But we're also talking about hundreds of benign species of lepidopteran that feed adjacent to those cornfields, on the native flora. The Nature publication had an international effect. It prompted the European Union to freeze the approval process for one type of Bt corn. Several strains have already been approved. Some countries objected - and reacted by banning importation and planting.
Bt corn is a hot political issue.
The study raised interest and concern, but it also inspired a great deal of criticism, on several counts. And any time pesticides are tested, they're tested in the laboratory first. The paper didn't state specific amounts of pollen used, which made it difficult for others to replicate the study. But I may not have the results, because I really can't define exactly what the dose was. The researchers contend they were simply trying to see if a dusting of Bt pollen would kill monarch larvae.