Overcollecting big time!

[MCCORKLE, DAVID - Natural Science]

                                                                        Feb. 27, 2000

Mr. Bill Funk, Natural Resources
USDA Forest Service, Pacific Northwest Region
P.O. Box 3623
Portland, OR 97208-3623

Dear Mr. Funk:

I write in objection to the tussock moth spray program of over one 
half million acres planned for Oregon and Washington this year, 
and especially in objection to the use of Btk spray, documented to 
have serious impact on a broad spectrum of lepidoptera species 
(Miller, 1990).  I have done research on the ecology of several 
species of forest lepidoptera, principally on Mitoura spinetorum and 
M. johnsoni, lycaenid butterflies whose larvae help contain 
infestations of various species of dwarf mistletoes (Arceuthobium) 
(McCorkle, 1973).  Mitoura spinetorum is widespread in the 
proposed spray area and is likely to be in the larval stage from May 
to August depending on the elevation.  For instance, I recorded it in 
the larval stage at Canyon Meadows in the Malheur N.F. 
(T15S,R33E) as follows:  May 25 and July 9 on Arceuthobium 
americanum infesting Pinus contorta, July 9 on A. douglasii on 
Pseudotsuga Menziesii (Douglas Fir), July 6 on A. laricis on Larix 
occidentalis, and Aug 21 (probably a second brood) on A. 
camplylopodum on Pinus ponderosa, these dates on various years. 
 There are also various moth species whose larvae feed on 
Arceuthobium, for instance, the microlepidopteran Dasypga 
alternosquamella, which would likely be affected by a Btk spraying.

In the absence of quantitative data on the reduced wood fiber 
production caused by an increase in dwarf mistletoe infestation due 
to the destruction of the insects that feed on it by an insecticidal 
spraying, I suppose it would be hard to calculate the significance of 
this factor in determining the degree of economic advantage of your 
spray program.  But it is surely real, and therefore an error in your 
calculations.  Remember too, that dwarf mistletoe infestations may 
have a much extended impact compared to a normal tussock moth 
outbreak, and affect more species of conifers than does the 
tussock moth.

Due to the chaotic nature of population fluctuations, I suppose it is 
difficult to know the precise causes of any particular tussock moth 
outbreak.  However, because it is a native species well integrated 
into the ecology of our forests, it seems reasonable to assume that 
this natural phenomenon has a function, at least some aspects of 
which could be viewed as positive from a human's perspective.  For 
instance, is this a natural way of selecting against genetically 
inferior tree stock?  Is it a functional way of altering the biotic 
components of ecosystems in shifting ecotone zones?  (Such as 
with global warming?)  If certain tree species are stressed during 
certain weather regimes and are destined to perish, to what extent 
do defoliators such as the tussock moth diminish the danger or at 
least the intensity of forest fires?  And, of course, there is the 
abundance of food provided to insectivores during outbreaks.  
<Apparently, even coho salmon benefit, at least with adult 
budworm moths, as winds carry them offshore and deposit them on 
the ocean surface (Dr. Paul Hammond, OSU Entomology Dept., 
personal communication).>

There are many other lepidoptera species severely vulnerable to 
Btk spraying as documented by Miller's work cited above.  This 
can have consequences of both diminished abundance and 
biodiversity.  Presumably, the ecosystem will become even less 
stable as a result, especially if such spraying is a long term policy. 
 Perhaps the loss of biodiversity could be minimized by providing 
spray refugia.  In this sense, the long term health of the forest 
ecosystem would be better served by the area not sprayed rather 
than by the area sprayed!  Thus it would seem reasonable to set 
aside at least one section of each township, to be selected on the 
basis of the degree of biodiversity present.  (John Hinchliff's atlases 
of butterfly distribution in Oregon and Washington, and the data 
base upon which they were made, would be helpful here.  It should 
be noted that the data on which they are based are contributed 
largely by amateur COLLECTORS.)  Such refugia would, obviously, 
also harbor the spray program target species which could then, in 
time, reinvade the sprayed areas along with the non-target species. 
 However, if environmental conditions have changed meanwhile, 
this may not be at outbreak proportions, and the species could 
resume its normal forest ecosytem role.  If, indeed, a new outbreak 
wave results, at least the pesticide companies involved could again 
realize a profit on their investments.  

On another aspect, how is it that "commercial take" of lepidoptera  
has been approved in Washington State?  The impact on 
lepidopteran wildlife of the proposed spray program, which is for 
commercial purposes, will be profound beyond belief!  At the same 
time, apparently the Washington Wildlife Department has a policy 
of denying permits for commercial collecting of insect.  If they have 
not nor do not issue a take permit for your operation, it may be that 
you will be liable for lawsuit.  Should it be that it is reasoned that 
because the killed insects are not sold for profit and, therefore, you 
are not subject to permitting requirements, the policy would be a 
mockery of common sense, if not of reality!  Would that there were 
a commercial industry in lepidoptera specimen sales that 
outweighed the commercial loss of woodfiber production as a 
consequence of not spraying.  The ecosystem would be saved! 

Please reconsider your spray program plans.  At least minimize 
the use of any broad spectrum lepidopteracide such as Btk, 
especially in areas of high biodiversity that could serve as refugia.  
If such areas are not identifiable in all townships, err on the side of 
caution for now and instate a program of survey collecting that will 
be useful in the long term.  And, above all, at least monitor the 
impact of whatever you do on non-target species.  Dr. Jeffery Miller 
informs me that he is ready and willing to further his research in 
this regard if funding is available.  

Thank you for this opportunity for input.

Sincerely,


David V. McCorkle, Ph.D.
Professor Emeritus of Biology
Western Oregon University  

References:
Miller, Jefferey C.  Field Assessment of the Effects of a Microbial 
Pest Control Agent on Nontarget Lepidoptera.  The American 
Entomologist, 36:135-139, Summer, 1990.

McCorkle, David V.  Final Report, Forest Service Contract No. 19-
157, Nov. 1973.  (Abstract enclosed.)