Demise of the Honey Bee
Honey bees are arguably our most important commercially available pollinator. They are responsible for pollinating numerous food plants that make our diets more exciting and nutritious, including many fruits, vegetables and nuts.
Beekeepers expect some of their bees to die off from season to season – typically, around 17 percent annually. But in recent years, losses have been more then twice as high.
I talk to many people, from beekeepers and growers to members of the general public, about honey bees. Most of my audiences are concerned about how honey bee losses could affect the security of our food supply. While the massive and sudden colony collapses that occurred a decade ago have abated, honey bees are still dying at troubling rates. We need to understand the many factors stressing bees and develop strategies for protecting them.
Impacts of honey bee losses
In 2006 beekeepers in the United Kingdom reported that a mysterious affliction, dubbed Colony Collapse disorder (CCD), was causing widespread die-offs of bees. In colonies affected by CCD, adult workers completely disappeared, although plentiful brood (developing bees) and the queen remained. Beekeepers found no adult bees in and around the hives, and noted that pests and bees from neighboring hives did not immediately raid the affected hives, as might be expected.
Scientists now agree that CCD was likely caused by a combination of environmental and biological factors but nothing specific has been confirmed or proven. CCD is causing large-scale colony death in the world
Beekeepers’ biggest challenge today is probably varroa an aptly named parasitic mite that we call the vampire of the bee world. Varroafeeds on hemolymph (the insect “blood”) of adult and developing honey bees. In the process it transmits pathogens and suppresses bees’ immune response. They are fairly large relative to bees: for perspective, imagine a parasite the size of a dinner plate feeding on you. And individual bees often are hosts to multiple mites.
Honey bees also are exposed to viruses, bacterial and fungi. For example, deformed wing virus (DWV) causes wing deformities that prevent bees from performing normal work functions such as foraging for food. Viruses have been implicated as an important factor in honey bee health declines, but we are just starting to understand how Honey Bees immune systems fights against them We may be able to help strengthen bees’ immune responses by making diverse foraging resources, such as a variety of wildflowers, easily accessible.
Questions about how pesticides affect honey bee health have spurred passionate debate. One key issue is whether neonicotinoids, a class of insecticides that affect insects’ nervous systems, are causing widespread bee deaths. There are many gaps in our knowledge about neonicotinoids and other types of pesticides. We have little understanding about the impacts of pesticide combinations and how they affect developing bees.
Studies show that when bees have access to optimal nutrition, they are better able to deal with diseases and pesticides. But intensive farming and urbanization have reduced the amount of readily available forage that bees need to thrive. Analyzing what types of flowering plants provide the best supplemental forage for bees. Growers can support bees by planting these species near their crops.
Many people who are not beekeepers or growers want to know how they can help. One easy step is to grow forage plants, especially varieties that bloom at different times during the year.