Effects on non-target organisms
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18 Projects on 2 pages
Research Projects
Research into the impact of Bt maize (Cry 3Bb1) on non-target organisms living in the soil
(2005 – 2008) Biological Research Centre for Agriculture and Forestry (BBA) (since 2008 Julius Kühn Institute (JKI)), Institute for Plant Protection in Field Crops and Grassland; Braunschweig
Labratory Cry3Bb1 Bt protein in maize plant litter did not affect the development of sciarid fly larvae in tested amounts of up to 16.45 micrograms per gram.
A significant reduction in offspring production was observed in the rove beetle Atheta coriaria after it had consumed sciarid fly larvae that had been reared on MON88017 Bt maize litter.
Field trial MON88017 Bt maize litter did not take longer to decompose in the field than maize litter from non-Bt varieties. Neither was the diversity of two-winged flies (dipterans) affected.
Research Projects
Research into side-effects of Bt maize (Cry3Bb1) on non-target organisms
(2005 – 2008) Biological Research Centre for Agriculture and Forestry (BBA) (since 2008 Julius Kühn Institute (JKI)), Institute for Biological Control, Darmstadt
Leaf beetles are related to the Western corn rootworm, which is targeted by the Bt maize variety being studied in this project (MON 88017).
Young larval stages in particular of three of the leaf beetle species studied were found to be sensitive to pure Cry3Bb1 protein on their food plants. The mortality rate was higher; weight gain and pupation rates were lower.
By contrast, when maize pollen was fed to two species of leaf beetle larvae, no negative effects on larval mortality, weight gain or pupation rate were observed.
Acute damage to the species investigated is unlikely under field conditions, since the amount of toxin ingested via the pollen is probably a lot less than the calculated LD50 dose.
Neither were any indications of possible chronic toxicity or sublethal damage found as a result of ingesting pollen from MON88017 maize.
Research Projects
Impacts of the cultivation of Diabrotica-resistant Bt maize on the maize ecosystem
(2005 – 2008) RWTH Aachen University, Institute of Environmental Research (Biology V) Chair of Ecology, Ecotoxicology and Ecochemistry
In the field trial a comparison of the feeding activity of the soil fauna in the various maize variants - MON88017 Bt maize, the isogenic variety and two other conventional varieties – found no differences. A comparison of the feeding activity on different types of bait in one maize variant (isogenic) found variety-specific differences in some years.
In mesocosms (model field system, soil cores, diameter 30 cm, height 40 cm) no difference in feeding activity was found between the different maize varieties.
Ground beetles: No differences in ground beetle numbers or species spectrum were found between the various maize variants.
The level of Bt protein decreased by at least a factor of 20 along the food chain (maize – European corn borer – ground beetle).
Biotests did not find any acute Bt effect on ground beetles.
Research Projects
Effects of the cultivation of Diabrotica-resistant Bt maize on the maize ecosystem II
(2005 – 2008) RWTH Aachen University, Institute of Environmental Research (Biology V), Chair of Environmental Biology and Chemodynamics
Varietal differences were found among the insects in the herbaceous layer and among the pollen feeders and flower visitors, but no Bt effect was found. Fluctuations were attributed to differences in soil and weather conditions. There were also fluctuations from year to year.
Research Projects
Effects of Cry3Bb1 on the Theridion impressum spider
(2005 – 2008) Agroscope Reckenholz-Tänikon ART research station, Zurich, Switzerland
Laboratory and field studies show that the brown comb-footed spider absorbs Bt toxin through its prey. Lower concentrations (than in their prey) indicate that the toxin is broken down and eliminated and does not accumulate in the spider. Preliminary laboratory trials with prey fed on Bt maize showed no negative effects on survival or reproduction of the spiders.
Research Projects
(2005 – 2008) Institute for Biodiversity - Experts Network, Regensburg
A large number of nematodes were found in the soil samples – two to four million per square metre. No significant differences were seen in the composition of the communities in terms of feeding types or diversity between the different maize varieties. Nematode biotest: No Bt effect was measured in the soil samples. This is attributed to the fact that the concentration in the soil never exceeded 1 ng/g dry weight of soil. In the laboratory, an effect was first measured concentrations above 36 mg/L; i.e., the concentration in the soil was far below the concentration that can produce an observable effect on the nematodes. In addition, no differences in nematode growth were found in tests with different leaf samples.
Research Projects
Monitoring the effects of Bt maize (Cry1Ab) on non-target organisms
(2005 – 2007) Federal Biological Research Centre for Agriculture and Forestry (BBA) (since 2008 Julius Kühn Institute (JKI)), Institute for Integrated Plant Protection, Kleinmachnow
Varietal differences were found among the insects in the herbaceous layer and among the pollen feeders and flower visitors, but no Bt effect was found. Fluctuations were attributed to differences in soil and weather conditions. There were also fluctuations from year to year.
Research Projects
Bt maize: Effects on soil organisms – a Swiss field study
(2005 – 2006) The Zoological Institute, University of Bern, Switzerland
Overall, no significant differences were found either in the number of soil-dwelling decomposers or in the breakdown of the leaf material between the different maize varieties. There were no preferences for individual maize varieties, i.e. the varieties are comparable in terms of their nutritional quality.
Research Projects
Safety research project: Environmental effects of Bt gene
(2000 – 2004) Bavarian State Research Center for Agriculture, Freising
The cultivation of Bt maize has been shown to have no negative effects on beneficial insects (earthworms, springtails, aphids, cicadas, parasitic wasps, lacewings, hover fly larvae, ladybirds, predatory bugs and spiders). It was noticed that there were shifts in occurrence of some groups in Bt maize fields. However, these shifts did not always occur consistently during the trial period. Application of an insecticide had a clear negative effect on various species.
Butterflies: In the laboratory, maize pollen from Bt176 varieties was found to have an adverse effect on caterpillars, but this has not been replicated in field trials, where no adverse effects have yet been found.
Research Projects
Effects of Bt maize cultivation on various arthropods found in maize fields
(2001 – 2004) RWTH Aachen University, Institute of Environmental Research (Biology V) Chair of Ecology, Ecotoxicology, Ecochemistry
Analyses give no indication that Bt maize has any effect on the frequency and species diversity of non-target organisms. However, the sprayed insecticide was found to have a clear effect on some insect groups.
Butterflies in associate farmland flora: No differences were found between the Bt variant and the isogenic control in any of the three trial years. However, significantly fewer caterpillars were recorded on their fodder plants in the plots which had been treated with insecticide.
Research Projects
Effect of Bt pollen on butterflies
(2001 – 2003)
Diamond-black, cabbage white and young peacock caterpillars presented higher mortality rates, ate less and grew more slowly in feeding experiments with Bt pollen (Bt176) compared with untreated control insects, showing varying levels of sensitivity. Older caterpillars are less sensitive than younger ones.
By contrast, cutworms (caterpillars that pupate in the soil) were scarcely affected by ingesting Bt pollen.
Mon810 pollen has a very low Bt toxin content. With Mon810-pollen no damage was found on the most sensitive species, the diamond-back moth, even with 80 pollen grains per caterpillar.
Research Projects
Investigating the influence of Bt maize on aphids and their specialized antagonists
(2001 – 2004) University of Göttingen, Institute of Plant Pathology and Plant Protection, Agricultural Entomology section
Laboratory: Research into the developmental stages of aphids: No differences were found between the individual maize variants.
Tent trials: The transgenic maize strains were not found to have any effect on the parasitization activity of the parasitoids (parasitic wasps as aphid antagonists) in the tent trial. Nor was any impact detected on the composition of parasitic wasp populations.
Field: The transgenic maize varieties studied were not found to have any effect on the population development of the aphids, but varietal differences were found.
Research Projects
Effects of Bt maize pollen on the honeybee
(2001 – 2004) Jena University, Institute of Nutrition and Environment
Laboratory: Feeding bees with pollen containing up to 100 times the concentration of the toxin found in Bt maize pollen produced no effects. Feeding experiments with larvae did not produce any effects either.
Field: In tent-like enclosures, bee colonies were fed Bt maize pollen with up to 10 times the normal toxin concentration. No negative effects were observed. There were no differences in the number of bees, foraging and brood care activity or hatching weight compared with bee colonies fed on non-Bt maize pollen.
A chance parasitic infestation (microsporidia) caused more significant damage to the Bt-fed colonies. The mechanism behind this was not discovered.
Research Projects
Toxicity of Bt maize for parasitic waps
(2001 – 2004) Federal Biological Research Centre for Agriculture and Forestry (BBA), Institute for Biological Control; Darmstadt
Trichogramma parasitic wasps are natural antagonists of the European corn borer and so are also used as a means of control.
Feeding trials: Research into the toxic effects of various Bt maize plant parts on Trichogramma showed no significant negative effects on parasitization or life span.
Field trials were not carried out because the laboratory experiments showed no significant effects.
Research Projects
Effects of Bt maize on butterflies and their antagonists
(2001 – 2004) Max Planck Institute (MPI) for Chemical Ecology, Department of Biochemistry, Jena
When damaged by caterpillar grazing, maize plants emit volatile substances (scents) which attract the caterpillars’ antagonists (parasitoids). In this way the plant defends itself indirectly against the insects that feed on it. This interaction between plant, caterpillar and parasitoid could be affected by altered scent emissions in Bt maize.
There were no qualitative differences in field and laboratory tests between the scents emitted by the different pairs of maize varieties (transgenic/non-transgenic).
Normal varietal differences are far greater than the difference between Bt maize and its parent variety.
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