Impacts of transgenic proteins, pollen and colony affiliation on survival and longevity of honeybee workers
P 1.1 in Ecosystem Function
The ecological and economic importance of pollination makes the honeybee a key test species in assessing possible adverse effects of genetically modified (GM) crops. Until now, no adverse effects of transgenic maize were reported for honeybees. However, new maize varieties with multiple resistances have to be tested yet. Under laboratory conditions worker bees are exposed to transgenic proteins Galanthus nivalis (snow drop) agglutinin (GNA), Cry1A.105, Cry2Ab2, Cry3Bb1 or a mixture of the three Cry-proteins to detect acute oral toxicity. In long-term survival tests honeybee workers are exposed in single or group cages to the pollen of the stacked maize variety MON89034xMON88017 to evaluate effects of transgenic proteins on survival and longevity. The results support safety assessments that have not detected any direct negative effects of Bt-crops. In contrast GNA has a significant effect on survival of worker bees at the highest concentration (1% w/v) and the estimated LD50 is in a similar range as observed in bumble bees and parasitoid wasps which should be considered in the commercialization of GNA-crops. Life expectance in single cage testing was lower than in group testing. Nevertheless, single testing appears to be more robust against colony effects.