Is it a Virus? Navigating the theories behind Colony Collapse Disorder

To some, it is not pesticides or fungicides, but rather viruses, and in particular the Israeli Acute Paralytic Virus, that play an important role in Colony Collapse Disorder (CCD). How is one to plot a course around all these differing opinions?

In this age where an abundance of information is at our fingertips, it is easy to give in to a natural desire to jump to conclusions when it comes to suggesting the causes of  Colony Collapse Disorder (CCD).  CCD  is a complex synergistic phenomenon where a number of factors have been identified as contributing to the decline of the bee colonies.  On this point everyone in the scientific community agrees, says Renee Johnson, specialist in agricultural policy for the Congressional Research Service.   As part of my research to date, I have focused on pesticides, in particular neonicotinoids, that, lacing the pollen, end up being stored in the hive, and on fungicides that wreak their havoc in the heart of the hive,  destroying the bee’s intestinal flora.   Among the other factors identified as playing a role in CCD are viruses.

Viruses behave in a similar manner whether they infect bees or humans.  According to Beeologics, an international firm that focuses on protecting bees from viruses, viruses will infect the host in a variety of manners: through varroa mite bites, through the alimentary track during feeding, or through trauma on the body.  They will spread throughout the colony either horizontally — from bee to bee, from fecal matter or infested food –, or vertically — from the queen to her eggs.  Just as in humans, viruses will strike a colony more effectively when it is weakened by stressors such as overcrowding, lack of forage diversity, pesticide-laden pollen, or the reduced genetic pool of the queen bees.  Furthermore, bad flying conditions that relegate the bees to their hive and lead them to defecate in the hive also have an effect on the spread of disease.

Honeybee with deformed wings-- Courtesy of Klaas de Gelder/ Flickr Creative Commons

Among the many viruses that affect honey bees, the Israeli Acute Paralysis Virus (IAPV) has been given particular attention across scientific disciplines.  Given how bees and humans transmit viruses in similar ways, there has been, according to  Science News article, ” Virus Implicated in Colony Collapse Disorder in Bees,” a  “profound synergy within the [research] group bringing together entomology, microbiology, and bio-informatics.”  Closely related to the Acute Bee Paralysis Virus, IAPV, transmitted by varroa mites, is, as Beeologics points out on its website, “the most consistent  indicator of Colony Collapse Disorder.”  First identified in Israel in 2004, IAPV, as science reporter Roxanne Khamsi points out in a News scientist article, causes “bees to develop shivering wings and eventually become paralyzed, leading to death just outside the hive.”   The U.S. strain of IAPV is distinct from the Israeli one and seems to be rapidly changing and spreading throughout the U.S.

Beeologics is very involved in researching this virus.   In a phone interview on November 8, 2011, Eyal Ben-Chanoch, CEO of Beeologics, discussed the experiment his researchers had conducted  on hives to ascertain the role of IAPV in CCD:  “we were able to show in controlled trial that when we inoculate healthy hives with the virus, we get similar symptoms to CCD.  It’s not necessarily a one to one [cause and effect] because other things can do it too, but we showed that when you inoculate the virus into a healthy bee hive after very short period you get CCD-like symptoms.”

Even though the results of this scientific experiment point to the very important  role of IAPV in the decline of honey bee colonies, Ben-Chanoch stressed that this is only one small step in understanding the nuances of the issue.   In discussing the spread of the virus among bees, he underscored the complexities involved in studying infectious diseases: “[The spread of infectious diseases] is not well understood in any infectious disease.  Again, it is science in progress, but if somebody will tell you that they know, they just make statements that are irresponsible.”

Jeff Pettis, Research leader for the United States Department of Agriculture speaks about IAPV and underscores the fact that the findings concerning the correlation between IAPV and CCD are not conclusive:

In my October 27 post, I highlighted the conviction of some people in the industry that pesticides, in particular neonicotinoids, played, without a doubt, a crucial role in CCD.  Today, my research led me to viruses and in particular to IAPV which, in the view of researchers at Beeologics, for instance, play a salient role in CCD.

How are we to navigate amidst so many firm convictions?

Professor Donald Steinkraus, entomologist at the University of Arkansas, stresses the need to distinguish between speculation and science when reporting on potential causes of CCD. He hearkens back, in a phone interview with me on November 8, 2011, to the basic experimentation principles of Louis Pasteur, and in particular to the importance of testing hypotheses on randomized samples.  As a scientist he does not like to speculate:

As we continue to explore the factors possibly contributing to CCD, Donald Steinkraus reminds us that science is not a discipline of rapid solutions driven solely by passion but rather a field driven by hypotheses, data, and patient analysis.