Author: Sudhir Rani
To bee, or not to bee. Unfortunately, that’s not the question. The question is: what is killing entire colonies of bees? Recent articles in the New York Times, NPR, PBS and others have highlighted the mysterious mass disappearance and death of millions of honey bees. (http://www.nytimes.com/2013/03/29/science/earth/soaring-bee-deaths-in-2012-sound-alarm-on-malady.html?pagewanted=2&_r=0)
As a kid, everything I knew about bees had to do with honey and trying not to get stung at pool parties. But now that I have worked with TerViva on oilseed crops, it’s hard to overestimate the importance of bees to the human ecosystem. According to the USDA, honey bees pollinate over 100 crops, flowers, nuts, fruits and vegetables, representing nearly 33% of all food items we eat annually–directly or indirectly.
The problem is that bees are disappearing and dying on a massive scale. There has been a major escalation of Colony Collapse Disorder (CCD), in which bee hives are found deserted with no sign of what happened to the bees, resulting in a 50-70% loss of bees in the hive. Typically, only the queen bee and a few nurse bees remain in the CCD-affected hive. Thousands of worker bees normally occupying the hive are gone. There are many theories as to what is causing CCD (climate change, monoculture farming, mites, stress, pesticides, etc). USDA’s Animal and Plant Health Inspection Service (APHIS) says that “numerous causes for CCD have been proposed, but it now seems clear that no single factor alone is responsible for the malady.”
But there is something else going on here. There have recently been a large amount of dead adult bees found in and around hives, which may or may not be related to CCD. These bees are found with abnormally high levels of neonicotinoids pesticides. For example, in Germany there was an incident (May 2008) where bees were inadvertently exposed to a pesticide used in corn. Corn is typically planted before canola blooming attracts bees. But early rains delayed the corn planting that year, which meant that the seeds were sown later than usual, when nearby canola crops were in bloom and bees were present. This caused massive bee deaths. In the US, these pesticides are typically applied directly to a corn seed, which should theoretically not affect bees; but farmers discovered that harvesting corn releases pesticide-filled dust, which carries to nearby fields where honey bees are foraging.
But it is not clear that CCD, which is the disappearance of large numbers of bees from a hive, and recent high levels of honey bee deaths are linked or have the same cause. Neonicotinoids have been used since the 90s, but CCD has only become an issue in the past seven years. Maybe the effects of pathogens took decades to manifest; or maybe the worker bees finally got fed up of the queen bee’s demands and bounced. The point is, we don’t know. More research is needed to fully understand CCD. So let’s focus on what we do know, which is that certain pesticides are harmful to bees. Some industry players are taking steps to address that problem, replacing powdered pesticides with a sticky alternative that reduces the likelihood of pesticides becoming airborne. Let’s hope that new techniques such as this will start to reverse the startling decline in bee populations while continuing to meet pressing agricultural needs.