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

WASHINGTON D.C., 20460

June 6, 2006

  SEQ CHAPTER \h \r 1 OFFICE OF

PREVENTION, PESTICIDES AND TOXIC SUBSTANCES

MEMORANDUM  

SUBJECT:	Alternatives Assessment for Methomyl on Grapes, DP# 321899

FROM:	Monisha Kaul, Biologist	

		Biological Analysis Branch

T J Wyatt, Agricultural Economist	

Economic Analysis Branch

Biological and Economic Analysis Division (7503P)

THRU:	Arnet Jones, Chief 	

Biological Analysis Branch

Timothy Kiely, Acting Chief 	

Economic Analysis Branch

Biological and Economic Analysis Division (7503P)

TO:		Kelly Sherman, Chemical Review Manager

		Susan Lewis, Chief    

		Reregistration Branch 1

		Tom Myers, Team Leader

		Margaret Rice, Chief

		Reregistration Branch 2

Special Review and Reregistration Division (7508P)

Product Review Panel Date:  May 17, 2006

Summary

Methomyl is a systemic carbamate pesticide used on grapes to control
several insects including leafhoppers, the omnivorous leafroller, the
grape berry moth, and thrips.  As part of the carbamate cumulative risk
assessment, BEAD identified potential alternatives for the control of
these pests.  There appear to be alternatives for each of the target
pests, although few provide control for the entire pest complex.  BEAD
has not quantified the impacts on growers of switching to alternatives. 
Production costs would likely rise, possibly substantially, but yield
and quality are unlikely to be affected.  In the Northeast, one of the
most likely alternatives is carbaryl, another carbamate with
broad-spectrum control and similar cost.

Background

As part of the cumulative risk assessment for carbamate pesticides, BEAD
is assessing the availability of alternative chemical and non-chemical
control methods that may also be used to protect grapes from the main
pests targeted by methomyl.  This memo first discusses grape production
and utilization.  We then discuss methomyl usage and primary target
pests.  Finally, we examine possible alternatives with a discussion of
advantages and disadvantages compared to methomyl.

Grape Production and Utilization

Grapes are produced in nearly every state of the U.S.  The most recent
statistics indicate that about 940,000 acres of grapes are grown in the
U.S. (USDA NASS, 2006).  Over 85% of the total acreage is in California.
 Washington and New York are the other main producers.  Total grape
production is about 6.7 million tons annually with a total value of
about $2.9 billion.  Producer prices average around $430/ton, but vary
considerably by state and by end use.  Table 1 provides acreage,
production and value figures as reported by USDA.

Table 1.  U.S. grape acreage, production and value, 2001 – 2005
average.

Region	Bearing Acres	Production

(1000 tons)	Yield

(ton/acre)	Value

($1000)	Price

($/ton)

California	809,400	6,057.8	7.4	2,623,964	435

Pacific Northwest 1	61,720	351.8	5.7	169,463	485

Northeast 2	58,380	311.9	5.3	76,460	245

South 3	8,900	23.9	2.7	22,596	945

U.S.	940,260	6,752.7	7.2	2,884,764	425

Source:	Noncitrus Fruits and Nuts Summary (USDA NASS, 2002-2005, 2006). 
U.S. totals do not equal the sum of the columns because some states are
not included in the table.

1	Oregon and Washington.

2	Michigan, New York, Ohio, and Pennsylvania.

3	Arkansas, Georgia, Missouri, North Carolina, Texas, and Virginia.

Grapes belong to the Vitaceae family.  There are over 100 species, and
many more varieties, identified in the literature.  Grapes may be sold
fresh or processed into juice, wine, raisins or other products. 
Typically, certain varieties are targeted into specific uses, although
there is some flexibility.  For example, the Thompson seedless grape is
considered a raisin variety (CDFA, 2006), although it may also be grown
for the fresh market (table grapes) or crushed for wine, juice and other
products.  Wine is produced in all parts of the U.S.  In contrast,
raisins are almost completely produced in California.  According to the
Noncitrus Fruits and Nut Summary (USDA, 2002-2005, 2006), juice accounts
for less than 10% of national production, but they are the dominant
varietal types in the Pacific Northwest and the Northeast while
California produces little or no juice varieties compared to other
types.

USDA data assume that all California grape tonnage crushed is used for
wine.  However, data from the California Department of Food and
Agriculture (CDFA, 2002 - 2006) indicate that some of what USDA lists as
wine is actually processed into other products including juice
concentrate, juice not from concentrate, vinegar, brandy and other
distilling materials as well as jams and jellies.  About 16.3% of the
grape crush (juice extraction), averaging about 600,000 tons between
2001 -2005, is used to make concentrate.  Wine grapes make up the
majority of the amount crushed.  Raisin varieties, including Thompson
seedless, make up about 13.5% of the total crush, while table grape
varieties make up only 2.5%.

Table 2 presents BEAD’s estimation of grape utilization, based on NASS
and CDFA statistics.  We assume that the amount of concentrate produced
in California approximates the amount of grapes crushed for juice.  Not
all juice is made from concentrate, but concentrate may also be
converted into other products.

Table 2.  Grape utilization, amount (tons) and percent of U.S. total,
2001 – 2005 average.

Region	Fresh

(% of total)	Raisin

(% of total)	Juice

(% of total)	Wine and Other

(% of total)

California	885,600

(98.8%)	1,533,600

(98.3%)	600,800

(56.9%)	3,093,000

(81.2%)

Pacific Northwest 1

	219,400

(20.8%)	131,000

(3.4%)

Northeast 2	3,560

(0.4%)

234,820

(22.3%)	57,040

(1.5%)

South 3	2,080

(0.2%)

	18,680

(0.5%)

U.S.	896,420	1,560,570	1,055,020	3,806,960

Source:	Noncitrus Fruits and Nuts Summary (USDA NASS, 2002-2005, 2006);
Grape Crush Report (CDFA, 2002-2006).  Totals may equal the sum of
columns because of rounding or because minor uses are not reported. 
U.S. totals may not equal the sum of the columns because some states do
not report specific utilization.

1	Oregon and Washington.

2	Michigan, New York, Ohio, and Pennsylvania.

3	Arkansas, Georgia, Missouri, North Carolina, Texas, and Virginia.

Methomyl Use and Usage

According to data from the California Pesticide Use Reports (CDFA,
2000-2005), methomyl use on wine grapes appears to have declined
slightly between 1999 and 2004, from about three percent to about one
percent of the acreage.  Methomyl use on table and raisin grapes has
been steady during this period, at about six percent of the bearing
acreage treated.  Reports do not distinguish between table and raisin
grapes.  Additional data from the National Agricultural Statistics
Service, USDA (2000, 2002, 2004), indicate that methomyl is mainly
applied to table grapes, with about 26% of table grape are treated. 
This may simply be an assumption on the part of USDA, since California
data is sometimes categorized as “processed” and “other,” rather
than “wine” and “other.”  Thus, USDA may simply assume that
anything not “processed” is fresh or table grape.  However, other
sources indicate that table grapes are more likely to be treated against
some insect pests than are raisin grapes (California Grape Advisory
Team, 2002).

The total amount of methomyl applied to all grapes in California
averages about 30,000 lb active ingredient (a.i.) (CDFA, 2000-2005; USDA
NASS, 2000, 2002, 2004).  There is typically one application per year,
but about 20% of the acreage is treated multiple times.  The average
application rate is about 0.9 lb a.i./acre per year.  The majority of
methomyl is used on table and raisin grapes in California.  On average,
about 22,000 lb a.i. is applied at a rate of almost 0.95 lb a.i./acre
per year.  Rates appear to be declining, however, from about 1.2 lb
a.i./acre in 1999 to about 0.75 lb a.i./acre in 2004.

Data from other states are sparse.  The National Agricultural Statistics
Service, USDA (2000, 2002, 2004), surveys few states and publishes
limited information.  Methomyl use is reported throughout the country,
but is not quantified.  Outside California, most grapes are processed
into wine or juice.  Given that methomyl appears to be used primarily on
table, and perhaps raisin, grapes, it would be consistent that little
usage of methomyl would be observed in other states.  However, there may
be increases in methomyl usage as a result of recent restrictions on
azinphos-methyl and possible restrictions on phosmet, two broad-spectrum
organophosphates that target similar pests.

Methomyl Target Pests

California

Leafhoppers

Leafhoppers are a major pest of California grapes.  Grape leafhoppers
are a pest of the Central Valley, North Coast and Central Coast.  The
variegated leafhopper is a pest of southern California and the Central
Coast.  The grape leafhopper has one to two generations per year.  The
first generation is generally not treated so natural enemies may provide
suppression (California Winegrape Work Group, 2004).  The second
generation feeds on actively growing leaves and, therefore, the most
important period for monitoring and control is later in the season when
fruit is developing (California Grape Advisory Team, 1999; California
Minor Crops Council, 2003).  High leafhopper populations can delay and
reduce yield as well as lower fruit quality.  

Thrips

Grape and Western flower thrips are considered an important pest of
California table grapes and a minor pest of wine grapes.  Western flower
thrips are generally more damaging than grape thrips (California Grape
Advisory Team, 1999; California Grape Advisory Team, 2002).  Adult and
nymph Western flower thrip populations peak around bloom and are usually
treated just after bud break, but may also be treated later.  Thrips
feed on growing shoot tips, which disfigure or stunt shoots (California
Grape Advisory Team, 1999).

Omnivorous Leafroller (OLR) 

The omivorous leafroller is a major pest of wine, table, and raisin
grapes in California.  This pest may cause serious damage in the
Northern and Southern regions of the San Joaquin Valley.  According to a
previous assessment by BEAD (Cook and Kiely, 2001),

“[The OLR] feeds on leaves, flowers, and developing berries.  Damage
to . . . berries allows rot organisms to enter the fruit.  OLR larvae
overwinter in old grape clusters (mummies) and vineyard weeds.  In
spring, the larvae complete their development and moths emerge and lay
shingle-like egg masses on grape leaves.  After about 5 days these eggs
hatch, and larvae web together leaves or cluster parts to form a nest in
which they feed.”  

Insecticides are generally not required until after bloom.  According to
the California Minor Crops Council (2003), the post-bloom period, but
not immediately prior to harvest, is an important time to manage the
OLR.

Northeast

Grape Berry Moth (GBM)

The grape berry moth is a serious pest of wine and juice grapes in the
Northeast.  Up to three generations may emerge during the growing
season, with later generations causing most of the damage by feeding on
developing fruit (Cook and Kiely, 2001).  

Grape Leafhopper

The grape leafhopper is also an important pest of wine and juice grapes.
 The grape leafhopper has one to two generations per year.  Adults
overwinter in litter on or near the vineyard floor.  In mid to late
June, eggs are laid on the underside of the grape leaf.  Both adults and
nymphs feed on the underside of grape leaves, which may result in leaf
drop and reduced fruit quality if vines are heavily infested (Johnson,
2004).  Control of the grape leafhopper coincides the timing of GBM
control (Weigle, et al., 2000b).

Pacific Northwest

Although grape production in the Pacific Northwest is higher than the
Northeast, there is little to no use of methomyl.  Methomyl is available
for control of cutworms and leafhoppers, which are important pests in
Washington State wine grapes, but it is rarely used and considered too
disruptive to non-target species (Western IPM Center, 2004).  

Chemical Controls for Target Insect Pests

California

Less than half of wine and raisin vineyards receive treatments for grape
and variegated leafhoppers, while most table grape vineyards are treated
at least once per year (California Grape Advisory Team, 2002).  Because
the second generation of leafhoppers are potentially most damaging, this
is the most crucial time for monitoring and control.  Although methomyl
provides good leafhopper control, it is highly toxic to predatory mites.
 Imidacloprid, of the chloronicotinyl family, is the most commonly used
insecticide for leafhopper control because it is very effective and
provides some residual control, although it has the potential for
resistance (California Grape Advisory Team, 1999).  Carbaryl and
dimethoate also provide leafhopper control, but pose the same problem as
methomyl; they are highly toxic to predatory mites. Table 3 provides a
list of recommended controls of leafhoppers in California. 

Table 3.  Recommended controls and efficacy ratings for methomyl target
pests in California1.

Alternative	Leafhoppers	Thrips	Omnivorous Leafroller	Cost 2

$/acre

Methomyl 	E	G	F-G	16.00

Carbaryl 	F

G	11.00

Imidacloprid 	E

	29.00

Dimethoate 	G	F

9.00

Endosulfan 	F

	9.00

Naled 	G

	9.00

Phosmet

F	F	12.00

Fenpropahrin

G

12.00

Cryolite

	E	12.00

Bacillus thuringiensis

	F	8.00

Pheromone mating disruptors2

	F-G

	Diazinon

	F	8.00

Methoxyfenozide

	E	16.00

Propargite	F	P	P	28.00

Sources:  California Minor Crops Council, 2003; California Grape
Advisory Team, 1999.

1	This is not a comprehensive list of registered chemicals.  The list
includes only the registered alternatives recommended by the above
sources.  Efficacy ratings:  E = Excellent, G = Good, F = Fair.

2	Average chemical cost per acre for treatment of target pests,
2001-2004, according to EPA proprietary data.  Costs for non-chemical
controls are not available.

Western flower thrips occasionally require insecticide treatment in the
spring if populations are high (California Grape Advisory Team, 1999;
California Minor Crops Council, 2003).  Methomyl provides good control
of thrips, but may be harmful to beneficial organisms.  There are
relatively few good alternatives for thrip control (Table 3).  According
to the Pest Management Strategic Plan for Table Grape Production in
California (California Minor Crops Council, 2003), fenpropathrin also
provides good control of thrips.

The OLR is mainly controlled using cryolite and Bacillus thuringiensis (
B.t.) in the spring.  Broad spectrum organophosphates or carbamates,
such as methomyl or carbaryl, are used for late season control if the
OLR was not present in the spring (California Grape Advisory Team,
1999).

EPA proprietary data indicate that impidicloprid is the most commonly
used chemical control, used on about half the acres treated for the
target pests, despite its relatively high cost.  In comparison, methomyl
is applied to less than five percent of the acres treated for the target
pests.  Fenpropathrin and propargite, with less than 10% of the acres
treated for the target pests, are the next most commonly used chemical
control. 

Northeast

Chemical control of the GBM usually occurs post bloom when the first
generation adult emerges.  Treating the first generation generally keeps
later generations under control.  Applications may be repeated once or
twice throughout the summer if needed.  Table 4 lists the recommended
controls of the GBM.  In 2000, carbaryl was the most commonly used
insecticide for GBM control followed by methomyl (Weigle, et al., 2000a;
Weigle, et al., 2000b).  Since then additional chemicals have become
available, such as fenpropathrin, bifenthrin, and methoxyfenozide. 
Carbaryl, methomyl, phosmet, fenpropathrin and bifenthrin are all highly
effective against the GBM (Isaacs, 2005). Methoxyfenozide and Bacillus
thuringiensis (B.t.) are effective selective insecticides (Isaacs,
2005), although methoxyfenozide is not registered for use in New York. 
Bacillus thuringiensis requires two applications for every one
application of a conventional pesticide, which may make it less
economically feasible (Weigle, et al., 2000a).

Table 4.  Recommended chemicals for methomyl target pests in the
Northeast1.

Alternative	Grape berry moth	Grape Leafhopper	Cost 2

$/acre

Methomyl	G	G	9.00

Bacillus thuringiensis	G

14.00

Carbaryl	G-E	G-E	10.00

Phosmet	G-E	F-G	12.00

Imidacloprid

E	20.00

Pheromone mating disruptors	F



Diazinon 3	G	F-G

	Fenpropathrin	G-E	G	10.00

Methoxyfenozide 3	G-E



Bifenthrin 3	E



Acetamiprid 3

E

	Sources:  Cornell University Cooperative Extension, 2006; Isaacs, 2005;
Midwest Fruit Workers Group, 2006; Wise, et al., 2005; Weigle, et al.,
2000a; Weigle, et al., 2000b.

1	This is not a comprehensive list of registered alternatives.  The list
includes only the registered alternatives recommended by the above
sources.  

2	Average chemical cost per acre for single treatment of target pests,
2001-2004, according to EPA proprietary data.  Costs for non-chemical
controls are not available.

3	Insufficient usage to estimate treatment cost.

Insecticides for grape leafhopper control is only required if no GBM
control is used.  Leafhopper resistance to carbamates has been reported
in some locations, so it is recommended that insecticides such as
carbaryl and methomyl be avoided in these situations (Isaacs, 2005). 
Recommended chemical controls include imidacloprid, phosmet,
fenpropathrin, and diazinon by Johnson (2004), while more recent
guidelines suggest imidacloprid and acetamiprid provide excellent
control of the grape leafhopper (Wise, et al., 2005).  

According to EPA proprietary data, carbaryl is the most commonly used
chemical control, used on about half the acres treated for the target
pests.  In comparison, methomyl is applied to less than two percent of
the acres treated for the target pests.  Fenpropathrin, at about 30% of
the acres treated for the target pests, is the second most commonly used
chemical control.  Azinphos-methyl and phosmet have been relatively
important tools, applied to almost 10% and over 5% of the area treated
for these pests, respectively, for the grape berry moth.  However,
azinphos-methyl use on grapes was cancelled in 2001, with growers
allowed to use existing stocks through 2005.  Growers may also face a
longer restricted entry interval for phosmet, which could lead growers
to switch to alternative control methods.  Some users of these
organophosphates may switch to methomyl.

Non-Chemical Controls for Target Insect Pests

California

Non-chemical controls for leafhoppers include basal leaf removal, weed
control, sticky tape, and limiting vine growth (California Grape
Advisory Team, 1999).  Anagrus are predatory wasps that provide control
of small populations of grape leafhoppers.  Another predator, lacewings,
may provide some control.  Biological controls alone usually do not
provide complete leafhopper control (California Grape Advisory Team,
1999).

Little information is available on the cultural and biological control
of thrips (California Grape Advisory Team, 1999).

Because the OLR overwinters in old grape clusters on the vineyard floor,
the old clusters should be removed or destroyed.  Natural predators and
parasitic species may also suppress OLR populations.  It is recommended
not to use chemicals harmful to these natural enemies (California
Winegrape Work Group, 2004; California Grape Advisory Team, 1999).

Northeast

Pheromone mating disruptors are used around bloom when the first
generation adult of the GBM emerges (Johnson, 2004).  There is no
effective, stand alone cultural or biological control, although leaf
removal, weed control, and wild grape removal help with GBM control.

There are no recommended cultural controls for the grape leafhopper and
biological controls are limited (Weigle, et al., 2000b, 2000).  

Conclusion

Methomyl is a broad-spectrum insecticide that primarily targets
leafhoppers, thrips and leafrollers in California, and the grape berry
moth and leafhopper in the Northeast.  There appear to be alternative
chemicals available to control these pests, although few provide control
of the entire suite of pests and some pests, particularly the thrip,
have more limited control options.  Production costs would likely
increase if growers were forced to use other options, but yield and
quality of grapes may not be affected.  In the Northeast, the most
likely alternatives include carbaryl, another carbamate with broad
spectrum control and a similar cost.

In recent years, broad-spectrum insecticides, such as carbamates, 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.  The final outcome may depend on the crop, region
and pest complex.

References

California Grape Advisory Team.  1999.  Crop Profile for Grapes (Table)
in California, December.  Web address: 
http://www.ipmcenters.org/CropProfiles/docs/cagrapes-table.html

California Grape Advisory Team.  2002.  Crop Profile for Grapes (Wine)
in California, February, revised.  Web address:   HYPERLINK
"http://www.ipmcenters.org/cropprofiles/docs/cagrapes-wine.html" 
http://www.ipmcenters.org/cropprofiles/docs/cagrapes-wine.html 

California Minor Crops Council.  2003.  A Pest Management Strategic Plan
for Table Grape Production in California, November. Web address:  
HYPERLINK "http://www.ipmcenters.org/pmsp/pdf/CATableGrapes.pdf" 
http://www.ipmcenters.org/pmsp/pdf/CATableGrapes.pdf . 

California Winegrape Work Group.  2004.  A Pest Management Strategic
Plan for Winegrapes in California, November. Web address:    HYPERLINK
"http://www.ipmcenters.org/pmsp/pdf/cawinegrapes.pdf" 
http://www.ipmcenters.org/pmsp/pdf/cawinegrapes.pdf 

CDFA (California Dept. of Food and Agriculture).  2002 - 2006.  Final
Grape Crush Report.  California Department of Food and Agriculture,
Sacramento, March, at http://www.nass.usda.gov/ca/bul/crush/indexgcb.htm

CDFA (California Dept. of Food and Agriculture).  2000-2005.  Usage of
Agricultural Pesticides in California: Pesticide Usage Report.
California Department of Food and Agriculture, Sacramento, at  
HYPERLINK
"http://www.ipmcenters.org/pmsp/pmsp_form.cfm?usdaregion=National%20Site
"  http://www.ipm.ucdavis.edu/PUSE/puse1.html  .

Cook, C. and T. Kiely, 2001. Grape Benefits Assessment for
Azinphos-methyl and Phosmet.  EPA unpublished report. Web address:
http://www.epa.gov/pesticides/op/phosmet/bead_Grapes1.pdf.  

Cornell University Cooperative Extension, 2006.  2006 New York and
Pennsylvania pest management guidelines for grapes. Web address:   
HYPERLINK "http://ipmguidelines.org/grapes/4_InsectManagement.htm" 
http://ipmguidelines.org/grapes/4_InsectManagement.htm .  

Isaacs, R., 2005. Early-season grape berry moth management. Michigan
State University Fruit Crop Advisory Team Alert, 20(7).  Web address:   
HYPERLINK "http://www.ipm.msu.edu/CAT05_frt/F05-24-05.htm#4" 
http://www.ipm.msu.edu/CAT05_frt/F05-24-05.htm#4 .  

Johnson, H.  2004.  Crop Profile for Lubrusca (Juice) Grapes in
Michigan, Michigan State University, January.  Web address:   HYPERLINK
"http://www.ipmcenters.org/CropProfiles/docs/FLcitrus(major).html"  
http://www.ipmcenters.org/cropprofiles/docs/MIlabruscagrapes.html 

Midewest Fruit Workers Group, 2006. Midwest commercial small fruit and
grape spray guide 2006. Web Address:   HYPERLINK
"http://www.hort.purdue.edu/hort/ext/sfg/06SprayGuide.pdf" 
http://www.hort.purdue.edu/hort/ext/sfg/06SprayGuide.pdf .  

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

USDA NASS.  2000-2005.  Noncitrus Fruits and Nuts, Summary.  National
Agricultural Statistics Service, U.S. Department of Agriculture, July,
at   HYPERLINK
"http://usda.mannlib.cornell.edu/reports/nassr/fruit/pnf-bb/" 
http://usda.mannlib.cornell.edu/reports/nassr/fruit/pnf-bb/ 

USDA NASS.  2000, 2002, 2004.  Agricultural Chemical Usage, Fruit
Summary.  National Agricultural Statistics Service, U.S. Department of
Agriculture, at
http://usda.mannlib.cornell.edu/reports/nassr/other/pcu-bb/#fruits

Weigle, T., G. English-Loeb, W. Wilcox, R. Dunst, B. Shaffer, and Lake
Erie Processors Group.  2000.  Crop Profile for Grapes (Labrusca) in New
York, May, available at
http://www.ipmcenters.org/cropprofiles/docs/nygrapes-labrusca.html.

Weigle, T., G. English-Loeb, W. Wilcox, R. Dunst, B. Shaffer, T.
Mitchell and T. Collins.  2000.  Crop Profile for Grapes (Vinefera and
French Hybrid) in New York, May, available at
http://www.ipmcenters.org/cropprofiles/docs/nygrapes-vineferaandfrenchhy
brid.html.

Western IPM Center.  2004.  A Pest Management Strategic Plan for
Washington State Wine Grape Production, May. Web address:   HYPERLINK
"http://www.ipmcenters.org/pmsp/pdf/WAWineGrapePMSP.pdf" 
http://www.ipmcenters.org/pmsp/pdf/WAWineGrapePMSP.pdf 

Wise, J., A. Hanley, R. Lamb, M. Haas, L. Duynslager, 2005. 2006
Michigan fruit management guide. Michigan State University, Extension
Bulletin E-154.  Web address:    HYPERLINK
"http://web1.msue.msu.edu/epubs/pestpubs/E154/1-TOC.pdf" 
http://web1.msue.msu.edu/epubs/pestpubs/E154/1-TOC.pdf .  

 PAGE  1 

