Imidacloprid:  Disturbing info   Ray Weber
  Mar 12, 2007 10:25 PST 

I received word that the Massachusetts DCR has
banned the use of that great chemical Will and others
are using to save hemlocks, claiming it pollutes groundwater.

I did suggest to one of them a while back to use the
method that Matt Largess has used successfully in Southern
New England, namely injecting into the tree rather than
spreading it on the ground.

The foresters made a statement a few weeks ago that they
are going to preemptively harvest some hemlocks on the Mount
Holyoke range, since "they are going to get adelgid anyway,
we are taking them while they have some value".

Lets hope they stay out of the old growth. There is language in
many of these reserve "plans" allowing harvesting to avoid spread of
something like adelgid.

Ray W
RE: Disturbing info   Will Blozan
  Mar 12, 2007 15:02 PST 

Ray,

I know that a lot of the fear is based on old information and improperly
applied chemical. They need to update their libraries!

Will
RE: Disturbing info   rayof-@ndws.com
  Mar 12, 2007 17:46 PST 
imidacloprid from what I was told by two seperate sources. Bob Leverett
mentioned it first to me.

Ray
Re: Disturbing info   symplastless
  Mar 12, 2007 19:08 PST 

I would say, if you cannot inject it into an apple tree which humans eat
from, then it would not be suitable for trees that wildlife eat from. I
have been an arborist for over 20 years and still have not found favor in
injections or systemic. I don't know. many people agree and some disagree.

Its too easy to place a tourniquet around a neck for a nose bleed.
Sincerely,
John A. Keslick, Jr.
Arborist
RE: Disturbing info   Will Blozan
  Mar 12, 2007 20:02 PST 

John,

I am not exactly sure what you are trying to say. Imidacloprid does not kill
everything, destroy the entire soil biota that hemlock (or ash) depends on,
nor any bird that lands on the tree. It is non-toxic to predatory spiders,
mites and mammals (although some mites are a terrible pest).

There is another option to control HWA, and that is foliar spray of soap or
dormant oil. This method "wipes the slate clean" of all invertebrates on the
tree, is not applicable to forest stands, and has to be repeated 2-3X more
often than a soil injection of imidacloprid. It is also far more costly in
the long run. I rarely use this option since the hemlock typically has just
one lethal pest, the HWA. Imidacloprid destroys HWA very effectively without
adverse effects on other species or wiping out the soil biota. Until someone
convinces me otherwise, I feel it is the best option at the time.

I know you are an avid follower of the late Dr. Shigo, but I wonder where
YOU stand, as you quote Dr. Shigo repeatedly, seemingly without much
personal input. I agree with most of Dr. Shigo's work, but modern
arboriculture has new facets perhaps he wasn't prepared to deal with. I
could be wrong but the loss of an ecosystem is a far greater impact than the
death of some critters in the immediate injection site. The retention of the
ecosystem and all viable components should be the goal, not the impacts on a
single tree. It is time to see the forest, not the trees.

Will
Re: Disturbing info   orw-@fas.harvard.edu
  Mar 13, 2007 12:09 PST 
Hello all, enclosed is a proceedings paper presented at the last HWA
meeting in Asheville, NC (2005). As suggested previously, Imidacloprid
is mobile, and may enter water supplies, however, as Will points out,
the concentrations found were extremely low, and this paper points out
how low in reference to what are considered harmful levels.   thanks
much,   

DAVE ORWIG
Back to Dave   Robert Leverett
  Mar 13, 2007 13:14 PST 

Dave,

Thanks for weighing in. I'm not sure that people on this list realize
that you are one of the foremost researchers in the country on the
hemlock woolly adelgid. Any posts you would care to make on the spread
of the adelgid or approaches to slowing it down will be greatly
appreciated by all.

   Back to imidacloprid. I am troubled by DCR's banning (total, I
presume) of the use of this chemical. Based on what I'm learning, their
decision seems to be highly pre-mature. I hope DCR's attitude isn't tied
to the willingness of the timber community in Massachusetts to see the
hemlock population crash. The hemlock's low value as a timber tree is,
of course, the reason. But the hemlock has immense ecological value as a
species and DCR should recognize that. I'm starting to worry that the
"green certification" label is on its way to becoming a license for
restructuring our forests around early successional species, purportedly
for wildlife, and a few high value timber species. I hope I am wrong.

Bob
RE: Disturbing info   Will Blozan
  Mar 13, 2007 18:26 PST 

Dave,

Wasn't one of the main critiques of this article the lack of a BEFORE (i.e.
control) water sample? I could be wrong but I think there are golf courses
that may drain into the lake.

Will
RE: Disturbing info   Will Blozan
  Mar 13, 2007 15:58 PST 

John,

Currently, almost all my work is in old-growth eastern hemlock forest, from
top to bottom. I am working on fairly large-scale conservation areas in the
Smokies (soil injections of Imidacloprid) and the Tsuga Search Project to
document the superlatives. I am literally immersed in the old-growth hemlock
forests of the Great Smokies almost daily. I am also personal witness to
their death.

Will
RE: Disturbing info   Brandon Gallagher
  Mar 13, 2007 18:01 PST 

I just got off the phone with Jim DeMaio, Chief Forester DCR Bureau of
Forestry for MA. The news about the state's use of imidacloprid has not
changed.

Three years ago when the state was developing an HWA response program
they looked at using imidacloprid as part of the plan. They decided at
the time because Nassau County in NY had chosen to not allow soil
application due to ground water risk (Nassau Co does not allow ANY
product to be applied to soil) that they would not use it on their state
park, forest, and watershed management land either. He said they are
aware of trunk injected imidacloprid but the state has not used it. I
did not ask him what the management plan for HWA in MA did entail, but I
am assuming it is the "preemptive harvesting" suggested by Ray earlier.

In summary, imidacloprid is still a registered product in MA used by
arborists and private forest managers, just not by the state who never
used it to begin with. Nothing is scheduled to change in the near
future.

Brandon Gallagher Watson
Plant Healthcare Specialist
ISA Certified Arborist MN-4086A
RE: Disturbing info APPLES AND ORANGES   Will Blozan
  Mar 13, 2007 18:16 PST 

John,

There is a subtle but crucial difference in your argument:

1) Apples are not native, and may "need" extra help be it chemical or
"organic". Also, apples are highly genetically selected for resistance
traits and varieties. Apples are not on the verge of local extinction from
late frosts, various rots or fire blight.

2) The eastern and Carolina hemlocks are native to the US, and have evolved
with native pests for millennia. The non-native hemlock woolly adelgid is a
fatal pest that the hemlocks have never had to deal with. They will be
killed and in the case of Carolina hemlock, likely driven extinct in the
wild without chemical treatment.

In both scenarios we (humans) have introduced new species to our continent;
one invited, the other not. But to answer your question- yes, you can inject
chemicals into an apple tree, but I wouldn't eat it. There is not a fair
comparison between the two actions. Apples to oranges.

Will

-----Original Message-----
From: John Keslick, JR. [mailto:sympla-@comcast.net]
Sent: Tuesday, March 13, 2007 1:37 PM
To: ENTST-@topica.com
Subject: Re: Disturbing info


So you are saying the chemicals can be injected in apple trees?

Sincerely,
John A. Keslick, Jr.
Arborist
Re: Disturbing info   Holly Post
  Mar 13, 2007 19:29 PST 

That is terrible news as I thought a good portion of
the state's old growth are Hemlocks. This would open
up a good excuse for the harvesting of them.
RE: Disturbing info   Robert Leverett
  Mar 14, 2007 04:18 PST 

Ed,

   I wholeheartedly second your comments. Will Blozan has personally
donated literally tens of thousands of dollars of his money to funding
efforts to save the eastern hemlock from extirpation from an alien
insect. I know of no human being on the planet who has made a greater
effort in terms of personal commitment to the species. He has put his
money where his mouth is and we all are the richer for it.

    Whether or not we let a species disappear due to our own neglect is
a matter of individual conscience. But, I take inspiration from the
efforts of people such as Will who accept the challenge of saving a
species from extirpation while our species as a whole plows onward
trashing the planet.

    In terms of time spent in old-growth, Will is one of the foremost
eastern old growth researchers in the country. I say that without a
moments hesitation. That is how I first met him. He was plowing through
mountains of rhododendron documenting the hemlock and Northern red oak
stands of the Smokies as a NPS employee in advance of the adelgid and
gypsy moth infestations. He had fire in his belly then and that fire has
grown steadily as has his accomplishments.

Bob

Bob   


Edward Frank wrote:
 
John,

Will's company, Appalachain Arborists, provides a variety of tree
related business services not just treatments for adelgid. They do tree

trimming and removal and similar arborist services. Actually many of
the areas that have been treated for the adelgid has been paid for by
his company and by Will personally out of pocket. The
reason for pursuing the treatment of the hemlocks is to save the species

and related ecosystem from extinction, rather than to make a large
profit. I fully support and applaud his efforts as does everyone else
with concern about the future of our eastern and Carolina hemlock
forests.

Ed Frank
RE: Disturbing info   rayof-@ndws.com
  Mar 14, 2007 06:15 PST 
Bob et al, we take our hats off to Will, he is dedicated, and working
miracles to save the old growth hemlocks in the smokies.

The arborist our group works with raves about his great work down there.

Great work Will, keep it up.

Ray Weber
FORSP
Re: Disturbing info   dbhg-@comcast.net
  Mar 14, 2007 10:02 PST 
Holly,

   I have this growing fear that premature harvesting has been the underlying plan all along.

Bob
Imidacloprid Wars   Robert Leverett
  Mar 14, 2007 10:44 PST 

ENTS,

   The rapid change of e-mails on the scientific evaluations of
imidacloprid reflect different points of view. Below, please find
extracted information from a DEC letter to Bayer CropScience about tests
in Suffolk county, NY.

    Comments?

Bob


==============================================================
     The New York State Department of Environmental Conservation
(Department) registered the active ingredient imidacloprid in March
1995. The professional nursery, turf, ornamental and agricultural uses
were registered in the spring of 1995, while the consumer turf use was
registered in January 1996. As indicated in our registration decision
letter dated March 24, 1995, after review of the technical studies
submitted, the Department had concerns regarding the long-term
environmental fate and environmental persistence of the active
ingredient imidacloprid and degradates when used over sole source
aquifers. Groundwater modeling performed by the Department prior to the
registration of imidacloprid indicated the potential for accumulation
and persistence of imidacloprid and its degradates in groundwater after
repeated annual applications. The Department was especially concerned
about the use of imidacloprid on Long Island which has been identified
as a sole-source aquifer. The letter also stated that the continued
registration of all imidacloprid products within New York State will be
dependent upon the annual review of groundwater monitoring data
collected within the Long Island aquifer.
        In a registration letter dated October 24, 1996, the Department
again expressed its concerns. Imidacloprid is persistent and
potentially mobile. Soil degradation is slow, with half-lives ranging
from 120-365 days. While photolysis in water is very rapid, with a
half-life of 4.2 hours, imidacloprid is stable to hydrolysis. Field
dissipation studies performed by the registrant for the Merit products
indicate that imidacloprid can dissipate fairly quickly from the soil
application zone. Due to the leaching potential, combined with its
persistence, the potential distribution and widespread use of
imidacloprid in New York State, both the Department's Division of Water
and the New York State Department of Health expressed concerns regarding
the potential for multi-year residue build-up in groundwater.
     
        The Department has been working closely with the Suffolk County
Department of Health Services (SCDHS) and has provided funding to the
county for groundwater monitoring in Nassau and Suffolk Counties. When
the Quality Assurance Project Sampling Plan (QAPP) entitled
"Imidacloprid Groundwater Monitoring Project Plan" was signed by
representatives from Bayer CropScience and the Department in 1996, an
"action threshold" of 25 ppb (half of the New York State drinking water
standard) was discussed and agreed upon. The intent of the monitoring
was to detect levels of imidacloprid in the groundwater directly beneath
the site specified and being used at maximum label rates in conjunction
with the groundwater monitoring project. In a Bayer CropScience letter
dated May 22, 1998, Bayer stated that if multiple groundwater detections
occurred at or above 10 ppb, mitigation steps would be taken. These
"action thresholds" were intended for groundwater samples taken from the
monitoring wells established for the imidacloprid groundwater monitoring
project. While the Department expected to find imidacloprid in the
groundwater monitoring wells immediately under and adjacent to test
sites, the Department was surprised to find that imidacloprid had
rapidly migrated down gradient to private homeowner wells. The first
detection of imidacloprid in a private homeowner well (far removed from
the intended monitoring zone) was in April 2000. To date, imidacloprid
has been detected at concentrations (0.2 to 7 ppb) in 12 monitoring
wells and 16 down gradient private homeowner wells. Imidacloprid has
also been recently detected at 0.24 ppb in two Suffolk County community
water supply wells (85 feet and 90 feet deep). Additionally,
imidacloprid has now been detected at a golf course monitoring well
(0.43 ppb) and at monitoring wells near trees (0.2 to 5.1 ppb) that have
been treated with imidacloprid by trunk injection for the Asian
Longhorned Beetle (ALB).

        The New York State Department of Health is concerned about the
presence of any pesticides in private or community drinking water
supplies. Impact to community supply wells at depths of 85 and 90 feet
is of particular concern to the Department of Health. Additionally,
imidacloprid is fairly resistant to breakdown once it moves into
groundwater. So far, monitoring has only shown the presence of the
parent imidacloprid compound. It is unknown if any degradates are
present in the groundwater. This concern is heightened by the fact that
imidacloprid pesticide products have been registered for a short period
of time (nine years).

    Given the above, both the Department and the New York State
Department of Health are concerned about the continued unrestricted use
of all nursery, turf, ornamental, agricultural and consumer registered
use patterns. Consistent with the United States Environmental
Protrection Agency's (USEPA) philosophy of developing Best Management
Plans (BMPs), when impacts to groundwater/drinking water are detected,
the Department intends to be proactive and ensure the responsible use of
the affected products. While the detected level of imidacloprid in
groundwater samples has not reached the action thresholds, the
Department is troubled by the increasing frequency of detections of the
parent compound with respect to the short duration of registration and
its use at less than maximum labeled rates in New York State. The
Department is particularly concerned about the increasing number of
detections in samples from public and private drinking water wells.
        In cooperation with Bayer CropScience, Cornell Cooperative
Extension, representatives of regulated users and the Department,
targeted BMPs for imidacloprid have been developed. The Department must
take steps to evaluate the impact of various use patterns on
groundwater. The Department's goal is to manage the current labeled
uses of all imidacloprid products in order to protect the groundwater
resources of Long Island and, at the same time, preserve its use for
crops and other use patterns where no alternatives for insect control
exist. The Department intends to maintain the registration of the
critical uses (in conjunction with the BMPs) of imidacloprid on Long
Island while also gathering more information so that we may resolve our
groundwater concerns.

        The Department first met with Bayer CropScience on July 30, 2002
to discuss our concerns, and possible use pattern modifications. Bayer
CropScience was also informed in a letter dated July 11, 2002 that until
this issue is resolved, the Department will not register any additional
imidacloprid products (basic or supplemental distributor). Subsequent
meetings and conference calls have taken place on October 1, 2002;
November 4, 2002; July 28, 2003; May 18, 2004; July 15, 2004 and July
22, 2004.

     The Department received a letter dated October 21, 2004 from Bayer
CropScience expressing dissatisfaction with the Department's technical
position. We interpret this letter as Bayer's final positions on the
various imidacloprid product related registration matters that we have
been negotiating for some time. We find Bayer's positions inconsistent
with many of our previous discussions. Our discussions on the "trigger"
related concentration agreement thoroughly highlighted the difference
between such concentrations being present in near surface waters versus
deeper aquifer zones. The New York State Health Department was present
to aid in understanding the concerns associated with the sampling
results from the drinking water wells. Such data is not representative
of the agreed upon "mitigation triggers" as your letter suggests.

      You also stated in your October 21, 2004 letter that only 1% of
the samples collected by Suffolk County have detected imidacloprid.
However, the detections that the Department is most concerned about are
not from the monitoring wells established for the imidacloprid
groundwater monitoring project. As noted above, there has been an
increasing number of detections in private homeowner wells which are far
removed from the intended monitoring zone.

        We further shared the sound scientific reasoning behind our
intentions to limit the application of imidacloprid products to
professional and agricultural use by classifying the products as
"restricted use" while we further evaluated the means by which this
compound migrates through the soil matrix. As we discussed, limiting
the application of this product to those persons who are certified
applicators would also ensure that we would receive annual reporting
information on use location and amounts. To provide further explanation,
products which are classified as "restricted use" in New York State are
restricted in their purchase, distribution, sale, use and possession in
New York State. Furthermore, restricted products may only be purchased,
sold and used by a certified applicator in New York State.

    According to New York State Department of Environmental Conservation
Regulations    6 NYCRR 326.3(a): "It shall be unlawful for any person
to distribute, sell, offer for sale, purchase for the purpose of resale,
or possess for the purpose of resale, any restricted pesticide unless
said person shall have applied for, and been issued a commercial
permit."

    Also, the Pesticide Reporting Law (PRL) in Article 33 Title 12 of
the Environmental Conservation Law requires all certified commercial
pesticide applicators to report information annually to the Department
regarding each pesticide application they make.
Commercial pesticide retailers are required to report all sales of
restricted pesticide products. If no sales are made within New York
State, a report must still be filed with the Department indicating this
is the case.

      There is no practical mechanism for obtaining annual reporting
information on use location and amounts for imidacloprid products which
are currently registered as "general use" in New York State and used by
the general public. Therefore, in order to protect the groundwater and
obtain accurate use data which can be tabulated and used in statistical
analysis, the Department maintains that the consumer products should be
prohibited from use on Long Island. In order for the affected consumer
products to be registered, use modifications must be made. An example
of label language that addresses these concerns is: "Not For Sale, Use
or Distribution In or Into Nassau, Suffolk, Kings or Queens Counties,
New York." Affected currently registered consumer products will be
placed into discontinued status. The island of Long Island is
physically comprised of these four contiguous counties. The Department
believes that due to the inherent difficulties of controlling the sale,
distribution and use of "general use" consumer products, the prohibition
should be extended to the natural physical boundaries of the island.

    In all of our communications, our position has been shared openly
with Bayer in the realm of sound environmental management based on the
available scientific data. We find the notion that this was an
"arbitrary decision" to be without basis.

      The Department does not consider the use of imidacloprid consumer
products to be critical on Long Island. Homeowner lawns, and ornamental
flowers and shrubs will still be able to be treated with imidacloprid by
licensed trained applicators. As New York State restricted use
products, all professional use and commercial sales will be reported to
the Department in accordance with the Pesticide Reporting Law. The
dates, amounts and specific locations of imidacloprid applications will
be provided to the Department annually. This information, along with
eliminating the consumer use (of which the Department would have no
application or reporting records), will allow the Department to evaluate
the other use patterns and attempt to determine which uses are most
problematic. This will allow further use decisions to be made if
necessary.

     Therefore, as a result of the Department's intention to continue
registration for the critical uses to professional applicators and still
be protective of human health and the environment, we register the
aforementioned products as restricted use products, in accordance with 6
NYCRR 326.23(e), in New York State. The Department intends to protect
the groundwater/drinking water of Long Island, while still preserving
the use of imidacloprid where no viable alternatives exist.
        
        Although the Department has received and reviewed your October
21, 2004 letter, our technical concerns remain and have not been
adequately mitigated by Bayer CropScience's proposed registration
conditions.

   With regard to imidacloprid products, the Department will proceed to:
          
1. Classify as "restricted use" in New York State, as of January 1,
2005, all currently registered professional use products. Our authority
for this action lies in 6 NYCRR Part 326.23(e). This includes all
professional turf, ornamental, nursery and agric
ultural use products, except seed treatments and fly baits.



==============================================================

Robert T. Leverett
Cofounder, Eastern Native Tree Society
RE: Imidacloprid Wars   Brandon Gallagher
  Mar 14, 2007 13:03 PST 

As a retailer of imidacloprid (Xytect) I can tell you the restricted use
applies to CA and NY, which means we can only sell the product to
professionals. It is not a federally restricted product so if we so
chose we could sell to the general public in every other state (which we
don't because we believe ONLY professionals should be applying these
chemicals). Even Bayer's homeowner version (Advanced Tree and Shrub
Care) is specifically labeled for no distribution, application, or sale
into the Long Island counties.
These are specific to Long Island because of the unique hydrology of the
area.
The label clearly states the risk of groundwater contamination but it is
really up to applicator to use his/her judgment for determining if a
soil treatment is proper in a particular situation. This really speaks
to the importance of environmental education for those considered
"professionals" in our industry. The fate of many of these products, all
the EPA/university science aside, is in their hands.


Brandon Gallagher Watson
Plant Healthcare Specialist
ISA Certified Arborist MN-4086A

Rainbow Treecare Scientific Advancements
Re: Imidacloprid Wars   wad-@comcast.net
  Mar 14, 2007 13:11 PST 
Bob

I was an applicator of pesticides commercially for 2.5 years in the DC/metro area. I always thought it would be wise to restrict the use of all pesticides, except maybe round up in a premixed solution, from all residential use (homeowner use) The american idea of more is better causes many folks to over apply pesticides or just use them improperly altogether. A man in Md. poisoned a boatload of Canadian Geese when he dumped the majority of a container of insecticide in his lawn in an effort to kill ants. I realize that many of us can do it properly, but it sure would cut back on improper use. I realize that some commercial applicators are bozos too. I guess you can't stop everything.

Scott
Re: Imidacloprid Wars   symplastless
  Mar 14, 2007 14:08 PST 
Do sap suckers visit hemlock trees?

HWA are not the only organisms to eat hemlock parts. Like I said.   I base my decision on the fact that a chemical that cannot be injected into apple trees for human consumption is not suited for trees which their associates eat their parts.


My search is showing that some birds do eat hemlock seeds. Deer browse also on the foliage.

(Western Hemlock) Seeds eaten by squirrels, chipmunks and birds in the winter. Deer and elk browse twigs.

Tsuga martensiana (Mountain Hemlock) Seeds eaten by siskins, juncos, finches, crossbills, squirrels, chipmunks. Dense foliage provides protection.

Hemlock seed is a preferred food for American goldfinch, boreal chickadee, ruffed grouse, pine siskin and red-winged and white-winged crossbills. Many other species of birds and mammals also eat the seeds, and snowshoe hare browse young shoots. Large, old hemlock are used by raccoon for dens and provide cavities and nesting sites for a wide variety of birds. Hemlocks also offer great cover and protection for both small and large birds and at Macphail Woods the largest hemlock contains a hive of honeybees that has overwintered for many years. As large trees start to break up and die, red-backed salamanders are common under the loose bark on standing trees. Amphibians can also be found under and around hemlocks that have fallen to the ground.


Sincerely,
John A. Keslick, Jr.
Arborist
RE: Imidacloprid Wars   Will Blozan
  Mar 14, 2007 16:03 PST 
John,


It is not ALL about what eats the seeds of leaves. You obviously don't
realize that we are talking about an ecosystem collapse here. You also must
not realize that these associated species, some perhaps Tsuga specialists-
will have to make some quick adjustments to find alternative food sources as
their preferred hosts die and crumble. The amphibians, trout, and whatever
else (some species perhaps not even discovered yet) will die or attempt to
move on with the loss of the forest. If they are niche specialists in
hemlock forests they are toast.

Will
RE: Disturbing info-- Wait a minute!   Will Blozan
  Mar 14, 2007 16:17 PST 

ENTS,

I have been involved with OG work for quite some time but continue to learn
from folks far more knowledgeable than me. Jess Riddle and Josh Kelly come
immediately to mind. I may have more miles in the Smokies than Jess or Josh
but they have more miles with the fine tuning and keen eye I did not have
early on. I still do not have the skills of these two and likely never will.
I am fine with that as we all have our skills, interests, and besides, there
is no competition here anyway!

I bring the funding and exposure for ENTS and the Tsuga Search Project via
my NPS contacts and passion for the species. I am proud to be able to do it
and don't regret a dime spent even though it has been a huge financial hit
for me. We have but ONE chance to do what we are doing with regards to
eastern hemlock. I saw the chance and took it with much uncertainty about
the funds to get it done. It was a whim that has proven to be successful.
Plus, I love to climb huge trees!

Will
Re: Imidacloprid Wars   symplastless
  Mar 14, 2007 17:56 PST 
Hemlocks of sawlog size are notoriously subject to wind-shake (481), to radial stress cracks, and, following sudden exposure, to sunscald of the bark, and to death. These reactions may be the result of many adverse effects associated with a changed regime of solar heat and soil moisture and culminate in a decline often referred to as post-logging decadence. When hemlocks are left as residual trees following partial cutting, and when they are exposed, through road or other construction or clearing, they often die, even when their root area is covered with understory brush (661). Eastern hemlock is also considered to be one of the species most sensitive to sulfur fumes from smelters (1933). An interesting type of hemlock ring-shake follows sapsucker injury (1292).



Reference: Hepting, George, H.       July 1971        
Disease of Forest and Shade Trees of The United States 
US. Dept. Agric. Forest Service Handbook Number 386           658 pages.
Re: Imidacloprid Wars   symplastless
  Mar 14, 2007 17:58 PST 
Why should we pollute their food supply with these chemicals? That's unheard of. As I said: a tourniquet around the neck will stop a severe nose bleed.

What are we talking here? Injecting chemicals which find their way to seeds and needles, which many eat, that no one would think of injecting in their own apple tree and feeding the apples to their children. Hemlocks do not tolerate fragmentation. Maybe that's the problem to address.

Sincerely,
John A. Keslick, Jr.
Arborist
http://home.ccil.org/~treeman
and www.treedictionary.com
Beware of so-called tree experts who do not understand tree biology.
Storms, fires, floods, earthquakes, and volcanic eruptions keep reminding us that we are not the boss.
RE: Imidacloprid Wars   Will Blozan
  Mar 14, 2007 18:20 PST 
Hemlocks will not survive HWA. Fragmentation is not a relevant point. I
agree that we disagree. 

One more difference I would like to point out. You feel it is wrong to
poison an apple tree and feed the fruit to our children. I agree, but I also
feel it is wrong and irresponsible to not leave my children a grove of
hemlocks to visit, climb, and enjoy (not to mention the myriad possibilities
of research and further ecological and mechanical studies- that you quote so
often).

I have taken the opportunity to leave a legacy of hemlocks in the southern
Appalachians for the future. Down here, the untreated groves will be dead
(along with much of the critters that depend on them). I may eventually find
this mission wrong, but I doubt it.

I'm out.


Will
Re: Imidacloprid Wars   symplastless
  Mar 14, 2007 18:33 PST 
I would say that the chemicals injected are in the sap. What about the sap suckers?

Sincerely,
John A. Keslick, Jr.
Arborist
Re: Imidacloprid Wars   MICHAEL DAVIE
  Mar 14, 2007 19:14 PST 
John,
Hemlocks do not tolerate death or mass extinction, either. I think it's important to balance the potential incidental damage to some generalist feeders on hemlocks or those up the food chain from there, in very minor and localized amounts, to the loss of an entire species. Any hemlock-specific species will die along with the hemlocks.
Yes, yes. The tourniquet comment. Very clever. How can you correlate the logic to the situation at hand? Please elaborate.
Michael
RE: Imidacloprid Wars   James Smith
  Mar 14, 2007 20:23 PST 


MICHAEL DAVIE wrote:
 
   Yes, yes. The tourniquet comment. Very clever. How can you >correlate
   the logic to the situation at hand? Please elaborate.

Nah. Not very clever, at all. Rather reactionary, in my opinion.

The simple fact is that, barring an amazing discovery and treatment in
the next couple of years, both species of hemlocks in the east will
become extinct. If this happens, every creature that depends upon them
for survival will also likely go belly-up. Barring some amazing leap in
their habits (doubtful). By treating some groves with the insecticide,
you're at least giving them a few more years for some new and effective
tactic to come to the fore. Putting up with short-term toxicity for
long-term survival seems a mild risk.
RE: Imidacloprid Wars   Gary A. Beluzo
  Mar 15, 2007 05:17 PST 

Okay, how many species are obligate or facultatively obligate for hemlocks
and/or the environmental conditions that they create? I remember Dave Orwig
doing a presentation at the Forest Summit regarding the HWA and he
identified the other TREE species that would most likely supplant Tsuga.
Also, I know that Lee Frelich has been writing about neighborhood effects of
species like Tsuga so in that instance I would image that other species
would become established, exert their neighborhood effects, and the ecology
would shift to a more deciduous-based system.

Other information?

Gary
RE: Imidacloprid Wars   Gary A. Beluzo
  Mar 15, 2007 05:20 PST 
I am just catching up with my email today after a short hiatus and find this
discussion interesting. Has anyone provided a synopsis of the ecotoxicology
of imidacloprid? Half life of biodegradation, intermediate and final
metabolites, LD50, etc?



Gary
RE: Imidacloprid Wars   Gary A. Beluzo
  Mar 15, 2007 05:21 PST 
Will,



Yes, you are absolutely correct, the sap that results from their drilling
attracts insects which are then fed upon by the sapsuckers, I have observed
yellow-bellied sapsuckers doing this.



Gary
RE: Imidacloprid Wars   Gary A. Beluzo
  Mar 15, 2007 05:25 PST 
Will,



Any evidence out there that there are resistant individuals? Normally the
genetic variation in any population will provide a long-term solution to the
presence of a pollutant, that is unless the pollutant or pathogen is just so
damaging that no individuals survive. Has anyone seen resistant individuals
in the field? Dave Orwig?



Gary
RE: Imidacloprid Wars   Gary A. Beluzo
  Mar 15, 2007 05:31 PST 
Here is an analogy to help think through this imidacloprid discussion.



Pharmaceuticals are given to people despite the fact that MANY are
potentially toxic to the body (and the trick is to keep the drug above the
effective dose (ED50) but below the lethal dose (LD50). The liver and other
organs metabolize the drug. Think specifically about chemotherapy. There
are many chemotherapies which have short-term toxicity to the body (and that
is why they kill cancer cells) but unless they are mutagenic or carcinogenic
the body recovers afterwards.



I think the analogy may be appropriate here. If the imidacloprid
"pharmaceutical" is biodegradable within a relatively short period of time,
if it doesn't biomagnify/bioaccumulate up the food chain, and if the
metabolic byproducts are innoculous then the short term toxicity to the
adlegid may outweigh any short-term risk to the ecosystem. I'll try to get
some ecotoxicology data on the chemical.



Gary
RE: Imidacloprid Wars   Gary A. Beluzo
  Mar 15, 2007 05:35 PST 

Brandon,

Can you please give us a synopsis of the toxicology and ecotoxicology of
Xytect? Are the application levels of the chemical for HWA below the LD50
for most test organisms?

Gary
RE: Imidacloprid Wars   edward coyle
  Mar 15, 2007 06:23 PST 

Hi All,

Sapsuckers DO eat sap as a primary source of food. They also eat insects
stuck in the sap, as well as capturing them apart from sap. It is
interesting that they often dip their prey in sap before consumption.
Their favorite tree species are Yellow and Paper birch. Second order trees
would be linden, maple, cherry, and white pine. Hemlock is likely used, but
not as a primary source.
Yellow-bellied Sapsuckers, the only type likely found in the discussion
area, make two types of feeding holes in trees. One utilizes xylem, and the
other phloem sap. The 'sap well' area can be used for up to four days before
drying up. At any given, time several trees are being used as a food source.
There is a sub-species endemic to the Appalachians.
To further complicate the issue, a whole host of animals and insects utilize
these same 'sap wells', to include several types of hummingbirds, orioles,
nuthatches, warblers, finches, squirrels, various flies and wasps.
I have included information below concerning toxicity.

Ed Coyle


TRADE OR OTHER NAMES: Imidacloprid is found in a variety of commercial
insecticides. The products Admire, Condifor, Gaucho, Premier, Premise,
Provado, and Marathon all contain imidacloprid as the active ingredient
(223).
REGULATORY STATUS: Imidacloprid is a General Use Pesticide, and is
classified by EPA as both a toxicity class II and class III agent, and must
be labeled with the signal word "Warning" or "Caution" (223). There are
tolerances for residues of imidacloprid and its metabolites on food/feed
additives ranging from 0.02 ppm in eggs, to 3.0 ppm in hops (328).

INTRODUCTION: Imidacloprid is a systemic, chloro-nicotinyl insecticide with
soil, seed and foliar uses for the control of sucking insects including rice
hoppers, aphids, thrips, whiteflies, termites, turf insects, soil insects
and some beetles. It is most commonly used on rice, cereal, maize, potatoes,
vegetables, sugar beets, fruit, cotton, hops and turf, and is especially
systemic when used as a seed or soil treatment. The chemical works by
interfering with the transmission of stimuli in the insect nervous system.
Specifically, it causes a blockage in a type of neuronal pathway
(nicotinergic) that is more abundant in insects than in warm-blooded animals
(making the chemical selectively more toxic to insects than warm-blooded
animals). This blockage leads to the accumulation of acetylcholine, an
important neurotransmitter, resulting in the insect's paralysis, and
eventually death. It is effective on contact and via stomach action (1).

Imidacloprid based insecticide formu-lations are available as dustable
powder, granular, seed dressing (flowable slurry concentrate), soluble
concentrate, suspension concentrate, and wettable powder (223). Typical
application rates range from 0.05 - 0.125 pounds/acre. These application
rates are considerably lower than older, traditionally used insecticides. It
can be phytotoxic if it is not used according to manufacturer's
specifications, and has been shown to be compatible with fungicides when
used as a seed treatment to control insect pests (329).

TOXICOLOGICAL EFFECTS

Acute Toxicity: Imidacloprid is moderately toxic. The oral dose of technical
grade imidacloprid that resulted in mortality to half of the test animals
(LD50) is 450 mg/kg body weight in rats (223), and 131 mg/kg in mice (1).
The 24-hour dermal LD50 in rats is >5,000 mg/kg. It is considered
non-irritating to eyes and skin (rabbits), and non-sensitizing to skin
(guinea pigs) (1). Some granular formulations may contain clays as inert
ingredients that may act as eye irritants. In acute inhalation toxicity
tests with rats, the airborne concentration of imidacloprid that resulted in
mortality to half of the test organisms (LC50) is > 69 mg/meters cubed air
in the form of an aerosol, and >5323 mg/meters cubed air in the form of
dust. These values represent the maximum attainable airborne concentrations
(1).
Signs and Symptoms of Poisoning: Although no account of human poisoning was
found in the literature, signs and symptoms of poisoning would be expected
to be similar to nicotinic signs and symptoms, including fatigue, twitching,
cramps, and muscle weakness including the muscles necessary for breathing
(330).
Chronic Toxicity: A 2-year feeding study in rats fed up to 1,800 ppm
resulted in a No Observable Effect Level (NOEL) of 100 ppm (5.7 mg/kg body
weight in males and 7.6 mg/kg in females). Adverse effects included
decreased body weight gain in females at 300 ppm, and increased thyroid
lesions in males at 300 ppm and females at 900 ppm. A 1-year feeding study
in dogs fed up to 2,500 ppm resulted in a NOEL of 1,250 ppm (41 mg/kg).
Adverse effects included increased cholesterol levels in the blood, and some
stress to the liver (measured by elevated liver cytochrome p-450 levels)
(331).
Reproductive Effects: A three generation reproduction study in rats fed up
to 700 ppm imidacloprid resulted in a NOEL of 100 ppm (equivalent to 8
mg/kg/day) based on decreased pup body weight observed at the 250 ppm dose
level (331).
Teratogenic Effects: A developmental toxicity study in rats given doses up
to 100 ppm by gavage on days 6 to 16 of gestation resulted in a NOEL of 30
mg/kg/day (based on skeletal abnormalities observed at the next highest dose
tested of 100 ppm) (329). In a developmental toxicity study with rabbits
given doses of imidacloprid by gavage during days 6 through 19 of gestation,
resulted in a NOEL of 24 mg/kg/day based on decreased body weight and
skeletal abnormalities observed at 72 mg/kg/day (highest dose tested) (331).
Mutagenic Effects: Imidacloprid may be weakly mutagenic. In a battery of 23
laboratory mutagenicity assays, imidacloprid tested negative for mutagenic
effects in all but two of the assays. It did test positive for causing
changes in chromosomes in human lymphocytes, as well as testing positive for
genotoxicity in Chinese hamster ovary cells (331).
Carcinogenic Effects: Imidacloprid is considered to be of minimal
carcinogenic risk, and is thus categorized by EPA as a "Group E" carcinogen
(evidence of noncarcinogenicity for humans). There were no carcinogenic
effects in a 2-year carcinogenicity study in rats fed up to 1,800 ppm
imidacloprid (328).
Organ Toxicity: In short-term feeding studies in rats, there were thyroid
lesions associated with very high doses of imidacloprid (331).
Fate in Humans and Animals: Imidacloprid is quickly and almost completely
absorbed from the gastrointestinal tract, and eliminated via urine and feces
(70-80% and 20-30%, respectively, of the 96% of the parent compound
administered within 48 hours). The most important metabolic steps include
the degradation to 6-chloronicotinic acid, a compound that acts on the
nervous system as described above. This compound may be conjugated with
glycine and eliminated, or reduced to guanidine (1).
ECOLOGICAL EFFECTS

Effects on Birds: Imidacloprid is toxic to upland game birds. The LD50 is
152 mg/kg for bobwhite quail, and 31 mg/kg in Japanese quail (223, 1). In
studies with red-winged blackbirds and brown-headed cowbirds, it was
observed that birds learned to avoid imidacloprid treated seeds after
experiencing transitory gastrointestinal distress (retching) and ataxia
(loss of coordination). It was concluded that the risk of dietary exposure
to birds via treated seeds was minimal. Based on these studies, imidacloprid
appears to have potential as a bird repellent seed treatment (332, 333).
Effects on Aquatic Organisms: The toxicity of imidacloprid to fish is
moderately low. The 96-hour LC50 of imidacloprid is 211 mg/l for rainbow
trout, 280 mg/l for carp, and 237 mg/l for golden orfe. In tests with the
aquatic invertebrate Daphnia, the 48-hour EC50 (effective concentration to
cause toxicity in 50% of the test organisms) was 85 mg/l (1). Products
containing imidacloprid may be very toxic to aquatic invertebrates.
Effects on Other Animals (Nontarget species): Imidacloprid is highly toxic
to bees if used as a foliar application, especially during flowering, but is
not considered a hazard to bees when used as a seed treatment (1).
ENVIRONMENTAL FATE

Breakdown of Chemical in Soil and Groundwater: The half-life of imidacloprid
in soil is 48-190 days, depending on the amount of ground cover (it breaks
down faster in soils with plant ground cover than in fallow soils) (334).
Organic material aging may also affect the breakdown rate of imidacloprid.
Plots treated with cow manure and allowed to age before sowing showed longer
persistence of imidacloprid in soils than in plots where the manure was more
recently applied, and not allowed to age (335). Imidacloprid is degraded
stepwise to the primary metabolite 6-chloronicotinic acid, which eventually
breaks down into carbon dioxide (336). There is generally not a high risk of
groundwater contamination with imidacloprid if used as directed. The
chemical is moderately soluble, and has moderate binding affinity to organic
materials in soils. However, there is a potential for the compound to move
through sensitive soil types including porous, gravelly, or cobbly soils,
depending on irrigation practices (337).
Breakdown of Chemical in Surface Water: The half-life in water is much
greater than 31 days at pH 5, 7 and 9. No other information was found.
Breakdown of Chemical in Vegetation: Imidacloprid penetrates the plant, and
moves from the stem to the tips of the plant. It has been tested in a
variety of application and crop types, and is metabolized following the same
pathways. The most important steps were loss of the nitro group,
hydroxylation at the imidazolidine ring, hydrolysis to 6- chloronicotinic
acid and formation of conjugates (1).
Analytical Methods: Methods are available for determining imidacloprid
residues (the 6-chloropicolyl moiety) in plant materials using HPLC with
u.v. detection (338).
PHYSICAL PROPERTIES
RE: Imidacloprid Wars   edward coyle
  Mar 15, 2007 06:39 PST 

Hi Again,

The important points below(understood by me) is that birds learn to use a
different source for food, if they sense any adverse affects, and that
Imidacloprid is already being used on food crops.
RE: Imidacloprid Wars   Gary A. Beluzo
  Mar 15, 2007 06:44 PST 

Thanks Ed, I stand corrected regarding the sap-sucking behavior. Although
the name DOES suggest that I had never actually observed in the field.

Considering the ingredients in imidacloprid (nicotinyl) perhaps we should
all start smoking around hemlock trees when we work. Incidentally it is the
chlorine atom that makes pesticides very persistent, just as CFCs persist
until they get into the stratosphere and are broken down by ultraviolet
radiation.

I wonder if a formulation with just NICOTINE would be effective (although it
may not hang around long enough to kill the adelgid without the chlorine).
Before synthetic pesticides nicotine was actually one of the more common
ingredients in natural, biodegradable pesticides.

Thank you for the toxicological data.

Gary
RE: Imidacloprid Wars   Gary A. Beluzo
  Mar 15, 2007 06:48 PST 
THAT'S interesting! Are they all clones? So..the one's that were originally
released were all female? What about the BALSAM wooly adelgid?

The shallow gene pool for hemlock trees suggests that resistance isn't very
likely in any population.

Gary

_____

From: Will Blozan 
Sent: Thursday, March 15, 2007 9:28 AM
Subject: RE: Imidacloprid Wars

Gary,

From what Lee has said, eastern hemlock resides in a shallow gene pool. The
adelgid, all clones, don't even have a pool to swim in.



Will
RE: Imidacloprid Wars   Gary A. Beluzo
  Mar 15, 2007 07:18 PST 

Ed,

Are you suggesting that birds can "sense" the presence of Imidacloprid?

Generalists will obviously have an easier time of shifting food sources but
what about any specialists (hemlock-obligate species) that need hemlock to
nest in, feed in, etc.?

Gary
RE: Imidacloprid Wars - Toxicity info    Brandon Gallagher
   Mar 15, 2007 08:06 PST 
I've attached the MSDS for Xytect 75WSP (same as MERIT 75WSP). It
includes decomposition products, toxicology, and ecological information.
If you are interested in learning more about LD50 ratings you can check
out this link. http://www.ccohs.ca/oshanswers/chemicals/ld50.html The
thing to remember is the higher the LD50 number the less toxic the
product is.

Imidacloprid (used as directed) is less toxic than many things you
encounter in life. Xytect has an LD50 oral of >4500 mg/Kg. That means
you would have to ingest 4500 mg of active ingredient for every Kg of
body weight to kill half a population of the animal you were testing on.
By comparison, you would have to ingest 50 mg/Kg of nicotine, 3000 mg/Kg
of table salt, or 2080 mg/Kg of my beloved ethanol alcohol. Other LD50
ratings can be found by doing some Google searches. It is quite
interesting to see where many of our common household products fall.

The point is not that you should be eating or drinking imidacloprid but
if used under all the guidelines required by the label the product has
minimal toxicity for people and non-target animals. Sapsuckers would
have to suck a lot of sap to get enough active ingredient to be fatal.
The toxicity to aquatic organisms is clearly stated on the label and the
MSDS. Don't get it in water! The biggest issue our sister company,
Rainbow Treecare, ever had to deal with was a broken rig hose that
sprayed MERIT into a client's koi pond!

As far as the conversation surrounding the treatment of apples or other
crops foods...read the label. The EPA allows treatment of imidacloprid
up to a week before harvest in pome fruits and up to the DAY of harvest
in grape. We did not seek agriculture labeling for Xytect (we focus on
arborists) so you cannot apply OUR product in commercial orchards or
vineyards but there are many imidacloprids out there that have ag on the
label. Ours can be used by homeowners wanting to protect their trees or
vines and want to consume the fruit.

Hopefully this was helpful.


-bg

Brandon M. Gallagher Watson
Plant Healthcare Specialist
ISA Certified Arborist MN-4086A
Re: Imidacloprid Wars   orw-@fas.harvard.edu
  Mar 15, 2007 08:14 PST 

Gary et al. there is ongoing work searching for hemlock resistance. the
citation below is a paper that was recently presented by researchers at
the University of Rhode Island, University of Massachusetts and myself
that is basically the initial protocol for such an effort:
Examine heavily hit stands, find remaining trees, take cuttings,
propagate seedlings, introduce HWA, evaluate for resistance/tolerance.
It is still too early to tell for sure, but initial work suggests that
there may indeed be resistance out there, but much more work is needed.


2007. Poster presented: 18th U.S. Department of Agriculture interagency
research forum on gypsy moth and other invasive species. Annapolis, MD
“Production and Evaluation of Eastern Hemlocks (/Tsuga canadensis/)
potentially resistant to the Hemlock Woolly Adelgid (/Adelges tsugae/)”,
with T. Caswell, R. Casagrande, E. Preisser, B. Maynard, J. Elkinton.
and D. Orwig.


There may be other research projects that are investigating this, but I
am not aware of them. thanks DAVE ORWIG
RE: Imidacloprid Wars   Andrew Joslin
  Mar 15, 2007 09:02 PST 

I think Ed is saying there is a feedback/aversion mechanism - ie: gut
discomfort = don't eat seeds from that tree anymore. It would be very
interesting to see if a Black-capped Chickadee (for instance) would
stop eating ALL hemlock cone seed or would learn not to feed on a
particular treated hemlock. The current scenario as you all know is
that Will (and hopefully others) are treating only specific trees as
a short-term holding action. Knowing that birds are exceptionally
intelligent I'd expect that hemlock feeding birds would learn quickly
to avoid a particular treated tree.

More detailed info would be helpful as to how much imidacloprid ends
up in hemlock cone seeds and other "consumable" hemlock parts
following soil injection treatment. As far as YB Sapsucker feeding
habits goes, I expect they drink more sap from the tastier hardwood
species as opposed to the conifers. The avian imidacloprid
feedback/aversion mechanism described in Eds post might be extended
to sap drinkers as well as seed eaters.

Andrew Joslin
Jamaica Pain, MA
RE: Imidacloprid Wars   Andrew Joslin
  Mar 15, 2007 09:50 PST 

Nesting Black-throated Green Warbler is often associated with
hemlock. In woods in eastern Massachusetts if you want to find a
singing BTG Warbler in breeding territory just find a hemlock grove
or individual large tree. Unfortunately I'm finding many less of
these delightful birds on breeding territory the last three years. It
was sad to find a lone male BTG Warbler singing in a decimated
hemlock grove a few seasons ago.

Andrew Joslin
Jamaica Plain, MA
RE: Imidacloprid Wars   edward coyle
  Mar 15, 2007 11:00 PST 

Gary,

In the body of Imidacloprid information it states that Red-winged Blackbirds
and Brown-headed Cowbirds will change food sources that cause them to
experience vomiting and or loss of coordination.

Ed
Re: Imidacloprid Wars    Edward Frank
   Mar 15, 2007 19:53 PST 
ENTS,

What you need to think about is what are the benefits and costs of each of the options of a) Not Treating the hemlocks, b) Treating them with Imidacloprid, and c) Other options.

In summary a) No Treatment.
a.. Almost all of the hemlocks will DIE and become EFFECTIVELY EXTINCT
b.. The species that are obligate tsugaphiles will ALL DIE
c.. Creatures that get much of their food from hemlock will need to find other sources with SOME MORTALITY. There should be no loss of species in this group
d.. Creatures that occasionally feed on hemlock will need to find other food. There should be no loss of species in this group.
e.. Creatures that she