Science Policy For All

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To bee or not to bee: Protecting pollinators through national action

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By: Lynn Mirigian, PhD

One in every three bites of food we take can be attributed to the work of a honeybee, or less often, to another pollinator. Apples, almonds, avocados, and strawberries are just a few crops that require pollinators, but pollinator populations are seriously declining. The 70 billion dollar global (USA-15 billion) crop industry that is fueled by pollinators is being threatened by dwindling pollinator populations.1, 2 In addition, loss of pollinators may pose public health risks. In developing nations, for example, it is hypothesized that a decrease in pollinators could lead to an increase in Vitamin A deficiency which could double the risk of mortality from malaria, measles, and diarrhea.3 Because of the serious economic and public health consequences of pollinator population collapse, an inter-agency task force directed by President Obama has announced the National Strategy to Promote the Health of Honey Bees and Other Pollinators.

Honey bee colonies were first introduced to the US in the early 1600’s and are now commercialized. There are between 2,000-3,000 professional US beekeepers employed for both pollination services and to support honey production.1 In addition to honey bees, 4,000 wild bee species, as well as butterflies, bats, birds, and other animals function as pollinators in the US.4 Numerous species of bees live alone in isolation, but many key pollinators exist as a superorganism in a colony. The colony is supported by a queen, who mates with ~20 reproductive drones early in life to provide a lifetime supply of sperm, and the queen lays all of the eggs the colony needs for up to 4 years. The vast majority of bees produced in the colony are worker bees, following a career trajectory of hive and brood maintenance then foraging duties. Foraging bees collect pollen and nectar as a protein and carbohydrate source, respectively. Attracted to brightly colored flowers, bees travel from flower to flower, collecting food but also transferring pollen to facilitate plant reproduction (i.e. fruit formation). Colony success and survival is predicated on all members collectively working together. Over the past 3 decades, honey bee populations have dwindled for reasons only partially understood.

One challenge to healthy bee populations is habitat loss and reduced availability of diverse foraging and nesting resources. These problems likely arise from increased pesticide usage. Insecticides and herbicides are commonly used in commercial agriculture and are highly toxic to pollinators, such as honey bees. Herbicides can be harmful for bees’ survival, by killing valuable “weeds” that are both potential nesting sites and valuable food sources that improve pollen diversity necessary for bee health and proper nutrition. Besides herbicide usage, habitat transformation can also cause malnutrition, which affects gene expression in worker bees,5 and increases lethality to pesticides.6 Since specifics behind the ideal honey bee habitat and nutrition remain unknown, implementing large scale changes and policy is not yet realistic. Experiments are ongoing to determine whether buffer zones between commercial agriculture fields and bee colonies or planting tailored seed mixes to improve habitat will positively affect bee colony success.

Most relevant to honey bees, neonicotinoids are a class of insecticides used on rapeseed, which is used to make canola oil. Although neonicotinoids are coated onto seeds in an attempt to eliminate direct contact with pollinators, they can still affect bees in two ways. The insecticide dust created during planting kills the bee immediately upon exposure, and small amounts of the toxin remain in the nectar and pollen of the mature rapeseed plant. The toxicity of these trace amounts of neonicotinoids on bees has been hotly contested, demonstrating the need for further research. Research suggests that even small amounts of neonicotinoids can impact a bee’s brain function and prevent them from foraging well or being able to return home,7 however scientists still do not understand how much insecticide bees actually ingest and how often they are exposed to these chemicals in their native environments. In the absence of a more complete picture of bees’ experiences in their natural habitats, it is difficult to propose bee-safe farming insecticide practices.

Besides pesticide use and habitat transformation, arthropod pests, pathogens, and colony collapse disorder (CCD) represent additional factors underlie recent reductions in bee numbers. The Varroa destructor mite feeds on honeybee blood (hemolymph), grows its young on developing bees, and can increase bees’ susceptibility to viruses. As a potential protective mechanism, some bees possess a behavioral trait (varroa sensitive hygiene) that drives them search out and cannibalize developing bees that have been infected with the young mites. Breeding for this trait is an avenue of research currently being pursued. A large problem in preventing the spread of pests and pathogens is that most bee colonies travel throughout different parts of the US. For example, 60-70% of all commercial bee colonies are relocated to almond orchards every spring, a large majority of which are in California.8 So many bee colonies in one place can lead to disease spread, compounded by the fact that wild bees can also become infected.9 Finally, CCD, a syndrome in which there is a rapid loss of adult worker bees not attributed to parasite or disease, has claimed numerous bee colonies in the past few years. While CCD is still not well understood, the proportion of losses due to the disorder has been reducing each year.

The multiple causes of honey bee decline are addressed in the National Strategy to Promote the Health of Honey Bees and Other Pollinators. This strategy recommends a 34 million dollar budget increase in 2016 from 2015. Pertaining to the honey bee, the plan’s goals are to “Reduce honey bee colony losses during winter to no more than 15% within 10 years” and “Restore or enhance 7 million acres of land for pollinators over the next 5 years through Federal actions and public-private partnerships.” To achieve those goals the task force proposes the following:

  • The Pollinator Research Action Plan
  • The Pollinator Best Practice Management Guidelines for Federal Building and Designed and Natural Landscapes
  • The National Seed Strategy for Rehabilitation and Restoration
  • A public outreach and education strategy

Previous strategies to address honeybee decline have been ongoing since 2007 and have seen little success, as made evident by the continued decline of the honeybee population. This National Strategy hopes to achieve what other programs have failed to do by expanding past plans, collaborating between multiple federal agencies and the private sector, and by supporting numerous research initiatives to determine the precise reasons for declining bee numbers by making evidence-based recommendations for how to restore pollinator populations.

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Written by sciencepolicyforall

May 27, 2015 at 9:12 am

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  1. […] Source: To bee or not to bee: Protecting pollinators through national action | Science Policy For All […]


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