UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

APR 1 3 2010

OFFICE OF

PREVE NTION, PESTICIDES AND

TOXIC SUBSTANCES

MEMORANDUM

SUBJECT: Review of a Supplement to a Label Amendment Request for Azinphos-methyl

(DP #375971)

FROM: Nikhil Mallampalli, Entomologist

Biological Analysis Branch

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T J Wyatt, Senior Economist J1

Economic Analysis Branch -rLr tz: 'Vfil 2010

Biological and Economic Analysis Divisi n (750 3P)

Arnet Jones, Chief Il

Biological Analysis Branc.r

Timothy Kie ly, Chief /L \/'v\., I12

Economic Analysis Branch "-J .,)

Biological and Economic Analysis Div ision (7503P)

Thomas Harris

Insecticide and Rodenticide Branch

Registration Division (7505P)

Katie Weyrauch, Chemical Review Manager

Margaret Rice, Chief

Risk Management and Implementation Branch 2

Pesticide Re-evaluatio n Division (7508P)

BEAD Product Review Panel date: April 7, 20 10

Introduction

Unde r the cancellation agreement for azinphos-methyl (AZM), EPA and the registrant agreed to

a detailed phase-out schedule for several fruit crops, including app les, blueberries, cherries, and

pears (EPA, 2006). The phase-out was implemented to allow growers a period oftime to

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identify and transition to new pest control method s, in part because BEAD estimated that there

could be significant impacts on growers ofthese crops if AZM were cancelled. Under the phaseout, seasonal application rates are reduced in stages, beginni ng in 2009, with use of AZM fully

cancelled after the 2012 growing season. The rate reductions were designed to begin to address

the risks posed by AZM to workers and the environment while still allowing growers the use of

at least one application of AZM , perhaps as a rescue treatment.

In June 2009, the registrant, Makhteshim Agan North America (MANA), submitted an

application for a label amendment that would maintain seasonal application rates at the 2009

level through the phase-out period on the grounds that impacts to growers will be sizeable.

BEAD evaluated the registrant's submission, as well as comments from university extension

personnel, individual growers and grower associations received in response to the application.

BEAD concluded that the submission did not prov ide any new information that would suggest

the impacts would be larger than BEAD had estimated at the time EPA decided to cancel AZM

(Atwood et al., 2010).

On March 15, 20 I0, the registrant submitted to the Registration Division an additional request to

consider what it claims is new information relevant to their proposed label amendment for tart

cherries. As with the original request, at issue is whether any new information regarding the

impacts of cancelling AZM would suggest that EPA should revisit the decision to lower seasonal

application rates for the remainder of the phase-out period. BEAD reviewed this new

submission and again finds that it does not provide any new information that would lead BEAD

to revise its previous estimates of the impact of cancelling AZM (Atwood and Wyatt, 2005).

Description of the MANA submission

The submission by MANA consists of an explanatory letter from the registrant, in which they

appear to focus on the need for AZM at 2009 application rates to control plum curculio in tart

cherrie s. Under the phase-out terms, cherry growers had been able to use AZM at a rate of 1.5 Ib

ai/acre per year through 2009. Beginning in 2010 and continuing through the end ofthe phaseout in 2012, the application rate is limited to 0.751b ai/acre per year. MANA claims that the

label amendment to increase the label rate through the end ofthe phase-out is necessary to allow

growe rs at least two applications, since the typical use rate is 1 lb ai/acre.

This letter is followed by excerpts from research grants proposals made by Michigan State

University scientists in response to USDA-CSREES grants programs such as the Pest

Management Alte rnatives Program (PMA P) and Crops at Risk (CAR) program. The letter states

that these excerpts constitute a "problem statement/issue analysis" relevant to the request.

BEAD's response focuses on the substance ofthe excerpts.

The points made in the submission that are related to BEAD' s impact assessments appear to be

identical to those made in many of the comments submitted in 2009. Major points include:

Maximum Residue Levels (MRLs), which are essentially international tolerances, have

not been established for all potential AZM alternatives in all export destinations and

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where MRLs have been established they may be lower than tolerances allowed in the

U.S.

AZM has the ability to penetrate fruit and thus kill pests feeding internally as well as

externally for an extended period oftime (a so-called 'c urative' power).

Phosmet has significantly lower efficacy that AZM, ifmixed in with alkaline water.

The plum curculio is the most critical pest for cherries and may not always be adequately

controlled by AZM alternatives. Research trials over the last six years have shown more

'failures' in fields treated with reduced risk alternatives such as thiamethoxam, spinosyn,

and indoxacarb, as compared to fields treated with AZM. Failure is defined as any

detection of one ofthe key pests, especially plum curculio and cherry fruit fly, or a

situation where the grower resorted to an application of AZM or phosmet.

BEAD r esponse

BEAD assessed the impacts of the removal of AZM as a pest control tool in 2005 (Atwood and

Wyatt, 2005). Based on the availability of efficacious alternatives to AZM to control plum

curculio and cherry fruit fly in tart cherries, BEAD concluded that the bene fits derived from the

use of AZM were likely to be small. In the absence of AZM, growers would most likely use

phosmet to maintain the local, state, and federal mandated zero tolerance for these pests. BEAD

concluded that use of phosmet would likely raise production costs by around $10 to $25 per acre.

This could amount to two to four percent of a grower' s net cash returns (gross revenue minus

operating costs). However, BEAD also noted at the time that recent increases in the price of tart

cherries may mean that the benefits ofAZM as a percent of net cash returns would be smaller.

BEAD also noted that MRLs were not yet in place for all the likely alternatives at the time of

assessments, which could affect producers targeting export markets.

BEAD responded to most of the points made in the submission under review in this paper, in

another recent memorandum (Atwood et al. (20 10). To reiterate the relevant portions of that

response:

BEAD appreciates the information on those export markets of key importance for cherry

growers. MRLs for these markets are being tracked by the Agency and it appea rs that there are

levels established for some, but not all, AZM alternatives in many countries importing U.S.

cherries. BEAD noted this concern for the feasibility of using some alternatives by growers

targeting the export market but was not able to quantify the impact. The comments provide no

basis on which to quantify the impacts now.

Regarding the comments on the failures ofAZM alternatives in research trials, BEAD highlights

two caveats as to the utility of the information as it was described:

1) A lack ofinformation on the exact details ofthe "paired comparisons" between AZM and

the reduced risk alternatives means that BEAD cannot use the data to determine whether

the 2005 assessment of the utility ofJikely combinations of such alternatives along with

other conventional materials (such as lambda-cyhalothrin, a synthetic pyrethroid, and

phosmet, an organophosphate) was significantly incorrect.

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2) Based on the information provided in the comment, it is not possible to extrapolate from

the number of failures seen in research trials ofreduced risk materials to the larger

grower community in a reasonable manner. For example, how can the results be used to

determine the frequency ofsuch failures in commercial production, especially where

combinations ofreduced risk and conventional insecticides are likely to be used? Since

the cited failures were seen in fields where either a suite of 'reduced risk' (RR) or 'OPalternative' insecticides had been used, the information cannot reasonabl y be used to

predict whether or not increased failures are likely to occur when phosmet is used, either

alone or in combination with a synthetic pyrethroid or neonicotinoid insecticide. In fact,

in a previous submission citing the same research trials, failure was defined as "RR and

Oft-alt. orchards that resorted to OP-sprays (AZM or phosmet) , and known failures that

did not spray" (Whalon, 2009, emphasis added).

Furthermore, BEAD's 2005 assessment acknowledged that phosmet was less effective than

AZM and may require multipl e applications and that synthetic pyrethroids may reduce

populations of beneficial insects. Phosmet and synthetic pyrethroids may have disadvantages

relative to AZM, but failure to include them as possible control measures overestimates the

impacts ofthe loss ofAZM.

Regardin g the ineffectiveness of phosmet when used in alkaline conditions, BEAD notes that this

constraint existed at the time of its impact assessments in 2005 as well. This issue continues to

be highlighted in extension service advice to growers. For example, the Michigan State

University Fruit Management Guide (MSU, 2010) mentions the importance of keeping pH below

neutral (7). Despite this limitation, phosmet was, and still is, recommended as an option for

plum curculio (and other pest) control (Wise et al. 2008, MSU 2010). BEAD acknowl edges that

some control failures with phosmet may occur, but the information as provided in the MANA

letter does not provide a basis on which to revise the 2005 impact assessments.

Regarding the "curative' powers ofAZM, BEAD notes that other insecticides registered for use

against plum curculio in cherries, are suggested to growers in at least one recent Michigan State

University publication (MSU 2008) because oftheir own curative abilities. Pesticides mentioned

as having this ability include phosmet and the neonicotinoids acetamiprid (Assail @), thiaclopri d

(Calypso ®), and thiamethoxam (Actara ®). BEAD acknowledges that the reduction in

application rates of AZM in 2010 may leave growers with only one seasonal treatment with the

material. However, the availability ofthese other "curative' options (along with several others

that have only external contact toxicity, such as synthetic pyrethroids and indoxacarb, an

oxadiazine) indicate s to BEAD that growers have some effective, relatively new avenues for

plum curculio controL Success of pest control with these alternatives depends, of course, on

continuing research and grower education throughout the phase-out.

Finally, BEAD examined data on AZM application rates in Michigan cherry production to

determine ifthe label rate of 0.75 lb ai/acre would impose unanticipated impacts on growers

during the final years ofthe phase-out. Data are from a marketing survey conducted annually by

GfK Kynetic and follow statistically valid collection procedures. Data from 2006-2008 , which

was prior to the start ofthe phase-out, indicate that the application rate is at or below O.751b

ai/acre on nearly 98% of the Michigan cherry acres treated with AZM. Thus, BEAD concludes

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that the current allowable rate of 0.75 Ib ai/acre is sufficient to provide a " rescue" treatment for

the duration of the phase-out if an alternative control regime were to fail.

Citations

Atwood, D., and T. Wyatt. 2005. 2005 Grower Impact Assessment ofAzinphos-methyl Use on

Tart Cherries (DP 307589). Available at www.regulations.gov.

Atwood, D., D. Brassard, N. Mallampalli, S. Smearman, and T. Wyatt. 2010. Review of a Label

Amendment Request for Azinphos-methyl, including Public Comments (DP # 373559).

Available at www.regulations.gov.

EPA. 2006. Final Decisions for the Remaining Uses of Azinphos-methyl. Office ofPrevention,

Pesticides, and Toxic Substances, November 16. Available at

http://www.epa.gov/pesticides/reregistration/azm/azm remaining uses.pdf.

MSU. 2010. Michigan Fruit Management Guide (2010). Extension Bulletin E-154 of the

Michigan State University, East Lansing, Michigan. 144 pp.

Whalon , M. 2009. General comment. Department of Entomology, Michigan State University.

Available at www.regulations.gov, docket EPA-HQ- OPP-2009-0365, document 0022.

Wise, J., N. Rothwell, D. Epstein, L. Gut, and M. Whalon. 2008. Optimizing insecticide sprays

for plum curculio. Fruit Crop Advisory Team Alert Newsletter, Vol 23 (7): pp 2-3.

Available on the web at: http://www.ipm.msu.eduJcat08fruit/f05-20-08.htm.

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