My own personal guess? No conspiracy just major mistakes which have cost us many a native to North America only asset such as the Chestnut Blight. In the Appalachians before logging had really took off there were six foot plus diameter Chestnut Trees. What happened? Someone brought in the non native Chinese Chestnut which carried the blight it was resistant too. The Chestnuts roasting over an open fire are likely Chinese grown here. The American trees are making a very slow comeback.
I believe the Bee issue will eventually also be traced back to importing what was not native to this region.
Seems to me when you introduce a killer plant to a population that can't tell the difference you're going to run into problems.
It also seems to me that the people who do these things know what will happen.