The researchers were interested in the effect of GM-wheat on fly larvae that decompose plant residues in the soil and so are involved in maintaining the soil fertility. Aphids were also chosen for study as they feed almost exclusively on plant sap and so are sensitive indicators for the food quality of the fodder plant.

Fly larvae: Important for soil fertility

Studies on fly larvae have been carried out by scientists at the Institute of Ecology and Evolution of the University of Bern. They fed larvae of two species of flies occurring in Switzerland with leaves from six different genetically modified wheat varieties. For comparison, larvae were also fed exclusively on six conventional strains of wheat. The researchers observed the development and the reproduction of the flies emerging from these larvae over four generations to see if there were any long-term effects. The different food sources had no effect on the fitness of any of the animals in any case.

Aphids: Sensitive indicators

A similar approach was chosen by the researchers at the Institute of Evolutionary Biology and Environmental Sciences at the University of Zurich in collaboration with the Research Station ART (Agroscope Reckenholz-Tänikon) for their project on aphids. In environmental chambers, 30 different aphid colonies were fed with eight different wheat species, four of which were genetically modified lines. The mortality, weight and fertility of the animals were recorded. All the measured parameters for all the differently fed aphids were comparable. No effects due to the genetic modifications were seen.