2016-2017 Winter Hive Losses
This winter, I've lost 7 hives, and the winter isn't over yet. Last year I lost 1, and the previous two years, none. I can't recall years before that- but it was very few to none. Never more than 2.
There seems to be a plague raging through them, despite diligently treating them, and ensuring that they are as healthy as I could make them. Yet it wasn't enough. I contacted a WSU extension zoologist (Dave Pehling), who has been very helpful, and supportive, in helping me to understand what might possibly be the cause of all of this. He referred me, in particular, back to the information that Randy Oliver has provided, and so I printed out what seemed to me the most pertinent articles and have been reading them with a highlighter. Very pertinent stuff, and its causing me to re-think a lot of what I do and what I might do in the future.
For some reason, as my hives have done so well until recently, I thought that I had escaped the "bullet", and found a method of managing moisture which was effective, and felt I was managing the mite population. That was fantasy and this year totally changed my perspective.
Obviously, no one, at this point, really knows what is going on with the honeybee. However, it appears that the massive die offs are caused by known agents, not mysterious ones, and act in combinations, and in ways that were not expected. Its the usual suspects: viruses (of which there are only 18 or so known types at this point), Nosema ceranae (the microsporidium), and possible bacterial infections (from mite wounds). All of these interact with, and are acerbated, by Varroa, but in ways that are only now becoming clear.
Reading Mr. Oliver's papers is encouraging, and although much of the science is beyond me (being at a molecular and genetic level), he does a good job of pinpointing actions that a beekeeper can take to combat the dangers. In particular, to start considering that the primary problem is viral- and to start managing in a way that accounts for this.
It isn't obvious to me what killed my hives so far- though they all died in a similar way. The first few, died in a classic CCD fashion- all bees disappeared, except the queen and a few attendants, and left large amounts of brood and eggs to die as well. Later hives died more messily, with thousands dying inside the hives. I speculate that the same agents are at work, but I can't be sure.
Two things I am sure of, which I observed. The first was that the mite infestations I saw and treated for 3 times this year (with MAQS, each with massive mite kills), were not under control when the hives went into winter. I assumed they were, but when I started opening dead capped brood, I found up to 60% of the capped brood had mites in them. There were guanine deposits everywhere (though not in all hives). That was a shock (especially considering the level of treatment I gave them).
The second was that I found an exploded level of Nosema infection - far more than I saw last year (although I have only tested a few random bees out of one dead-out, and need to do more). This was the first year that I did not treat with Fumidal, but as I understand it, it isn't necessarily effective anyway. I did, however, use a "unscientific" product called HiveAlive, which claimed that it was effective against Nosema (though anecdotally). Obviously, it wasn't (and I see no reason to continue to use this product).
Those two observations pretty well account for everything- and fit very much into the scenario of colony collapses outlined by Mr. Oliver.
One of the biggest changes I am going to make, both now (before Spring), and next Fall when preparing for Winter, is to start wrapping my hives against cold- and even consider, when I can, providing low heat to the hives. I have, this past week, wrapped all of my hives in plastic bubble wrap (2 foot rolls fit 3 Westerns perfectly), and though its late, I feel that I might be helping to protect brood in the smaller colonies. Its late, but easy to do. Without doubt, the biggest killer of my colonies was the cold- which Mr. Oliver points out was not a problem in the pre-Nosema/Varroa days, but now is.
Although I realize that this won't combat the actual infections, I am hoping that it will allow the hive population to sustain itself through the critical months.
In addition, I am being more aggressive in my Winter treatments with oxalic acid. I have already treated twice this Winter, and will treat more. I have see a large mite kill even the stronger hives, so this seems essential. Last year, I treated with MAQS in April, as the mite population was so high.
There are a handful of other actions I plan to take- certainly to consider raising my own queens from the strong hives I have- and other options. Hopefully this year will be better.
There seems to be a plague raging through them, despite diligently treating them, and ensuring that they are as healthy as I could make them. Yet it wasn't enough. I contacted a WSU extension zoologist (Dave Pehling), who has been very helpful, and supportive, in helping me to understand what might possibly be the cause of all of this. He referred me, in particular, back to the information that Randy Oliver has provided, and so I printed out what seemed to me the most pertinent articles and have been reading them with a highlighter. Very pertinent stuff, and its causing me to re-think a lot of what I do and what I might do in the future.
For some reason, as my hives have done so well until recently, I thought that I had escaped the "bullet", and found a method of managing moisture which was effective, and felt I was managing the mite population. That was fantasy and this year totally changed my perspective.
Obviously, no one, at this point, really knows what is going on with the honeybee. However, it appears that the massive die offs are caused by known agents, not mysterious ones, and act in combinations, and in ways that were not expected. Its the usual suspects: viruses (of which there are only 18 or so known types at this point), Nosema ceranae (the microsporidium), and possible bacterial infections (from mite wounds). All of these interact with, and are acerbated, by Varroa, but in ways that are only now becoming clear.
Reading Mr. Oliver's papers is encouraging, and although much of the science is beyond me (being at a molecular and genetic level), he does a good job of pinpointing actions that a beekeeper can take to combat the dangers. In particular, to start considering that the primary problem is viral- and to start managing in a way that accounts for this.
It isn't obvious to me what killed my hives so far- though they all died in a similar way. The first few, died in a classic CCD fashion- all bees disappeared, except the queen and a few attendants, and left large amounts of brood and eggs to die as well. Later hives died more messily, with thousands dying inside the hives. I speculate that the same agents are at work, but I can't be sure.
Two things I am sure of, which I observed. The first was that the mite infestations I saw and treated for 3 times this year (with MAQS, each with massive mite kills), were not under control when the hives went into winter. I assumed they were, but when I started opening dead capped brood, I found up to 60% of the capped brood had mites in them. There were guanine deposits everywhere (though not in all hives). That was a shock (especially considering the level of treatment I gave them).
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| An opened dead worker brood cell showing the mites (also dead) that were in 60% of the cells |
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| Typical infection level- the small oval cells are Nosema. There are also some possible coccid bacteria strings here (per my friend at WSU) |
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| A more dense area of infection |
One of the biggest changes I am going to make, both now (before Spring), and next Fall when preparing for Winter, is to start wrapping my hives against cold- and even consider, when I can, providing low heat to the hives. I have, this past week, wrapped all of my hives in plastic bubble wrap (2 foot rolls fit 3 Westerns perfectly), and though its late, I feel that I might be helping to protect brood in the smaller colonies. Its late, but easy to do. Without doubt, the biggest killer of my colonies was the cold- which Mr. Oliver points out was not a problem in the pre-Nosema/Varroa days, but now is.
Although I realize that this won't combat the actual infections, I am hoping that it will allow the hive population to sustain itself through the critical months.
In addition, I am being more aggressive in my Winter treatments with oxalic acid. I have already treated twice this Winter, and will treat more. I have see a large mite kill even the stronger hives, so this seems essential. Last year, I treated with MAQS in April, as the mite population was so high.
There are a handful of other actions I plan to take- certainly to consider raising my own queens from the strong hives I have- and other options. Hopefully this year will be better.
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