In the beginning everything was simple. Bt maize was supposed to be just on the field, and nothing else would be affected: No organism that wasn't on the field, no organisms that would prey on maize pests. But over the years things became more complicated and now it's common knowledge that parts of the Bt plants make it off the field themselves, that predators can be affected indirectly in the food web. And still the question whether the field crop maize could also water organisms seems to be one step too far for most risk assessments.

[img_assist|nid=104|title=|desc=|link=none|align=right|width=150|height=65]Rosi-Marshal et al. (2007) just published a long overdue study about whether Bt plant residues got into headwaters during or after cultivation, and whether the Bt-toxin would have adverse effects on water insects like caddies flies, close relatives to butterflies. In both cases the answer was yes. This laboratory study gives enough indication to at least include water insects in the monitoring of Bt crops.