Document ID: EPA-HQ-OPP-2002-0354-0009
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2006-06-09T04:00Z

SEQ CHAPTER \h \r 1 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

April 19, 2006

  SEQ CHAPTER \h \r 1 OFFICE OF

PREVENTION, PESTICIDES AND TOXIC SUBSTANCES

MEMORANDUM

SUBJECT:	Qualitative impact assessment of extensions to restricted entry
intervals for phosmet in pears (DP # 296575)

FROM:	David W. Brassard, Senior Entomologist

Biological Analysis Branch

Biological and Economic Analysis Division (7503C)

Stephen Smearman, Economist	

Economic Analysis Branch

Biological and Economic Analysis Division (7503C)

THRU:	Arnet Jones, Chief 	

Biological Analysis Branch

Biological and Economic Analysis Division (7503C)

Tim Kiely, Chief, Acting 	

Economic Analysis Branch

Biological and Economic Analysis Division (7503C)

TO:		Diane Isbell, Chemical Review Manager

		Margaret Rice, Chief

		Reregistration Branch II

Special Review and Reregistration Division 

Product Review Panel:  April 7, 2006

Summary

EPA is considering mitigation strategies to address concerns for workers
exposed to phosmet following applications to pear orchards.  This is a
preliminary, qualitative assessment of the impact of extending the
restricted entry interval (REI).

The current REI for pears is 3 days.  A REI greater than seven days
would interfere with irrigation, mowing, scouting and hand harvesting
activities and a REI greater than 14 days would interfere with fire
blight removal activities.  If a longer REI is imposed, growers would
have to replace phosmet with one or more of several available
alternatives.  BEAD tentatively concludes that no yield or quality
losses are likely if growers switch to alternative insecticides. 
Production costs would likely increase by 3% because alternatives are
more costly and have to be applied more often.

Background

Based on post-application worker risk assessments, EPA is considering
mitigation strategies, including extending the restricted entry interval
(REI) for phosmet use on pears.  The risk assessment indicates that an
REI of 28 days would be necessary to reduce risks to worker below the
Agency’s level of concern.  The current REI for pears is 3 days and
the current preharvest interval is 7 days. The purpose of this
assessment is to provide a preliminary, qualitative assessment of the
impact of increasing the REI to 28 days on pear producers and the pear
industry.

Pears

The most recent available statistics indicate that about 64,700 acres of
pears are grown in the US (USDA NASS, 2004).  Over 94% of the acreage is
in the western states of California, Oregon, and Washington.  Colorado,
Connecticut, Michigan, New York, Pennsylvania and Utah grow the
remaining 6% of the pear acreage.  Production has averaged about 800,000
tons annually with a total value of about $295 million.  This is
illustrated in Table 1 below.  Producer prices are around $340/ton and
growers gross revenues average $4,600/acre (USDA NASS, 2004).

Table 1. Pear Production, Value, and Phosmet Usage*

States	Acres in Production	Production as a Percentage of Total US
Production 	Phosmet Usage 2003** (Percent of Crop Treated)	Total
Production (metric tons)	Total Value of Production (1,000 dollars)

California	17,000	26%	10%	244,101	80,149

Oregon	17,600	27%	33%	188,747	72,748

Washington	26,300	41%	18%	350,272	131,483

Connecticut	n/a	n/a

900	n/a

Michigan	800	n/a

3,460	n/a

New York	1400	n/a

16,500	n/a

Pennsylvania	900	n/a

4,500	n/a

Utah	130	n/a

300	n/a

US Total	64,700

21%	806,261	295,531

*Sources: USDA/ NASS 2004, Noncitrus Fruits and Nuts, 2004. 

**USDA/NASS Agricultural Chemical Use Database 2006a

Recent Use of Phosmet

Phosmet is applied to about 21% of the U.S. pear acreage (USDA/NASS,
2006a).   Usage is quite variable from state to state and from year to
year.  In 2003, California pear growers treated only 10% of the pear
acreage (USDA/NASS, 2006a) but, by 2004, 23% of California pear acreage
was treated with phosmet (CDFA.2006).   U.S pear growers apply phosmet
at an average of 1.2 applications per year at an average application
rate of 3.2 lbs ai/acre (USDA/NASS, 2006a).   California growers apply
an average of 1.5 applications of phosmet per year at an application
rate of 4.2 lbs ai/acre.  The usage and importance of phosmet is likely
to increase if azinphos-methyl were unavailable.

Maximum Feasible REIs

The 2001 BEAD assessment concluded that the maximum REI that would not
interfere with orchard activities is around seven days for irrigation,
mowing, scouting and hand harvesting activities and 14 days for fire
blight removal (Cook and Kiely, 2001).  Extension of phosmet REI(s
beyond these periods would interfere with these practices and would
force growers to abandon the use phosmet on pears.    SEQ CHAPTER \h \r
1 

Impacts of Extending the REI beyond the Maximum Feasible Length

Extending the REI beyond the maximum feasible length (7 days) would
result in growers turning to one of several available alternatives for
control of pests targeted by phosmet.  These pests include the codling
moth and the grape mealybug.

Alternatives

Alternatives (chemical class) for control of these pests are:

azinphos-methyl, chlorpyrifos, diazinon and naled (organophosphate);

acetamiprid, imidacloprid, thiacloprid, thiamethoxam (neonicotinoids)

indoxacarb (oxadiazine)

carbaryl (carbamate);

esfenvalerate, fenpropathrin, lambda-cyhalothrin, and permethrin
(synthetic pyrethroids);

diflubenzuron, methoxyfenozide, novaluron, pyriproxyfen, and
tebufenozide (insect growth regulators);

spinosad (actinomycete derivative);

Bacillus thuringiensis (biopesticide)

mating disruption (pheromones)

Kaolin (clay)

BEAD believes that acetamiprid and methoxyfenozide are among the most
effective and promising alternatives to phosmet.  BEAD’s review of
available efficacy data concluded that acetamiprid and methoxyfenozide
are somewhat less effective than phosmet and will have to be applied
more frequently to achieve equivalent levels of control (Brassard and
Smearman, 2005, 2006; Brunner et al, 2005; Doerr et al, 2004).  BEAD
believes that growers are likely to substitute two applications of
acetamiprid and one application of methoxyfenozide for two applications
of phosmet.  See attachment 1 for a comparative efficacy table of
phosmet alternatives and annotated efficacy summary of Brunner et al
(2005) and Doerr et al (2004) studies in references section.

Azinphos-methyl is as effective as phosmet but its long REI’s (7-14
days) and preharvest intervals (14-21 days) severely hamper its
usefulness as an alternative.  Additionally, the pear use of
azinphos-methyl is currently undergoing reregistration review and its
use on pears may be further restricted in the near future. Some of the
alternatives, such as pyrethroids, are less compatible with integrated
pest management (IPM) and mating disruption programs than is phosmet. 
Pyrethroids often precipitate secondary pest outbreaks, such as spider
mites, and cause growers to resort to the use of miticides, which may
cost over $50 per acre.

In addition, extension of the REI for hand-harvesting beyond 7 days may
lead to unnecessary prophylactic insecticide applications to ensure crop
protection prior to harvest.

In recent years, broad-spectrum insecticides, such as organophosphates,
are being replaced by insecticides with a narrower activity spectrum. 
The older chemicals not only controlled the target pest(s), but also,
most other exposed insects.  A consequence of the shift to newer
chemistries is that crop damage from insects that until recently were
considered minor pests appears to be increasing.  However concomitantly,
the shift to narrower-spectrum chemicals may result in less mortality
for beneficial species, including natural enemies, which should in turn
increase natural mortality for some insect pests, ultimately leading to
less pesticide use. To the extent that these pest dynamics continue to
evolve and remain rather difficult to predict, this analysis examines
only potential short-term  (two to three years) impacts of replacing
phosmet with insecticides with a narrower activity spectrum.

Impacts

Because a REI for phosmet beyond seven days (or 14 days prior to fire
blight thinning) would interfere with key crop production and pest
management practices, growers would likely stop using it altogether and
turn to one or more of several available alternatives.  Based on the
availability of new alternatives, BEAD tentatively concludes that yield
or quality losses are unlikely if phosmet could not be used.  It is
likely that production costs will increase because alternatives are more
costly, would have to be applied more often, or would result in
applications of additional pesticides to control secondary pests.  

BEAD’s alternative scenario of substituting two applications of
acetamiprid and one application of methoxyfenozide for two applications
of phosmet would result in a cost increase of $112 per acre which is
equivalent to a 3% increase in production costs (or 12% of net
revenues).

Request for Additional Information in Stakeholder Comments

As this is a preliminary assessment, BEAD would welcome data that could
be used to refine this assessment if necessary.  Useful information
would include:

usage information for states other than California;

particular regional or pest problems leading to phosmet use;

comparative product performance data, including yield and quality
impacts;

relative product costs; and

restrictions or other constraints on the use of alternatives.

Information on the feasibility of use, comparative efficacy, and/or cost
of use of non-chemical alternatives to phosmet.

References

Brassard, D.W., and S. Smearman. 2005.  2005 Grower Impact Assessment of
Azinphos-methyl Use in Pears (DP 307589).  Internal Document. 
Biological and Economic Analysis Division, Office of Pesticide Programs,
U.S. Environmental Protection Agency, 1200 Pennsylvania Ave., NW,
Washington, DC 20460-0001

Brassard, D.W., and S. Smearman. 2006.  BEAD Response to Comments
Received Regarding 2005 Grower Impact Assessment of Azinphos-methyl Use
in Pears.  Internal Document.  Biological and Economic Analysis
Division, Office of Pesticide Programs, U.S. Environmental Protection
Agency, 1200 Pennsylvania Ave., NW, Washington, DC 20460-0001

Brunner JF, Beers EH, Dunley JE, Doerr M, Granger K. 2005. Role of
neonicotinyl insecticides in Washington apple integrated pest
management. Part I. Control of lepidopteran pests. 10pp. Journal of
Insect Science, 5:14, Available online:    HYPERLINK
"http://www.insectscience.org/5.14/Brunner_et_al_JIS_5_14_2005.pdf" 
http://www.insectscience.org/5.14/Brunner_et_al_JIS_5_14_2005.pdf 

[Contains efficacy data from 33 heavily infested apple orchards in
Washington.  In these efficacy tests, the grower standard
(azinphos-methyl and/or phosmet) provided significantly better control
of codling moth than acetamiprid in 20 out of 33 trials. 
Azinphos-methyl averaged 94% control in these trials compared to 82%
control achieved by acetamiprid and 71% control achieved by
thiacloprid.]  

Cook, C. and T. Kiely, 2001.  Biological and Economic Analysis of AZM
and Phosmet on Pears.  Unpublished Report.  Biological and Economic
Analysis Division, Office of Pesticide Programs, Environmental
Protection Agency 20460. 
www.epa.gov/oppsrrd1/op/azinphos/bead_Pears1.pdf 

Crop Data Management System.  2006.  ChemSearch Database.

Doerr, M., J. Brunner, E. Beers, J. Dunley, and V. Jones. 2004. 
Building a multi-tactic pheromone based pest management system in
western orchards.  Unpublished Progress Report.  Tree Fruit Research and
Extension Center, Wenatchee, WA

[Contains efficacy data from 15 operational apple orchards using mating
disruption in Washington.  In these efficacy tests, the grower standard
(azinphos-methyl and/or phosmet) provided levels codling moth control
equivalent to those seen in methoxyfenozide and other
selective/non-organophosphate insecticides.]

UC Pest Management Guidelines.  2006.  Pear.  University of California,
Statewide 	Integrated Pest Management

CDFA.2006.  Usage of Agricultural Pesticides in California: 2004
Pesticide Usage Report. California Department of Food and Agriculture,
Sacramento, CA 95814,    HYPERLINK
"http://www.ipm.ucdavis.edu/PUSE/puse1.html" 
http://www.ipm.ucdavis.edu/PUSE/puse1.html  

USDA/NASS, 2006a.  Agricultural Chemical Use Database. 
http://www.pestmanagement.info/nass/

USDA/NASS.  2006b.  Noncitrus Fruits and Nuts, 2005 Preliminary Summary.
 National Agricultural Statistics Service, U.S. Department of
Agriculture, January, at   HYPERLINK
"http://usda.mannlib.cornell.edu/reports/nassr/fruit/pnf-bb/ncit0106.pdf
" 
http://usda.mannlib.cornell.edu/reports/nassr/fruit/pnf-bb/ncit0106.pdf 
.

Attachment 1. Comparative Efficacy of Phosmet Alternatives on Pears*

Alternatives (commercial name in parenthesis)   	Efficacy Ratings of
Alternatives **

	From BEAD’s 2001 Benefits Assessment for AZM and Phosmet on Pears
(Cook and Kiely 2001)	From 2003 Pest Management Strategic Plan for Pears
(USDA 2003) and Brunner et al. (2004)	From Efficacy Data Submitted by
Bayer (White 2004) ++

	Codling Moth	Grape mealybug	Codling moth	Grape mealybug	Codling moth

Phosmet (Imidan)	G-E	G-E	F-G

G-E

	Abamectin**

	F-G

G

Acetamiprid (Assail)***

	G-E	G	G

Azinphosmethyl (Guthion)	G-E	G-E	G-E

G-E

Bacillus thuringiensis**

	P	P

	Buprofezin****

E

	Carbaryl (Sevin)	F

G

Chlorpyrifos (Lorsban)

G	G

Codling moth granulosis virus***

	F-G	P

	Diazinon	F

F

Diflubenzuron (Dimilin)***

	F

F

Diflubenzuron + Summer oil

	G

Esfenvalerate (Asana)	F-G

E

Fenpropathrin (Danitol)	F-G

G

F

Imidacloprid

F

G

	Indoxacarb (Avaunt)***

	P

F

Kaolin (Surround)**

	F	P

	Lambda-cyhalothrin (Karate, Warrior)***

	Methoxyfenozide (Intrepid)***

	G	P	G

Naled (Dibrom)

	F-G

Neem/Azadiractin**

	P	P

	Novaluron (Diamond) *****

	G-E

Permethrin (Ambush, Pounce)	F-G

Pheromones

	F-G

Pyriproxyfen (Esteem)***

	F-G	P

	Spinosad (Success, Spintor, Tracer))

	P-F

Summer oil**

	F-E

F

Tebufenozide (Confirm, Mimic)***	P

F	P	F-G

Thiacloprid (Calypso)

	G-E	F-G	G-E

Thiamethoxam (Actara)***

	P	G-E

	* BEAD has not determined that these potential alternatives could serve
as one to one AZM replacements.  

**  =  registered in 2001 but not considered as an alternative in
BEAD’s 2001 benefits assessment

*** New alternatives

**** Currently unregistered

*****Not registered in California

P = poor, F = fair, G = good, E = excellent, based on USDA (2003).

++ All rankings are relative to AZM , whose performance was assumed to
be good to excellent based on Cook and Kiely (2001) and USDA (2003).  
For example, diflubenzuron, which usually performed worse than AZM, got
an F rating whereas diflubenzuron plus oil, which worked nearly as well
as AZM got a G rating.

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