action plan.

(2) Investigation of Reports of Unexpect ed Levels of Damage by the Target

Pests:

The registrant will follow up on grower, extension specialist or consultant reports of unexpected levels of damage by the lepidopteran pests listed on the pesticide label. The registrant will

instruct its customers to contact them if such in cidents occur. The registrant will investigate all legitimate reports submitted to the comp any or the company's representatives.

If reports of unexpected levels of damage lead to the suspicion of resistance in any of the key target pests (ECB, SWCB, and CEW) , the registrant will implemen t the actions described below, based on the following definitions of suspected resistance and confirmed resistance.

Suspected resistance

EPA defines suspected resistance to mean field reports of unexp ected levels of insect feeding damage for which:Optimum AcreMax B.t. Corn S eed Blends Page 44 of 54 Biopesticides Registration Action Document

 the corn in question has been c onfirmed to be lepidopteran-active Bt corn;

 the seed used had the proper percentage of corn expressing Bt protein;

 the relevant plant tissues are ex pressing the expected level of Bt protein; and

 it has been ruled out that speci es not susceptible to the prot ein could be responsible for the damage, that no climatic or cultural reas ons could be responsible for the damage, and

that that there could be no othe r reasonable causes for the damage.

The Agency does not interpret suspected resistance to mean grower reports of possible control failures or suspicious results from annual ins ect monitoring assays, nor does the Agency intend

that extensive field studies and testing be undertaken to confirm scientifically the presence of

insects resistant to Bt corn in commercial production fields before responsive measures are

undertaken.

If resistance is suspected, the registrant will instruct growers to do the following:

 Use alternative control measures in the Bt corn fields in the affect ed region to control the target pest during the immediate growing season.

 Destroy Bt corn crop residues in the affected region within one month after harvest with a technique appropriate for local production practices to minimize the possibility of

resistant insects over-winteri ng and contributing to the next season's target pest population.

Additionally, if possible, and pr ior to the application of alte rnative control measures or destruction of crop residue, the registrant will collect samples of the insect population in the affected fields for laboratory re aring and testing. Such rearing a nd testing shall be conducted as expeditiously as practical.

Confirmed resistance

EPA defines confirmed resistance to mean, in the case of field re ports of unexpected levels of damage from the key target pests, th at all the following criteria are met:

 There is > 30% insect survival and commensurate inse ct feeding in a bioassay, initiated with neonate larvae, that uses methods that are representati ve of exposure to Bt corn hybrids under field conditions (ECB and SWCB only).

 In standardized laboratory bioassays using diagnostic concentrations of the Bt protein suited to the target pest in question, the pest exhibits resistance that has a genetic basis and the level of survivorship indicates that there may be a resistance allele frequency of ≥ 0.1 in the sampled population.

 In standardized labora tory bioassays, the LC 50 exceeds the upper limit of the 95%

confidence interval of the LC 50 for susceptible populations su rveyed both in the original baselines developed for this pest species a nd in previous years of field monitoring.Optimum AcreMax B.t. Corn S eed Blends Page 45 of 54 Biopesticides Registration Action Document

(3) Response to Confirmed Resistance in a Key Target Pest as the Cause of Unexpected Levels of Damage in the Field

When field resistance is confirmed (as defined above), the following steps will be taken by the registrant:

 EPA will receive notification within 30 days of resistance confirmation;

 Affected customers and extension agents will be notified about confirmed resistance within 30 days;

 Monitoring will be increased in the affected ar ea and local target pest populations will be sampled annually to determine the ex tent and impact of resistance;

 If appropriate (depending on the resistant pest species, the extent of resistance, the timing of resistance, and the nature of resistance, and the availabi lity of suitable alternative control measures), alternative control measures will be employed to reduce or control target pest populations in the affected ar ea. Alternative control measures may include advising customers and extension agents in th e affected area to incorporate crop residues into the soil following harvest to minimize th e possibility of over-wintering insects, and/or applications of chemical insecticides;

 Unless otherwise agreed with EPA, stop sale and distribution of the relevant lepidopteran-active Bt corn hybrids in the affected area immediat ely until an effective local mitigation plan approved by EPA has been implemented;

 The registrant will develop a case-specific resistance management action plan within 90 days according to the characte ristics of the resistance even t and local agronomic needs. The registrant will consult with appropriate st akeholders in the development of the action plan, and the details of such a plan shall be approved by EPA prior to implementation;

 Notify affected parties (e.g. growers, consulta nts, extension agents , seed distributors, university cooperators a nd state/federal authorities as a ppropriate) in the region of the

resistance situation and approved action plan; and

 In subsequent growing seasons, maintain sales suspension and a lternative resistance management strategies in th e affected region(s) for the Bt corn hybrids that are affected by the resistant population until an EPA-approved local resistance management plan is in place to mitigate the resistance.

A report on results of resistance monitoring and investigations of damage reports must be submitted to the Agency annually by August 31 st each year for the duration of the conditional registration.

The Agency is imposing the following cond itions for this corn rootworm toxin:

In addition to the existing two-pronged appro ach to insect resistance monitoring (monitoring insect populations using the diet bioassay and investigations of fi eld reports) that are required for Cry34/35 for Herculex Rootworm Insect Prot ection (29964-4) and Herc ulex Xtra Insect Protection (29964-5), Pioneer must also conduc t enhanced monitoring using the SublethalOptimum AcreMax B.t. Corn S eed Blends Page 46 of 54 Biopesticides Registration Action Document

Seedling Assay as a complement to the diet bi oassay method. Pioneer must submit a detailed OAM XTRA/OAMRW-specific resistance monitori ng plan to the Agency by December 1, 2010.

With respect to the implementation of the Sublethal Seedling Assay:

1. Pioneer must monitor for resistance and or chan ges in target pest susceptibility that will lead to increased injury potential in west ern and northern corn rootworm feeding on the rootworm component of OAM XTRA products. Sampling must be focused in the four regions of highest risk of resistance deve lopment: Region – 1 (Illinois, Indiana); Region 2 (Iowa, Missouri), Region 3 (Nebraska and Kansas), and Region 4 (Minnesota, South Dakota and Wisconsin).

2. Pioneer must provide the EPA its detailed we stern corn rootworm resistance monitoring plan for approval by December 1, 2010, and its northern corn rootworm resistance monitoring plan for approval by December 1, 2011. These plans will include baseline (benchmark) susceptibility data and an enha nced annual resistance monitoring plan. The reports will contain:

 Sampling scheme: annual collection s hould target a range of 16-20 western and/or northern rootworm populations (4-5 per region), with a minimum number of 2,000 beetles collected per population.

 Bioassay methodology (precision, detecti on level, etc.). Pioneer must bioassay a target of 3000 larvae on 59122 plants for each population.

 A description of how monito ring results relate to and are predictive of changes in field efficacy, and change in inju ry potential to DAS -59122-7 constituting product failure and development of a remedial action plan.

3. Pioneer will provide the EPA with an a nnual OAM XTRA resistance monitoring report by August 31 st of each year beginning with 2011 for western corn rootworm and 2012 for northern corn rootworm, reporting on populat ions collected the previous year. In addition to screening of wide-area corn rootworm populations as outlined above, for the second prong of resistance monitoring Pion eer must investigate grower, extension specialist or consultant reports of less-tha n-expected efficacy or field performance of OAM XTRA products.

i) Remedial Action Plan for Corn Rootworm and OAM XTRA Corn

The remedial action plan is designed as a tier ed approach for mitigating western and northern corn rootworm resistance development specifi cally due to the commercialization of OAM XTRA corn. The following program summary describes, in order of events, the step s that must be taken to implement a remedial action plan if re sistance to target pests is confirmed.

Pioneer will complete a benchmark study of suscep tibility of western corn rootworm using the Sublethal Seedling Assay and analyz e field efficacy data to set a benchmark for expected levels of damage to finalize the OAM XTRA reme dial action plan by December 1, 2010, so that decision points regarding crop damage and target pest resistance are established, and a remedial action plan can be initiated when needed. Although northern corn rootworm is difficult to rear in the laboratory, Pioneer will attempt to complete a benchmark study for susceptibility of northern corn rootworm using the Sublethal Seedling Assay.Optimum AcreMax B.t. Corn S eed Blends Page 47 of 54 Biopesticides Registration Action Document

1. Suspected Resistance from Population Monitoring

Definition of Suspected Resistance - Resistance will be suspected if investigations of target pest injury potential to OAM XTRA maize from the Sublethal Seedli ng Assay show that:

 Injury potential of a target pest population obtained as part of the annual insect monitoring program has increased to a le vel representative of product failure in field conditions;

 The seeds used in the investigation of this population’s injury potential contain Cry34/Cry35Ab1 at levels representative of (and in the same genetic background as) the benchmark study; and

 The change in injury poten tial has been documented as a heritable characteristic of the target pest population and not a result of experimental error.

If resistance is "suspected", Pioneer will inform growers in the area of the potential benefit of augmenting CRW control such as ad ulticide treatment and/or crop ro tation or use of soil or seedapplied insecticides at rates providing corn rootworm control the following year. These measures are intended to educate growers of th e potential for change in efficacy, reduce the possibility of grower loss from change in efficacy and reduce potentially resistant insects contributing to the following year's pest population.

2. Confirmed Resistance from Population Monitoring

Definition of Confirmed Resistance - Resistance will be confirmed if all of the following criteria are met by progeny from a subsequent rootwo rm population collected from the area of "suspected resistance" the following year:

 Injury potential of the su bsequent field-collected r ootworm population feeding on plants containing DAS-59122-7 remains at a level likely to produce repeated product failure in field conditions;

 The change in injury poten tial has been documented as a heritable characteristic of the target pest population;

 Greenhouse node-injury evaluation confirms product failure;

 Subsequent populations collected from the area and assayed show that the results are repeatable; and

 Continued monitoring of th e area suggests that the change is spreading.

3. Suspected Resistance – Invest igation of Field Reports

The registrant will follow up on grower, extension specialist or consultant reports of unexpected product performance due to corn rootworm species listed on the label. The registrants will

instruct its customers to contact them if such in cidents occur. The regist rants will investigate all such reports submitted to the company or the company’s representatives.

 Confirm the corn in question is rootworm-active Bt corn;

 Confirm the field in question contains th e correct blend rate of refuge corn;

 Confirm that species not susceptible to the protein are not responsible for theOptimum AcreMax B.t. Corn S eed Blends Page 48 of 54 Biopesticides Registration Action Document

damage, that no climatic or cultural reasons could be responsible for the damage, and that all other reasonable cau ses based on historical experience for the observed root damage have been ruled out;

 If not due to other reasons, the regist rant will conduct a th orough investigation

of the factors known to affect the mani festation of corn rootworm feeding damage.

 If the investigation fails to rule ou t target pest resistance as the cause, resistance is suspected.

If resistance is "suspected", Pioneer will inform growers in the area of the potential benefit of augmenting CRW control such as ad ulticide treatment, crop rotation the following year or use of soil or seed insecticides the following year. Th ese measures are intended to educate growers of the potential for change in efficacy, reduce the possi bility of grower loss from change in efficacy and reduce potentially resistant insects contribu ting to the following year's pest population.

Pioneer will collect insects as s oon as possible from the area for laboratory studies to test for resistance by comparing with benchmark suscep tibility data. These studies will be performed following the same laboratory protocols as used for the benchmark determination and monitoring

programs.

4. Confirmed Resistance – Invest igation of Field Reports

 Injury potential of the field-collected rootworm population feeding on plants containing DAS-59122-7 remain s at a level likely to produce repeated product failure in field conditions;

 Subsequent populations collected from the area and assayed show that the results are repeatable;

 The change in injury poten tial has been documented as a heritable characteristic of the target pest population;

 Greenhouse node-injury evaluation c onfirms product failure; and

 Continued monitoring of the area suggests that th e change is spreading.

5. Remedial Action

When resistance is "confirmed", the following steps will be taken:

 The EPA will receive notification within 30 days of confirmed resistance;

 Affected customers and Extension specia lists will be immedi ately notified about confirmed resistance;

 Affected customers and Extension specia lists will be strongly encouraged to implement alternative CRW control measur es such as adulticide treatment, crop rotation the following year, or use of soil or seed insecticides the following year;

 Within 60 days of notification, Pioneer a nd EPA will jointly determine the extent of the mitigation needed and determine whether sales should be stopped on an appropriate geographic (i.e., c ounty or regional) basis; and

 Pioneer will develop a case-specific resi stance mitigation action plan within 90 days according to the characteristics of the resistance event and local agronomicOptimum AcreMax B.t. Corn S eed Blends Page 49 of 54 Biopesticides Registration Action Document

needs. Pioneer will consult with appropr iate stakeholders in the development of the action plan, and the details of such a plan shall be approved by the EPA prior to implementation. The resistance manage ment plan could include such measures layering additional technologies in future OAM XTRA products.

f) Remedial Action Plan for lepidopteran pests and OAM XTRA Corn

When field resistance is confirmed (as previously defined), the following steps will be taken by the registrant:

• EPA will receive notification within 30 days of resistance confirmation;

• Affected customers and extension agents will be notified about confirmed resistance within 30 days;

• Monitoring will be increased in the affected area and local target pest populations will be sampled annually to determine the ex tent and impact of resistance;

• If appropriate (depending on the resistant pest species, the extent of resistance, the timing of resistance, and the nature of re sistance, and the availability of suitable alternative control measures) , alternative control measures will be employed to reduce or control target pest populations in the affected area. Alternative control measures may include advising customers and extension agents in the affected area to incorporate crop residues into the soil following harvest to minimize the possibility of over-wintering insects, and/ or applications of chemical insecticides;

• Unless otherwise agreed with EPA, stop sale and distribution of the relevant lepidopteranactive Bt corn hybrids in the affected area immediatel y until an effective local mitigation plan approved by EPA has been implemented; • The registrant will develop a case-specific resistance manageme nt action plan within 90 days according to the characteristics of the resistance event and local agronomic needs. The registrant will consult with appropriate stak eholders in the development of the action plan. and the details of such a plan shall be approved by EPA prior to implementation;

• Notify affected parties (e .g. growers, consul tants, extension agents , seed distributors, university cooperators and state/ fe deral authorities as appropriate) in the region of the resistance situation and approved action plan; and

• In subsequent growing seasons, maintain sales suspension and a lternative resistance management strategies in th e affected region(s) for the Bt corn hybrids that are affected by the resistant population until an EP A-approved local resistance management plan is in place to mitigate the resistance.

A report on results of resistance monitoring and investigations of damage reports must be submitted to the Agency annually by August 31st each year for the duration of the conditional registration.

g) Refuge Assurance Program for OAM XTRA CornOptimum AcreMax B.t. Corn S eed Blends Page 50 of 54 Biopesticides Registration Action Document

Pioneer must implement a Blended Seed Refuge Assurance Program designed to ensure OAM XTRA products are formulated with the appropri ate rate of refuge seeds. The program must include the following four elements:

5. Trait purity check on seed lots prior to blending;

6. ISO 9000 Standard Operating Proced ures for the blending process;

7. Calibration of blending equipment; and

8. Records and data retention records for seed blend products.

 Calibration records - Pioneer will retain documentation for a specified period of time on the equipment calibration including the procedure, when it was conducted

and the results.

 Blend proportion records (weight and ke rnel based) - Pioneer will retain documentation for a specified period of time on the kernel per pound data of the components, the calculations to determ ine the proportions based on weight and the actual weights that are blended t ogether to make up an OAM XTRA product by seed lot.

All records must be maintained at the Pioneer blending facility and must be available for the EPA review upon request.

h) Annual Reporting Requirements for OAM XTRA Corn

7. Annual Sales: reported and summed by state (county level data available by request) January 31 st each year, beginning in 2012;

8. Grower Agreements: number of units of OAM XTRA corn seed shipped or sold and not returned, and the number of such units that were sold to persons who have signed grower agreements, January 31 st each year, beginning in 2012;

9. Grower Education: substantive chan ges to education program completed previous year, January 31 st each year, beginning in 2011;

10. Compliance Assurance Program: compliance assurance program activities and results for the prior year and plans for the compliance assurance program for the current year, January 31 st each year, beginning in 2012;

11. Compliance Survey Results: results of annual surveys for the prior year and survey plans for the current year; full report January 31 st each year, beginning in 2012;

12. Insect Resistance Monitoring Result s: results of monitoring and investigations of da mage reports, August 31 st each year, beginning in 2012 for

western corn rootworm and northern corn rootworm.

VI. REFERENCES

Bailey, L., R. Binning, L. Higgins, D. Langer, R. Layton, S. Lefko, T. Nowatzki, E. Owens, and T. Rood. 2008. Trait Durability Plan for Optimum® AcreMaxTM1 Insect Protection Following Commercialization. Unpublished report submitted to the US EPA (MRID 473567- 09).

BPPD, 2011a. EPA Review of Pioneer’s new pr oduct registration request, Optimum AcreMaxOptimum AcreMax B.t. Corn S eed Blends Page 51 of 54 Biopesticides Registration Action Document

Insect Protection, expressing Cry1F and Cry1Ab in a 5% seed blend to control lepidopteran pests

of corn. Memo from JC Martin ez to M. Mendelsohn dated May 18, 2011.

BPPD, 2011b. Agency deficiency letter sent by Dr. Sheryl Reilly in June, 2011 addressed to Tracy Rood from Pioneer/DuPont.

BPPD, 2010a. Science Assessment of Pioneer’s mode ling addenda in support of their application of registration for Optimum AcreMax1 Insect Protection. Memo from JC Martinez to M. Mendelsohn dated February 4, 2010.

BPPD, 2010b. Science risk assessment to evaluate the durability of a 10% Cry34/35 seed blend refuge deployment of Cry34/35 co rn relative to the durability predicted for a 20% block in regards to Pioneer/DuPont’s Optimum AcreMax1. Memo from JC Martinez to M. Mendelsohn dated April 22, 2010.

Caprio, MA, T Nowatzki, B Siegfried, LJ Mein ke, RJ Wright & LD Chandler. 2006. Assessing the Risk of Resistance to Aerial Applications of Methyl-Parathion in the Western Corn Rootworm. Journal of Economic Entomology, Vol. 99(2): 483-493

Caprio, M. A., D. Sumerford & S. Sims. 2006b. Evaluating transgen ic plants for suitability in pest and resistance management programs, 2nd edition. L. Lacey & H. Kaya [eds]. Field Manual of Techniques for the Applicati on and Evaluation of Entomopathogens.

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Davis, P. and S. MacIntosh. 2008. Benef its Document of Optimum® AcreMaxTM 1 Insect Protection. Unpublished report subm itted by Pioneer Hi-Breed Intern ational, Inc. to the US EPA (MRID 473567-10).

EPA MRID No. 47339601 Bailey, L. (2008) 2007 Insect Resistance Management Compliance Assurance Program Report for Corn Borer-Protect ed B.t. corn, Corn Rootworm-Protected B.t. corn, and Corn Borer/ Corn Rootworm-Protected Stacked B.t. corn. Project Number: CAP/2007. Unpublished study prepared by Agricultural Bi otechnology Stewardship Technical Committee. 17 p.

EPA MRID No.47356701 Lefko, S.; Binning, R. (2008) Characterization of Instar-Specific Response and Larval Recovery of Western Corn Rootworm Exposed to 59122 Maize. Project Number: PHI/2005/053.Unpublished study prepared by Pioneer Hi-Bred In ternational, Inc. 34 p.

EPA MRID No.47356702 Lefko, S.; Binning, R. ( 2008) Effect of Off-Type Seeds on the

Precision of Sublethal Corn Rootworm Seedli ng Assay Results. Pr oject Number: PHI/2006/042. Unpublished study prepared by Pioneer Hi -Bred International, Inc. 13 p.

EPA MRID No.47356703 Lefko, S.; Diehn, S. (2008) An Observational Study Characterizing the Relative Quantity and Distribution of Cr y34Ab1 and Cry35Ab1 Insecticidal Proteins in Roots of Maize Containing Event DAS-59122-7. Project Number: PHI/2006/119. Unpublished studyOptimum AcreMax B.t. Corn S eed Blends Page 52 of 54 Biopesticides Registration Action Document

prepared by Pioneer Hi-Bred International, Inc. 22 p.

EPA MRID No.47356704 Lefko, S.; Binning, R. ( 2008) Quantifying the Concentration of Cry34Ab1 and Cry35Ab1 in 59122 Maize Grown in the Sublethal Corn Rootworm Seedling Assay System. Project Numb er: PHI/2006/171. Unpublished st udy prepared by Pioneer HiBred International, Inc. 11 p.

EPA MRID No.47356705 Nowatzki, T. ; Thompson, S.; Peters, M. (2008) Field Measures of Adult Corn Rootworm (Coleoptera: Chrysomelid ae) Production When Refuge is Deployed as a Seed Blend with DAS-59122-7 Maize. Proj ect Number: PHI/2007/075. Unpublished study prepared by Pioneer Hi-Bred International, Inc. 57 p.

EPA MRID No.47356706 Nowatzki, T.; Meinke, L. (2008) Impact of Western and Northern Corn Rootworm Larval Exposure to DAS-59122-7 in a Block Planting and a Seed Blend on Life History Traits of Adults. Project Numb er: PHI/2007/076. Unpublished study prepared by

Pioneer Hi-Bred International, Inc. and Un iversity of Nebraska-Lincoln. 31 p.

EPA MRID No.47356707 Lefko, S.; Binning, R. (2008) I nvestigating the Effect of Insecticidal Proteins Cry34/35Ab1 on Western Corn Rootworm Host Searchi ng Behavior. Project Number: PHI/2007/126. Unpublished study prepared by Pion eer Hi-Bred Internat ional, Inc. 17 p.

EPA MRID No.47356710 Davis, P.; MacIntosh, S. (2008) Benefits Document for Optimum AcreMax 1 Insect Protection. Project Numb er: PHI/2007/145. Unpublished study prepared by Pioneer Hi-Bred International, Inc. 21 p.

EPA MRID No.47663301 Bailey, L. (2009) 2008 In sect Resistance Management Compliance Assurance Program Report for Corn Borer-Protect ed B.t. Corn, Corn Rootworm-Protected B.t. Corn, and Corn Borer/Corn Rootworm-Protect ed Stacked B.t. Corn. Project Number: CAP/2008. Unpublished study prepared by Agri cultural Biotechnology Stewardship Techn. Committee. 15 p.

EPA MRID No.47683801 Binning, R.; Langer, D. ( 2009) Additional Responses for "Pioneer's Benefit Documentation in Support of a Sec(3) Product Registration for Optimum AcreMax 1 Insect Protection, also Known as Stack Hercul ex XTRA (Cry34/35Ab1 + Cry1F) with Herculex I (Cry1F, Refuge Seed for CRW) [MRID 473567- 10 and Supplemental Data]": Final Report. Project Number: PHI/2009/026. Unpublished study pr epared by Pioneer Hi-Bred International, Inc. 11 p.

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