If at first you don't succeed

[van from Arkansas]

HP, thanks.  Well explained.

I am confused about the number of treatments, 7.  You used a full brood cycle, should not 9 days be used instead?  I am figuring capped brood only.  Thanks for your time.

Van

[TheHoneyPump]

Remember, the brood is in continuous development over time. The laying queen does not start-stop on # day intervals. Could probably figure this out down to the minute if wanted to cut it that fine. What we are doing is attempting to find the most effective but practical regimen which may be said as:  the largest interval and minimum number of periods that effectively covers the phases progression of brood development over one brood cycle.
When starting the first OAV blast there are bee eggs that have been freshly laid and there are many mites already under brood caps. The last of those having been capped just moments before the OAV was applied.  Those last ones will not be exposed until that phase of the brood cycle completes and the mites emerge with the new bees. After emergence there are 5d or less to catch those before the next cell they have infested is capped

To catch them all, or as many as is practically possible, the total time is that brief period (5d) of larvae stage before capping, plus the time capped for those missed in the first shot (24-9=15d), plus the brief period before those last mites find refuge with new larvae under new caps (5d).  That totals 25 days from the first OAV treatment to the last OAV treatment.  At 4 day intervals, 25/4 is 6.25 treatments.  6 gets the job mostly done, 7 finishes it off.

Not sure if that makes sense enough or not.  But there it is.  ;)

[van from Arkansas]

continuous brood cycle.

Of course, thank you HP.

[Bobbee]

OK I have a big smile on my face. All of this thread has been pure gold for me.
The questions I have now are the amount of OA per treatment and how that is calculated.
I will be starting next year with two packages with a further one or two five frame nucs when they are available in June. (local source)
The package bees will go into five frame nuc boxes containing five frames of drawn comb with a second 5 frame nuc box over the top for feeding purposes.
When the nuc needs more room I will add five frames of drawn comb to the upper box and reverse the boxes leaving the empty drawn comb below the now full frames.
The five frame nucs that I buy will go directly into a ten frame deep each with a further five frames of drawn comb.
My YouTube searches have found results of one to three grams to treat a colony.Very few if any actually even mentioned the volume of the hive at all nor how many grams of OA has been found to be optimal.

[van from Arkansas]

Research demonstrates: 1 gram of oxalic acid vaporized per 10 frame deep.  Two grams for a double deep.  I use 0.5 gram per 5 frame nuc.  Note I said Oxalic acid and I did not say Oxalic acid hydrate.
Hope this helps.

I can direct you to research papers, OAV per hive,  if you wish.  Let me know.

[beesnweeds]

https://pubmed.ncbi.nlm.nih.gov/26412538/

BTW:  I just read the above article that treating honeybees with Oxalic acid lowered Nosema spores in bee gut.  Nice to have a double whammy effect of Oxalic acid; mites and Nosema.  Not sure if I should have created a separate, new topic.  BobBee, I will move this post to a new thread and realist if you wish.  Just let me know.

Van

Great post.  I attended a seminar that Randy Oliver presented at and he did mention lower nosema counts after OAD treatments.  He guessed that it may purge the bee gut, nothing definite.  I did notice lower nosema counts and less instances of dysentery in my hives which could be coincidental but Im going to stick with December OAD treatments.

[Bobbee]

Research demonstrates: 1 gram of oxalic acid vaporized per 10 frame deep.  Two grams for a double deep.  I use 0.5 gram per 5 frame nuc.  Note I said Oxalic acid and I did not say Oxalic acid hydrate.
Hope this helps.

I can direct you to research papers, OAV per hive,  if you wish.  Let me know.

I am very interested in reading those research papers.
Also you raised an interesting point in making a distinction between Oxalic acid dihydrate and Oxalic acid.Do you dry your Oxalic acid before using ?And do you use a spoon to measure the dose or a scale.
I was quite surprised when I checked and found an approximately 30% difference in density between  the two forms.

[van from Arkansas]

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Requested article:  a very detailed article with data generated over 18 months to verify effects, of OAV on future hive health. 

I use a scale to verify my spoon holds one gram of Oxalic acid.  My spoon I believe is 1/4 teaspoon.

[little john]

LJ, as always you provoke thought with your question;  why a phoretic stage?

Hi Van - I owe you an apology ...

No sooner had Bobbee posted: "It Ain't What You Don't Know That Gets You Into Trouble. It's What You Know for Sure That Just Ain't So - Mark Twain", than I posted something as a statement of fact, only for it to turn out not to be true !  Talk about coincidence ...  Ok - so I now need to get some of that egg off my face. 

Back in 2017 I came across this:

Proceedings of the 2017 American Bee Research Conference

39. Varroa destructor feed primarily on honey bee fat body not hemolymph

Samuel D. Ramsey and Dennis vanEngelsdorp. Department of Entomology, University of Maryland, College Park.

Efforts to mitigate the elevated losses of honey bee colonies have reached a global context as one of the primary drivers of these losses, Varroa destructor, has achieved a nearly ubiquitous distribution. Better understanding of the association of this parasite and its host is integral to developing sustainable management practices but very little study, if any, exists as support for the heretofore uncontested conclusion that Varroa feed exclusively on the hemolymph of adult and immature honey bees. This study was conducted to determine the primary host tissue composing Varroa?s diet. Findings in a preliminary study suggest that the mites may feed on fat body. To test this hypothesis, honey bees were reared to specific ages corresponding to the development of the fat body and fed one of two fluorescent biostains ad libitum. The Uranine O biostain persisted in the hemolymph and Nile Red biostain persisted in the fat body. Mites were allowed to feed on these bees for 24 hours and were then crushed and placed in a spectrophotometer. The biostain associated with the fat tissue was present in Varroa in significantly greater proportions than the hemolymph biostain in all 4 honey bee age treatment groups. Varroa consumed 3 times as much fat body as hemolymph when allowed to feed on the age group associated with nurse bees, at which time fat body is at peak development. To determine the importance of each host tissue in Varroa?s diet, adult female mites were collected from uncapped brood in several untreated colonies. These mites were then placed in queen rearing cups lined with beeswax and fed fat body, hemolymph, or a combination of the two through an artificial membrane. Fecundity was measured and analyzed.  Varroa fed hemolymph produced no eggs while Varroa produced eggs in all treatments containing fat body. We are currently conducting studies of survivorship of mites fed on these two host tissues. Preliminary data shows Varroa fed only fat body have greater survivorship as well, which suggests that the ingestion of hemolymph may not be integral to growth and development of this mite.

At around this same time Brushy Mountain posted a 'webinar' (who makes up these awful names ?) in which the speaker focused upon the calorific content of fat-body viz-a-viz haemolymph, which appeared to suggest that the rationale for the feeding upon the fat-body of mature bees was in order to acquire enough stored energy to produce eggs - and at that point the whole thing began to make sense (to me).
That is - that there are 3 stages in the life-cycle of the mite: 2 feeding phases and one phoretic phase in which the mite hitches a ride in order to spread it's genetics further afield.

Two feeding phases are required: the first of these being contained within a sealed environment which is ideal for producing young without the risk of predation or dessication - the second being to acquire enough calories in order to be able to lay eggs within that first phase. Hence the confidence shown in what I wrote ...

But now Ramsey tells us that the larva is largely comprised of fat-body, and thus there will be sufficient calories within each larva in the form of fat-body to lay eggs !  Now the need for the second feeding stage (on the adult bee) doesn't make too much sense.  It's necessary for winter survival, sure, but would only cause an unnecessary reduction in the mite's reproduction rate during the season.

Unless ... the fat-body in the adult bee contains some component necessary for the juvenile mite to reach maturity - a component which doesn't exist within the larval fat-body ?  Well - it's a theory ...

One of the questions I'll be asking Samuel is whether the two types of fat-body have been subjected to comparative analysis.  My guess is that this will have already been done. 

'best
LJ

[van from Arkansas]

Hello LJ: no apologies needed, Buddy.

Samuels proved that the adult mite positions itself, with one leg extended like a tick, to latch on to a bee.  Most likely a nurse bee.  Assumption is a mite needs more food determine by mimic of a tick trying to acquire a host by latching on with the extended leg.  I know this all to well in Arkansas, tick area.

Some facts about mites:

1.  Must eat every 48 hours or starve.
2.  Reproduction of a mite is 28 days+-.
3.  Mite eggs are huge compared to body size of a mite, thus lots energy required.
4.  Mites lay multiple eggs in a cell, first egg develope into small male mite.
5.  Mites utilize a sense of smell as they are blind, deaf.
6.  Mites only feed on the FatBody, liver, power plant of a bee.
7.  The FatBody of a bee is greatly reduced in size after mite feed.
     a.  Reducing energy of a bee.
     b.  Energy reduced so much a bee can fly to flower but not enough energy to return to the hive.
     c.  Question: is the FatBody so reduced in size a mite seeks new host; extended leg.

Bee larva are mostly composed of FatBody which provide the energy for metamorphosis: worm to flying bee.  I still opinion that a mite is seeking new/more food entering what we call the phoretic stage.  Evolution may have instilled this hitching a ride to spread genetics is another possibility, which LJ stated.

I have deliberately not mentioned virus to avoid widening the subject base.

Health to your bees.

Van

[TheHoneyPump]

This one is a fairly decent article that pops up on a google search.

http://entnemdept.ufl.edu/creatures/misc/bees/varroa_mite.htm

Enjoy ...

[van from Arkansas]

Just a note.  Samuels did not discover the stretching of parafilm to feed an insect.  That was discovered by the Rocky Mountain Laboratories, NIH/NIAID upon feeding ticks in vitro, test tube.  I was surprised that Samuels took credit for this technique which was discover in the 1990?s by Schwan and Karstens.

[little john]

This one is a fairly decent article that pops up on a google search.

http://entnemdept.ufl.edu/creatures/misc/bees/varroa_mite.htm

Enjoy ...

Yes - a good article - but it needs to be supplemented with two more recent discoveries: the first is that we now know that the mites feed on fat-body, and not haemolymph as stated in that article. The second is perhaps even more devastating (if that's possible): the writers of that article apparently didn't know what was discovered in 2016, - that re-infestation can also occur via flowers !! - where the mite dismounts from one forager bee, and waits for another to come along.  How can anyone eradicate a mite which has all the bases covered like this ... ?

Link: https://www.researchgate.net/publication/311629056_Varroa_destructor_Mites_Can_Nimbly_Climb_from_Flowers_onto_Foraging_Honey_Bees/fulltext/5851982608ae7d33e0150ffa/Varroa-destructor-Mites-Can-Nimbly-Climb-from-Flowers-onto-Foraging-Honey-Bees.pdf

'best
LJ

Video: https://www.youtube.com/watch?v=Oij1HOxD3iU

(The mite is sitting on a petal on the left-hand side of the flower - keep your eye on that as the video runs)

[Bobbee]

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Requested article:  a very detailed article with data generated over 18 months to verify effects, of OAV on future hive health. 

I use a scale to verify my spoon holds one gram of Oxalic acid.  My spoon I believe is 1/4 teaspoon.

I see the picture but When I try to search for the article online no luck...so far.

[van from Arkansas]

That is an impressive video LJ.  That mite wasted no time to latch onto the bee.  Thanks for taking your time, well spent I might add.  Ding dang mites, is the best I can say for Varroa.

[van from Arkansas]

https://www.tandfonline.com/doi/full/10.1080/00218839.2015.1106777

This is link to article I posted above about Varroa and Oxalic acid.

This link works,I just tested.  This article is very detailed, many, very many detailed pages, no stones left unturned.
Van

[The15thMember]

Wow, that video is insane, Little John!  Somebody mentioned to me offhand one time that they thought they had seen a couple varroa mites on their flowers and I totally blew them off.  I figured there was no way that was possible.  Shows how much I know. . . . 

[beesonhay465]

my advice is to use an attractant and an old brood comb in a full sized hive. this should attract a good sized swarm of native bees. they have made it through a winter and are adapted to local conditions . feed, and when the brood box is 80% put on a super and stop feeding. dont harvest til next spring.got 26 lb of comb honey. worked for me. they swarmed 3 times this spring .caught 2. decided to get out of bees[age] and sold all three hives.$800