I asked him why there were fewer bees this year, because the past years, I have observed that even all the many millions of thyme flowers in my garden are almost entirely without bees. There where simply not many, really just a few coming to collect nectar. The beekeeper, far from being an environmental apostle, explained that especially many indigenous plants have disappeared. He assumes that the reason of it is the use of pesticides. He then mentioned additionally "also these indigenous flowers are replaced by cultured flowers. These flowers are indeed beautiful to look at but useless for bees."
Until recently, the evidence was inconclusive on the cause of the mysterious “colony collapse disorder” (CCD) that threatens the future of beekeeping worldwide. But three new studies point an accusing finger at a culprit that many have suspected all along, a class of pesticides known as neonicotinoids. Neonics are absorbed by the plants’ vascular system and contaminate the pollen and nectar that bees encounter on their rounds. They are a nerve poison that disorient their insect victims.
Numerous scientists believe that exposure to toxic pesticides is only one factor that has led to the decline of honey bees in recent years. The destruction and fragmentation of bee habitats, as a result of land development and the spread of mono-culture agriculture, deprives pollinators of their diverse natural food supply. This has already led to the extinction of a number of wild bee species. The planting of genetically modified organism crops – some of which now contain toxic insecticides within their genetic structure – may also be responsible for poisoning bees and weakening their immune systems.
Meanwhile, entire armies of people in Peoples Republic of China pollinating flowers manually because there are no more bees anymore...
here is more about this on Mother Jones