[Margaret Sloan]

This is our first year overwintering a top bar with the entrance at one end. At the end of summer we had plenty of bees and honey. You could see a ton of bees through the observation window. By September, bees covered about 6 bars of comb. But then the amount of bees got smaller and smaller, until by December you could see no bees at all through the observation window.

However, there has been a steady stream of bees coming and going all winter. We thought we'd lost the hive, and these were robber bees. We opened the hive a month ago (we're in California and it wasn't that cold) and found that there were combs still full of honey toward the back of the hive, but that the bees were all hanging out on an empty comb near where the brood nest would be if there were one, and it looked like they were cleaning the comb. We didn't look any farther, to avoid upsetting the queen, if there was one.

Two weeks ago I saw bees emerging from the hive and doing what looked like orientation flights.

How small can a winter cluster get anyway? Could the cluster just have gotten so small we couldn't see it through the observation window? Could it be we still have a hive?

 

[Michael Bush]

A very small cluster can sometimes make it and get going again. The darker bees seem to be able to survive with smaller clusters than the Italians... time will tell if you have a colony or not.

 

[Riley]

The cluster can get pretty small. A couple of years ago I had a colony dwindle to where I think it could have fit in a two-cup measure by late April. I gave it a new queen and somewhat to my surprise the hive built back over the summer, accumulated enough stores for overwintering with no fall feeding, and last summer it produced about 140 pounds surplus with about 100 pounds left on the hive for winter. So you never know.

 

[KQ6AR]

Hi Margaret,
I'm over here in Concord, One of our hives has a very small cluster the other is stronger. Both hives had eggs being laid when we looked a couple weeks ago.

 

[odfrank]

CCD is still going fierce here on the peninsula. I am finding clusters the size of golf balls that will be gone in a few days. I am working in Woodside if you would like me to come over and give my opinion.

 

[Margaret Sloan]

Thanks. I'm waiting for the weather to warm up enough I can go into the hive. There are still bees coming and going.

 

[Fuzzy]

Margaret,

Watch the entrance for a few minutes. Are the bees bringing in pollen ? There is currently LOTS of pollen available. If they are bringing in pollen then they are most likely raising brood. We took a hive off of an unprotected tree branch 2 weeks ago. They still had lots of brood being raised.

 

[odfrank]

I found one yesterday that has an orange size cluster but does not fly when others do.......I guess they give up as they die out.

 

[Margaret Sloan]

Well, it looks like that hive is gone. No bees are coming and going at all, not even a few.

Strange, because last week there were bees cleaning the hive, dragging out dead bees like crazy.

Now, my question is, can I reuse the equipment, if I don't know why they died? Now, it's possible I killed the queen, but I don't know that for sure.

 

[odfrank]

I am reusing my CCD equipment until someone determines what the causal agent is, and suggests that the equipment should not be re-used. Since your hive is a topbar, your investment would be less to make new bars and scorch the box.

 

[Margaret Sloan]

Ugg. We just opened up that dead hive. There was a layer of dead bees about a half in thick all over the bottom of the hive, and some spectacular molds growing on some of the cells in the brood nest (but there was also a lot of pollen in the brood nest.)

There were a few cells (maybe 7) with a half emerged bee (well formed, not a pupae), head out and tongue sticking out. There weren't many cells with capped brood, and I didn't think to check them for AFB.

I'll throw away the bars and scorch the box. Will that be enough if there is some AFB?

I'm thinking that moisture did them in, as it was pretty damp and mildewy in there.

 

[Michael Bush]

AFB is not what kills bees in the winter. Starvation, Varroa, Tracheal mites, dysentery, lack of ventilation etc. are more likely to contribute to winter losses. I would look for little white specs in the brood comb and dead Varroa on the bottom board. If Varroa were the primary cause you'll find thousands on the bottom plus the white specs of Varroa feces in the brood cells. If you don't find those, look for the cluster. If the bees look like they were not clustering, then Tracheal mites are a likely cause. If they were clustered and the cluster was not in contact with honey, then they starved because they were not getting to the stores.

 

[odfrank]

You might also consider `CCD?' which has struck our area big time again for the third year in a row. I am seeing 50%+ losses all around your area, Atherton, Palo Alto, Woodside, San Mateo, Hillsborough, Burlingame. It is not starvation, the dead hives are full of honey. We have also had the most overcast winter I have seen my 40 years as a beekeeper and landscaper in this area. Many hives have been wet inside this year much more than usual. We did not have those weeks of sunny warm winter weather we usually have but the die of is caused by more than that. I posted pictures of the huge die offs we had after cold rainy weeks in December and January. This die off has continued slowly until this time. The last three years have been nothing like I have seen in the last 40. I am guessing a combination of mite caused viruses. I see a lot of DWV and possibly IAPV.
Mold in dead hives is common and harmless, it is unlikely AFB in a new hive. Don't throw away your bars. Cleanup the hive, dribble a few drops of lemongrass oil on a comb and at the entrance. Your box will be filled up with a baited swarm before the end of April.

 

[Margaret Sloan]

Wet conditions could certainly have played a part. Since there were dead bees all over the bottom of the hive, I discounted CCD. Aren't bees supposed to vacate a hive with CCD?

 

[odfrank]

CCD does not really have a yet pinpointed causal agent, and manifests itself in different ways. Thats why i said `CCD?'. I have found empty hives, hive with tiny clusters, and hives with dead clusters. One host told me he saw a group of bees from one of my declining hives fly off in the middle of winter. All I know is that we have had an unusual and large die off of hives here on the peninsula the last three winters.