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Discussion Starter · #1 · (Edited)
I have conducted a paired Treat - No Treat apiary test since 2002 in coastal California, and this experience has led me to question the various TF prescriptions promoted on the i'net as non-efficacious.

This post is not about that data. A forum member criticized my skepticism saying that an unconscious bias corrupts my results, and a legitimate test of TF practices requires belief (rather than objective skepticism) in the philosophy

The "Center for Honeybee Research" in Asheville, NC received local funding to conduct a paired test of TF practices. The non-profit CHBR (see Http://WWW.CHBR.ORG ) are vociferously promoters of "natural beekeeping", so their research cannot be objected to on the ground they didn't "believe".

The set up two 10 hive apiaries several hundred yards apart on the grounds of the Asheville Zoo in 2012 and have monitored these since. The hives were stocked with nucs from a nationally- known advocate of local, survivor stock nearby in North Carolina. This obviates the objection that TF advocates often raise to T/TF pairs is that the originating stock is not blessed with TF lineage.

The "commercial" group was hived on foundation, and the TF group used a foundationless system.

The study does show bias - they set an unrealistically high threshold of 100 mites/24 hour on a SBB as their treatment cue. This meant their first treatment was mid-September 2012, when the hives were already showing steep decline. Treatment was thymol. They label the treatment as "commercial", but postponing treatment until after the August exponential jump doesn't seem "commercial" or wise.

Results are very interesting, and may inadvertently point to a economic treatment threshold. I've annotated these images (copied from the Spring 2014 newsletter of CHBR.org )





1. In Summer 2012 to Spring 2013, losses were 80% in aggregate. The foundationless group had lower mites through the summer, a drop of 40/24 hours was maintained through the critical winter bee raising period in the fall. Survival was 40%. The foundation group didn't drop below the 40/day threshold until after winter bees were already raised, and the hive was becoming broodless. The differential mite count could be attributed to foundation (see next paragraph) or an artifact of inter-colony dynamics in the two locations (i.e. Horizontal Transmission).

2. In the Summer 2013 to Spring 2014 period, losses were 60% in aggregate. The exponential rate of growth in mites in the two groups to the August-September peak showed no differences. This implies that "natural comb" does no good in combating mite populations among locally adapted survivor bees in the the North Carolina piedmont. I intuit the mite drop in the Thymol group was a treatment (which would be under the protocol threshold, email sent to clarify). The foundationless group maintained a mite level above 40/day throughout the winter bee brood period, dropping only when brood rearing shut down for the winter.

3. Segregating the groups empirically into those with mites > 40/day vs. those with mite <40/day shows marked differential survival. I think this division is supported because waiting until mite population peak in the fall is TOO LATE to affect winter survival. The >40 group shows 20% survival /80% loss, and the <40 group shows 45% survival/55% loss.

The research supports my own data and observations: a) Natural comb is largely a red-herring in mite survival, b) mites populations equalize within closely situated colonizes (high horizontal transmission) c) waiting for mites to peak in population before responding leads to unacceptable losses.
 

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My bees have been treatment free since 2005. They either live or die strictly on their own ability to control mites. I don't see those exponential increases in mite count that are commonly reported with commercial bees. In an average year, my losses are about 10% usually in the January to February time frame. I'm not arguing with the methodology used. I'm not even quibbling about the horizontal transmission of mites. My bees are alive. Without treatments, theirs would surely be dead.

I use small cell, but don't credit that as the reason my bees survive. I use it because it fits very well with my management which includes 11 frames in the broodnest. I still have a few colonies on large cell, but they survive just the same as the small cell bees.
 

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Disregarding whether they survived, wow, that's a crazy high daily mite drop. Even for the hives that survived, it would HAVE to have a very serious effect on colony productivity.

The supplier of these treatment free bees, any idea what kind of survival, and productivity, he gets in his own location?
 

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Discussion Starter · #4 ·
I don't see those exponential increases in mite count that are commonly reported with commercial bees. In an average year, my losses are about 10% usually in the January to February time frame..
Fusion,
I believe you have already posited the difference you observe. You started with known resistant breeding and saturated your local area with this phenotype.

This leads to a mechanism I name as "the virtuous cycle". Once a foothold is established against mites in a **closed** population, the dynamic for the mites switches to selecting for hypo-virulence. This is not just due to queen lineage selection (as a few years won't alter that), but the mites themselves select for clonal lines (of themselves and their parasite virus) of lessened virulence.

This is why horizontal transmission of mites is so important --- in an open system, there is no effective selection for mites to become good citizens.

The "virtuous cycle" doesn't take hold in most landscapes, because breeding is wide open, and the resistant phenotype in bees is quickly bred out of existence in the free mating of drones.

On an island or in a mountain hollow, or in a small oasis surrounded by miles of unsuitable habitat (think Nebraska cornfields, here), the virtuous cycle can shift the balance of equilibrium to favor kind and gentle mites and semi-resistant bees.
 

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So you are saying if everyone stopped treating and allowed only the mites that are less virulent to reproduce we could lick this problem ?
 

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Discussion Starter · #6 ·
So you are saying if everyone stopped treating and allowed only the mites that are less virulent to reproduce we could lick this problem ?
No, island biogeography only works at a restricted scale. Too large an effective population, and there is too large a variance reservoir and too many transmissions. The process will work best with natural restricted breeding populations. Examples abound (viz the preliminary results of Seeley on isolated colonies). This is the "tragedy of the commons" at a parasite level -- in a large population, there is no advantage in absorbing the cost of lessened virulence because the greedy organism gets there first, and wins the distribution prize.
 

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JWC, I'm buying TF queens and leaving a drone frame in my best hives (untouched during brood season) to flood the area with my drones. Also providing queens to beekeepers in three mile radius to do same. .....Will that work to produce one of your virtuous zones?
 

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Short term possibly, long term depends on surrounding pressure.

Also consider that in the experiment in the Opening Post, treatment free survivor foundation stock was used but in a new location. Mite damage even year one was pretty horrific. They eventually treated which to my mind is a shame I would have liked to see it run full course, perhaps they saw no point in losing all of them. So you may or may not, get your "virtuous zone".
 

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Once a foothold is established against mites in a **closed** population, the dynamic for the mites switches to selecting for hypo-virulence. This is not just due to queen lineage selection (as a few years won't alter that), but the mites themselves select for clonal lines (of themselves and their parasite virus) of lessened virulence.

This is why horizontal transmission of mites is so important --- in an open system, there is no effective selection for mites to become good citizens.
i'm trying to grasp this jwc. how is it advantageous for the mites to become less virulent. wouldn't horizontal transmission still be present in the 'closed' populations you describe? how does this hypothesis fit with the large expanses of wooded areas in the southeastern united states where unmanaged hybrids are resisting varroa?
 

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Not JWC but the idea is consistent with evolutionary theory, and past evolutionary leaps are thought to have often happened in a population bottleneck.

The idea is that in a small population, virulent mites exterminate their hosts, the less virulent allow the host to survive which perpetuates their own survival. This is most likely in a small, closed population. Because in a huge widely spread population there is constant ability for virulent mites having killed their hosts, to simply find new pastures. If such a situation existed, without mans interference, it could only become possible for less virulent parasitic strains to get established once the host population was nearly wiped out and so thinly spread that the virulent parasites had trouble finding a new host once they had exterminated their existing one.

Apologies JWC if I got that all wrong, that's just my understanding of it.
 

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Discussion Starter · #11 ·
Oldtimer has it completely correct.

The data manager for the paired test project responded to my email. Sounds like Jennifer Berry is endorsing a 40 mite drop threshold, which just coincidentally is how I see this data as well :
Hi John

Without referencing the reports - I can tell you we treated three hives in 2013. L-3, L-4, and L-10 (L denotes the "Lower" treatment yard)
These exceeded our "threshold" of 100 mites/24 hr drop.

They received 25 mg ApiGuard thymol gel on a 4 x 4" cardboard strip in late Aug. or early Sept. - placed between two brood deeps - two times for two weeks each. The top was closed off from ventilation by 'blue-board' solid insulating material during the treatment although no attempt was made to close the screened bottoms which were left open. Daytime temps were in the low 80s. The treatment was deemed effective because subsequent counts dropped < 20. All three hives survived Winter - although it should be noted that these were the strongest hives with the greatest excess stores. L-3 even gained 10 lb. after the first hard freeze (likely harvesting less fortunate colonies:)?

This year we lowered our threshold to the < 40 number recommended by Jennifer Berry U of GA. All 10 hives in the lower yard exceeded this number by mid-July 2014. (all Upper 10 hives receive no treatment - surprisingly they have averaged less than half the average mites for three seasons!)


We've changed our method of application and have just completed treatment of all lower ten:

each got three applications of 25 mg ApiGuard thymol gel, between the deeps as above, once every 4 days. It was noticed thymol vaporizes within 3-4 days (or is eaten/removed by bees). A total of 12 days is speculated to overlap the time pupae spend under cappings.

Our next counts will be in a few days to determine the efficacy of the treatment.

I'd be interested in comparing notes. Where are you located?

Carl​
 

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Oldtimer has it completely correct.
i get how that works on geographically isolated populations, but fusion power and myself are not isolated geographically, and there are many opportunities for 'new pastures' around us. i'm not making the connection between saturating a local area leading to the virtuous cycle when that local area has no effective border.
 

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I would think if you were treatment free in a sea surrounded by treated managed hives, but I would think that if your bees are only competing with the natural dispersion of Ferrell colonies that any horizontal movement would be dispersed among non virulent varieties of verroa thus watering down their ability to completely take over a host, maybe this is the case in the areas that are not isolated that TF is working ? to those that have non isolated TF areas Did these areas experience near complete dieoffs prior to TF working ?
 

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What OT and JWC have written is consistent with known theories on evolution and parasite/host dynamics. I believe I forwarded these thoughts to Peter Loring Borst(sp?), adn he could deny their plausibility.

Population density seems to be one of the keys to how the bees/mites inter react. It is my opinion that if the density is low enough, any virulent mite will kill the host BEFORE it has a chance to reestablish itself in another hive, and thus die with the hive. This leaves the less virulent mites that do not kill the hive. This mechanism may explain the successes of Squarepeg and Fusuinpwer, and possibly an individual from Corn country.

Crazy Roland
 

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Examples abound (viz the preliminary results of Seeley on isolated colonies).
People continually refer to the Seeley work with bees in the Arnot Forest. The original work was done ten years ago, and raised several questions as to why bees in the woods might survive. People generally home in on the concept of less virulent mites. That was a conjecture which in the following ten years has never been supported. He also said

Still a third possible cause of the longevity of the Arnot Forest colonies could be related to frequent swarming, which is typical of feral colonies in this locality
This information, if true, leads where? Don't super the bees, let them swarm? That is in fact what he is doing with some forty hives set in various spots around the county. But if that is the answer to long term survival of colonies, what good is it? Now, some people have suggested that by simulating swarming (shake the bees into new hive) you could get the same effect. But I don't know that it really works.
 

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On average, my bees swarm much more often than my previous experience with Italian, Caucasian, and Buckfast bees. Carniolans swarm about the same amount in my climate. Countering this is a single colony that produced 120 pounds of surplus honey this year and did not even attempt to swarm. I take this to indicate that selection for reduced swarming while retaining high mite tolerance is possible. I have one other colony that produced about 80 pounds of honey with no effort to swarm, but they have some undesirable traits such as being more aggressive.

One of my colonies is very aggressive. They are not as bad as Africanized bees, but significantly worse than I normally allow to stay alive. They are very mite tolerant. If they had produced a decent crop of honey, I would not get rid of them. They did not make a crop, so it is time for regicide.

I know of 14 beekeepers within a 10 mile radius of my location here in North West Alabama. Two of them are using mite tolerant stock which they got from me. There are at least 2 more that are not treating their bees, but they are having very heavy winter losses. I don't know of any commercial beekeepers within 50 miles. The number of people interesting in getting a few colonies of bees was the highest this year that I have seen.
 

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Interesting discussion.
I think, that since varroa outbreak, the bee-population was thinned enough that at least in some places the virulent mites did not survive (died with host). It lefts less virulent mites. I guess, mites themselves compete too. Place already occupied by less virulent mites can somehow prevent aggressive mites... Bees also adapted - both processes caused the pockets with survived bees and mites, who live in some sort of balance. The balance is fragile and our intervention usually shifts this balance towards mites.

My bees have survived for 4+ years TF. In old days I counted mites on sticky board. It was so stressful: sometime I had 20/24hr, sometime - 120. But reality was that all beehives survived does not matter how many mites I count. I stopped counts. I have steady growth of my "apiary." I lost one hive for unknown reason (absconding or CCD?). My approach is to flood the area with my drones (no limits). I am working hard to prevent swarming, but they swarm sometime - all swarms were hived and now are in my neighbors backyards. In 4 years 2 original beehives turned into 8 beehives, 75% increase per year.
My point is that TF requires entirely different approach and in this sense can not be comparable with "treated" approach - approaches are different. If I feel my bees need treatment - I will treat if I have efficient treatment handy. So far, my bees do great without treatment.
 

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Hi Bernhard
Sorry for arithmetic error - you absolutely right - it is not 100% increase per year:
Year 1: 2 hives
Year 2: 4 hives
Year 3: 8 hives
Year 4: 16 hives

[..would be 100 % each year]
I corrected it, sorry for mistake, but it did not change my statement :)

Which means in pounds of honey per hive and year? :)
I estimate ~ 20-40 kg extra honey per hive per year. I keep ~10 kg in the beehive in any given moment. My hived swarm within the month made 2 gallons extra honey to my neighbor - he is very happy. Honey production depends from available nectar. This year is tough in our area - we have a record drought, which affects even city. We had yesterday event in Down Town Los Angeles and poor bees come to forage on sweet Mexican drinks ... they covered completely the leaking bottle with water ... it was very sad. Speaking about bees and public places - we literally had attack of bees - a thousand come for sweet drinks = 1 sting. What was really hilarious, is that boy, who got stung, won a jar of my honey in the raffle :) People was joking, that my bees follow me.
 
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