Many people ask me about honeybee health and Colony Collapse Disorder, or CCD. So how are the bees?
Colony Collapse Disorder (CCD)
Around the winter of 2006, a beekeeper in Pennsylvania named David Hackenberg reported losses of many of his hives in what was since named Colony Collapse Disorder. Since then, he became a major proponent of protecting the delicate pollinators and opposing various possible culprits. But what are those culprits? That depends on who you ask.
Before we proceed: Checkov’s Gun – Lack of Genetic Diversity
The preamble to the whole episode lies in how bees were cultivated and domesticated, the culprits being the beekeepers themselves. Beekeepers always wanted to have the best bee-genetics possible – bees that produce lots of honey, are gentle and docile, will not have strong swarming urge, and will not rob honey from other colonies. All but the last one were answered by careful selection of Italian Honeybees (apis mellifera ligustica, for those who like Latin).
Beekeepers would get their queen from a queen breeder ,who would typically use eggs from an artificially inseminated “breeder queen” to make new queens. Those breeder queens were carefully selected from lines that had the above-mentioned characteristics, thus reducing the genetic diversity of the population. Furthermore, honeybees are an introduced species to North America, meaning that all there is here are bees we (humans) artificially brought over, there are no feral, natural bees to diverse the gene pool.
When all is well – resources are plenty, no threatening diseases, no environmental pressure – species do not need much genetic diversity to survive. Some species resort to asexual reproduction under these conditions, but once stress is introduced, they revert to sexual reproduction which offers a much better diversity and chances of finding the gene combination that has the best chances of survival (yeast is an example of such species with two modes of reproduction, depending on environmental factors). When everything was fine, the lack of genetic diversity that we created within the bees was not an issue. Then the problems introduced themselves and we paid for our past sins.
Along cAme CCD
The loaded gun from the first act came in the form of mysterious disappearing colonies in alarming numbers. It is characterized by an apparently healthy hive, which then over a short period of time is discovered to have very few bees, some brood, honey, and an apparently healthy queen. The colonies in this condition were doomed and died shortly after. Where did the workers go and why – that was the big question. Bees are stubborn creatures – when questioned they refused to disclose the reason for the disappearance. Interrogating them at Guantanamo under threat of waterboarding provided no further information. We had to find the answer ourselves, there were many theories, each environmentalist accused their favorite environmental pet-peeve, among those:
- Cellphone radiation
- Genetically modified crops
- Bees monoculture, i.e. everyone are using the same breed of bees
- Crops monoculture, i.e. huge fields full of the same crop
- Migratory pollination, i.e. hauling beehives from one place to another
- Insecticides, mainly neonicotinoids
- Various bee diseases, especially nosema
- Various bee parasites, especially varroa mites
As various factors were eliminated, the consensus settled on the issue being combination of the effect of a bee parasite called varroa mite and a complex set of circumstances. If you want a full description of one of these explanation read this post by Matan Shelomi, a gifted entomologist. I should comment here that Dr. Noah Wilson-Rich, a Bost0n-based bee scientist, has made a very keen observation that about every eighteen months there’s a new and supposedly final conclusion as to the reason behind CCD, which holds true until the next one comes six months later. Truth be told that it’s a complicated problem that is beyond my grasp.
What are Varroa Mites and what are they doing to the bees?
Varroa Mites or Varroa Destructor are small red/brown bee parasite. They originate in Primorsky Krai, an area in Far-Eastern Russia, on the shores of the Sea of Japan, bordering China and North Korea. They are about 1.5-2mm in size (about 1/16 inch), they reproduce on the bees’ larva and feed on the bees hemolymph (bees’ “blood”). In the process they weaken the bees (making them more susceptible to disease) and directly infect them with various viruses (e.g. deformed wing virus and Israeli acute paralysis virus).
Varroa mites were rather uncommon, but they gradually spread throughout the world, arriving in the US around the late 80s. These days they are found virtually in each and every hive in the country. Beekeepers do not try to keep their hives varroa-free, as that is unrealistic, but rather try to minimize their numbers through various means (from essential oils to screened bottom-boards to harsh medication). The most promising directions are growing queens with varroa-resistant traits, the two most note-worthy efforts being the Russian queens project and Minnesota hygienic Italian queens developed by the wonderful Dr Marla Spivak (of whom I only heard and haven’t met).
The Russian queens are bees brought from Primorsky Krai, under the assumption that as they lived with the varroa mites the longest, they have developed evolutionary means to deal with them. The Minnesota hygienic Italian queens is a project to develop hygienic traits among Italian queens, such that will make them open cells to check for varroa mites and get rid of them.
In the meantime, every beekeeper in the country has seen varroa mites in their hives. There is a lot of research as to their connection to CCD and other bee diseases as well as how to deal with them. It would appear that varroa mites have wrecked havoc on feral western honeybee population, in many parts of the world the feral bees were pushed almost to extinction and these were only supported by the occasional domesticated bee swarm.
What are Neonicotinoids and what are they doing to the bees?
Neonicotinoids, or neonics for short, are a relatively new class of insecticides used in plants to protect them from insects.
Old insecticides that we know from the past, e.g. organophosphates, were relatively short-lived. They were sprayed on the plant and provided short-term protection from insects. If it was used after the plant no longer bloomed, they were unlikely to affect pollinators (e.g. honeybees).
Neonics are different. They are systemic (affect insects that digest them, not by contact), they are very long lived, and they are absorbed by the plants to which they are fed, spreading to all the plant’s parts, growing with the plant and affecting any creature that digests portions of the plants, mostly insects (but yes, we eat those insecticides as well). They are so wide-spread in use, that recently I saw an email from a beekeeper looking to buy neonicotinoid-free flowers for her garden. She went to Windy Lo, Mahoney’s, Frans and Russel Garden Center, all were using neonics, none of them offered any plants not treated with neonics. These insecticides are far more prevalent that we realize.
There was research required to approve the use of neonics, but that research focused on how directly toxic neonics are to honeybees, to make sure the bees will not directly die due to it. That research used the traditional research route, to check what is the exposure level that kills a bee (LD50 – the amount that kills 50% of the exposed bees). However, with this type of insecticide, high percentage of the bee population will have low-level exposure to it. It is in the nectar, the bees make honey out of it (which is very concentrated nectar), they feed it to their young, they feed it to the queen, they consume it during the winter. How does it affect them long-term? Not too well, apparently. There is research showing that neonics exposure lowers honeybee resistance to various viruses.
As the search for the culprit(s) for CCD was on its way, strong economic forces intervened. Neonics have a strong lobby, they bring a lot of profit to the manufacturers, most prominently Bayer CropScience. There was a lot of economic push and funding into research showing Varroa Mites are to blame for the honeybees’ problems, and far less funding into reviewing the issues around neonics. But some scientists still looked into it.
More information from Wikipedia
As a result, EFSA, the EU’s equivalent of the FDA, conducted an assessment risk, that came back with “there might be an issue, we need more data to know for sure.” Alarmed by having insecticides on the market that might be harming the environment, the EU voted on April 2013 and restricted the use of three neonics. There is a push for the US to do the same.
CCD aftermath
Then, as mysteriously as CCD appeared, it left us.
So now what? It seems that CCD is no longer with us. Bees no longer suffer from it. According to Dr. Wilson-Rich, the last confirmed case of CCD in Massachusetts was in 2011. It appeared in 2006, and we’re not 100% sure why, it left us in 2011, and again, we’re not quite sure why.
Are bees safe now? Hardly. CCD is not a synonym for a dead hive, hives can die of multiple reasons, CCD being just one of them. Hive losses remain quite high, some of the big enemies of bees are varroa mites (a large mite that is visible to the human eye), nosema ceranae (a single-cellular fungus) and habitat loss. Winter losses are still extremely high, the bees need our help more than ever.
Things you can do to help bees
- Have a bee-friendly garden with untreated plants.
- Don’t use insecticides or be extra-careful if you have to.
- Buy honey from local beekeepers.
- Become a beekeeper or suggest to a local beekeeper to put a hive on your property.
- Neonicotinoids are a more complex issue, given the missing information. If you believe we are to “play it safe,” then sign every petition you see to have similar ban to the one the EU has.