Determining Loss of Hives

Question for Jacqueline: How can I best determine the cause of death of a hive? I started beekeeping with a purchased Carniolan colony in 2012. Last year, I had 4 Warre hives that grew to 6, but, sadly, 3 died out I think around September/October, before going into winter. In looking inside, it just seemed like a lot of dark, empty comb. No capped cells or honey. A few bees in the cells with tails sticking out, but not many. Dead bees on the bottom board, but not thousands. There were also a lot of hive beetles. I am wondering how to tell why they died. My guesses are:

Summer dearth of pollen and nectar caused starvation or left the hive so weak, it allowed hive beetles to take advantage;

Too much moisture in the hive (we had SO much rain in the Northwest! I am on the Olympic Peninsula) - we kept the inner dimensions on the Warre design but built them out of 2" lumber (i.e., 1.5" actual) - it seems better at helping them to hold the heat and they are very sturdy hives, but I am wondering whether an open bottom screen would help with circulation during warmer months;

Too much space? Two of them had an empty box on the bottom. I have trouble adding boxes to the Warres because I don't have a lift system and am reluctant to take each box off to add one on the bottom, and by the time I decide I had better add one because they are running out of room, they are on the verge of swarming - which might be a different issue, but maybe it left too much room with a smaller remaining colony?

Perhaps they lost their Queen? The 3 lost hives were relatively small colonies - either new swarms or from a colony that swarmed;

Wasp raids - but I thought this unlikely. I did not notice many yellowjackets around the hives - I had paper wasps in my greenhouse that kept bugs down and bald-faced hornets in the willows on the aphids, but I did not see them around the hives;

Mites and/or disease? I am not seeing signs of mites and diseases in these hives. I take a lot of pictures and zoom in on them on the computer, and the bees look healthy. I don't see the problems I read about on various beekeeping sites. I do not dust for mites. I just grow a lot of medicinal herbs, flowers, and berries and trust that the bees will be healthy through a diverse diet - and that they will choose what is best for them.

They got into something? I did not see a lot of dead bees outside the hive, but it would be difficult to tell because of the grass. Only a small area is covered with groundcloth - and weeds have managed to grow through it.

Late swarm? I did not notice swarms in late summer, but I suppose it could have happened. I would be surprised, though, on 3 hives.

Other?

The hives are all located relatively close to one another, but not right next to each other. I have never harvested any honey - I can't bring myself to take away what they have worked so hard to acquire to get themselves through the winter - and by the time the nectar flows again, they are swarming, and I wouldn't want to take away from a new hive or one that is trying to rebuild!

Of my 3 surviving hives, 2 are doing well; the girls are returning with pollen and purpose. The 3rd, however, appears weak. It also appears to be a different kind of bee - a darker body; less fuzzy. I see a little activity, but not much. I am holding on to hope, but if they don't make it, what are the main things you look at in a deceased hive?

Hi Blythe,

I live over near Port Ludlow and experienced a hive loss earlier this year. I did a post mortem and found many of the same symptoms you describe - most notably few dead bees, no brood, and no real distinct signs of starvation or disease. I saw them flying on "warm" days up to about 3 weeks before I pulled the lid and saw it was a dead out. The best guess from a number of beeks is that the queen failed/died/whatever in late fall, and the survivors dwindled and they eventually lost enough mass to keep themselves warm and froze.

Aaron

Aaron Althouse wrote: I saw them flying on "warm" days up to about 3 weeks before I pulled the lid and saw it was a dead out.

Hi Aaron--that pretty much describes it. I was quite taken aback. I thought they were doing fine, and then they, like you say, dwindled. I noticed that the barn swallows had 3 broods last year, and I wondered how many bees they were "swallowing" - or who knows. I was hoping it wasn't negligence on my part, but if it were, that I could at least learn from it.

If you want to see pictures and read more details on my post mortem, search my name and "bees" in google (aaron althouse bees) and you should come up with links to the other forum I frequent. If that doesn't work, send me a Mooseage and I'll follow up with you.

Very detailed pictures & descriptions! Thank you, Aaron! Most helpful! So much to learn and understand - and the more I learn, the more I empathize with these tiny creatures upon whom, in so many ways, the whole world spins - and how important it is to recognize how each of us are in position to make their life-work easier, and thereby have an important role in the sutainability of life as we know it. They face so many challenges - so many things can de-rail the whole system in a heartbeat! Kind of mind-blowing when you think about it. I get so attached to "my" bees - it is really sad when they don't make it.