Bt corn variety OK for black swallowtails The first published field study of butterflies and genetically altered corn finds no harm to black swallowtail caterpillars from a common corn variety. Losey, J.E., L.S. Rayor, and M.E. Carter.
Transgenic pollen harms monarch larvae.
Wraight, C.L. . . . Absence of toxicity of Bacillus thuringiensis pollen to black swallowtails under field conditions. Proceedings of the National Academy of Sciences . Milius, S. 1999. BT-corn pollen can kill monarchs .