Home » Biotechnology »Environment »News » Currently Reading:

Bee Learning Behaviour Affected by GMO Toxin

October 21, 2008 Biotechnology, Environment, News No Comments

Jonathan Latham and Allison Wilson

Concerns over bees, especially the European honey bee (Apis mellifera) have rarely been higher. Although there are few hard data there is a general consensus that both solitary and social bee populations are declining and that recently the still-mysterious colony collapse disorder (CCD) has dramatically worsened this situation. No definitive cause for CCD has yet been established but there is widespread agreement that CCD is caused by more than one factor (Calderone, 2008 ; Oldroyd, 2007).

One of the speculated contributors to this decline is transgenic crops and specifically those containing Bt proteins since these are insect-active toxins to which bees are exposed through various routes. In particular, bee larvae are exposed since they consume large quantities of pollen which they sometimes source from maize plants (Sabugosa-Madeira et al. 2007). Up to now however there has been no specific evidence that any Bt toxin has negative effects on bees, but equally such studies have been rare. Particularly lacking are studies on sub-lethal effects of Bt toxins on bees.

In the view of many, there is clear evidence from laboratory settings that Bt toxins can affect non-target organisms. Usually, but not always, affected organisms are closely related to intended targets (reviewed in Lovei and Arpaia 2005 and Hilbeck and Schmidt 2006). Typically, exposure is through the consumption of plant parts such as pollen or plant debris or through Bt ingested by their predatory food choices. Nevertheless, due to significant data gaps, the real-world consequences of Bt transgenics remain unclear.

Thus the lepidopteran-active Cry1Ab is, not unexpectedly, toxic to some butterflies (e.g. Losey et al 1999 and Lang and Vojtech 2006) while more distantly-related organisms affected by Cry1Ab are ladybird larvae, caddisflies and Daphnia Magna (Rosi-Marshall et al 2007; Bøhn et al 2008; Schmidt et al 2008). Other variants of Bt, such as Cry3Bb, are considered coleopteran-active but have been the subject of less research. Nevertheless, these may also affect non-target coleopterans such as ladybird larvae as well as more distantly related organisms such as lacewings (Hilbeck and Schmidt 2006; Schmidt et al 2008).

A recent paper adds to the non-target story by demonstrating that honey bees fed on the active form of purified Cry1Ab protein can be affected in the learning responses necessary to associate nectar sources with odourants (Ramirez-Romero et al 2008). This learning response is important in bee foraging behaviour and it has attracted the attention of CCD researchers since it is known to be inhibited by the insecticide imidacloprid (e.g. Decourtye et al 2004). In this latest study bees consuming artificial nectar containing 5000ppb of Cry1Ab continued to respond positively to a learned odour even in the absence of a food reward, while normal bee behaviour is to become discouraged and seek more abundant food sources.

Left unstudied by the authors, however, was the likely mode of action of this behavioural effect. This is of considerable interest since the principal means of Bt lethality, which is thought to be a receptor-mediated effect on gut integrity, fails to explain the observed behavioural modification. The new finding is therefore particularly interesting since it lends weight to a previous suggestion that Bt toxins may have other, non-lethal effects which become apparent only when the normal (i.e. lethal) effect is absent (Hilbeck and Schmidt 2006; Schmidt et al. 2008). If there were to be multiple modes of Bt action then many more non-target organisms would likely be at risk from Bt transgenics.

The authors propose that bees are unlikely to be exposed to the quantity of Cry1Ab that led to the defects in behaviour they observed. However, this conclusion seems premature since Bt concentrations in plants are highly variable (Lorch and Then 2007). It is also probable that in real situations bees may be exposed earlier in their development and over longer periods. Bt Researcher Angelika Hilbeck believes that experiments simulating real-world bee experiences are still lacking. “What really needs to be looked at are combinations of both the Bt toxin AND imidacloprid and not Bt toxin OR imidacloprid, and in a form that simulates the exposure routes in the field”.

Please see the response from Dr Jack Heinemann:

http://independentsciencenews.org/wp-content/uploads/2012/03/Jack-Heinemann-Bt-letter-v3.pdf

 

References

Bøhn T., Primicerio R., Hessen D.O., Traavik T. (2008) Reduced Fitness of Daphnia magna Fed a Bt-Transgenic Maize Variety. Arch. Environ. Contam. Toxicol. 55:584-92

Decourtye A.; Armengaud C., Renouc M.; Devillers J.; Cluzeau S.; Gauthier M. and Pham-Delègue M-H. (2004) Imidacloprid impairs memory and brain metabolism in the honeybee (Apis mellifera L.). Pesticide Biochemistry and Physiology 78: 83-92

Hilbeck A. and Schmidt J.E.U. (2006) Another View on Bt Proteins – How Specific are They and What Else Might They Do? Biopestic. Int. 2: 1-50

Lang A. and Vojtech E. (2006) The effects of pollen consumption of transgenic Bt maize on the common swallowtail, Papilio machaon L. (Lepidoptera, Papilioni). Basic and Applied Ecology 7: 296-306

Lövei G.L. and Arpaia S. (2005) The impact of transgenic plants on natural enemies: a critical review of laboratory studies. Entomologia Experimentalis et Applicata 114: 1-14

Lorch A. and Then C. (2007) How much Bt toxin do MON810 plants actually Produce? www.greenpeace.de/fileadmin/gpd/user_upload/themen/gentechnik/greenpeace_bt_maize_engl.pdf

Losey J.E. Rayor L.S.; and Carter M.E. (1999)Transgenic pollen harms monarch larvae Nature 399: 214

Oldroyd B. (2007) What’s Killing American Honey Bees? PLoS Biol 5(6)

Ramirez-Romero R.; Desneux N.; Decourtye A.; Chaffiol A.; Pham-Delègue M.H. (2008)Does Cry1Ab protein affect learning performances of the honey bee Apis mellifera L. (Hymenoptera, Apidae)? Ecotoxicol Environ Saf. 70:327-33

Rosi-Marshall, E.J.; J. L. Tank; T. V. Royer; M. R. Whiles; M. Evans-White; C. Chambers; N. A. Griffiths; J. Pokelsek and M. L. Stephen (2007) Toxins in transgenic crop byproducts may affect headwater stream ecosystems. Proc Natl Acad Sci USA 104: 16204–16208

Sabugosa-Madeira B.; Abreu I.; Ribeiro H. and Cunha M. (2007) Bt transgenic maize pollen and the silent poisoning of the hive Journal of Apicultural Research 46: 57-58

Schmidt J.E.; Braun C.U.; Whitehouse L.P.; Hilbeck A. Effects of Activated Bt Transgene Products (Cry1Ab, Cry3Bb) on Immature Stages of the Ladybird Adalia bipunctata in Laboratory Ecotoxicity Testing. Arch Environ Contam Toxicol. 2008 Aug 20

Comment on this Article:

Science News on the Web

Why Independent Science News?

Scientific inventions and ideas shape the future. As science becomes ever more beset by commercial and ideological pressures, there is urgent need for scientific reporting and analysis from an independent, expert, public interest perspective. With this standard, Independent Science News works to shape a future that is biodiverse, just, and healthy for everyone.
More about us...

Sign up to our mailing list

E-mail address:
Name (optional):

Related News Articles

How “Extreme Levels” of Roundup in Food Became the Industry Norm

Can the Scientific Reputation of Pamela Ronald, Public Face of GMOs, Be Salvaged?

No Scientific Consensus on Safety of Genetically Modified Organisms

The Experiment Is on Us: Science of Animal Testing Thrown into Doubt

New Report Links Food, Climate and Agricultural Policies

Psychiatrists plead to continue funding of genetic approaches to disease

23andMe disproves its own business model

How Agriculture Can Provide Food Security Without Destroying Biodiversity

Commentaries

Edward Snowden’s Testimony to the European Parliament on NSA Spying and its Consequences

Edward Snowden Barton Gellman/Getty Images

Independent Science News has decided to reprint (1) in full the March 7th testimony of Edward Snowden to the European Parliament. Snowden’s testimony is vitally important for every citizen in every country to understand, yet it has barely been covered by the commercial or (non-commercial) global media. At stake is the …

The Health Care Doctors Forgot: Why Ordinary Food Will Be the Future of Medicine

Apple and a Pear

by T Colin Campbell, Jacob Gould Schurman Professor Emeritus, Cornell University The problem Few issues have become so intensely debated and politically charged as the need to reform the health care system. This debate has resulted in the ObamaCare program (The Affordable Care Act), which aims to expand and improve …

Fakethrough! GMOs and the Capitulation of Science Journalism

Biotechnology

by Jonathan Latham, PhD Good journalism examines its sources critically, it takes nothing at face value, places its topics in a historical context, and it values above all the public interest. Such journalism is, most people agree, essential to any equitable and open system of government. These statements about journalism …

The Founding Fables of Industrialised Agriculture

Farming in Italy

by Colin Tudge Governments these days are not content with agriculture that merely provides good food. In line with the dogma of neoliberalism they want it to contribute as much wealth as any other industry towards the grand goal of “economic growth”. High tech offers to reconcile the two ambitions …

More Commentaries...

Reviews

Biology as Ideology: The Doctrine of DNA

Biology as Ideology

Author: by Richard Lewontin ISBN: 0140232192 Publisher: Penguin books (1991) Biologists know that complex traits are typically associated with genetic variation between individuals. Nevertheless, if we hear on the news that obesity, antisocial behaviour or some other disorder has a strong genetic component, we are likely to attach special significance …

The Unsettling of America

The Unsettling of America

Author: Wendell Berry ISBN: 0871568772 Publisher: Sierra Club books (1977) In 2002, peasant associations from all over Asia organised an international scientific conference. The motivation for the conference was the fact that peasants and their leaders had no dialogue with agricultural scientists, either from their own countries or with those …

More Reviews...