If at first you don't succeed

[Bobbee]

After losing my first two bee colonies this past year I have decided to do up a plan and run it past the beekeepers here at the bee master forum.
Step one is to obtain new nucs. I plan on sticking with the same local supplier.His 5 frame nucs cost less that a package from the bee supply stores in the area.
A change will be both hives equipped with screened bottom boards in order to monitor mite drop after an OA treatment.
Rather than accept his word that the nucs are varroa free this time.I would like to treat at the 30 day mark with 3  treatments 3 days apart of 1.5 to 2 gm s per treatment.
I plan (at the moment ) to treat without doing a wash or roll as 300 bees from a new nuc seems a little much.With a sticky board I think I will get a good idea of the mite count from the drop.
After another 30 days three hundred bees will be less of a hit to the colony and I can do a wash.? (Opinions)
On the subject of mite treatment I will not use Apivar or any other synthetic pesticide/miticide.
Another change will be moving to a single deep brood with a QX. I watched a video by Devan Rawn and he made a lot of sense to me that it will make monitoring colony health  much more simple.
Feeding?? 1:1 SW I will keep giving it to them as long as they accept it. Pollen supplement however I am less sure of. Dry or patties? If patties I would like to make my own. If dry Would a 50/50 mix of Bee Pro and  re powdered fresh bee pollen be a good start?I have 2 lbs of fresh pollen vacuum sealed in the freezer.
That is about how far my thinking has got me. I want very much to succeed next year.Losing my bees twice in a row? Not really an option.

[little john]

3 treatments 3 days apart is not enough to cover the brood life-cycle of 20 (+/-1) days for workers, or 24 (+/-1) days for drones.  I now multi-treat during the season at 5 day intervals (although a 4 day interval would probably be even better), and one good dose on a mild day during mid-winter, when the colonies are hopefully broodless.

With regard to boxes, if you decide to install 5-frame nucs into 10-frame boxes, suggest you make and use a dummy (or follower) board at first to minimise the cavity size, and then gradually open-up the size as each nucleus colony develops.  Another possibility would be to employ two nuc boxes in a five-over-five stack. I find that small colonies grow very quickly within that format.

If your aim is solely to get colonies alive through the season and subsequent winter, rather than take a honey crop, then you might want to re-consider the use of a QX.

I'd also suggest you consider giving them smaller amounts of a thicker syrup - that will occupy less space in the combs for a given amount of energy. Although the nucs will certainly benefit from being fed, it's essential that the queen is not denied room to lay.
Best of luck.
LJ

[Bobbee]

Ty for your reply.
The 3 treatments 3 days apart are not meant to cover the whole life cycle of the bee.It is meant to cover the period of time the cell is capped and not susceptible to the effect of OA.Those cells that are capped during this period will be (hopefully) free of varroa While those bees that emerge during this period will be exposed to OA right off the bat before the mites  have had time to migrate to a new cell.
I like the idea of follower boards and 5 over 5..I'm going to look into that .It makes sense

[little john]

An interesting strategy - let us know how you get on.  I'm relying on memory now (which isn't all that good) - but I seem to remember that the 'whole life-cycle protocol' was adopted following measured VOA success rates of around 97%, in an attempt to catch that missing 3% which might possibly have been due to mites entering cells earlier than expected, which then protected them from the OA dust.  Of course, that small percentage could also have been due to re-infestation from outside the hive. Lots of unknowns ...

It'll be good to hear how you get on.
LJ

[TheHoneyPump]

Ty for your reply.
The 3 treatments 3 days apart are not meant to cover the whole life cycle of the bee.It is meant to cover the period of time the cell is capped and not susceptible to the effect of OA.Those cells that are capped during this period will be (hopefully) free of varroa While those bees that emerge during this period will be exposed to OA right off the bat before the mites  have had time to migrate to a new cell.
I like the idea of follower boards and 5 over 5..I'm going to look into that .It makes sense

1st.  Do not doubt your supplier. The nuc may truly bee mite free when you get it, or at least below detectable threshold.  However, soon as you place it in a communal area with neighbouring beekeepers the infestation from others begins.
2nd. On the OA treatment. If you want to catch them all, including drone dwelling mites, then your prescribed regiment is:  4 days between treatments X 6 treatments.  7 treatments will knock out that last 1 to 3 percent.    Imho, Your 3x3 proposed is not going to be effective at all.  Suggest to not bother with it unless you are prepared to step up the regimen.
With mites there is no half baked effort, no middle ground, no partial or tempered approach to be taken.  If you are going to keep bees; you have to go all in, have an effective full assault plan, or do not bother. 

Hope that helps!

[Beeboy01]

I had a bad year with nucs this year. All were split offs from my current hives with larger brood populations and done for swarm control as well as trying to build up the yard some. Now in retrospect looking back at the problems my yard suffered I can only think the nuc losses were due to not treating for mites in a timely manner. I also was deficient on jumping on small hive beetle control in the nucs. 

If anything I made the mite problem worse by transferring extra brood frames over to the nucs to help maintain their population as they requeened. My bee yard is pretty tight so there had to be some drift between hives also.

 I'm totally with HP about going all out for mite control, any half way measures just isn't going to work. Lost three nucs out of four and one hive due to my miss management this year.

  I'm re-evaluating my goals and management philosophy over the winter with effective pest control moving into the first position. Planning on building some screened bottom boards with trays for the nucs as a start.

[van from Arkansas]

Regarding treatment with Oxalic acid, OAV, one needs to know how long the residual effects of the acid last in the bee hive to determine the time frame between treatments: 3 day? 4 days? 5 days?

I do not know how long OAV remains effective at killing mites in a hive.  I know both LJ and HP are successful with bees so I am listening.  However, I have never seen a study to determine effective time of OAV.  After treatment with OAV,  I see a significant mite drop on bottom board after 24 hrs with sustained but lessor mite drop for up to a week.

I realize the acid is affected by buffering agents within a hive causing a degree of variation between hives... I am just asking for a general idea of WHAT IS THE TIME FRAME OXALIC ACID KILL MITES IN A HIVE?

Nice to have you back Lil John.

[little john]

Regarding treatment with Oxalic acid, OAV, one needs to know how long the residual effects of the acid last in the bee hive to determine the time frame between treatments: 3 day? 4 days? 5 days?
[...]
Nice to have you back Lil John.

Hi Van - thanks.

The time-frame between treatments is determined not by residual potency, but by the period during which the mite is 'phoretic' (*) - and thus vulnerable to death from contact with Oxalic Acid. This phoretic period is generally considered to be between 5 and 11 days, so a 5-day interval appears to be the recommended maximum between treatments, with 4 days being safer. I have seen some research which demonstrated that the majority of mites had a phoretic period of 7 days - but when treating we're really after those '5 day' characters.
Hope this helps.
LJ

(*) It ain't true phoresy - but the term has stuck, so we might as well use it, even though it's not absolutely correct.

BTW - how is your Cordovan queen-breeding project doing ?

[van from Arkansas]

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

[van from Arkansas]

Regarding treatment with Oxalic acid, OAV, one needs to know how long the residual effects of the acid last in the bee hive to determine the time frame between treatments: 3 day? 4 days? 5 days?
[...]
Nice to have you back Lil John.

Hi Van - thanks.

The time-frame between treatments is determined not by residual potency, but by the period during which the mite is 'phoretic' (*) - and thus vulnerable to death from contact with Oxalic Acid. This phoretic period is generally considered to be between 5 and 11 days, so a 5-day interval appears to be the recommended maximum between treatments, with 4 days being safer. I have seen some research which demonstrated that the majority of mites had a phoretic period of 7 days - but when treating we're really after those '5 day' characters.
Hope this helps.
LJ

(*) It ain't true phoresy - but the term has stuck, so we might as well use it, even though it's not absolutely correct.

BTW - how is your Cordovan queen-breeding project doing ?

Agreed the mites are not phoretic, but like you said the term is here to stay.  My Alpha Cordovan queen lived 4 years two months.  I am in process of selecting a new breeder queen but as you know this takes over a year to find such a gem

What if the Oxalic acid is neutralized prior to mite leaving capped cell entering phoretic stage?   Like say a mite is safely under a capped cell for 7 days and I treat on day one, I.e. would the acid have effect 6 days later?  Thanks for your time Lil John.

Health to your bees, everyone.
Van

[Beeboy01]

Back a few years ago when I treated a heavily infested hive and counted the mite drop on a daily basis I ended up finding the most effective control was treating when the kill count had dropped to 50% of the initial count done at 24 hours. In other words if the drop at 24 hours was 250 mites I would treat again when the count was 125 mites which was a rough lethal dose of 50% . That always seemed to occur after 72 hours or three days. I ended up treating then performing the next treatment on the third day after the initial treatment. Using this spacing between treatments I would recommend six or seven treatments to cover two mite life cycles. There wasn't any way to actually monitor the level of oxalic acid in the hive which could of dissipated after the first day but I was more interested in the daily mite kill.  Just my take on it.
 
  My losses this year were because I didn't follow my own advice.

I'll post my graph if anyone is interested.

[van from Arkansas]

3 days, thank you BEEBOY, that seem to coincide +- with LJ and HP above text.

[Bobbee]

A couple of pics or ...https://www.flickr.com/photos/184569342@N05/with/50574767047/
Larva capped brood and pollen from one of my dead hives. From the two hives combined I pulled 8liters if honey. Approximately 2 us gallons.

[Bobbee]

I want to thank everyone for their input.It is the response I was hoping for.
I have been reading and rereading all the posts I can see that I need to continue  studying.I need to mesh what I am learning here with what I know And re examine what I "know" to be sure that it is so.
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)

[little john]

What if the Oxalic acid is neutralized prior to mite leaving capped cell entering phoretic stage?   Like say a mite is safely under a capped cell for 7 days and I treat on day one, I.e. would the acid have effect 6 days later?  Thanks for your time Lil John.

Hi Van

first of all it's useful to know why a varroa mite needs a phoretic period at all - why not just keep emerging from cells and re-enter new ones immediately ? It's because there's not enough energy-rich nutrition to be obtained from the larvae.  Indeed, there's not enough energy-rich nutrition to be obtained from the bee's haemolymph either - that was the observation which kicked-off Samuel Ramsey's brilliant discovery that mites actually feed on the bees' fat-body - which is energy-rich.

So - no matter what circumstances might affect each individual mite, it must spend a number of days (currently thought to be a minimum of 5) feeding from the energy-rich fat-body of a bee before undergoing reproduction - either in the host hive, or if it can catch a ride (which then of course would be true phoresy) out of the hive to infest another. It's during that 5-day period (whenever that should happen) when it becomes vulnerable to OA - hence the need to cover an extended period, more than that which simple theory alone suggests.

Sorry to hijack your thread, Bobbee - I just wanted to answer Van's question.
I like your Mark Twain quote - I'll be using it myself in a few days. So thanks for that.
LJ

[Bobbee]

Sorry to hijack your thread, Bobbee - I just wanted to answer Van's question.

All good.Knowledge gained is always welcome.
BTW science has found that varroa does not feed on hemolymph but rather the bees fatbody. Ill look for the vid and post the link.

[Bobbee]

https://www.youtube.com/watch?v=z2plL5NIRcw

[little john]

it's useful to know why a varroa mite needs a phoretic period at all - why not just keep emerging from cells and re-enter new ones immediately ? It's because there's not enough energy-rich nutrition to be obtained from the larvae.  Indeed, there's not enough energy-rich nutrition to be obtained from the bee's haemolymph either - that was the observation which kicked-off Samuel Ramsey's brilliant discovery that mites actually feed on the bees' fat-body - which is energy-rich.

Bobbee - many thanks for the link to that video.  The story has changed somewhat since I first saw Ramsey's presentation (which was before he was awarded a PhD). That presentation was less entertaining (LOL) than the one you linked to, and focused more on calculations of energy requirements etc. Most significantly there was no mention at that time that larvae contain large amounts of fat-body - which throws my understanding of the fundamental need for a 'phoretic stage' completely out of the window.

So - if larvae can indeed provide sufficient nutrient, there would appear to be no obvious advantage in having a phoretic stage at all - the mite could simply reproduce in the cell, emerge, and then re-enter another open cell immediately, and so reproduce at a much faster rate - causing havoc in the process (until winter, of course, which would seal it's fate). I'll drop Ramsey a line and see what his thoughts are.
Again, thanks.
LJ 

[van from Arkansas]

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

Ramsey demonstrated a mite cannot survive longer than 48 hours without access to FatBody.  Now hold that thought.  Also note a mite is deaf and blind.  Now consider a single larva
FatBody  is depleted by mites as the feed.  The mites run out of food and have to find more FatBody before 48 hrs or the mite is starved to death.  With no eyes, no ears and only a sense of smell the mite leaves a cell hungry and hops on the first available food source, a nurse bee.

So why not jump into an adjacent cell?  The adjacent cell may be capped, empty or just have an egg that takes 3 days to develop into a larva, but in 3 days, the mite is starved so again, hitching a ride in an immediately available nurse bee would be a bird in hand compared to two in the bush.

The above sound logical, yes I am stretching a bit, hypotheses, which is scientifically sound way of saying I am flat out guessing.

Best of all things, across the pond.

[TheHoneyPump]

Just fyi, I base my treatment interval of 4 days not on the mite lifecycle but on the honeybee life cycle. 
Bee Egg = 0 - 3.5 days
Bee Larvae = 3.5 - 9 days

Varroa enter the cell some time during the larvae stage. The mite either walks over from another cell or hitches a ride on a nurse bee to get to a new larvae. The time of opportunity for a mite to do so is the exposed bee larvae stage of 9-3.5 = 5.5 days.  To set a treatment interval, consider the scenario that the day of the OAV is the same day (or just before) that batches of eggs are hatching into minuscule larvae and is the same day (or just before) that new bees are emerging from under capped cells with mites on their backs.  Those mites were under caps, having just missed the OAV and now have their pickings of fresh new larvae.  They have 5.5 days to pick their next meal before the cells are capped, blocking them out. If the next OAV is in less than 5 days most of those mites should be exposed and killed.  If the next OAV is in more than 5 days those mites are again snuck under cappings and protected, being missed by the treatment. Thus the 4 day interval target.

How many treatments?  Same thing, use the lifecycle of the honeybee not the mite.  The cell is capped on day 9.  The bee emerges on day 21, day 24 for drones.  To catch all the mites emerging over the full period of the honeybee brood cycle, including those that snuck under a capped cell the day before the first treatment, then looking at 24 divide by 4 + 1 = 6 +1 treatments = 7 for total mop-up.

As for how long is the residual lethal effect of OAV on the mites, no idea. By observation, can only say that the bees hygiene and grooming activities are very prominent the following day and not as much after that.  By the end of 2nd day after the OAV treatment there are piles of dead mites being swept out the entrances, yet no where near as much grooming-like activity. Day 3, not much is going on that would indicate residual effects.

The 4 days works, longer interval does not imho.  Like others, this season I lapsed a bit here and there as I did not get back to some hives for 6 to 7 days.  Those 6/7d ones are by far the weakest colonies at end of October going into winter. I actually expect to lose 30%-50% of those over winter.  The ones that got the 4d shots x 6times, are strong healthy and happy - if you can tell when bees are happy. ;)

Hence, imho the full regimen is 4 day interval x 6 intervals to be most effective for my bees.
Do what fits best for you and your bees.


For a rather excellent read of how real world experience lines up with the hypothesis, take some time to go through and digest the full content and context here:
https://beemaster.com/forum/index.php?topic=51618.0