Bt Toxin and Imidacloprid from ‘Lethal Trees’

Forestry Tasmania has denied the use of GM trees that might be responsible for toxic scum and water found in North East Tasmania.

In August 2009, Forestry published an article on it’s website called ‘Some Trees Can be Lethal!’ (1)and how right they were.

The article discusses a method of producing more pest-resistant trees by injecting them with an insecticide. 1% of trees in a plantation would be injected to entice insects away from other trees.

The doctor responsible for the programme, Dr Jane Elek, has published a number of papers investigating the use of a biotoxin tocontrol specific pests on Eucalyptus, including Eucalyptus nitens plantations (2,3).

This particular biotoxin, Bacillus thuringiensis, or Bt, is a genetically modified endotoxin and is commonly added to GM crops around the world.

In the document titled, ‘Implementation of Tasmania Regional Forest Agreement 2002 -2007’, 4 Novodor, one of Bt’s trade names is mentioned as being useful for controlling autumn gum moth. This
article suggests Bt is already being used in Tasmania. Bacillus thuringiensis can colonise crops and pass into the soil and waterways through root exudates. (5,6).

It can alter ecosystems in a number of ways by poisoning freshwater mussels (7), altering soil microbes (8,9), affecting non-target insects (10), including butterflies (11) and altering plant herbivore interactions (12). It can also be passed directly on to future generations (10). Trees genetically modified with Bt, breakdown less easily than non-Bt plants(13).

Insects can become resistant to Bt toxin (14), as they can with any pesticide, so it is yet another unsustainable move by industry that will ultimately create more problems than it solves.

Forestry’s interest in this toxin suggests that it intends to use it, if it has not done so already. By using, or intending to use a genetically modified organism to control crops, it could be breaching Tasmania’s strict GM laws.

To be sure, the matter requires further investigation. Bt is a possible suspect in the search for toxins responsible for toxic scum and water in the North East of the state.

Another article called ‘Testing the efficacy of Lethal Trap Trees’ (15), published online by the Cooperative Research Centre for Forestry, in March 2009, mentions injecting trees with imidacloprid pesticide.
This pesticide is a neurotoxin and was banned in France in 1999 for almost wiping out bee populations 17. It contaminates waterways (18), is very toxic to certain species of birds (19) and can cause eggshell thinning (21) in the same way DDT did.

It could be another source of toxins in the North East of the state.

Forestry’s article, ‘Some Trees can be Lethal!’ claims that injecting trees with insecticide is its chosen method of pest control, because it is cost effective, more socially acceptable and environmentally
responsible.

What methods were used to establish these claims?

Have the public been widely consulted to establish if they find it an acceptable choice of pest management? How many people in the general public are aware of this activity, or are in a position to judge the future health and environmental impacts of this experimental technology?

What happened to participatory planning models and environmental justice?

References:

1) Elek, J., (2009), Some Trees Can be Lethal, Branchline; News from Forestry Tasmania, Forestry Tasmania, 24 August, 2009, available online from:
http://www.forestrytas.com.au/branchline/branchlineaugust-24-2009/ (cited 01/03/10)
2) Elek, J. A. and Beveridge, N. (1999) Effect of a Bacillus thuringiensis subsp. tenebrionis insecticidal spray on the mortality, feeding and development rates of larval Tasmanian eucalyptus leaf beetles (Coleoptera: Chrysomelidae). The Journal of Economic Entomology 92, 1062-1071
3) Beveridge, N and Elek, J.A. (2001). Insect and host tree species influence the effectiveness of a Bacillus thuringiensis subsp. tenebrionis based insecticide for controlling chrysomelid leafbeetles. Australian Journal of Entomology, 40, 386-390.
4) Department of Infrastructure, Energy and Resources, Tasmanian Government, (2002), Implementation of Tasmanian Regional Forest Agreement 2002-2007, (DIER)
5) Saxena, D., Flores, S., Stotzky, G., (2002), Bt toxin is released in root exudates from 12 transgenic corn hybrids representing three transformation events, Soil Biology and Biochemistry, 34, 133-137
6) Douville, M., Gagne, F., Blaise, C., Andre, C., (2006), Occurrence and persistence of Bacillus thuringiensis (Bt) and transgenic Bt corn cry1Ab gene from an aquatic environment, Ecotoxicology and Environmental Safety, 66, 195-203
7) Douville, M, Gagne, F., Andre, C., Blaise, C., (2009), Occurrence of the transgenic corn cry1Ab gene in freshwater mussles (Elliptio complanata) near corn fields: Evidence of exposure by bacterial ingestion, Ecotoxicology and Environmental Safety, 72, 17-25
8) Icoz, I., Stotzky, G, Fate and effects of insect-resistant Bt crops in soil ecosystems, (2007), Soil Biology & Biochemistry, 20, 559-586
9) Griffiths, B., Caul, S., Thompson, J, Birch, N., Cortet, J., Anderson, M., Krogh, P., (2007), Microbial and microfaunal community structure in cropping systems with genetically modified plants, Pedobiologia, 51, 195-206
10) Zhang, G., Wan, F., Loveri, G., Liu, W., Guo, J., (2006), Transmission of Bt toxin to the predator, Propylaea japonica (Coleoptera: Coccinellidae) through its aphid prey feeding on transgenic Bt cotton, Environmental Entomology, 35, 143- 150
11) Hansen Jesse, LC., Obrycki, JJ., (2000), Field deposition of Bt transgenic corn pollen: lethal effects on the monarch butterfly, Oceologia, 125, 241-248 12) Hjalten, J., Lindau, A., Wennstrom, A., Blomberg, P., Witzell, J., Hurry, V., Ericson, L., (2007), Unintentional changes of defence traits in GM trees can influence plantherbivore interactions, Basic and Applied Ecology, 8, 434-443
13) Flores, S., Saxena, D., Stotsky, G., (2004), Transgenic Bt plants decompose less in soil than non-Bt plants, Soil Biology & Biochemistry, 37, 1073-1082 14) Tabashink, B., Cushing, N., Finson, N., Johnson, M., (1990), Field development of resistance to Bacillus thuringiensis in diamondback moth (Lepidoptera: Plutellidae), Journal of Economic Entomology, 83, 1671-1676
15) Elek, J., (2009), Testing the Efficacy of Lethal Trap Trees, BioBuzz, Cooperative Research Centre for Forestry, Issue 8, available online at:
http://www.crcforestry.com.au/newsletters/biobuzz/biobuzz8.html (cited 01/03/10)
16) Benjamin, A., (2008), Soil Association Urges Ban on Pesticides to Halt Bee Deaths, The Guardian, UK, Monday September 2008, available online
17) Fossen, M., (2006), Environmental Fate of Imidacloprid, Department of Pesticide Reculation, CA, US, April 2006, available online at:
www.cdpr.ca.gov/docs/emon/pubs/fatememo/Imidclprdfate2.pdfc (cited 01/03/10)
18) Berny, P., Buronfosse, F., Videmann, B., Buronfosse, T., (1996), evaluation of the toxicity of imidacloprid in wild birds. a new high performance thin layer chromatography (hptlc) method for the analysis of liver and crop samples in suspected poisoning cases, Journal of Liquid Chromatography & Related Technologies, 22, 1574-1559
19) United States Environmental Protection Agengy (1994), Pesticide fact sheet: Imidacloprid., Office of Pesticide Programs, Washington, D.C., Mar. 18, 1994

Malini Alexander is 27; with an undergraduate degree in chemistry and mathematics and a Master of Environmental and Business Management. He has lived and worked in India for 3.5 years on a number of environmental projects in rural areas: “Through this I gained experience in traditional Indian sustainable practices. My special interests are toxicology, (pesticides, waste management, toxic chemicals in industry), Indian medicinal plants and ecological anthropology.”