Acute Winter Kill

[Dr. Abe]

Hello All!

Yesterday I went out and checked 6 of my hives and added some "emergency" sugar bricks. I didn't see activity in one hive and further investigation revealed an entirely dead hive. At least 3 inches of dead bees on the floor.

This is odd because this hive was one of my strongest and looked great going into the winter. To be clear, they did not starve! The top deep is still 90% full of honey stores and there was a small amount below that. Also, we have been having rather warm weather. I treated for varroa in summer and late fall.

Any ideas regarding the colony loss and whether it would be okay to use the deep box full of honey to feed another hive or not would be appreciated! Basically, if it was a disease or pesticide I want to be careful to not spread it.

 

[jenkinsbrynmair]

I doubt it's either disease or pesticide, without actually seeing it, my guess would be late autumn queen failure so the colony just dwindled and died.
What varroa treatment did you use?

 

[hemo]

Virus, varroa?
Also with varroa any signs of white varroa poo within the cells.

Another cause may be isolation starvation , did the lower combs show signs are any dead brood ?

 

[Buzzo]

had exactly the same situation last year at the same time - fed the remaining frames to other hives with no problems.

 

[ericbeaumont]

was one of my strongest

treated for varroa in summer and late fall.

we have been having rather warm weather

The strongest will succumb quickest because varroa load will be significant, and the likelihood of this factor depends on your chosen treatment and timing. Bear in mind also that even though you treated, a mild autumn and winter will have led to the laying of brood (and so varroa).

What and when was your treatment?

 

[Dr. Abe]

The strongest will succumb quickest because varroa load will be significant, and the likelihood of this factor depends on your chosen treatment and timing. Bear in mind also that even though you treated, a mild the autumn and winter will have led to the laying of brood (and so varroa).

What and when was your treatment?

Makes sense. I treated with Formic Acid in August and with Oxalic Acid 3 Weeks ago. I think some bees were still alive when I did the Oxalic treatment because the top of the frames in the lower box were thickly sprinkled with dead Varroa. Also, I have a screened bottom board and quite a few mites were on the tray.

 

[Dr. Abe]

Virus, varroa?
Also with varroa any signs of white varroa poo within the cells.

Another cause may be isolation starvation , did the lower combs show signs are any dead brood ?

Yes, the lower combs had some spotty, still capped, dead brood in them.

 

[jenkinsbrynmair]

first treatment a bit early and the second a bit too late I'd say, and by the looks of it they had a heavy mite load

 

[hemo]

Does sound more like varroa and the resultent viruses taking it's toll and signalling the deathknell for the colony. Sadly it does occur and treatment timings will need adjusting as may treatment type.

Here in the UK there are those who have had Q issues using formic products . Q's going awol or being replaced, late or poor matings leading to drone layers.
As for timing of treatment typically this side of the Alantic we typically don't treat until early to mid September as the weather is still very mild and ivy is a major later forage source for winter stores, though a large number of us will subliminate with Oxalic over a complete brood cycle that will take us in to early October as well.
Monitoring for mite loads helps during the summer months to know the mite loading, before end of summer I have now and then treated a colony with oxalic during main flows when mite load has been higher then expected (temporarily removing supers though newspaper between brood and supers would suffice).
I believe though in the US one doesn't need to separate supers.

 

[jenkinsbrynmair]

the weather over there is much like ours although the winter months (around about now) seem to have more teeth than ours

 

[Dr. Abe]

Does sound more like varroa and the resultent viruses taking it's toll and signalling the deathknell for the colony. Sadly it does occur and treatment timings will need adjusting as may treatment type.

Here in the UK there are those who have had Q issues using formic products . Q's going awol or being replaced, late or poor matings leading to drone layers.
As for timing of treatment typically this side of the Alantic we typically don't treat until early to mid September as the weather is still very mild and ivy is a major later forage source for winter stores, though a large number of us will subliminate with Oxalic over a complete brood cycle that will take us in to early October as well.
Monitoring for mite loads helps during the summer months to know the mite loading, before end of summer I have now and then treated a colony with oxalic during main flows when mite load has been higher then expected (temporarily removing supers though newspaper between brood and supers would suffice).
I believe though in the US one doesn't need to separate supers.

Thanks for all the helpful advice! guess I was surprised partly because I requeened with a mated queen following the formic treatment.

In my area there is really no good nectar flows in August and honey is usually extracted by late August.

I should have kept better track of the mites, but, sometimes I get busy and push off treatments. I really should have at least done Oxalic treatments in October/Early November.

Anyway, thanks again! I will try to keep my other hives alive and healthy.

 

[hemo]

We all lose colonies at some stage for one reason or another, I had two drone layers coming out of last winter into spring and two cases of CBPV.
One survived and went into this winter strong and the other perished in spring.

 

[ericbeaumont]

two drone layers ... and two cases of CBPV.

Those are unpredictable events, Hemo, but varroa is a known that can be dealt with well before disaster strikes. As you say, we all get it wrong at some point.

 

[hemo]

True , Dr Abe just has to adjust his treatment timing and monitoring of varroa in the summer for colonies showing above acceptable mite loads.

3% is the upper threshold where load start to become fatal but a low threshold is always best.
We A few others on here and I use a sugar shake method to check on mite load during summer or peak flow periods as this is when mite production and bee exposure to other infested bees will cross paths when out in the field.
A cup full of bees (approx. 300) in to a closed two piece beaker /container and a T-spoon of icing /dusting sugar to gently role the bees in for two - three mins. Open the container and allow the bees to return to the colony , pour some water onto the icing sugar remnants to dissolve it and then count mites . Three mites or more means typically a 3% mite load so treating is urgently required, oxalic is the easiest to remove the parasitic mites or cage the exclude the queen for a cycle and remove the limited brood she produces.

 

[elainemary]

Sounds like the Formic acid didn’t penetrate the brood sufficiently and didn’t kill enough mites. Did you use Formic Pro or Maqs?

I used formic pro on a very strong double brood colony early August. As I monitored mite drops after use, I noticed mites dropping in large amounts well after use of FP. I used another treatment in September. Fortunately this second treatment worked well and the colony is still alive - I’ve just given it its OA winter treatment.

Suspect if Formic pro, as a different release system to Maqs, it’s not that effective on large colonies, leaving enough mites behind between Aug and now to multiply and colony failure from PMS

 

[Dr. Abe]

Sounds like the Formic acid didn’t penetrate the brood sufficiently and didn’t kill enough mites. Did you use Formic Pro or Maqs?

I used formic pro on a very strong double brood colony early August. As I monitored mite drops after use, I noticed mites dropping in large amounts well after use of FP. I used another treatment in September. Fortunately this second treatment worked well and the colony is still alive - I’ve just given it its OA winter treatment.

Suspect if Formic pro, as a different release system to Maqs, it’s not that effective on large colonies, leaving enough mites behind between Aug and now to multiply and colony failure from PMS

I used Formic Pro. (2 strips)

 

[elainemary]

I used Formic Pro. (2 strips)

Same as me, I’m not convinced of its efficacy on large colonies. Like you I did a sugar shake and had a high infestation, around the same level. Fortunately I spotted it hadn’t worked well enough and treated the colony again with a different treatment

 

[rdartington]

We all lose colonies at some stage for one reason or another, I had two drone layers coming out of last winter into spring and two cases of CBPV.
One survived and went into this winter strong and the other perished in spring.

I have just found a colony dead with only a palm-sized patch of dead bees left on comb . Lots of stores remaining. . Bees were hairless and an even deep black all over.
`Virus? Which one ?

 

[pargyle]

I have just found a colony dead with only a palm-sized patch of dead bees left on comb . Lots of stores remaining. . Bees were hairless and an even deep black all over.
`Virus? Which one ?

CBPV - often also associated with a heavy varroa load ... it can really decimate very large colonies ... very quickly.

 

[jenkinsbrynmair]

sounds more like just bees been dead for a while and got damp and claggy