[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[SANET-MG] GM crops effect on honey bees : some effect or no effect



AgBioWorld recently put out some testimony in a Congressional Committee claiming that there was no effect of Bt crops or bacteria on honey bee. I am reminded of my discussion with the editor of the British Food Journal over an article on GM sweet corn which I thought should be removed because their was evidence of fraudulent methods in opinion gathering. His reply, published in the journal proclaimed that "There is a common misconception that science is about facts"Alas, that seems to be the guiding principle of peer review in biotechnology. However, the evidence on GM crops and bees needs much more independent investigation. Nevertheless, the evidence on pesticides is clear and convincing.. The pr game has been , I believe, to focus away from the pesticide evidence to protect the corporations from liability. I keep trying to remind people that pesticides are clear threats while GM is a part of the pesticide issue. Their pr people focus on the absence of much evidence (not none) on GM crops while ignoring the pesticides. We should try to refocus the issue on the pesticides and GM as a pesticides or sources of herbicides used on resistant crops . Bee behavior modifications may be a deadly to a hive as is direct mortality. The enclosed comments and references are from my report on honey bee colony collapse "The Bacillus thuringiensis (Bt) toxin Cry1Ab caused reduced foraging activity before and after treatment with syrup containing the toxin. However,the Bt toxin produced less pronounced impacts on bee behavior than did the chemical pesticides deltamethrin or imidacloprid (18). Bt bacteria caused mortality in bees when fed in broth cultures or sugar solutions (19). A number of purified Bt Cry toxins have been studied in the laboratory to determine their toxicity to honey bees and bumble bees. For the most part, those studies showed little threat from the Cry toxins. However, sublethal effects on the bees were not recorded in the experiments (20).Transgenic glyphosate resistant canola pollen posed no threat to honey bees (21). Organic, conventional and herbicide resistant Canola were compared regarding the pollination by wild bees in Alberta, Canada. The herbicide tolerant canola plots had the greatest pollination deficit , while conventional and organic plots were equally well served by the wild bees (22). Fuller studies are needed to evaluate the impact of GM crops on sublethal effects such as learning and feeding behavior". 18. Ramirez-Romero,R,Chaufaux,J and Pham-Delègue,M. Effects of Cry1Ab protoxin, deltamethrin and imidacloprid on the foraging activity and the learning performances of the
honeybee Apis mellifera, a comparative approach Apidologie 36 (2005) 601-11
19. Hilbeck,A and Schmid,J. Another view of Bt proteins-How specific are they and what else
might they do Biopestic. Int. 2006,2,1-50
20. Malone,L and Pham-Delègue,M. Effects of transgene products on honey bees (Apis
mellifera) and bumblebees (Bombus sp.) Apidologie 2001,32,287-304
21. Huang ZY,Hanley AV,Pett WL, Langenberger M. and Duan JJ. Field and semifield evaluation of impacts of transgenic canola pollen on survival and development of worker honey bees. J
Econ Entomol. 2004 Oct;97(5):1517-23
22. Morandin,L and Winston,M. Wild bee abundance and seed production in conventional, organic and genetically modified canola Ecological Applications 2004,15,871-81

AgBioWorld, http://www.agbioworld.org April 11, 2007
Safety Assessment of Bt Crops for Adult and Larval Honeybees

- by Eric Sachs, Yong Gao and Jian Duan, Presented March 29, 2007, Public Hearing, Subcommittee on Horticulture and Organic Agriculture

Summary

--Entomologists have not been able to determine the cause of CCD (colony collapse disorder) in honey bees. While the cause is not yet clear, there is strong evidence that the production of specific insecticidal proteins from the soil bacterium Bacillus thuringiensis (Bt) in crops to control targeted caterpillar pests and beetles does not pose a risk to honeybees.

--There is extensive information on the lack of non-target effects to diverse groups of beneficial insects including honey bees and other pollinators from Bt microbial preparations that contain Bt proteins.

--Bt proteins are ideal for use in organic production and in Bt crops because they bind specifically to receptors on the mid-gut of sensitive caterpillar pests and have no deleterious effect on beneficial/non-target insects under the conditions of use, including predators and parasitoids of targeted caterpillar pests and honeybees.

--Scientists perform extensive honeybee safety assessments on all insect-protected crops, including Bt corn and Bt cotton. The Bt proteins in these crops have been shown to have no adverse effect on the honeybee.

--EPA risk assessments have demonstrated that Bt proteins expressed in Bt crops do not exhibit detrimental effects to non-target organisms in populations exposed to the levels of Bt proteins produced in plant tissues.

--Specific studies involving Cry1Ab provide strong evidence of the safety of MON 810 Bt corn to the honeybee (similar studies have been conducted with other Bt proteins in genetically modified crops). --The EPA concluded that based on the weight of evidence there are no unreasonable adverse effects of the Cry1Ab protein expressed in MON 810 Bt corn to non-target wildlife or beneficial invertebrates.
********************************************************
To unsubscribe from SANET-MG:
1- Visit http://lists.sare.org/archives/sanet-mg.html to unsubscribe or;
2- Send a message to <listserv@sare.org> from the address subscribed to the list. Type "unsubscribe sanet-mg" in the body of the message.

Visit the SANET-MG archives at: http://lists.sare.org/archives/sanet-mg.html.
Questions? Visit http://www.sare.org/about/sanetFAQ.htm.
For more information on grants and other resources available through the SARE program, please visit http://www.sare.org.