Honey bees need to collect nectar and pollen from blossoms. However, researchers at the University of California and the University of Sussex have now discovered that flowers can indirectly become a source of danger for honey bees. Parasites such as Nosema apis or Nosema ceranae can settle in quite comfortably between the petals and then lie in wait for worker bees. Infested bees then carry the parasites to other flowers that become an intermediate stop. “We can say that it is likely that heavily visited flowers may become more laden with parasites”, states Peter Graystock, postdoctoral researcher in the Department of Etymology at the University of California and leading author of the study.
But infested worker bees not only transmit the pathogens from blossom to blossom – they also carry them back to their hive, where they become a threat to the whole colonies’ health: Nosema for example causes diarrhea. Graystock particularly points out the danger posed by commercial honey bee colonies, as they additionally increase the spread of parasites. He recommends strict control as a countermeasure. In addition to honey bees, wild bees and bumble bees are also threatened by parasites such as Crithidia bombi or Apicystis bombi. These were also found in blossoms.
The problem worsens in places where fewer plants are growing as each blossom can harbor even more parasites. “Planting more flowers would provide bees with more options, and parasite density may thus be reduced”, explains Graystock. He is now investigating what different types of flowers contribute to the survival and development of honey bees. He also wants to find out how useful microorganisms might also use the flowers as a transfer station to find their way into a beehive.
You can find the report on AG Professional here.
You can also read an article on Scientific Blogging 2.0