Bt corn pollen debate
"Lincoln P. Brower" <brower@sbc.edu>
Lincoln.
From: Lincoln P. Brower
To: Scientific Advisory Committee
Office of Pesticide Programs
Environmental Protection Agency
122 Pennsylvania Avenue, NW
Washington, D.C. 20460
14 November 2000
Edited statements made by Dr. Lincoln P. Brower to the 19 October 2000 EPA meeting to the FIFRA Scientific Advisory
Panel in Arlington, VA in regard to the possible negative impact of genetically modified Bt corn pollen on the monarch
butterfly.
Thank you for allowing me to present a commentary on the EPA's deliberations about unanticipated potential adverse sideeffects of Bt corn pollen on the monarch butterfly. My name is Lincoln P. Brower. I am Research Professor of Biology at
Sweet Briar College, and Distinguished Service Professor of Zoology, Emeritus, University of Florida. My credentials
include a B.A. in Biology from Princeton University (1953) and a Ph.D. in Zoology from Yale University (1957). Over the
past 45 years, I have studied and published on numerous aspects of monarch butterfly ecology, chemical ecology,
physiology and behavior. I have followed the Bt corn pollen issue since before the publication of the Losey, Rayor and
Carter (1999) paper in May 1999, and I attended the Agricultural Biotechnology Stewardship Working Group scientists'
symposium in Chicago on 2 November 1999 (reviews in Yoon, 1999; Ferber, 1999). Dr. Myron P. Zalucki of the
University of Queensland, Brisbane, Australia also attended the meeting and we subsequently reviewed what we perceived
to be serious scientific deficiencies in the data and interpretations and recommended several research avenues that need
definitive study in order to make informed judgments on assessing the impact (if any) of Bt corn pollen on the monarch
butterfly (Brower and Zalucki, 1999). One of the purposes of the 19 October 2000 EPA FIFRA Scientific Advisory Panel
(SAP) open meeting was to review the currently available information on the possible negative effects of Bt corn pollen on
non-target species,especially the monarch butterfly, Danaus plexippus L., Lepidoptera, Danainae. This review is being
done so that EPA can make an informed and up-to-date scientific decision on whether or not to reliscence the use of these
GMO (genetically modified organism) corn plants for widespread agricultural planting. I have read and here cite several
documents that were distributed prior to
this EPA - SAP open meeting in Arlington VA, 18-20 October 2000. These documents included the following statements:
i)
"Based on the review of the submitted DCI data, the Agency concludes that the published preliminary monarch
toxicity information is not sufficient to cause undue concern of harmful widespread effects to monarch butterflies
at this time...." (Vaituzis and Rose, 2000, p. 53).
ii)
"The Agency concludes that continued cultivation of Bt corn is not sufficient to cause undue concern of harmful
widespread effects to monarch butterflies at this time (Anon,. 2000a., Question 2, p, 17).
Dr. Zalucki has critiqued a revised version of this statement and is in agreement with it. What follows is the reasoning
behind my scientific opinion that the above two preliminary conclusions are premature, and so, therefore, is the reliscencing
of Bt corn.
Major critique number one: unacceptability of the data base. I submit that the current EPA information base is
insufficient as a source of scientific data and extrapolations upon which EPA can make an informed and responsible
decision on this issue. Reasons for judging the EPA decision
as premature are as follows:
i)
The ABSTCMTF (i.e. the "Agricultural Biotechnology Stewardship Technical Committee Monarch Task Force")
document (Anon., 2000b) that represents Dow, Monsanto, Mycogen Seeds, Novartis, etc) appears to be the main
source of information upon which the EPA's review summary (Vaituzis
ii)
and Rose, 2000) was based. This document contains approximately 40 deletions of "proprietary" data purportedly
made available by outside scientists, companies and/or consultants carrying out various impact research or
modeling studies. The conclusions in paragraph 3 on page 7 are as follows: "Overall, considerations of milkweed
distribution, the frequency distribution (density over distance) of off-field corn pollen deposition on milkweeds,
toxicity of various types of Bt corn pollen, temporal overlap of pollen shed and monarch larval stages, and
oviposition and larval feeding patterns indicate that the probability for adverse effects on non-target lepidopteran
larvae from Bt corn is very low". The wording of several points in the Vaituzis and Rose (l.c.)EPA document are
virtual direct quotes from this task force document. Since the data for these studies do not exist in the public
realm, it was simply impossible for the 19 October EPA panel or any independent scientists to judge the merits of
the data.
iii)
The Vaituzis and Rose EPA document does not include the results of several field and laboratory studies that were
carried out in the summer of 2000, most of which were specifically funded by the US government and the biotech
companies for the specific purpose of addressing the issues.
iv)
Numerous older studies in the scientific literature that directly bear on questioning the validity of the arguments
contained in the task force and EPA documents purporting to show minimal effects of Bt corn pollen on the
monarch butterfly are ignored (see, for example the cardenolide fingerprinting studies of , Cockrell et al., 1993 and
Malcolm et al. 1989, 1993). These two publications showed definitively that Asclepias syriaca which grows
across the corn belt in the United States is the larval foodplant of more than 90% of the monarch butterflies that
migrate to Mexico.
v)
A major sophisticated study published by Wassenaar and Hobson (1999) in the Proceedings of the U.S. National
Academy of Sciences was effectively rejected for not having been performed for more than one field season.
These authors' data indicated that the majority of the summer breeding habitat of the monarch butterfly in eastern
North America virtually coincides with the area of major corn production in the USA. Taken together with the
above two cardenolide fingerprinting studies, playing down the importance of the Wassenaar and Hobson study is
unreasonable because the three independent studies resoundingly substantiate each other.
Major critique number two: ignoring new data. Based on statements read by EPA Pesticide Officer Dr. Zigfridas
Vaituzis at the 19 October 2000 meeting, it is evident that EPA has not factored in data showing that certain of the critical
assumptions upon which EPA made its decisions are without doubt simply incorrect. These include:
i)
The summer 2000 discovery by Dr. Karen Oberhauser and associates (University of Minnesota), and apparently by
other researchers as well, that extensive monarch butterfly breeding occurs within cornfields. This obviates the
best arguments that the pollen-drift modelers put forward in 1999 and early 2000 for minimal impact, based on
quantitative considerations of the newly documented short distance that most corn pollen drifts from the fields.
For example, the Wold (2000) document that was circulated by EPA prior to this meeting was a well done study.
However, the study's conclusions of minimal impact based on short distance pollen drift are nulled by the
biological reality that extensive breeding occurs within corn fields The EPA, in effect, was hoisted by its own
petard with this finding.
ii)
The EPA has chosen to ignore both substantive historical data (summary in Brower, 1995, 1999b) and the results
of current phenology data that show extensive temporal and geographic overlap of corn pollen shedding and
monarch butterfly breeding
iii)
The EPA document and the conclusions stated by Dr. Vaituzis at this meeting hold to assessments of pollen
concentrations on milkweed leaves that have apparently been shown to be incorrect by research carried out in the
summer of 2000.
iv)
New data presented by Dr. Oberhauser at the October 19, 2000 meeting indicate that there are serious effects on
later instar larvae of the Bt pollen.
Major criticism number three: failure of peer review of the data base. EPA 's (Vaituzis and Rose, 2000) apparent
reliance on data provided in the industry document (Anon., 2000b) is unacceptable because there is no indication or
evidence that completed scientific articles were peer reviewed by scholarly, international scientific journals before being
accepted as valid data by EPA. Peer review, or some equivalent review process, is a sine qua non for the integrity of
science.
Major criticism number four: undermining of good science. The proponents of Bt corn have attacked and belittled two
peer-reviewed scientific articles providing evidence that Bt corn pollen can poison monarch larvae while simultaneously
touting unpublished findings purporting to show no or minimal effects of the pollen. Particularly vituperative attacks on
the original Losey et al. (1999) study were made in the press (Anon., 1999; Beringer, 1999; Ferber, 1999; Yoon, 1999;
review in Brower, 1999a) as well as at the 8 December 1999 EPA hearing by a public commentator representing Novartis,
Inc. This pattern continued at the current hearing when EPA panel member Dr. Mark Sears vehemently criticized the peer
reviewed paper by Jesse and Obrycki (2000) that demonstrated toxic effects of the pollen under experimental field
conditions. While aspects of these criticisms may be correct and parts of or all of the published studies may be flawed, at
least they are OPEN to scientific scrutiny. Examples of unbalanced assessments of the scientific findings are in press
reviews of the study by
Wraight et al. (2000) that found no measurable effect of one Bt corn event on Black swallowtail butterfly larvae. However
a concluding remark in the same study stated that another Bt event had proven highly toxic to the larvae. Information
released to the press on this paper again touted the lack of effect of one corn event while ignoring the effect of the other
which was stated to be highly toxic.
Conclusions
1) Relying on the information released by EPA prior to this meeting does not allow a balanced and objective assessment
of the potential threat of Bt corn pollen to the monarch butterfly.
2) EPA is accepting information, most of which has not been subjected to the internationally required standards of peer
review.
3) EPA seems to be contributing to the undermining of scientific credibility by allowing itself to be unduly influenced by
Companyinformation and misinformation.
4) EPA is contributing to the politicization of the regulatory process on the Bt corn pollen / monarch butterfly issue.
5) Overall, the EPA review of this potential Bt corn problem is flawed and hence the conclusions lack credibility.
Overall, the process of reviewing the potential effects of Bt corn pollen on the monarch butterfly has been frighteningly
devoid of scholarship.
.
In summary, I conclude that the EPA's (Vaituzis and Rose, 2000, p. 53) conclusion that there is insufficient evidence of
negative effects of Bt corn pollen on monarch butterfly larvae to justify withholding the repermitting of Bt corn planting is,
at best, premature. It is a subjective judgement based largely on absent, incomplete, and, in some instances, incorrect data
and erroneous inferences. Crawley's (1999) call for rationality in the GMO debate needs to be heeded by EPA, industry,
scientists and the public.
Bibliography
Anon. (1999). Bt corn: environmental safety and a recent report on the monarch butterfly.
WWW.monsanto.com/monsanto/mediacenter /background/99may19_Monarch.html. pp. 1-2.
Anon. (2000a). October 18-20, 2000 FIFRA SAP Meeting: Bt Plant Pesticides Risk and Benefits Assessment. EPA
Document, distributed prior to the SAP meeting, pp. 1-21.
Anon. (2000b). Response to EPA's Data Call-In Notice Concerning the Potential for Adverse Effects of Bt Corn on Nontarget Lepidopterans. ABSTC (Agricultural Biotechnology Stewardship Technical Committee) Monarch Task Force and
Jellinek, Schwartz and Connolly, Inc. Performing Laboratory, 21 March 2000, pp. 1-55.
Beringer, J.E. (1999). Cautionary tale on safety of GM crops. Nature, 399, 405. Brower, L.P. (1995). Understanding and
misunderstanding the migration of the monarch butterfly (Nymphalidae) in North America: 1857-1995. Journal of the
Lepidopterists' Society, 49, 304-385.
Brower, L.P. (1999a). Will biotechnology doom the monarch? Defenders (The Conservation Magazine of Defenders of
Wildlife), 79, 39-41.
Brower, L.P. (1999b). Para comprehendar la migracion de la mariposa monarca (1857-1995). Instituto Nacional de
Ecologîa, Mexico, D.F., pp. 1-141.
Brower, L.P., & Zalucki, M.P. (1999). Bt corn and its effects on monarch butterflies: a note of caution. Monarch News, 10,
1, 4-5.
Cockrell, B.J., Malcolm, S.B., & Brower, L.P. (1993). Time, temperature, and latitudinal constraints on the annual
recolonization of eastern North America by the monarch butterfly. Biology and Conservation of the Monarch Butterfly, (ed.
by S. B. Malcolm and M. P. Zalucki) pp. 233-251, Publications of the Los Angeles County Museum of Natural History,
Los Angeles.
Crawley, M.J. (1999). Bollworms, genes and ecologists. Nature, 400, 501-502.
Ferber, D. (1999). News focus: GM crops in the cross hairs. Science, 286, 1662-1668.
Green, E. 2000. Monarchs fluttering through world of new perils. Los Angeles Times, 19 October 2000, pp. B2 (Science
File).
Jesse, L.C.H., & Obrycki, J.J. (2000). Field deposition of Bt transgenic corn pollen: lethal effects on the monarch butterfly.
Oecologia.
Losey, J.E., Rayor, L.S., & Carter, M.E. (1999). Transgenic pollen harms monarch larvae. Nature, 399, 214.
Malcolm, S.B., Cockrell, B.J., & Brower, L.P. (1989). Cardenolide fingerprint of monarch butterflies reared on common
milkweed, Asclepias syriaca L. Journal of Chemical Ecology, 15, 819-853.
Malcolm, S.B., Cockrell, B.J., & Brower, L.P. (1993). Spring recolonization of eastern North America by the monarch
butterfly: successive brood or single sweep migration? Biology and Conservation of the Monarch Butterfly, (ed. by S. B.
Malcolm and M. P. Zalucki) pp. 253-267, Natural History Museum of Los Angeles County, Los Angeles.
Marks, A. 1999. US poised for a biotech food fight. Christian Science Monitor, Wednesday, 17 November 1999, pp. 1, 4.
Wassenaar, L.I., & Hobson, K.A. (1999). Natal origins of migratory monarch butterflies at wintering colonies in Mexico:
new isotopic evidence. Proceedings of the National Academy of Sciences USA, 95, 15436-15439.
Wolt, J.D. (2000). Non-target exposure and risk assessment for environmental dispersal of Event 176 maize pollen. Report
from Dow AgroSciences LLC, Indianapolis, 26 January 2000, pp. 1-49.
Wraight, C.L., Zangerl, A.R., Carroll, M.J., & Berenbaum, M.R. (2000). Absence of toxicity of Bt pollen to black
swallowtails under field conditions. Proceedings of the National Academy of Sciences, May 2000...,
Yoon, C.K. 1999b. No consensus on the effects of altered corn on butterflies. New York Times, 4 November 1999, Section
A, p. 16.
Vaituzis, Z., & Rose, R. (2000). Review of data on the impact of non-target organism for crops conditionally registered by
EPA that express Bacillus thurigiensis Cry proteins for the purpose of reassessing their adequacy for continued registration.
Memorandum, United States Environmental Protection Agency, Signed 9/6/00, to Mike Mendelsohn, Regulatory Action
Leader,
OPP/BPPD/MPB (7511C), pp 1-65.
Professor Lincoln P. Brower - Research Professor of Biology
Sweet Briar College
Sweet Briar, VA 24595
(Distinguished Service Professor of Zoology Emeritus, University of Florida)
Telephone: Office: 804-277-5065 or 5655