Yes, monoculture is currently causing problems for bees. Since only one type of pollen is being brought back to the hive, there is a pollen shortage.
If I were to draw a parallel with humans, it's as if you were to eat cereal every day. At some point, you would run out of various nutrients. The same thing is true for bees. That is why biodiversity and crop biodiversity is essential.
Yes, this can cause problems for bees. Furthermore, when we talk about genetic modification, the problem is often that flowers that have been genetically modified no longer need to be pollinated by bees. So, they no longer hold any appeal or attraction for the bees, who will then not go and seek out their nectar. So, without nectar there is no honey.
When we use genetically-modified seeds, usually, it's to ensure less traffic in the fields and less soil compaction. However, we realize that yields are lower than they were previously. So if yields are lower, we need to grow crops on a larger area.
If we are talking about biofuels, the same thing holds true. We are currently producing corn, not to feed human beings or livestock but rather to produce fuel. Why are we experiencing a food crisis? We want to be able to produce biofuels, but we can no longer feed people. The question needs to be asked. Just how far can we go? When we introduce genetically-modified seeds and seeds coated with pesticides, we are directly and adversely affecting beekeeping in the short term. In the intermediate and long term, we still don't know how this will affect human beings. We see the prevalence of cancers; perhaps we need to start exploring those areas.
Numerous pesticides are banned or prohibited in Europe. Yet, in Canada, we are starting to approve them. Perhaps we need to ask the PNRA why we are approving products that have been banned elsewhere. We are somewhat behind certain other countries.