Good question. There's no work on phenotypic selection, or the selection of a characteristic in order to produce bees that tolerate pesticides. I've never seen this.
However, we've observed that it's very difficult to keep bees in a strongly agricultural region, such as Montérégie, and in a region where a great deal of corn is found.
I'm not necessarily saying that pesticides are the reason. The reason is a lack of flora biodiversity.