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Dare I winter on this much new comb?
In my experience, bees do not winter well on brand new comb, even if it is full of honey and capped.

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Thursday October 20th 2011
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I've been using a Bobcat borrowed from my friends to move a semi-trailer-load of bark mulch to where it is needed. We had the mulch delivered last spring.  It was actually cheaper to buy a full load, delivered, than to get a half-load.  We hired a local kid to assist in spreading it, but began to realise that the job would take the rest of this fall and some time into the spring, and, besides, the pile moulds if left a long time.  The Bobcat made the job easier and a lot quicker. I also managed to move some gravel and level some ashes after that job was done.

I have had a less than great opinion of skid-steers compared to articulated loaders like the Swingers we had for moving bees, but using this one has improved my opinion.  It is a tough, handy little machine and could do a good job of moving hives if fitted with forks and if operated by a patient driver on reasonably smooth ground.  Some sort of hold-downs would be essential, though.  We found we had no use for hold-downs on the Swingers and took them off in short order once we ballasted the tires with saltwater.  The ride was that smooth.  This Bobcat is not a smooth-riding machine. It tends to do wheelstands and bunnyhop if not carefully controlled.

At 2 PM, I rushed over to get the drop boards to learn the latest mite-drop news, and guess what?  I had forgotten to put boards back in when I pulled them out yesterday, so there are no results for today.  I'll have to extrapolate. tomorrow.  I suppose that I could extend the trend from yesterday right now, but the best solution is to wait for  tomorrow's results and average them with yesterdays -- I think.

We had friends over for supper.

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Friday October 21st 2011
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It's foggy this morning and there is a little snow on the ground.

Varroa drop results.  Click to enlarge
Click to enlarge

I see the mite drop is tapering off.  (Yesterday's drops are a credible fiction produced by averaging today and the day before).  Another observation is that there are still quite a few light-coloured mites and I assume from that there is still more than a little brood in the hives.

Eight days have now passed since the treatment and the benchmark curves I have consulted (example at right) are flattening by this time, as is the red line in the chart above. 

The example has a 78% drop, but we're only at 46% by my calculations, so it is obvious that we are not achieving the efficacy others did or that I had fewer mites than estimated.  The fact that there is brood and that I am counting quite a few pale-coloured mites (30%?) means there is brood and my population estimate could be high by as much as 50%.  If so, that would mean that we have achieved 46% x 150% = 69%.  The thing is, I really just don't know.

Medhat wrote this on BEE-L:

> Most of the time we find the screen bottom board is clogged with debris from bees, wax, pollen, etc. It will be hard for falling mites to go through. In some cases we have to replace screen bottom boards with clean ones or use pressured water to wash them. Thus we ensure that these screen bottom boards doing their jobs.

The second experience, bees can make so much honey and if mites are high a portion of the bees will die after making the crop and clog up the entrance leaving 1-3" of bees on the top of the screen. Falling mites will have problem going through the clogged screen.

I replied that they are clean.  I installed the screened bottoms on Wednesday August 24th 2011, and did not add boxes likely to cause much debris, but after thinking further, I should check. The screens are currently sitting under about 200 or 300 pounds of supers in most cases, but I can just hold a hand mirror under them and look or peek into the entrances.  In some cases, I may restack the hives, too, in which case, I will have a chance to examine the boards more closely.

Medhat brought up an interesting point which could be big factor in assessing the practicality of screened bottoms in commercial use.

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Saturday October 22nd 2011
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The temperature is minus three this morning, a sure sign that Indian Summer is over.

Varroa Drop (Sticky) Board with mites Applying Vaseline to a sticky board for varroa testing Applying Vaseline to a sticky board for varroa testing Applying Vaseline to a sticky board for varroa testing Applying Vaseline to a sticky board for varroa testing
Click to enlarge

Above is a series of shots showing a used drop board which has been counted and is ready to be prepared for another use, and the process of getting it ready to go back under the hive.

At left is the board with mites and debris. Next, scraping off the debris and then a smear of new Vaseline. Then the grease is spread very thinly with the putty knife.  Only a very thin film is necessary.  Last, a roller can be used to create a rough surface which catches the debris like Velcro.  This last step is not necessary, but makes the view using magnification more interesting. The entire process is very fast and neat.

I have also found that rolling Vaseline with a foam roller can be a bit stiff, so have taken to using a few squirts of baby oil onto the surface as well. I don't like the smell, but the dispenser is handy.  I suppose I could buy scentless next time or just refill from a mineral oil bottle.

The lines on the drop board are simply there to make examining the boards easier as they provide a track to follow when counting.  Without them, the eye cannot always know where it has counted and where not.

A good explanation of how varroa develop in cells.

Here is an Excerpt from COMPARATIVE ANALYSES OF SAMPLING METHODS FOR VARROA MITES
(Varroa Destructor Anderson and Trueman) ON HONEY BEES (Apis meiliferra L .)
Shawn Michael Devlin B.Sc., Simon Fraser University, 1998

Data collected from the colonies sampled in April were not able to predict the absolute mite level in each colony (Figures 1. 2 and 13). Most methods were able to detect some mites except for the ether roll and brood sampling in which no mites were found. The 24 or 48 hour natural mite drops were not predictive of absolute mite levels (R' = 0.43 1. P = 0.055), (R' = 0.149. P = 0.305) respectively. In addition. the alcohol wash was not predictive of absolute mite levels (R' = 0.183, P = 0.25 1). Absolute mite levels ranged from 1 to 68 and the mean was 40.

Data collected in June showed relationships between some of the sampling methods and absolute mite levels (Figures 3 - 5 and 13). The 24 and 48 hour natural mite drops were predictive of absolute mite levels (R' = 0.6 18, P = 0.007) and (R' = 0.544, P = 0.015). However, the alcohol wash did not predict mite levels (R' = 0.018. P = 0.71 3). nor did the ether roll (R' = 0.004. P = 0.868). Brood sampling was unable to detect any mites again. The 24 hourApistan drop was highly predictive of absolute mite levels (R' = 0.884. P < 0.000). Absolute mite levels ranged from 21 to 318 and the mean was 96.

Data collected in September showed a highly significant relationship between all the sampling methods and the absolute mite levels (Figures 6 - 8 and 13). The 24 and 48 hour natural mite drops were particularly good at predicting absolute mite levels ( R = 0.789. P < 0.000). (R? = 0.824. P < 0.000). as were the alcohol wash (R' = 0.579. P < 0.000) and the ether roll (R' = 0.849, P < 0.000). Brood sampling also was predictive (R' = 0.8 15- P < 0.000) The 24 hour Apistan drop predicted absolute mite levels well (R' = 0.678. P < 0.000). The absolute mite levels ranged from 561 to 10,952 with a mean of 2,583.

Recommendations for Management of Honey Bee Diseases and Parasites in Alberta 2011

On BEE-L:

> I am seeing as much as 40% pale mites and that indicates that there is brood in these hives.

> Why does pale colored mites indicate there is emerging brood in a hive? I have read this before, seen it in hives but do not know why. I have an idea why this is true but would like more than my imagination to back the statement up. I have searched the archives and Google but never saw the reason.

Varroa Mite Life Cycle ChartI thought the answer to that one would be easy, but nowhere is the answer clearly explained, or exactly at which point in the development process, a mite becomes able to live outside the cell.  The PDF at left comes close, but does not spell it out.

I spent the morning reading and searching an never did get a clear-cut answer explaining how to determine of a pale mite is an adult, has been mated, and is viable or not. It seems to get harder and harder to get real information on the web, as most sites seem superficial and many just repeat one another.

I did, however find various estimates for the lifespan of a mother mite and the low end is 50 days in summer.  If I use that number instead of the 100 days I have always used, which probably applies to fall populations with less brood than I have, then I am approaching 92% mite kill, not 46%.  I don't think so.  I'm guessing that the number lies somewhere in between.  If I don't count the palest mites, that would also change the results.

Bill did come across with at least a partial answer:

> ...The pail color is an immature mite which can happen only during reproduction cycle inside capped brood cell. When the bee emerges these fall off. They do not count as they cannot cause future damage.

> For complete info reed: http://www.mitegone.com/pdfpages/Varroa%20Reproductions%20Guideline.pdf

Here are today's mite drop results. The count is diminishing daily.  I am still seeing some immature mites in the drop. I checked the screens to make sure they are open.  From what I can see, there is no debris on them that would impede mite fall.

Varroa drop results.  Click to enlarge
Click to enlarge

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Sunday October 23rd 2011
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Live Varroa jacobsoni (Mesostigmata: Varroidae) fallen from honey bee (Hymenoptera: Apidae) colonies.
Webster TC, Thacker EM, Vorisek FE. - J Econ Entomol. 2000 Dec;93(6):1596-601.
Source: Community Research Service, Kentucky State University, Frankfort 40601, USA.

Abstract: The proportion of Varroa jacobsoni Oudemans that were alive and mobile when they fell from honey bees, Apis mellifera L., in hives was measured during a 20-wk period to determine the potential use of systems that prevent these mites from returning to the bees. Traps designed to discriminate between the live, fallen mites and those that are dead or immobile were used on hive bottom boards. A large fraction of the fallen mites was alive when acaricide was not in use and also when fluvalinate or coumaphos treatments were in the hives. The live proportion of mitefall increased during very hot weather. The proportion of mitefall that was alive was higher at the rear and sides of the hive compared with that falling from center frames near the hive entrance. More sclerotized than callow mites were alive when they fell. A screen-covered trap that covers the entire hive bottom board requires a sticky barrier to retain all live mites. This trap or another method that prevents fallen, viable mites from returning to the hive is recommended as a part of an integrated control program. It also may slow the development of acaricide resistance in V. jacobsoni and allow the substitution of less hazardous chemicals for the acaricides currently in use.

*   *    *    *    *   *    *    *   

Further, quoting from this most amazing study:

"Lobb and Martin (1997) found that ’50% of the mites falling from hives in England were alive. During fluvalinate (Apistan) treatment in Kentucky hives, ’60% of the fallen V. jacobsoni were alive whentheyfell(WebsterandThacker1999).J.S.Pettis (personal communication) found that ’40% of the fallen mites in Maryland hives were alive when they fell"

I'm not seeing any live mites.  Can it be I am not looking closely enough?  Am I not trapping them? Are the ambient temperatures too low?

"The total mitefall and the proportion live mitefall tended to follow temperature (Fig. 4 A and B). A modest positive correlation was found between the proportion of live mitefall and mean daily high temperature (R 5 0.515), overall mean weekly temperature (R 5 0.508), and weekly mean low temperature (R 5 0.452). Weekly highest temperature was not correlated with proportion live mitefall (R 5 0.047). The longevity and mobility of adult female mites should not be underestimated. Often we observed live mites in the traps 2 or 3 d after they had been moved from the hives to the laboratory for examination.

And this:

"The large number of live mites falling from the bees during acaricide use suggests the possibility that these mites tend to be more resistant to the acaricide than those mites that were dead or immobile when they fell.

And this:

"Although the darker, sclerotized adult mites are overall more mobile than the callow mites, the latter also should be considered a threat to the bee colony. Lobb and Martin (1997) found that even the callow, fallen mites were often able to produce offspring when artificially introduced into honey bee brood cells.

*   *    *    *    *   *    *    *   

Survival of the mite Varroa jacobsoni Oud. (Mesostigmata: Varroidae) in broodless colonies of the honey bee Apis mellifera L. (Hymenoptera: Apidae)
F. Calatayud and M. J. Verdú

Abstract: Varroa mite free colonies of the honey bee Apis mellifera L. were artificially infested, with either parasitized bees or infested worker brood. Queens were kept in cages to provide broodless conditions during the experiment. Parasites that fell to the bottom of the hive were monitored at 3–4 days intervals for three months. An acaricide treatment was used to recover mites still alive after this time period. Survivorship at each interval was calculated and life table functions of the phoretic mite cohorts were obtained. Trends in survival of Varroa cohorts showed maximum lifespans ranging from 80 to 100 days. Life expectancy of these phoretic cohorts at the beginning of the experiment ranges between 19 to 41, with a mean of 31 days.

*   *    *    *    *   *    *    *   

Here are some excerpts:


Click to enlarge

"The figures include four functions: Ix or fraction of the original cohort alive at a given age class (each 3-4 days interval); qx or period mortality represent the probability of dying over these time intervals; dx or fraction of the original cohort that die in the age interval x to x+l; ex or life expectancy at age x. Slobodkin (1962) defined four survival curve patterns (lx). In type II a constant number of Varroa mites die per unit of time. In type III, period mortality or qx is constant. Our survival curves are a combination of patterns II and III of Slobodkin. Large portions of the curves are close to an exponential decrease of the mite survival. We managed samples of adult mites and nearly all had reached mature stage, thus mortality should not act heavily on the first age intervals. Nevertheless, almost all dx curves show the highest values at the beginning. It seems to be that a fraction of 20 to 60% of phoretic Varroa mites have a higher probability of dying in the first 20 days. Survival percentage ranges between 40 to 80 at this age. With respect to qx curves, there is a significant trait that should be mentioned. Beyond 50--60 days, probability of death reached the highest values, with great increases and decreases.

*   *   *   *   *   *   *   *   *  

I notice there is more drop today and that the bees are more active than yesterday.  Yesterday, they weren't coming out much, but today, they are flying quite a bit.  The drop is up too.  I am still seeing some tan-coloured and immature mites, but fewer as the days pass.

Below is the latest chart of the mite drop being recorded on the six hives in my yard.  I have changed the estimated lifespan of mites in the spreadsheet temporarily to 60 days from 100 and that has altered the curve. The ultimate number has yet to be determined.  The daily drop has not yet returned to the natural level observed before the treatment. 

From my reading, above, I don't know what to use as an estimated mite lifespan for the calculations.

Some might say that I'm "cooking the books", a trick that we all learn in university labs where we know what the result should be and arrange to arrive at that answer by whatever means necessary.  It can be an exercise in intellectual dishonesty and can be very destructive, but here everything is laid out in full view.

FWIW, although I sometimes revise my posts going back a few days as I see how they are misstated or ambiguous, I don't revise back further than that, so hopefully my errors and misapprehensions are there to see.

Looking at the benchmark at right, we can expect the accelerated drop to continue for several more weeks.  I am stretching the comparison, though since we do not know the original drops in the sample and also our hives have some brood, judging by the drop of light-coloured mites.

Varroa drop results.  Click to enlarge      Bee Yard Location on Map
At right, above, is where the hives are located right now, marked by a yellow pushpin.
Click to enlarge
Google Earth view

From BEE-L again:

> Jeff Pettis found that if the gap between the mesh and the collection tray was only half an inch all the living mites found their way back upstairs

That brings us back to the question: How sticky does a sticky board have to be to trap them?

Will a thin layer of Vaseline stop them?

Does anyone know?

A reply:

> I sure find wiggling mites stuck to vaseline on my sticky sheets.
Dave
South East Idaho

Why am I not seeing live mites?  Maybe I'm not looking closely enough?

Above is a picture from this interesting site, showing an adult and some nymphs

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Monday October 24th 2011
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At this point, I have learned some things about mite drops and sampling, even though I may not have observed and verified them myself, yet.

  • the mite ecosystem in a beehive is complex and not susceptible to simple analysis or accurate prediction

  • a significant percentage of the mites that drop -- up to half -- are alive  (I'm not seeing this)

  • if the conditions are right, live mites get back up into the cluster

  • where treatments are used, falling mites that live may be chemical resistant and only stunned

  • sticky surfaces, oil or physical distance from the bottom to the hive or open bottoms can prevent mites recovering

  • I may not have been using enough grease/oil and my earlier readings maybe low on that account (?)

  • up to half the mites that drop when brood is being raised are mites that were not mature (non-viable)

  • typical life expectancy of a mature adult mite which is forced to be phoretic varies from 20 to 100 days +/-

  • not all mites dropping in a hive necessarily get to the floor.  Some can be hung up and bees may carry some out.

  • using '100' as a multiplier when there is brood and when the entire floor surface is counted is too high

  • there is a great deal of variability between populations and no method of sampling is likely to be at all precise

  • statistical analysis requires homogeneity and that cannot be assumed, hence statistical analyses are suspect

  • there are always outliers when sampling and they may mean nothing.  Means are more illuminating

  • estimated mite loads alone may not give reliable warning of impending loss, especially where the mites are vectoring other pathogens

  • thresholds offered by researchers rely on set conditions and also on confidence in the results of sampling, which we know to be imprecise

  • yard averages may conceal the presence of severely infested hives which, due to their lowered resistance and multiple infested cells, are incubating pathogens which may spread through drifting and robbing

  • published thresholds, especially from out of region, should be regarded with distrust and used only as rough guidelines and upper limits

Here is today's mite drop charting.  I went early today by three hours and adjusted the counts to a 24-hour basis. I am still not seeing live mites or any sign that they have been moving around on the drop board.  Maybe it is still too cool when I collect the boards?  Mite drop and the percent of live mites in the drop are said to increase with temperature.


Click to enlarge

I'm still using 60 as a multiplier and I see that, arriving at the 90% estimated mite kill which using that multiplier gives, we are ahead of one benchmark (right).  That benchmark shows about 83% kill on day 11, so 60 may be may be too low, but our estimate is right in line with the other benchmark (the lower, pink line on image at left) which also shows 90% on day 11.

I am still seeing some pale mites, but fewer. The multiplier is not simply a guess at average mite lifespan, but a parameter which also must include in some consideration of the non-viable short-lived young mites in the drop. 

Perhaps, rather than trying to find one number and one calculation which accommodates both the mature mite life expectancy and the amount of new emergence, it would be wiser to calculate each separately, using the dark mite count for the former and the pale mite count for some latter calculation. The latter number should in some way correlate to the number of new mites emerging from cells. The results of the two computations would then be added in some fashion.  Then it would be best to count the dark mites and the pale ones separately.

By all accounts, it seems the oxalic vapour treatment effect is pretty well over by day 15, and for all intents and purposes completely attenuated by day 21.  Thus it seems that a repeat treatment could take place any time after day15, but it seems to me to be prudent to wait a bit longer to be sure that brood rearing has ended to whatever extent it will. By the end of the first week in November hives should be a close to broodless as we will be.

I don't know.  Have you noticed?  I seem to be getting quite obsessive about this mite drop thing. I'm even a bit shocked that the info on the web for us plebs is quite, what can I say? dumbed-down?  Yup.  That's it.  We're not stupid, but the real dope is hidden behind $30+ charges for a grab bag that is often as not full of feces.  The public sites are pretty superficial and incestuous.

I have  a few really good studies here, offered thanks to my buddies on the inside at the Skonk Works,  and shared some snippets.  Still, it seems a shame that what the people in the know offer to those of us outside the ivory tower is mostly Pablum.  We're not that stupid, yet we pay for the research through taxes and tuition for kids, and then have to pay for the scant offerings from within on a pay per view basis without really knowing if it is substantial or just fluff until it is bought and paid for.  The abstract (teaser) often says very little.  Typical prices can be $35 for a few pages of questionable worth.  That's crazy -- and wrong.

Information wants to be free.

I had enough -- I know when I have cabin fever -- and went to Airdrie to do some shopping,.

I bought some groceries and looked a flat screen TVs.  I never and I mean never watch TV, but do watch Netflix on my comp

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Tuesday October 25th 2011
Two Months until Christmas

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As I noted yesterday, I've been obsessing about the varroa drop.  Maybe it has to do with the loss last winter; maybe it has to do with not having spotted any earlier, then finding that I may have been missing them; or maybe I just have too much time on  my hands. 

What ever the reason, I am now somewhat satisfied that the mite loads are less than I feared and nothing like the mite loads last fall.  I'll keep checking, but maybe step back to sampling over two or three days at a time.  I'll also keep wondering why I don't see any live mites in the tray.

At this point, I would really appreciate any comments or questions.  Please feel free to post them in the Honey Bee World Forum or write me. As you can see, this has been quite a voyage of discovery and I am finding there is a lot I don't know and can't (yet) find out.

I know that quite a few people these pages and wonder why only a few post in the Honey Bee World Forum.  It is a great place to comment.  Is there a problem with registering or something else?  If so, please write me and let me know.

If anyone reading has access to papers on the nature and behaviour of varroa or URLs that cover these topics more than superficially, I would appreciate getting copies or pointers. 

One thing that has me currently wondering is why I am not seeing live varroa on the drop board.  Is the 8 degree Celsius maximum daily temperature here these days too cool for them? I'm seeing other tiny bugs walking around on the drop boards.  I suppose that is a hint that they are not sticky enough? Wasps are flying.


Click to enlarge

The drops are slowly tapering off.  I'm still seeing some immature mites on the board, but nothing alive.  I think that I'll have to really smear on the oil and see what happens.  The thing is that oil will kill them, so what will I learn, except maybe see a higher count?  Again, the image from Jean-Pierre is offered below.  I'm seeing the full range except for the ones left of the cut-off line.  On one board, I counted 1/4 of them coloured like the one just right of the line.

Here is an illustrated sequence showing the development of the bee along with varroa in a cell.

Begging pays off!  Here are some promising references:

I found a good way to search for these studies.  It seems that cutting and pasting the title of one study into Google often brings up other related papers since those exact words appear in the bibliographies!  Otherwise, the same result might be so far down the search results that I never see it.

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Wednesday October 26th 2011
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Click to enlarge

Today the trend continues down.  I decided to assess the number of younger mites in the drop and here is what I see:

 

Hive 1 2 3 4 5 6
Young/Total 2/3 2/19 8/16 20/39 8/21 1/12

That indicates to me that some are still hatching brood and some are almost broodless.  The conclusion in my mind is that to use mite drops, a qualitative assessment must accompany a count to get a closer interpretation.  

The estimated kill is now at 95% and mites are still dropping, so I think my mite load estimate was low and will need a slight adjustment.

I also see a cumulative average drop of 773 mites per hive and that works out to 773/35000=.022 or 2.2% based on an estimated adult bee population of 35,000.  The highest drop was 1160 in hive #2 and the lowest 393.  The 1160 means that the mite drop so far represents a number equal to 3.3%of the estimated adult bee population.  Hive #2 has very few young mites dropping, so probably has little brood.  I'll have to take a look at it when I get a chance. The 393 is hive #1 and it has only 3 dropping today and 2 of them are young.

The hive scale reading has dropped by 13 pounds since the 18th.  There are three good hives and goner on the scale.  13/(26-18)/3=about a half-pound a day per hive.

After I did the drops, I drove top Calgary for an eye exam, then did some shopping, arriving home around 8:30.

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Thursday October 27th 2011
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I've been assuming the populations, and hive condition for the six I have been monitoring, but I'm thinking it is time to lift some lids and see if I have been making false assumptions.  Maybe the hives have dwindled since I last looked.  Maybe the populations are not as assumed.   After all, my calculations depend on the hives having populations around 35,000 bees.  I'm going to look stupid if I am 'way off.

I am also still learning how to make a drop board that catches everything, but is easy to maintain.  Yesterday, I discovered that mineral oil soaks into the masonite over a few hours.  I suppose that after a while, the board will be saturated, and I do still use Vaseline, but if the board does not stop mites in their tracks, it will give inaccurate counts.


Click to enlarge

 I adjusted my multiplier to 65, since the plot indicated we are approaching 100% kill, but we cannot be. There are still mites falling.

We are now at day 14 and since the worker bee capping period is 12 days, and since the mites go into cells just before capping, any foundress mites emerging from this point on should have been exposed to the oxalic vapour, and we should start seeing a decrease in young mites -- if the mothers were affected by the treatment.

*   *   *   *   *   *   *   *   *  

I checked the hives quickly for populations and I think my guestimates are close.  The weakest of the mite drop hives is in two boxes, weighs a ton and has bees showing on the bottoms of six frames when I tip it forward to look.  Their floor is clean, as we can see (left).  We can also see that a few mites land on the sides and the front and back of the bottom board and if a mite that lands there goes through the screen, it is only because a bee did not carry it out and it got brushed onto the screen or dropped by a house bee.  At right is what I see if I peel back the pillow on another of the hives.  Nine frames with bees, and more below, I am sure.

Mid-afternoon, I decided to start preparing the hives for winter.  As mentioned previously, some hives have newly-drawn comb on top and I am planning to put that on the bottom and put the established brood chambers on top.  I began, and the first hive I looked at was a drone layer.  No very encouraging.

It is also chilly, with a north wind blowing.  The bees are active though and it should all work out fine.  I don't plan to do more than a few today.

*   *   *   *   *   *   *   *   *  

I have 12 hives ready for winter now, so I'm almost half done.  They range from one which is five high to one which is a double. I may move them to a more sheltered spot before winter sets in.  Maybe I should add a box of feed under the double, too. Right now, though, it is in my varroa drop experiment and I don't want to disturb those colonies.

In moving the hives around, I separated a number of boxes so I could carry them, and can see that the hives are strong.  Interestingly, the top boxes are heavy, packed with feed and the bottom boxes are relatively light.  The bees are typically clustered in the bottom two boxes.  This would have been a perfect chance to to do oxalic acid drizzle since  exposed the tops of the boxes.  I placed the top boxes, which are packed with honey on new comb onto new floors and then reassembled the rest of the hive on top, taking care not to interchange or rotate the other boxes.

I did not pull frames.  My intent is to cause as little disruption as possible, and to leave as little damage for the bees to fix up after as possible, since it is late in the season.

The EPS (BeeMax) boxes separate quite nicely and are not suffering damage if I am careful to slide the hive tool in far enough and to be careful how I pry.  If the frames bottoms are stuck to the top bars below, which on occasion they are, prying carefully between the frames through a 2 inch crack at the front, created by lifting the front of the upper of the two boxes a bit, separates them with little problem.  Joe Standing on the new EPS bee box

A wooden wedge or block to hold the crack open would be handy, as these boxes weigh 80 pounds in some cases and holding the upper box while prying can be a bit of an exercise.

South-facing hivesThese BeeMax boxes are not strong and I exercised caution lifting them and them putting down.  The new Meijer EPS boxes are far stronger and can be handled more roughly, but are still not quite as tough as wood for taking abuse.  EPS dents more easily than wood.  This does not much matter except on the mating surfaces where a bad dent would lead to a poor seal.

A bit of air leakage might not necessarily be a bad thing, since I noticed a lot of moisture under the pillows on tall hives.  I had closed all the auger holes and decided to open them again.  EPS hives are quite airtight and they need some ventilation.  I did not have good luck with the EPS boxes until I drilled 1" auger holes in the front and back of each.  I close the back holes and any front holes I want to close up with 1" Caplugs.

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Friday October 28th 2011
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This morning is cool, dark, and a bit breezy.  I went out and got the drop boards.  I have to say that today, with thick Vaseline, they are hard to read.  The mites tend to fall edge-down and that makes them hard to identify.  They are very thin. The Vaseline is very shiny, too and the reflective surface adds to the difficulty.  I'm seeing fewer young mites now, as expected. I don't know if I caught any more mites than I did with less grease.

 
Click to enlarge

The counts have not changed much from before the treatment.   If indeed there was 92% kill, though, the drops should diminish from the beginning drops from before the treatment.  Using today's drops and a 65 multiple, as I would for natural drop, we still predict a total mite load of 1040 average and that is still 3%!  The 65 multiple should be high, though, assuming that the fumes reduced mite lifespan, but I just don't know.  Time will tell.

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Saturday October 29th 2011
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Click to enlarge

When I went out to get the boards, I found that I had forgotten to place a board under hive #3, so I just used the average for that hive from the past two days in the chart to keep the place filled and to compute the average.

I see the drop is slowly decreasing.  The young mite count is going down in the hives, too, but I am still seeing some, so there is still brood hatching.

Hive 1 2 3 4 5 6
Young/Total Oct 26 2/3 2/19 8/16 20/39 8/21 1/12
Young/Total Oct 29 0 0 ND 5/22 12/27 0

I'm tempted to put a strip of Apistan or Apivar into one of the monitored hives -- or all of them, just to get an idea of what the residual population of phoretic mites is, but I am holding off.  We plan to treat again, too, once the brood has all hatched, and I think the continuing drop of pale-coloured mites is an indicator that hives 3, 4, and 5 still are hatching brood.

My two benchmarks differ on their efficacy at this point, with one showing 96% of mites killed and the other showing 86% dead.  I'm just using these charts for reference curves and have no real idea what efficacy we have achieved here, but assume that our curve should have a similar shape, which it has so far. 

Both curves are for colonies with no brood and we do have some brood, so the fit is not perfect, and could be a ways off, especially as to the end point.  Even if we have the same kill curve, we might still conceivably have 50% of the mites left in the hives with brood.

Below are the individual curves for the six hives.  They are not all the same and some make me wonder if I somehow made an error and switched boards or somehow miscalculated, but when I look closely, I can't see where any data could have been interchanged. I chose to use the same scale for all.


Click to enlarge

Here is the chart for all six averaged.

BTW, you may notice some small errors in the daily presentations.  I usually catch them in a day or two.  Most of them come from Excel Hell.

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Sunday October 30th 2011
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Hive 1 2 3 4 5 6
Young/Total Oct 26 2/3 2/19 8/16 20/39 8/21 1/12
Young/Total Oct 29 0 0 ND 5/22 12/27 0
Young/Total Oct 30 0 4/16 8/21 6/18 6/22 4/18

Which am I calling "young"?  It is a bit of a guess, but I am calling any left of the 3 mites on the right (below), young.  They are not necessarily immature, but to my understanding, they are fairly recently emerged.

I'm looking at the drops to date and see the counts have leveled off and even ticked up a bit today.

Mid-afternoon, I wandered out to the yard and noticed robbing.  I had reduced some entrances but not others and moved some hives around on cool days and assumed that all would be well.  I could not identify any particular victim hive, but it seemed that when I opened top entrances to reduce moisture, that the neigbouring bees noticed, but the owners were half-asleep below. That happens.  It's a particular problem with filling hivetop feeders late in the fall.

I closed up holes and began working over the hives.  When I was

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Monday October 31st 2011
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Halloween

Hive 1 2 3 4 5 6
Young/Total Oct 26 2/3 2/19 8/16 20/39 8/21 1/12
Young/Total Oct 29 0 0 ND 5/22 12/27 0
Young/Total Oct 30 0 4/16 8/21 6/18 6/22 4/18
Young/Total Oct 31 0 0/28 22/42 14/30 30/91 1/13

I have been noticing dents in the top surface of some of the paler coloured dropping mites.  As I continue this investigation, I find that observe more. 

Yesterday, it was unexpectedly warm and there was some robbing in the yard.  I had not reduced all entrances equally and also, I had opened some top holes to reduce moisture. and the hives with screened bottoms seemed to be getting attention.  At any rate, I am wondering if the markedly higher drop may be the result of  the defenses or mites from robbing bees.  I found 10 or more bee legs on some of the boards, and figure this must be from tussles between guards and robbers.

Also, I noticed a lot more uncapping debris than usual on the boards, since the colonies were very active and, I assume, rearranging stores.  Some could have been from surreptitious "progressive" robbing, particularly where I found entire cappings on the board.

Additionally, I smoked hive #2 heavily and repeatedly over ten minutes to test the claim I have heard that smoke drops mites.  Comparing the drops from all six hives, I don't really see any effect at all.  I picked#2 because it seemed to be quite a typical hive, judging by its curves.

Obviously, I have brood ongoing in at least some of the hives and that has affected the effectiveness of the oxalic vapour.  At this point, I really don't know what is going on except that we did knock down some mites.  I think I'm dreaming, though if I think we got anywhere near 90%.

Today turned out to be warm, too, and I'm wondering if I should be charting temperature as well as drop.  Could they be related?

I changed the oil and the thermostat on the red van this afternoon after we returned from Three Hills, but did not do anything to the bees today except change mite boards.

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