Field deposition of Bt transgenic corn pollen: lethal effects on the monarch butterfly
Authors: Hansen-Jesse, L.C., Obrycki, J.J.
Journal, Volume, Year: Oecologia, volume 125:241-248, 2000
More thorough study of the effects of pollen containing the toxin from Bt var kurstaki on monarch larvae. This study used leaf discs from plants placed within and near corn fields to provide realistic pollen deposition rates. They found a significant increase in mortality in treatments with Bt corn pollen over treatments without pollen or with non-Bt pollen. No sub-lethal effects were found. The authors predict the possibility of effects up to 10 m from field borders.
Quantified toxin in pollen using ELISA. Did not calculate an LD50. Higher pollen deposition was observed for Bt than in non-Bt treatments. The pollen that caused toxicity came from event 176, which has been taken off the market.