Guthion™, Azinphosmethyl (AZM), Talking Point Outline for Comments to
USEPA 2006

Mark Whalon (  HYPERLINK "mailto:whalon@msu.edu"  whalon@msu.edu )
Michigan State University

Introduction.-  It is a fact that the USEPA risk managers have no choice
but to make regulatory decisions according to their statutory
responsibilities. Surprisingly, this Agency (USEPA) very much wants and
needs grower, field scientist and extension inputs. Your comments in
their decision making will be considered. Federal law and promulgation
of public policy provide for this opportunity. Therefore, each person
involved in tree fruit production has both the opportunity and the
wherewithal to make comments in the pesticide regulatory process. AZM
received a three year, Group 3 Conditional Registration from USEPA in
2003. This Conditional Registration is ending and AZM is again being
reviewed by the Agency through a six step process. Every step is tightly
regulated by policy. USEPA is asking for your help; more specifically
your comments. Regulators want to hear what they term “the benefits”
as apposed to the impacts and drawbacks of Guthion’s use. I’ve
prepared this document in an effort to help you comment with sufficient
background to be effective and on-target with your comments. 

Note that the first Reference Cited at the end of this document is an
outline of the information USEPA would like to receive in your comment
submission (1).

How to comment—directions for web-based comment.- The Federal Register
Notice published on 12/7, started the 60-day comment period on the
ecological risk assessment and potential grower impacts (benefits
assessment) is found below in a step by step format. You can also
comment by sending a letter in to USEPA and the address and directions
for this method of comment is also contained at the web site listed
below. Note that the docket number is the key to getting your comments
in the right folder so that it will be considered. Remember, at any time
during the year, our Government may be taking 100’s of different
comment dockets for numerous agencies. Therefore, it is essential that
you stay identify the correct docket location on the Federal Register
(FR) Notice = #45. Hopefully what follows will help you do this without
much difficulty.

USEPA Comment Period: Ending February 6th

Procedure for Submitting Comments to USEPA’s Guthion Docket:

go to:   HYPERLINK "http://www.regulations.gov"  www.regulations.gov 

select agency = ”EPA”

document type select "all document types"

keyword type in "opp-2005-0061"

select "any word" submit

Once the docket comes up, click on the docket number

EPA-HQ-OPP-2005-0061.  The recent submissions start with

#32. Note! This is in the second display window.

The FR Notice is # 45.  Note also, the numbers are not consecutive.
USEPA is still working on this site so be persistent!

Below you will find a number of points that will help you address the
potential loss of Guthion in tart and sweet cherry crop protection. 

Background- A Brief Insecticide Regulatory History:

Because processed cherries have a zero tolerance for worms in processed
product, growers face a daunting task in producing tart and sweet
cherries for the processing market. Over 98% of the upper Midwest cherry
harvest is processed. Historically, achieving the ‘zero tolerance’
was only possible through powerful chemistries like Azinphosmethyl
(AZM), Guthion™, which is an organophosphate (OP) insecticide. The
cherry processing industry in the US evolved during the
‘Organophosphate insecticide era’ when for 35 years growers
experienced outstanding control of fruit pests that would have otherwise
infested fruit before harvest depressing the marketing of a wholesome
and attractive product. Now the cherry industry has become dependant
upon the power of organophosphate chemistry to meet its demanding
marketplace quality standards. 

The passage of the Food Quality Protection Act (FQPA-1996) resulted in
an extended AZM preharvest interval (PHI) to protect against residues in
the diets of children and infants even though OP residues were below the
limit of detection (LOD) in processed cherries. The Pesticide
Reregistration Improvement Act (PRIA-2004) merged and streamlined the
reregistration statutes in different pesticide legislation including the
Federal Insecticide, Fungicide and Rodenticide Act (FIFRA-1972), FQPA
and the Endangered Species Act (ESA-1972) as amended into one process.
Together these federal regulations have placed great pressure upon USEPA
to mitigate or cancel the uses of organophosphates in specialty crops
like cherries. In addition, a number of environmental activists groups
have targeted the organophosphate class of insecticides for
cancellation. 

Yet one of the most significant AZM mitigations came through the
application of the Worker Protection statutes in the Federal
Insecticide, Fungicide, and Rodenticide Act (1972) where reentry
intervals (REI) were extended three years ago allowing Conditional
Registration of AZM by USEPA. In addition, the ecological and water
statutes in FIFRA, the ESA and Clean Water Act as amended continue to
cause USEPA to address these statutory responsibilities which may result
in reduction or cancellation in many pesticides that impact the
environment. 

Guthion has severe ecological impacts.- AZM is arguably the most
ecologically destructive pesticide insecticide in use in North America
today. A 2001 report on the impact of AZM on ecosystems, fish,
invertebrates, birds, etc. led USEPA officials to identify AZM as the
pesticide generating over 50% of all aquatic kill incident reports in
the US (2). But the issue before you in this comment period is not
whether or not AZM really is the most ecologically devastating pesticide
in use today, but rather, what are the benefits the cherry industry
derives from its use? Additionally, what would happen to the cherry
industry if AZM were not available? In a recent meeting with USEPA,
ecological risk assessors surprised all of the attending outsiders with
the statement that they were more concerned for the upper Midwest about
“run off” from orchards than “drift” from orchards. Essentially
they are basing this position on the half-life data they have on AZM
from a number of studies that are carefully outlined in the most recent
ecological assessment document published by USEPA.

Acute vs Chronic Data for Ecological Assessment: To answer the above
questions we must look at how USEPA determines ecological impact of an
insecticide. The Agency uses two principal types or categories of impact
data; 1) acute and 2) chronic toxicity. Foremost in their assessment of
ecological impact is acute toxicology data. These data are readily
acquired in the laboratory and analyzed unequivocally scientifically.
Registrants (pesticide companies) find these data comparatively
inexpensive to acquire and report. From bacteria through mammals, acute
toxicity methods are well defined, easily documented and almost without
major scientific disagreement in interpretation. These data are
therefore part of every USEPA pesticide registration and reregistration
process. Acute toxicological data are the backbone of USEPA’s
ecological assessment process on the way to granting or rejecting
registrations. 

However, acute toxicity is only part of the story of the impact of any
chemistry used in agriculture or the environment. Chronic toxicity
effects are all of the non-lethal impacts like reduced reproduction,
bioaccumulation from species to species up through the food web of life,
behavior changes like altered bird songs, changes in development time or
shape or structure. 

Mitigation.- With registration companies can legally manufacture,
distribute and sell their pesticide with a “LABEL” dictating how the
pesticide is to be used. USEPA often controls or reduces the negative
impacts of pesticides with changes to the Pesticide’s Label. Three
years ago (2003) AZM’s received a Conditional Registration Because
USEPA required certain changes on its use label. USEPA used these
changes to reduce AZM’s impact by “mitigating” worker exposure by
extending legal post application reentry intervals (REI), by mitigating
(reducing) AZM residues in food by extending its legal preharvest
interval (PHI) and by mitigating (reducing) both its acute (kill) and
chronic effects in ecosystems by reducing the total pounds that could be
applied in a season. All of these changes came to users through LABEL
CHANGES. And this process is known as MITIGATION of the negative effects
of AZM. 

Ecological Incident Reports.- With sales comes field use, and with field
use often incidents of both acute (kills) and chronic effects (reduced
reproduction, failed mating, changed development times, etc.) are
reported. Because AZM has a very bad history of causing fish kills,
water problems with sensitive species like mayflies and impacts on
birds, butterflies and endangered species it is currently facing a major
challenge for reregistration based on its Incident Reports record of
negative impacts in the environment. 

Measuring or counting killed fish, birds or butterflies is pretty
straight forward even if it is alarming publicly. However, understanding
and assigning chronic toxicity effects is very tricky. Today, chronic
environmental and ecological effects for regulatory purposes remain
controversial. Practical and meaningful studies of non-lethal effects
take longer and require more subtle information than counting the number
dead butterflies at such and such a rate of use. Therefore, many
practical and scientific issues and disagreements attend most chronic
impact information. Because the science is controversial so too
regulation based on chronic effects is controversial.

USEPA has to legally use ecological problem reporting from the field
(Incident Reports). Often these reports are more like forensic science
where regulators and state scientists try to recapitulate causative
agent(s), contributing circumstances and infer long-term outcomes
without really measure chronic impacts in a meaningful way. Thus these
incidents are produce anecdotal, expensive, and controversial regulatory
data. As a rule then, laboratory and incident related chronic ecological
impact assessment is rife with problems. Table 1 below represents a more
comprehensive orchard chronic effect analysis of AZM,
“OP-alternatives” and “reduced risk” insecticides.   

Understanding the acute vs chronic toxicity issue is especially
important in commenting on the inferred and reported ecological effects
of AZM (3). When we actually think about environmental and ecological
effects of pesticides, it is easy to believe that most pesticide
exposure in nature is actually chronic (subtle long-term) and not acute
(outright killing).  This means that our regulatory system is
practically and scientifically designed from an acute perspective, but
called upon to protect from the most common exposure which is not acute
but chronic. Therefore, the USEPA’s acute toxicity registration
paradigm can miss important subtle long-term effects as occurred with
compounds like DDT a chlorinated hydrocarbon. USEPA leaned the chronic
toxicity lesson from DDT the hard way, and as a result the Agency is
especially sensitive to criticism from chronic effects. However, we can
over react using the DDT experience to infer long-term effects with the
use of all compounds without data. This latter instance can lead to
subverting or replacing one compound for another based upon acute
criteria when the chronic effects of a replacement can not be fully know
until years after it has been used.

With AZM we have over 30 years of field use to estimate its chronic
effects. With many of its replacements, we have very little time; less
than 5 years for a few and less than 1 or 2 years for many reduced risk
compounds currently favored for registration. 

Therefore, by looking primarily at acute toxicity, AZM appears to be a
very disruptive chemistry which rapidly kills many different exposed
species. Its action is relatively quick and broad spectrum, but its
residues break down rather rapidly into various nontoxic carbon
molecules. For illustrative purposes, I like to characterize AZM’s
ecosystem impact as “deep” (broad spectrum), but short (residues
break down rapidly). In contrast, something like a neonicotinoid or
Insect Growth Regulator (IGR) may have “shallow” but “long”
impacts. The comparison of how both may impact the same orchard
ecologically is illustrated in Figure 1. The question for all of us is
which is better; a short deep impact or a long shallow impact? In this
instance, it may be more about trading off effects and your
comments/preference about choosing something we know vs. something we do
not know can be made just as well as the next persons.

Benefits of AZM USE.- We have learned how to use AZM effectively, and
the cherry industry’s current “zero tolerance” was achieved
through the “power” of the OP compounds. Since AZM’s residues
dissipate in the environment fairly rapidly, the long-term impacts are
limited in time. This is a significant “benefit” as chronic effects
of AZM have a relatively short-time to impact compared with other
compounds like the neonicotinoids. Building on residue breakdown as a
“benefit”, in a very important way, rapid breakdown limits AZM’s
residue at harvest and keeps pesticide residues below detectable limits
in processed products. This is a very real “benefit” from AZM use
compared to many of its OP-alternatives and reduced risk replacements. 

Further mitigation of AZM Environmental/ecological Effects.- The cherry
industry may want to offer additional AZM use changes in order to keep
its Conditional Registration for another three years. Essentially, any
reduction is use equals an environmental mitigation. But what tactics
could really reduce environmental and ecological impacts without
reducing the effectiveness of AZM for the cherry industry? Here are a
few you may want to consider:

Currently, the anti-drift measures on the label for Guthion Solupak 50%
WP registered on cherries reads, “for airblast applications, turn off
outward pointing nozzles at row ends and when spraying the outer two
rows.” If this is to be mitigated further, perhaps suggest spraying
inward on outer three rows? 

Consider adding a label distance to water restriction, essentially
establishing a specific ‘set back’ buffer, e.g. “x” number of
feet where x = 50, 100 or 150 feet,

Restrict airblast spraying to conditions below 8 mph wind velocity,
instead of “make aerial and ground applications when the wind velocity
favors on-target product deposition. Apply only when the wind speed is
less than 10 mph,”

Reentry Intervals and Worker Protection: Conclusions from the Bayer 2004
Tree Fruit Orchard Study Oregon and Michigan

Exposure to AZM treated crops after REI does not affect plasma or red
blood cell (RBC) cholinesterase activity.

MOEs (margin of exposures) for all monitored activities do not exceed a
reasonable level of concern.

Current REIs (reentry intervals) are more than adequate to protect
workers.

USDA Standards and Market Driven “Zero Tolerance” for Internal Worms
in Processed Cherries:

The “zero tolerance” for worms in cherries grew out of evolving
market standards dating back to the early part of the 1900’s. As early
as 1926 Michigan saw legislation enforcing the abandoned cherry orchard
removal and other strategies to reduce pesticide pressure and reach for
a zero tolerance in processed cherries. Chlorinated hydrocarbon
insecticides like DDT paved the way for the cherry processing industry
to evolve to a practical “zero tolerance” that came to be the
standard with the advent of powerful organophosphate insecticides
through both USDA quality standards, and more importantly, the
market’s demand which is now “zero” worms in processed product.
Essentially, with the development and use of organophosphate
insecticides the US cherry processing industry stabilized its global
position as suppliers of a worm-free product year after year. This
remains the quality standard today.

Now the US cherry processing industry has little choice; people refuse
to eat worms in their cherries! What’s more, other producers
internationally can achieve this standard by using OP’s that yield
below LOD residues even if the US bans AZM. In this event, the US
processing cherry industry would be severely penalized compared to their
international competitors. In other words, this would be a severe market
disadvantage for US producers and processors, especially in light of the
increased production costs and increased risk of infestation from
OP-alternatives and so called ‘reduced risk’ (RR) compounds
summarized below.

 

 Cherry Crop Profile.- Essentially, the USDA Cherry Crop Profile and
Pest Management Strategic Plan for tart and sweet cherries identify the
critical need to achieve the “zero tolerance” by primarily
suppressing plum curculio, Conotrachelus nenuphar and the cherry fruit
fly (Rhagoletis cingulata and R. fausta) along with a number of other
pests that can occur. These documents recognized willingness, but also
recognize the difficult “realities” of moving the cherry industry to
adopt other strategies, tactics and tools that can not reliably deliver
the “zero threshold” standard upon which the whole industry is
based. Therefore, the cherry industry has been more than a responsible
citizen by making the effort and investing the resources to accomplish a
“zero tolerance” without using organophosphate insecticides. To
date, these efforts are too premature to force a whole industry to do
away with AZM before proven and reliable alternatives are in place.

Extensive efforts to find Reduced Risk (RR) and OP-alternatives since
1996

Cherries were identified in the FQPA (1996) federal deliberations as one
of the 20 most consumed children’s foods. Hence cherries were “under
the microscope” by USEPA and USDA especially from crop protection
residues that were perceived to be harming children and infants. 

But all cherries are not equal. There are cherries and then there are
processed cherries. EPA (pre-FQPA) and the National Science Foundation
(4) did not understand production practices well enough to know that
fresh cherries for the most part are hand harvested and bear insecticide
residues to market. Processed cherries however, are harvested by
machines into water. In addition, processed cherries are cooled with
water washes for at least 3 hours before transport to a processor. Thus
organophosphate residues from AZM where hydrolyzed and dramatically
mitigated prior to processing.  

No Detectable Residues at Processing with AZM.- Michigan State
University in cooperation with the Cherry Marketing Institute and
Michigan Department of Agriculture did a number of studies from
1998-2001 linking pest management practices in the Michigan processing
cherry industry with residues before harvest, after harvest and after
processing (5). These studies revealed that Guthion (AZM) residues on
processed cherries were not just below legal tolerances, but below the
limit of detection (LOD) by modern analytical methods. The current USDA
cherry RAMP grant is conducting similar experiments and these data will
be available in March of 2006—too late for the AZM Comment Period, but
we fear that they will reveal that RR and OP-replacement compounds;
particularly the neonicotinoids (Provado, Actara, & Calypso), Insect
Growth Regulators (IGR) (Confirm, Esteem, Intrepid, Rimon) and old
OP-replacement compounds like Sevin (carbaryl) will leave residues in
processed fruit. 

Will USEPA Force the US Processed Cherry Industry to Put Detectable
Residues on Fruit by Canceling AZM?- If USEPA driven by FQPA, PRIA, ESA,
and FIFRA cancels AZM use on cherries, its decision will almost
certainly put reduced risk or OP-replacements residues into US processed
cherries. This decision could be the Achilles heal of an industry
struggling to remain profitable in the face of increasing foreign
competition. This situation would be especially odious since AZM use
would still be allowed internationally since AZM residues on imported
fruit would remain below the limit of detection just as those here in
the US have. 

Worker exposure already mitigated.- Since 99.9% of the US cherries that
are processed are machine harvested, worker protection issues and
reentry (REI) issues are already mitigated very significantly. Processed
cherries have almost no in-orchard operations during the short 60-64 day
growing season compared to apples and other stone fruits. With the
exception of spraying, IPM monitoring and very limited mowing no worker
tasks are necessary until harvest. Thus real worker exposure is
dramatically reduced compared with other crops that require thinning. 

Will OP-Alternatives and Reduced Risk Compounds Achieve the ‘Zero
Tolerance’?- The upper Midwest cherry industry (MI, NY, WS) has very
significant pests with ‘zero tolerance” in processed products for
worms at harvest. This is not a producer imposed standard, but an
industry, consumer and US law imposed standard. The two most significant
insect pests include the plum curculio and cherry fruit fly complex. But
other pests can also be problematic for growers to achieve the zero
infestation standards including the cherry fruitworm (Grapholitha
parckardi), and various other weevils (go to the web site-   HYPERLINK
"http://www.whalonlab"  www.whalonlab  and click on “Curculio
Identification” for a tour of other weevils in MI cherries). Only a
few of these pests, other than plum curculio, are problematic where
organic practices, reduced risk and/or OP-alternative compounds are
used.

Scientist in land grant universities like Michigan State University have
studied more than 25 reduced risk, OP-alternative, biopesticide,
kairomone and natural products to control internal cherry feeders
(primarily plum curculio and cherry maggots) in the last 7 years
(USDA/Special Grant, PESP, RAMP and CAR; USEPA PESP and AFT grants as
well as Gerber Products Co, Cherry Research Committee, cherry processors
and crop protection industry support). These efforts will be discussed
below by pesticide or management class.  

Imidan™) is an organophosphate and it is not as effective as AZM for
plum curculio control, but it is adequate for cherry fruit fly
management (Michigan Fruit Management Guide MSU E-154). Researchers and
extension field personnel have also compiled 25 years of field, research
plot and anecdotal information across seasons, orchards and observers
into a risk matrix using a number of compounds including Imidan (Table
1). Overall phosmet does not yield the same control assurance that AZM
does in cherries. If AZM were cancelled, phosmet use would probably
increase from 2 x to 3 ½ x in tart cherries but very little in sweet
cherries where phytotoxicity is a major concern. 

There are several likely candidates for Guthion (AZM) replacement for
control of Plum Curculio (PC) that are in various stages of development
and testing. These include Avaunt (indoxacarb), Calypso (thiacloprid),
and Imidan (phosmet). Phosmet has been used in cherries for many years
and is no longer classified by USEPA as an Extremely Hazardous Substance
(5).

Table 1.-Reduced Risk, OP-Alternative, Biopesticide, Kairomone and
Natural Products Tested

				  OP Replacement Ratingsa	      Ecological Impactb        .         
           

				For 3 Internal Feeding Pests	

EPA 

Class.	Class.

Chem	Cmpd.	PCc	CFFc	CFWc	Bees	Mite

Predators	Predators	Functional Ecology

Conditional

Registration	OP	Guthion	E	E	E	T	S	M	-20

	OP	Diazinon	P	G	P	T	M	T	-30

	OP	Imidan	Ph	Ph	Ph	T	S	M	-10

	OP	Lorsban	G	G	G	T	T	T	-40

	OP	Malathion	P	G	G	T	M	M	-30

OP-Alt	Carbamate	Sevin	N	G	G	T	T	T	-40

OP-Alt	SP	Asana	Ph	G	G	T	T	T	-60

OP-Alt	Pyrethrum	Pyganic	N	N	N	M	M	M	-5

OP-Alt	Spinosad	Entrust	N	N	N	M	S	M	+10

OP-Alt	SP	Ambush	G	F	G	T	T	T	-40

OP-Alt	SP	Pounce	G	F	G	T	T	T	-40

OP-Alt	Chlorinated Hydrocarbon	Thiodan	N	G	N	M	M	M	-20

OP-Alt	Pipronyl

Butoxide + Pyrethrum	Evergreen	N	N	U	M	M	M	-10

OP-Alt	SP	Warrior	G	G	G	T	T	T	-50

RR	IGR	Esteem	U	N	U	S	S	S,MG	+20

RR	IGR

Oxadiazine	Avaunt	E	N	U	T	S	S	-10

RR	IGR

Diacylhydrosine	Intrepid	N	F	U	S	S	S	+10

RR	Spinosad	GF-120	N	F	N	U	S	U	+10

RR	Spinosad	Entrust	N	F	U	M	S	M	-10

RR	Clay	Surround	G	E	U	N	M	M	-5

RR	Antifeedant	Neem	P	N	U	S	S	S	+5

RR	Neonicotinoid	Actara	G	G	U	T	S	M	-20

RR	Neonicotinoid	Assail	G	G	U	M	S	M	-20

RR	Neonicotinoid	Calypso	E	G	U	M	S	M	-20

RR	Neonicotinoid	Provado	F	G	U	T	S	M	-20

RR	Biopesticide	Mycotrol O	Ph	Ph	Ph	T	T	T	-10

RR	Biopesticide	Nematodes	Ph	Ph	Ph	T	T	T	-10

a Control Ratings as a Guthion (Azinphosmethyl AZM) replacement given a
zero tolerance for internal worms in processed cherries: E= currently
rated as yielding Excellent control in the Michigan Fruit Management
Guide as Excellent for control of the listed pest, Y = viable AZM
replacement, P = possible AZM replacement with more information, Ph =
possible AZM replacement with help from other pesticides and with
increased risks of rejected loads, N = not a possible replacement and U
= under investigation or unknown replacement value.

b Ecological Impact Assessments—HT = highly toxic, M = moderately
toxic, S = relatively safe, G = generational effects, MG =
Multi-generation effects and U = unknown. Functional Ecology rating is
from unsustainable to sustainable on a scale from -100 to zero to +100
where zero is an equilibrium neither breaking down the ecosystem nor
building it up.

c Cherry internal feeding insect names: Plum Curculio (PC), Cherry Fruit
Fly complex (CFF) and Cherry Fruitworm (CFW).

 

Imidan is another organophosphate (OP) with a better ecological
footprint than AZM. Yet it lacks AZM’s field performance and producers
are not as confident in this material. It is likely that phosmet users
will have to spray more to achieve AZM’s success. Whether increased
use of phosmet to achieve equivalent control will yield better or worse
cherry ecosystems is debatable. One very significant drawback for
phosmet as a AZM replacement is that it can not be used on sweet
cherries because it causes phytotoxicity. The harvest residue picture
for phosmet on processed cherries is similar to that of AZM and would
not put residues into processed product.

Indoxacarb (Avaunt), as an AZM replacement has very high potential.
However, it is not currently registered on cherries. In the recent
USDA/CSREES Apple study (2005 Fruit & Vegetable Expo, Grand Rapids, MI:
Report to the Apple Industry) and in the Cherry RAMP studies, Avaunt did
not yield more benign predator impact results than AZM, but it did add
substantially greater costs per acre ($24.98) in New York apples and
also in the preliminary Michigan cherry RAMP results. These reports
suggest and improvement of fruit quality when Avaunt is used in apples,
but this is an unsubstantiated in cherries. Another major problem with
Avaunt is that a major cherry producing county, Mason, was denied its
use under the Experimental Use Permit (EUP) issued by USEPA for
cooperators participating in the Michigan Cherry Ramp Grant. The EUP was
denied based on Endangered Species; Karner Blue Butterfly habitat
overlap with a RAMP cooperator site. We do not know if USEPA will make
similar determinations for at least 6 other Michigan and Wisconsin
cherry producing counties with known Karner Blue Butterfly habitats. 

In the first two years of the cherry USDA/CSREES RAMP study (MI, WS, UT)
and in various trials run at Trevor Nichols Research Station (MI),
Avaunt certainly has shown excellent PC control, but as in apples, the
cost per A will certainly be much higher to achieve the zero threshold
performance established through the OPs. The Cherry RAMP preliminary
data suggest at least a 2x increase in per acre costs if AZM were
cancelled now. 

One significant drawback with indoxacarb is that it is toxic to bees.
This is particularly troublesome because early spring pesticide
application timing in cherry for PC control occurs at petal fall.
Therefore, indoxacarb received a reduced functional ecology rating
(Table 1) because of its likely impact on native pollinators which tend
to forage on pollen in cherry orchards long after petal fall. In
addition, indoxacarb introduces uncertainty in cherry production for
producers and processors alike because at this time, the industry does
not know whether or not its use will result in increased residues on
processed product.

Thiacloprid (Calypso) also exhibited excellent control of PC in trials
conducted at Trevor Nichols Research Station (MI).  In the first two
years of the cherry RAMP study, researchers believe that thiacloprid
also contributed significantly to PC control in cooperator’s blocks.
Probably the most troublesome aspect of using neonicotinoid products
like Calypso, Assail and Provado is that they exhibit relatively
long-lived residues. Almost certainly, their use will result in
pesticide residues in processed product, and the cherry RAMP grant
should have data addressing this issue as early as March 2006.
Thiacloprid and imidacloprid may also have significant impacts on
natural enemies for long periods of the summer in tree fruit systems,
therefore neonicotinoids as a group may not be better than AZM based on
their low functional ecology scores (-20) Table 1.

 Actara (thiamethoxam) is one of the chemistries that the USDA/RAMP
grant is testing as an OP-alternative. It is only rated as “good”
for Plum Curculio and its use would likely lead to weevil larvae in the
fruit at harvest (MI Fruit Management Guide E-154).  It is also rated
only as “good” for Cherry Fruit Fly and could result in maggot
infested fruit at harvest if it were a stand alone strategy for
controlling this pest as well. Another problem with this chemistry is
its long residue window, and the industry is concerned about detectable
residues in finished product. For this reason, it is unlikely that
Actara would be recommended for pests close to harvest. Actara is
excellent for aphids and leafminers which can be problematic in some
year or may be pesticide induced in tree fruit ecosystems that have
decimated their natural enemies. 

Synthetic Pyrethroids and Carbaryl.- Some cherry producers currently
attempt to use synthetic pyrethroids (Asana, Pounce, Ambush & Warrior)
or a carbamate (carbaryl or Sevin) to control PC. In all of the
investigations conducted by the Whalon laboratory (2000 Report to the
Cherry Industry) at Michigan State University into infested loads of
cherries several factors contributed. First, synthetic pyrethroids and
carbaryl yield only poor to good control of key internal feeders like
plum curculio in cherries. Second, significant rain (>1/2 inch in < 2
hours) results in loss of residue and failed control. Third, poor timing
of the application(s) of these less effective compounds with PC and CFF
emergence and activity resulted in infested fruit at harvest. These
compounds therefore are not effective for PC or CFF control in some
years, and should not be cited as OP-replacements. Further, all of these
compounds net a more negative impact on the ecosystem than does AZM
because producers have to spray more frequently to achieve control
resulting in greater and longer perturbation of the cherry orchard
ecosystem (Table 1). 

Insect Growth Regulator (IGR) compounds like Esteem (pyriproxifen) and
Rimon (novaluron) may also have promise for control of plum curculio.
Several experiments in the laboratory and field (2004 & 5 Reports to the
MI Cherry Research Committee by Whalon et al.) indicate that
pyriproxifen breaks diapause in plum curculio summer generation beetles
(6) and this may be used by growers to elicit high overwintering
mortalities before spring eggs are deposited in cherry fruit. Yet this
work is just testing this hypothesis and much more work will be
necessary to confidently deliver this management approach to the
industry. In addition, such non-lethal impacts at what are thought to be
very low residue levels could have similar effects on critical
biological control agents in the cherry ecosystem and these effects are
unknown at this time (Table 1).

Novaluron has been shown to be vertically transferred from female plum
curculios to their eggs (2005 Report to the MI Cherry Research
Committee). In laboratory studies, treated females were unable to lay
eggs that emerged as larvae whether they were treated before or after
mating. This is a very encouraging result and more work is needed to
determine if egg mortality from novaluron would be an effective plum
curculio worm control. Again like pyriproxifen, the potential Functional
Ecology consequences of using this IGR with such its subtle effects are
unknown at this time (Table 1). 

 

Spinosad in either the GF-120 or the Entrust (Table 1) formulations were
rated as “fair” alternatives when compared to AZM for cherry fruit
fly control in the Michigan Fruit Management Guide (2005 E-154). In
either case, spinosad will be a more expensive alternative to fruit fly
management, but many cherry growers worry about their use given the
“Zero tolerance” and a few problems with infested cherries at
harvest have been reported. On the other hand, a to shift to spinosad
for REI and PHI reasons would be desirable perhaps because treatments
could be made 7 days closer to harvest than AZM. The Entrust formulation
of spinosad is rated with moderate bee and predator toxicity and
therefore has a poor Functional Ecology score (Table 1) although both
are better than AZM, especially GF-120 which can be used in organic
production too. Spinosad is not a control for plum curculio.

8- The Economics of OP-Alternatives and RR compounds.- The Cherry USDA
RAMP grant has deployed a reduced risk approach to managing cherry pests
in consultation with the tart cherry processing industry over two
seasons. Nine growers are comparing this program against the AZM-based
current system in paired plots. This project will be completed in 2007.
Although it is too early to conclusively assert and too much is at stake
to jump to early conclusions, yet it may be “technically” possible
to use a reduced risk program based upon indoxacarb, neonicotinoids and
spinosad as discussed in 7 above. At this stage of the research, several
major issues that have to be addressed before reduced risk compounds
could be substituted for AZM in processed cherry production; 1) the
specter of 2-3 times the expense per acre when compared to a AZM-based
control program (Table 2 & 4 below), 2) residues in processed product,
3) the ecological impact of supposed “reduced risk” compounds
compared to current AZM-based systems is largely unknown, but
preliminary information demonstrates that there is no net gain in
natural enemies in the reduced risk plots and 4) the uncertainty of
rebound pests like the Cherry Fruitworm in reduced risk blocks is
possible, but more work and time is needed to make any conclusions. 

      Table 2.- Cherry USDA/RAMP Grant: 2004 Insecticide Cost ($)
Comparison.

Conventional AZM-based Cherry Pest Management

$40.52 ($20.55 – $73.88)

RAMP Pest Management (based on the compounds below)

$91.45 ($31.64 – 154.78)

Average difference

$51.12 or 2.5x more to produce a cherry crop with Reduced Risk compounds
currently registered on cherry

Table 3.- Cherry USDA/RAMP Grant: 2003-4 Insecticide Program.

Insecticide	Label Rate	Spray Timing	Target Insect

SpinTorTM 2SC	4 - 8 oz/acre	Late bud burst/open cluster	green fruitworm

leafrollers

Avaunt®**	5 - 6 oz/acre	Shuck split

350 DD50 after bloom	plum curculio

ActaraTM 25 WG	4.5 - 5.5 oz/acre	12 mm fruit	cherry fruit fly

plum curculio

Provado® 1.6 Flowable	4.0 – 8.0 oz/acre	20 – 22 mm fruit	cherry
fruit fly

**Avaunt is not currently registered on cherries, but the RAMP grant is
authorized under an Experimental Use Permit granted to RAMP cooperators
except in Mason, Co. where Endangered Species, Karner Blue Butterfly,
habitat resulted in denied use by USEPA. 

Given the international competition, the current economics of processed
cherries and the likelihood of new production challenges, a 2-3 fold
increase in pest management costs could cause significant dislocation
and shrinkage of the US cherry processing industry. In turn, this would
significantly impact the rural economies of states like Michigan already
hard-hit by foreign competition in their manufacturing sectors. Although
it is difficult to predict the full extent of this implosion, no doubt
small and middle sized growers would be hardest hit and some if not many
would be forced to turn to other income alternatives. In addition, the
US processed cherry industry is already hard hit by two recent short
crops (2001-2) and foreign competition and could stand to loose its
prominence globally is production were further impacted. 

Table 4.- Preliminary conclusions from the 2003-4 USDA/RAMP Grant for
Michigan only. Data from Utah and Wisconsin is still being compiled.

The so called “reduced risk” insecticide program (Table 3 above) may
yield equal control to the AZM program, but it is too early to conclude
this after just two trials.

No worms in harvested fruit were detected in plots using reduced risk
insecticides (3 spray application applied alternate row).

Emerging issues associated with transitioning to reduced risk compounds
that will need addressing in the next 2 years of the RAMP grant:

Reduced risk blocks may need post harvest sprays for high Cherry Fruit
Fly pressure or adjacent Plum Curculio populations. Re-emerging or
rebounding of formerly managed pests is still an unanswered question and
may increase the reduced risk costs to even higher levels.

These results are without doubt, PRELIMINARY, the final performance
conclusions of reduced risk insecticides vs AZM will not be available
until January 2008 when all of the on-farm trial data from Utah,
Wisconsin and Michigan have been compiled, analyzed and reported
formally. Michigan State University is reporting this preliminary data
here because of the critical need to maintain AZM’s Conditional
Registration for another 3 years.

A number of new or rebounding insect pests were observed for the first
time in 2005 plots and we do not know if these detections represent
rebound condition in response stopping the use of organophosphates.

9- Is it time for USEPA to award “credits” to an industry for using
pesticide delivery systems that reduce drift and off-target deposition
of compounds like AZM?- The processing cherry industry has a employed a
number of innovations in spray delivery that USEPA should count as
mitigation of off-target deposition. Many producers have purchased and
use more efficient sprayer technology than is currently used in
USEPA’s model for drift simulation. These innovations include:

Laminar flow air curtain and tower delivery for directing sprays across
or down into trees,

Droplet size control exceeding historical airblast models,

Optical control of the spray nozzles reduces application and drift,

Electrostatics attract droplets to target leaves and reduces drift.

In addition, Dr. John Wise’s laboratory at MI State University has
demonstrated that there is a difference between droplet detection and
droplet biological activity downrange which would significantly curtail
USEPA’s “biologically” active drift profiles.

References Cited:

Memorandum to the Azinphos-methyl Docket

From: Diane Isbell, Special Review and Reregistration Division

Date: November 29, 2005

Subject: Questions to Consider While Reviewing the Assessments in the
Azinphos-methyl

Docket OPP-2005-0061

On October 19, 2005, EPA will announce availability the Environmental
Fate and

Ecological Effects Risk Assessment, dated September 29, 2005, the 2005
Grower Impacts

Assessments for Azinphos-methyl, and the BEAD Assessment of Citations
Submitted by

Plaintiffs (Case 2:04-Cv-00099-RSM) in Regard to EPA’s 2001 Benefits
Assessments for

Azinphos-methyl. These documents will be available for a 90-day public
comment period. These assessments pertain to the following crops:
almonds; apples and crab apples; blueberries, lowbush and highbush;
Brussels sprouts; sweet and tart cherries; nursery stock; parsley;
pears; pistachios; and walnuts. While all public comments are welcome,
certain types of information are most useful to the Agency for refining
these assessments and developing risk management options. The
information requested below is intended to guide commenters toward the
most pertinent types of information

Generally, comments supported by published literature or data are of
greater utility than

expressions of opinion. If you believe, based on your own expertise or
experience, that the assumptions used in the assessments are well
founded, that is also useful information to provide to EPA.

EPA will make the human health assessment available for public comment
in 2006, prior

to or in conjunction with the Agency’s proposed decisions on the
continued use of Azinphosmethyl for above listed uses. For the current
comment period, please confine your comments to the ecological and
grower impact assessments made available on October 19, 2005. The
following topics are suggested for comment:

1. The Agency is seeking data for pest management scenarios applicable
to commercial scale commodity production (that include domestic and
export markets) other than those discussed in the azinphos-methyl
assessments. Please describe in detail:

a) Whether these alternatives to azinphos-methyl would be likely to be
used by a

significant number of growers and if so, why.

b) The cost per acre of these alternatives.

c) The efficacy of these alternatives, focusing on yield and quality
effects.

d) The implications of the proposed scenarios on the marketability of
the commodity.

2. The Agency invites the submission of data or other relevant
information that addresses

economically important pests currently controlled most effectively or
only by AZM, and which were not discussed in the assessments, please
submit data that address the following:

a) The proportion of crop acres by region affected by the pest.

b) Details on the life cycle of the pest and nature of damage inflicted.

c) Efficacy studies comparing AZM to potential alternatives for control
of the pests,

focusing on yield and quality impacts. If such studies have been done,
also provide

copies of the studies, citations, or contact information so that we may
obtain the

studies.

3. If available, the Agency is seeking new crop budgets for any crops
discussed in these

assessments, please provide copies or citations for these documents.

4. The Agency is seeking any information related to the use patterns
(location where the crop is grown (county and state), application rate,
lowest effective application rate, number of applications, the timing of
each application, or increased buffer zones) that differs from what was
relied upon in the assessments.

5. The Agency is interested in information concerning any typical
practices, not reflected on current labels, that serve to reduce
exposure to non-target species and water resources, for example, special
equipment to reduce spray drift.

6. The Agency is seeking information related to any additional measures
that could be added to current labels to reduce exposure to non-target
species and water resources, for example, larger buffers for some or all
crops.

Azinphos-methyl: EFED’s Data Request, Risk Characterization, Risk
Reduction Options. October 19, 2001.

Azinphosmethyl Insecticide: Ecological Risk Assessment…Sept. 29, 2005.
PC Code: 058001, DP Barcode: D307568

NAS Pesticides in the Diets of Children

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Kathy Franklin, Office of Emergency Management, Office of Solid Waste
and Emergency Response at 202 564 7987; fax: 202 564 8444; e-mail:  
HYPERLINK "mailto:Franklin.Kathy@EPA.gov" \o
"mailto:Franklin.Kathy@EPA.gov"  Franklin.Kathy@EPA.gov  - EPA November
26 Federal Register:

Hoffmann, E.J., A. B. Coombs and M.E. Whalon. 2004. Reproductive
Development of Northern and Southern Strains of Plum Curculio. J. Econ.
Entomology 97:

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Background and Critical Issues for Guthion, Azinphosmethyl (AZM),
Comment to USEPA: M. Whalon January, 2006

