[Yunzow]

Hi, all,

I just wanted to be sure I got the basic facts right.

At this point, it would appear that varroa mites are basically endemic in honey bees in America, whether feral or kept as livestock?

The mites themselves don't directly kill honey bees, they just make them more susceptible to deformed wing virus?

Deformed wing virus doesn't directly kill a bee, but causes obvious problems with their ability to function?

We don't focus much on treating the deformed wing virus because the treatments for mites are more practical or perhaps there isn't a clear treatment for the virus?

Regards,
Thomas

 

[AR Beekeeper]

Just by feeding on the pupa and the adult bee the varroa mite can shorten the bees life span by about 1/3. The mite also vectors sever viruses that can kill the bees, both pupa and adults. The deformed wings is a visual clue of DWV, but not all the bees with the virus develop deformed wings. When the mite feeds on the fat bodies of the bee it damages the bees ability to fight viruses and bacteria so other diseases kill the bees. I know of no treatment on the market to treat DWV, so the only option is to control the varroa mites.

 

[Yunzow]

Thanks AR

Just by feeding on the pupa and the adult bee the varroa mite can shorten the bees life span by about 1/3. The mite also vectors sever viruses that can kill the bees, both pupa and adults. The deformed wings is a visual clue of DWV, but not all the bees with the virus develop deformed wings. When the mite feeds on the fat bodies of the bee it damages the bees ability to fight viruses and bacteria so other diseases kill the bees. I know of no treatment on the market to treat DWV, so the only option is to control the varroa mites.

 

[Yunzow]

To answer my own question.... I was poking around and found this article:

Here is the link to "Nutrition, immunity and viral infections in honey bees": https://www.sciencedirect.com/science/article/pii/S2214574515000863

 

[psm1212]

Thomas: I have absolutely zero scientific background or education, so please take this for what it is worth.

I have always believed that all of the focus on hygienic bees and mite mauler/ankle biter bees has been somewhat of a fruitless exercise. I don't want to offend those that have undertaken these efforts, but varroa mites are simply part of bee colonies now. We will not kill them all and neither will the bees. Their reproduction rates make rabbits look like celibate monks. Killing varroa mites may be all we can do now, but no wars will be won on that front.

Focusing on virus-resistance -- and possibly even inoculation -- seems to me to be the only real way forward. Dr. Olav Rueppell, UNC - Greensboro has done some incredibly interesting work, not necessarily directly on this point, but clearly in that area.

Quantitative patterns of vertical transmission of deformed wing virus in honey bees https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0195283


And, not Dr. Rueppell's work, but:

Transfer of Immunity from Mother to Offspring Is Mediated via Egg-Yolk Protein Vitellogenin https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1005015


Resistance (or maybe tolerance?) of the viruses that plague honey bees is the golden ring to reach for IMHO. But I took biology in the 9th grade. Beyond that, it was business and law classes. What do I know?

(Credit to Kevin Inglin of the BK Corner podcast for finding these articles and posting them to his show notes @ bkcorner.org.)

 

[trishbookworm]

People looking closely (ie scientists) have clearly shown that when the pupae are preyed upon by the mites, they are compromised. In high enough numbers, this will cause the hive to collapse. Not enough foragers, can't support the queen, negative feedback happens and the hive weakens so it is either robbed out or just dies when there is poor weather.

However, I live where there is WINTER. Not Vermont-style winter, but still. For 5 months, no pollen coming in means no brood is being raised. My bees don't start brood rearing until pollen comes in, something like late Feb to late March. I've looked in my hives, 2 years in a row, in early April (with first pollen late March) - certainly no capped brood. The "brood rearing starting in Jan" fable applies to those whose pollen flow starts in Jan, or feed pollen patties in the winter.

So, I have seen twice now 2 hives that had a confirmed alcohol wash in Aug-Sept, very low mites or at 9/300, and then so many mites by early Dec or early Jan that it is hard to count in a sample of 300 bees from the deadout. More than 60/300 bees.

Those mites were not born in the hives. Mathematically, it just isn't possible. 30 mites/300, sure. But not 60+. Those mites were imported from a dying hive, that the deadout robbed after frost sometime. Then in 2 months the hive dies. I think this is a big part of what takes down a strong hive - a sudden influx of enough mites - several thousand - that 10% of the strong hive is immediately compromised. Then the varroa move on to a nearby bee to feed...until the hive dies. This has not been carefully documented by people looking closely (ie scientists), but I have seen the evidence. Oh, and those hives had no signs of mite feces inthe cells - that means no mite reproduction happened in the hive.

That's right, I'm saying mites can kill adult bees. No predation on pupae - these hives were done brood rearing for the season. I've seen it happen. Not all areas of the country are at risk, because they get incoming pollen more months than I do. But this issue has shaped my fall mite treatment, such that my last treatment is in mid-late Nov. To catch any of my bees that went a-robbing. And I will not propogate those queens either - I check the mite drops post OAV in the fall, and note the numbers.

And I do free mite treatments (OAV) to any beekeeper in flight range of my bees...

 

[Yunzow]

Very interesting observation Trish, thank you.

People looking closely (ie scientists) have clearly shown that when the pupae are preyed upon by the mites, they are compromised. In high enough numbers, this will cause the hive to collapse. Not enough foragers, can't support the queen, negative feedback happens and the hive weakens so it is either robbed out or just dies when there is poor weather.

However, I live where there is WINTER. Not Vermont-style winter, but still. For 5 months, no pollen coming in means no brood is being raised. My bees don't start brood rearing until pollen comes in, something like late Feb to late March. I've looked in my hives, 2 years in a row, in early April (with first pollen late March) - certainly no capped brood. The "brood rearing starting in Jan" fable applies to those whose pollen flow starts in Jan, or feed pollen patties in the winter.

So, I have seen twice now 2 hives that had a confirmed alcohol wash in Aug-Sept, very low mites or at 9/300, and then so many mites by early Dec or early Jan that it is hard to count in a sample of 300 bees from the deadout. More than 60/300 bees.

Those mites were not born in the hives. Mathematically, it just isn't possible. 30 mites/300, sure. But not 60+. Those mites were imported from a dying hive, that the deadout robbed after frost sometime. Then in 2 months the hive dies. I think this is a big part of what takes down a strong hive - a sudden influx of enough mites - several thousand - that 10% of the strong hive is immediately compromised. Then the varroa move on to a nearby bee to feed...until the hive dies. This has not been carefully documented by people looking closely (ie scientists), but I have seen the evidence. Oh, and those hives had no signs of mite feces inthe cells - that means no mite reproduction happened in the hive.

That's right, I'm saying mites can kill adult bees. No predation on pupae - these hives were done brood rearing for the season. I've seen it happen. Not all areas of the country are at risk, because they get incoming pollen more months than I do. But this issue has shaped my fall mite treatment, such that my last treatment is in mid-late Nov. To catch any of my bees that went a-robbing. And I will not propogate those queens either - I check the mite drops post OAV in the fall, and note the numbers.

And I do free mite treatments (OAV) to any beekeeper in flight range of my bees...

 

[msl]

So, I have seen twice now 2 hives that had a confirmed alcohol wash in Aug-Sept, very low mites or at 9/300, and then so many mites by early Dec or early Jan that it is hard to count in a sample of 300 bees from the deadout. More than 60/300 bees. Those mites were not born in the hives. Mathematically, it just isn't possible.

sure it is...
The point is its a mite to bee ratio... Its so not so much the amount of mite reproduction, its the bee reduction!
when you drop form 48,000 bees with brood on, most of the mites in the brood and your rolling a 10 per 300 that's 6% total infection
0.06X 48k = 2880 mites
say that number stays the same with no new mites. the hive pop drops to 17,000 for winter and your rolling 50 mites per 300!, add in a lot of dieing bees flying off or being removed and the mite to bee ratio just climbs, but your not adding mites, just losseing bees

here is a graph from Randy Oliver's "First year beekeeping" that shows almost the numbers you discribe

Not saying you didn't catch a mite bomb or 2, just pointing out how the hive down seizing and going broodless effects what your wash is telling oyu

 

[GregB]

sure it is...
The point is its a mite to bee ratio... Its so not so much the amount of mite reproduction, its the bee reduction!

+1

As a matter of fact, the "bee component" fluctuations in the said ratio are by far more significant than the "mite component".
If anything is significant, it is "mite component" to "winter bee component" ratio.
Unfortunately, the "winter bee component" is not easily separable from the overall "bee component" in space and time.
Overlay that with any particular colony's behavior and traits in space and time.
With that, I just don't bother counting anything...

 

[msl]

If anything is significant, it is "mite component" to "winter bee component" ratio.
Unfortunately, the "winter bee component" is not easily separable from the overall "bee component" in space and time.

disagree on both
I feel the most significant is the mite to brood ratio when winter bees are raised, next is the nurse bees that will raize the winter bees. winter bees are the last round, maybe 2 of brood so we know were they are in space and time.
unpartized and low virus load winter bees raised by low virus load nurse bees is how you get long lived winter bees that make the turn and raize a round or 2 of brood to replace them selfs late winter

 

[GregB]

disagree on both
I feel the most significant is the mite to brood ratio when winter bees are raised, next is the nurse bees that will raize the winter bees. winter bees are the last round, maybe 2 of brood so we know were they are in space and time.
unpartized and low virus load winter bees raised by low virus load nurse bees is how you get long lived winter bees that make the turn and raize a round or 2 of brood to replace them selfs late winter

Unsure MSL.
Just per the latest rounds I am doing, some colonies (one captured commercial swarm for sure) propagate AS IF no winter is coming.
Some others are in the shutting down mode.
Some others are in between in various stages.
And this is only me - a very small homestead operator with very little attention/time allotment to keep track of the dynamics.
In my world, I have not a clue what is going in some segment of space at any given time.
I mostly gave up trying.... Why even should I?
Gotta have school calendars figured out - the actual priority

 

[Yunzow]

Also a very good point thanks MSL

sure it is...
The point is its a mite to bee ratio... Its so not so much the amount of mite reproduction, its the bee reduction!
when you drop form 48,000 bees with brood on, most of the mites in the brood and your rolling a 10 per 300 that's 6% total infection
0.06X 48k = 2880 mites
say that number stays the same with no new mites. the hive pop drops to 17,000 for winter and your rolling 50 mites per 300!, add in a lot of dieing bees flying off or being removed and the mite to bee ratio just climbs, but your not adding mites, just losseing bees

here is a graph from Randy Oliver's "First year beekeeping" that shows almost the numbers you discribe
View attachment 50675

Not saying you didn't catch a mite bomb or 2, just pointing out how the hive down seizing and going broodless effects what your wash is telling oyu