Colony postmortem #2
Here’s another chance to help a fellow beekeeper. Chris, a first-year beekeeper in Georgia, lost one of his two hives back in February. In order to figure out what went wrong, Chris did a detailed postmortem and recorded his notes for you to review.
I already gave Chris several ideas of my own, but both of us would love to hear what you think. Postmortems are great “thought exercises” and I always learn something by trying to sort through the clues.
Pencils ready! You may begin.
Colony Postmortem by Chris Grey
The history of the hive
I knew the hive was low on honey going into the winter last year and I was fully prepared to feed the bees through the winter with sugar. I started by putting sugar cakes on the rails, but they were making such a mess with the sugar letting it drop through the hive, through the screened bottom board, and onto the ground, I decided I’d try something different, a tray.
Somewhere around December, I figured out they didn’t like/couldn’t eat dry sugar. So I started wetting the sugar in the dish. However I was noticing them in the dish less and less as the outside temps got lower and lower. So I reluctantly pulled chunks out of the dish and put them on the rails and found they would eat that. Before I left for a 4-day vacation, I pulled out a few chunks and left them on the rails. One of the chunks I pulled out was a particularly pink chunk . . . pink from a crushed salt lick I put in the sugar mix.
Neither hive has shown a Varroa infestation since the summer when I was inadvertently raising a ton of drones (long story, not relevant here). There are Varroa that drop onto the board, but not nearly enough for me to be alarmed. At the end of the fall, I was averaging about 10-15 drop in a week. As little as the hives had, the hive that died curiously started having only one or two Varroa drop in a week period.
I had noted that both hive populations were growing from only covering about 2 frames to 4 frames. That increase happened through early January. However the dead hive seemed to stall. It never got smaller, but it didn’t seem to maintain the same pace of growth that the other hive did towards the end of January. Problem with the queen?
The other noteworthy thing about the dead hive is for weeks before it collapsed, the front landing board always had more dead carcasses than the hive that’s alive. I don’t know if that means anything or not. The live-hive would usually didn’t have any, but if it did, there were only 1 or 2. The dead hive would consistently have 8-10 carcasses on the front landing board. I’d clean them off and more would be there a few days later. Best I can figure is that hive just had lazier undertakers that didn’t drag the carcasses further away.
The findings of the postmortem
I went out of town for four days and the hive died sometime while I was gone. So I don’t know exactly how long before I got back. The first thing that was obvious was dysentery all over the walls of the top (empty) super and on the frame tops. This was unusual for either hive so it stood out to me immediately as a clue.
Digging into the hive, I found roughly a dozen capped brood in varying age from white to nearly ready to emerge. I expected far more brood than this. I didn’t notice any eggs or uncapped larvae. They may have been there and I just missed them. I do know what uncapped brood and egg look like in a cell so I would think if it was there, I would’ve noticed it. Again, weak queen?
Each frame had a few bees either on the frame or head-first in the cells. Most of the bees head-first in the cells were on end-frames. I did notice granules of sugar inside some of the cells. It wasn’t packed; just on the walls like someone had taken a salt shaker to the frame. I’m guessing it’s where sugar had gotten into the cells as it fell through the hive from being eaten by bees above.
There was NO honey in the hive, but that was no surprise given I knew they were light on stores going into the winter. What had been concerning all winter is their intake of sugar wasn’t nearly what I would’ve expected either. They were eating the sugar, but not nearly as fast as I assumed they should. Although the hive that’s still alive wasn’t eating theirs any faster and was equally light on stores last fall and they flourished even while the other hive was alive.
Once got to the bottom of the hive, I found all the bees lying on the screened bottom board. Some of the carcasses had sugar on their bodies. The pile seemed damp. I’m not sure if that was just from the weather and sitting on the bottom screen (of which did have the white board under it) or if that was a clue that the salt in their feed had something to do with their demise (salt being hygroscopic).
None of the debris had any signs of Varroa that I could see. But that wasn’t a surprise since very little had been dropping and very little was on the board after they were dead (no more than 3-4 on the entire board). I never found the queen in the debris, but I admit I didn’t look as hard as maybe I should have. I also noted a bald faced hornet in the debris, but I haven’t seen them hovering around the hives since mid-fall. My guess is this was a hornet that made its way into the hive but was successfully attacked by the hive back last year. While it’s possible, I highly doubt it had anything to do with the hive’s collapse…not at this point in the year.
1. The pink sugar had too much salt in it and the bees succumbed to basically salt poisoning which gave them dysentery, then death.
2. The colony just starved. Despite having food within their reach, they just weren’t taking it as fast as they actually needed it.
Since the collapse, I started feeding the other hive sugar water from jars again. I mixed the sugar up with 3 cups in a quart-size jar and filled the jars with hot water to the top. The bees immediately started taking the water and continued to until night when the temps dropped and they all joined the cluster. So now seeing they were hungry for sugar, I moved the jar to inside the hive so they could take from it 24-7…and they have. In the past 2 weeks, they’ve probably consumed more sugar than they have since early December. Also in these past two weeks their population has exploded. In a 10 frame box, they are now covering roughly 7 frames. And their Varroa counts are also quite low. As of this afternoon, I counted 3 Varroa on the board and the board was cleaned last week.
What I’ve taken from this
1. Skip on the salt-lick in the sugar. I’ll set a lick outside somewhere and see if they want it. That way they can opt into consuming it vs having to eat it in order to get sugar.
2. Feed the bees via a jar inside the hives all winter. With the jar inside the hive sitting right above the cluster, it stays warm enough for them to drink from AND not nearly cold enough to freeze. Add to that, I did some research and found that sucrose lowers water’s freezing point. The more sucrose that is added to the water, the lower the freezing point of the mix. At saturation, the freezing point is somewhere near 0°F…well below the coldest of temps we ever get here and certainly a lot lower than should be inside the hive near the cluster. So there’s no reason for me to fear the water freezing, bursting the jar, and raining cold water down onto the bees. My fear of this was the whole reason I didn’t feed my hives this way in the 1st place. Had I fed them this way instead of with the sugar cakes, I’d possibly still have 2 hives.
Thoughts, questions, theories, suggestions?