observation hive population drop

phill · October 05, 2011, 10:38:38 AM

About half the bees in my observation hive have disappeared, in roughly 24 hours. Any ideas what might have happened?

- There are lots of dead bees around the entrance, but not nearly enough to account for the population loss.
- The O-hive is in my office, and I was there most of the day yesterday; I surely would have noticed a swarm or robbing.
- It's been cold and rainy here. No frost yet, but I've been wondering whether I need to do something to protect them from cold air. (This is a new O-hive, approaching my 1st winter.)

Everything looked normal to me as of yesterday. They're low on stores but I've been feeding. The queen had slowed down laying, but it's that time of year. I'm stumped.

tandemrx · October 05, 2011, 11:06:17 AM

Do you have good enough viewing that you would for sure notice a swarm? It only takes a few minutes (well, there is a wind up period where they get very very active, but even that might only last a few minutes before take off).

My OH has the glass covered with cloth and I can't readily see the outside exit. I have seen them swarm before but only because I either happen to catch the outside activity or once I heard an unusually odd/loud buzz coming from the hive and peaked in to see the chaos before take off. But otherwise, they could easily swarm within a 10 minute period of me not being near the OH and I would miss the whole thing.

Does seem very late for a swarm in Mass. but with bees (and life) it seems to be "never say never".

Is your original queen still there? That would be some clue (if she was marked or you otherwise can recognize her easily . . . might be tough to distinguish her from a daughter though, other than size at that time point . . . or no queen if new virgin hasn't been born yet).

How many drones have you had in the OH? About the right time of year that they are all being kicked out (not likely to account for 50% obviously, but could be 10-15%). Maybe your foragers got tied up in some pesticide . . . although seems like an odd time of year for that to happen up north.

My observation hive is still packed to the gills, but am noticing a slow decrease and almost no brood at this point, although I catch the queen doing some odd egg laying here and there. They did a good job of collecting fall nectar and we have a good week of indian summer (temps >70 for another week), so I haven't had to feed and they have good stores at this point.

phill · October 05, 2011, 11:18:01 AM

My OH is covered, too. But I can see the outside entrance, and hear if there's unusual activity-- even outside. It's possible they swarmed while I was out of the office for a while. But would they swarm on a cold rainy day?

I can't find the queen now. She may be hiding, but...

The drones were long gone from this hive already.

D Coates · October 05, 2011, 04:24:23 PM

Are there queen cells anywhere? How about eggs?

phill · October 05, 2011, 05:55:31 PM

No queen cells. I don't see eggs, but the few remaining bees are now covering the comb around where the queen was last spotted.

The population has dropped by another 50% within the last several hours. Looks like they'll be all gone by morning.

Could this be CCD?

tandemrx · October 05, 2011, 06:46:27 PM

fascinating.

As you watch the entrance/exit . . . what does the traffic look like? Does it look like normal foraging flights?

What does the inside look like in terms of movement. When I have watched 2 swarms from the inside of the obs hive it looked like a cyclone was going on inside the hive. All the bees were moving very fast like a big stampede parading around the hive (not always towards the exit, often just stampeding all around the hive while some of the stampeded was heading for the exit and very few bees being still (whereas usually there are quite a few bees fanning and just hanging out).

Does the inside activity look kinda normal? Bunch of bees near the exit from the frames pretty busy, but otherwise other bees rather oblivious and going about their normal activities?

phill · October 05, 2011, 06:54:44 PM

Good question, Tandemrx. You remind me that the bees were pretty quiet yesterday. I might have missed a swarm, but wouldn't they have made some unusual buzzing noise beforehand? They didn't. On the contrary, unusually quiet all day.

Very quiet today, too. Slower activity than usual. I see almost no traffic in and out. Lethargic.

BlueBee · October 05, 2011, 07:23:47 PM

Summer bees don't live forever so attrition may account for some of the losses. A pest infestation will also drive the bees out, but you would probably see that in a OH if that was the case. My concern would be with your brood. If you don't have much capped brood, then something went amiss some time ago and you are now starting to see the effects of it. Takes 21 days for new workers to emerge. If you have little brood now, what was going on 21 days ago? If you had lots of brood layed 21 days ago, your OH should be bursting at the seams with new bees now.

I was out inspecting my nucs today and found a deep frame full of eggs in most. My queens in the nucs are still going strong and haven't cut back much yet.

Tommyt · October 05, 2011, 09:00:08 PM

Did your hive abscond now you have robbers and stragglers
I too think being so late in your location ,swarming would be
pretty much a death sentence,I say abscond because of no Qcells
I had a 3 frame nuc leave, they left brood not much but some
I saw no Qcells but thought I may have missed and they tore them down
The nuc was active for about 4/5 days,I kept thinking a queen would
show up and get the place back up and running,well I was wrong
Didn't do well at bee thinking 101
I hope at the very least, you find out what happened or is happening

Tommyt

D Coates · October 06, 2011, 10:33:16 AM

I'm at a loss... No eggs, no queen cells.

Moving forward, do you have another hive you can pull a frame with eggs from to put in there? If you do they'll tell you if there's a queen then you can act accordingly. Too late to mate a new queen but you'll at least know what you're dealing with.

phill · October 06, 2011, 10:50:38 AM

Good news: Now that the cluster is smaller I can see eggs and some more brood. Bad news: not enough bees remain to cover them.

Yes, I could pull some eggs & brood from another hive. But without a queen-- and I still haven't seen her-- they'd be doomed, right? At this point there aren't nearly enough bees to be sustainable. So unless I find the queen and figure out what happened, I'm planning to shake them off into another hive, clean out the OH, and start again in the spring.

I don't think they swarmed. 1) It was cold and rainy. 2) They were quiet. 3) There are lots of dead bees at the bottom of the OH and around the entrance outdoors. Something killed them-- quickly.

I'm mystified. This hive looked fine just 3 days ago. It's obvious now, from the shortage of brood, that the queen had "slowed down" much more than I realized. Still the sudden collapse throws me.

BlueBee · October 06, 2011, 12:33:22 PM

Maybe they got into some pesticide? It seems rather late for anybody to be using pesticides at this point; the plants and pests are about dead for the year. However you never know when people are involved.

I've seen clumps of my bees die from exposure just outside my hive entrances before. This happens if the hive is very warm, and they're on the landing board (to cool off), and a sudden cold rain comes along. However that probably doesn't fit your scenario either. I'm stumped.

D Coates · October 06, 2011, 12:47:12 PM

Hang tight Phil. If there are eggs the hive will let you know if there's a queen in there. If you're concerned about the population numbers you can add a frame of capped brood from another hive if so inclined. How cold is it there? They could be reacting to a cold snap by clustering a bit which makes the population looks smaller than it is. This is especially true if they are having to keep brood warm. Can you post any photos?

Kathyp · October 06, 2011, 01:46:47 PM

OB hives can be hard to maintain. i wouldn't waste resources at this time of the year. let them make it or not and repopulate the thing in the spring.

sounds like you might have had a late swarm. somebody found a better home :-) sometimes they don't all leave at once.

Tommyt · October 07, 2011, 01:07:22 AM

QuoteGood news: Now that the cluster is smaller I can see eggs and some more brood. Bad news: not enough bees remain to cover them

You can see eggs means you had a queen within 3 days I'd say she slowed down a while back and then something happened to the remainder,but with a queen and some bees your colony has a chance
can you get some nurse bees in to it?

Tommyt

Tommyt · October 09, 2011, 10:04:59 AM

Did you loose them ??

phill · October 10, 2011, 09:54:45 AM

They're hanging on. Their behavior is more normal now, and the numbers have stopped dropping. But there aren't enough of them to be viable. I still haven't spotted the queen, but they're in a fairly tight cluster and she could be in the middle. It's warm this week, and I imagine they'll spread out and give me a chance to see her if she's there. I can't see any new eggs now, so if she's still there I think she's stopped laying.

I really don't think they swarmed. In such cold wet weather it would have been suicidal. And I found an awful lot of dead bees in the hose leading to outdoors. (I cleaned that out this weekend.) Something was killing them, and it's stopped now, but the damage has been done.

If I spot the queen and some signs of life, I'll add a frame from another hive. Otherwise, "wait 'til next year."