Thursday, February 18, 2016

Where’s the Buzz? Reason for Honeybees’ Population Decline

The honeybee, Apis mellifera, is responsible for the pollination of flowering plants that make up roughly one third of the human diet (1).  In total, the honeybee makes $200 billion worth of food globally (2).  As important as these insects are, the honeybee populations are slowly dying off.  However, there is not one clear cut answer as to what is causing the bee decline but there is a lot of buzz surrounding the problem.  The first suspect is lack of flowers due to urbanization and destruction of natural habitat (1).  Bees are able to adapt by searching for other types of flowers, but it can also lead them to gravitate toward flowers with pesticides or diseases (1). In a similar vein, climate change is also a contributor to the death of bees preferred flowers and disease caused by parasites because warmer temperatures are allowing them to thrive (1). 
A varroa mite attached to the back of the honeybee
Source: 1
The varroa mite, a parasitic mite, is an increasing problem for the bees (3). The mite attaches itself to the adult bee and feeds on the host’s blood, thus making the host weak and susceptible to disease (3).  Bee keepers turned to a low dose of pesticides to help the fight against the mites, but bee keepers risk killing the bee.  Extensive research has been performed to breed queen bees with a grooming behavior in hopes the bees will be able to remove the mites themselves (3).  However, the challenge remains in keeping the self-grooming from mating with normal bees and reversing the progress made (3). Although progress is being made to help the bees continue the fight against the varroa mite, it still remains a huge problem for  beekeepers and hives alike.
The final suspect is a specific type of pesticides called the neonicotinoids.  These pesticides are known to linger in the environment and grow with the plant that it coats.  In doing so, bees carry the nectar laced with the neonicotinoids back to the hive.  The neonicotinoids have sickened both the hive and the queen bee which exert serious detrimental effects (4).  The queen bee is responsible for reproduction in the hive but neonicotinoids have caused queens to produce less offspring and are overall weaker than a normal queen, according to a recent research article published by Nature (4).  Due to the effects of neonicotinoids, two years ago, European Union banned the use of these pesticides to curb the declining bee population (5).  Recent studies in the European Union have suggested neonicotinoids are not the sole cause of the decreasing bee population because the hive compensates for the loss by producing more offspring (5).  

A farmer sprays the crops with a pesticide
Source: 1
In addition, the United States’ EPA also found inconclusive research that neonicotinoids are the primary reason due to some hives being greatly affected but did not affect other hives (2).In the United States, neonicotinoid use is not banned, despite public outcry (1). The European Union as of 2015 lifted their ban on the pesticide for an emergency application on oilseed rape crops but still regulated by the EU commission (5).  Although both the United States and European Union want to help the bee population, inconclusive evidence and pressure from the agricultural industry are permitting the use of the pesticide.
    With several different reasons being brought to the table, it is tremendously difficult to pin down a sole reason for the decline.  Issues such as climate change and loss of habitat are on-going problems which both people and bees are combating against.  Parasites are another reason that are killing the honeybees.  Pesticides pose a significant problem because its use leads to weaker queens and hive.  Despite this, research is inconclusive in whether or not the neonicotinoid use is the cause. Both policy makers and researchers around the globe are fervently working together to save the bees by banning pesticides and carefully breeding stronger queens.  After all, the symbiotic relationship with the bees is valuable and deserves to be protected.

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