What constitutes a "heavy" varroa load?

[For want of a better word]

1000 mites??????? try nearly 9000 one of my hives dropped this no in a month

How the mitey have fallen.... misquote


Great thread but nobody has given a definitive answer to the OP... yet !!

​

 

[Ed Woods]

On of my hives completely covered the Apiguard tray with Propalis - is that a normal thing for them to do?

 

[The Riviera Kid]

Great thread but nobody has given a definitive answer to the OP... yet !!

I was just logging on to comment on the same thing... It's reasonably obvious that I should try and keep the mite levels as low as possible.

Maybe I should have phrased the question differently:

1) What "natrual" mite drop level should I expect over a fixed period (e.g. 3 days) for a single brood BN hive in mid season?

2) And the same question again but while treating with Apiguard?

 

[oliver90owner]

try nearly 9000 one of my hives dropped

Just goes to show they can survive a heavy infestation. However not the best way forward, is it Prognosis for successful over-wintering is less good than if the infestation was decidely lower.

Any longer and that colony could have collapsed very rapidly (say, little brood as colony starts to contract, for a period, then open brood increases and all the phoretic mites dive in, out of reach, and really destroy the next batch of brood. Thee weeks later, foragers are old and expiring and nearly all emerging brood is seriously handicapped by the mite reproduction (and mites have suddenly nearly doubled again, too!!) Bye bye colony.

I am surprised the infestation level had not been perceived as high, prior to that mite drop, but Toby will now know he needs to observe/check more closely. Lesson learned, one hopes. It is fairly obvious that the particular colony was surviving with considerably more than 1000 mites and this is exactly what the FERA doc says.. Surviving, no comment on reduced output of honey - and no comment on the hive next door, should that have a similar loading. One thing for sure - they would not have survived for so much longer without that intervention!

The FERA 1 000 mite level is a maximum regarded as tolerable. All the treatment graphs and mite increase times (to threshold again) in that document use the 1000 level as the warning and as the treatment initiation point. They keep saying things like 'collapse before the end of the season'. Remember 1 000 mites now is 2 000 by a months time. 'About' a thousand could be +5% or -25% quite easily. So that 2 000 mites could easily be 3 000.

Finman said something about 2% level in spring may well seriously affect the honey crop. Too true, but needs reading in careful context to the ever changing numbers. 2% may well be 1 000 mites (50 000 bees) but if the colony stops expanding while the varroa doesn't, that 2% is very rapidly exceeded as the colony peaks in numbers but the varroa keep increasing exponentially (and likely even worse with drone brood present). Another 4 months down the line and you have a mediochre crop and a dead colony!

To be honest, I don't know the infestation numbers in my colonies. I am not interested in absolute figures. If infestation is light, that is good enough for me. It is expected. If infestation is heavy, I have failed. It is far better to remain on top of the problem than try to recover from an excess. EVERY TIME!.

If I have a easy opportunity to hammer the mites with no cost to the bees, I do it - A/Ss per eg. I do not encourage extra drone brood to cull if it is not needed - due to the cost to the bees. All decisions to be taken, on the ground, after observation and consideration of all options.

I made a brood trap but have never used it. 27 days worth of brood discarded does not improve the crop - but again, if needed, it is better than losing a colony later on, and the lost forager bees may not have made a great deal of extra crop, anyway, (if the flow had gone over by the time the emerged bees were three weeks old). All needs to be thought through. A considerable amount of bee effort and bee resources goes into a month of brooding (I think the FERA document surprisingly says this is a 'no cost' treatment. Rowlocks to that assumption, for a start!).

If FERA are saying the threshold is 1000 mites, so be it. I will not argue with them. Instead I just take note and go away and do my own thing. I do know I rarely have a large mite drop - because I keep a careful eye on the potential problem, fix them at any opportunity, and THINK about the bees.

All that said, I am not 100% happy with this season, but I do know why - so no surprises in store. I am fully aware of the possible effects of some later-than-ideal treatments. Am I worried about winter survival? No, I am not. If they all survive, there will be some uniting in the spring anyway.

RAB

 

[Suzi Q]

I was just logging on to comment on the same thing... It's reasonably obvious that I should try and keep the mite levels as low as possible.

Maybe I should have phrased the question differently:

1) What "natrual" mite drop level should I expect over a fixed period (e.g. 3 days) for a single brood BN hive in mid season?

2) And the same question again but while treating with Apiguard?

Hi, this is from my record book on a hive this year, although I'm not very precise at recording, so plus or minus one or two. Natural mite drop of 5 a day; after 1st treatment of apiguard about 42 a day or about 300 a week. After second treatment about 15 a day or about 120 a week. It was easy enough to record the natural drop but after apiguard my figures really just became guesstimates! The natural mite drop now is about 3 - 4 a day. I haven't seen any deformed wings etc, but there is a hive in the apiary I share where it is pretty obvious what a high mite level can do to bees. Lots of bees with deformed wings, some bees dead before fully emerged, and varroa running around on the brood frames.

 

[For want of a better word]

Exellent definitive reply Tractor Man!

conclusion?

How many mites in colony is giving a drop of 27 +- over 3 days?

Threshold of 1000 mites in colony (50000 bees) is considered point to treat?

September treat with Apiguard... hope for massive drop?

Oxallic acid by trickle or sublimation in the depths of winter?

Sublimation can be given any time?
Trickle only when no brood?

AS in spring ( to rid colony of mite in brood cells)?

Keep icing sugar for cakes!

Seriously there seems to be some very confusing and conflicting advice.......

Doing nothing is not the answer.

What effect does thymolated syrup feed 2:1 in Autumn have on mite, I know it helps prevent mold / nosema...............

Can thymolated syrup be used as a spring feed at 1:1 ????


Roll on spring... I can get back to bait sausages and bee whistles!!!

 

[For want of a better word]

Suzi Q....
I would be reprimanding your fellow beek for lack of adequate treatment, may be a source of mite to hop on the back of your clean bees!

or planning to move your hives to another site

IMO... before icing sugar gets thrown at me!!

 

[Hivemaker.]

What effect does thymolated syrup feed 2:1 in Autumn have on mite, I know it helps prevent mold / nosema...............

It helps,if done correctly.

Submitted to: Journal of Apicultural Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 30, 2009
Publication Date: August 1, 2009
Citation: Sammataro, D., Finley, J.V., Leblanc, B.W., Wardell, G., Ahumada-Segura, F., Carroll, M.J. 2009. Feeding Essential Oils and 2-Heptanone in Sugar Syrup and Protein Diets to Honey Bees (Apis mellifera L.) as Potential Varroa Mite (Varroa destructor) Controls and Traced by SPME (Solid Phase Micro Extraction) Fibers. Journal of Apicultural Research 48(4):256-262.

Interpretive Summary: Essential oils and oil components were fed to honey bees in a sugar syrup and liquid protein diet in order to determine if the oils were being incorporated into the bee larvae and could be traced by means of SPME. The compounds used were origanum, 2-heptanone, thymol and cinnamon oil. The main component of origanum is carvacrol and when fed in sugar syrup, this compound was found in Day 4 and Day 9 larvae. The four day old bee larvae had 0.13ppb of carvacrol and the nine day old larvae had over 3000ppb. Carvacrol was also detected in the cocoons. There was no activity in any bee larvae for the two different 2-heptanone formulations fed in sugar syrup. When the oils were fed in liquid protein diet, the Day 4 larvae had no detectable levels of either origanum (carvacrol) or thymol. The Day 6 larvae had 0.01 ppg of carvacrol but no thymol. Both Day 9 larvae and cocoons had large amounts of both carvacrol and thymol. The highest was over 1 million ppb in the whole Day 9 larvae. The thymol was only detected in the Day 9 larvae at 51,097 ppb. No 2-heptanone or cinnamon oil added to the liquid protein diet was detected in any of the larvae. The very high levels of both carvacrol and thymol in the whole Day 9 larvae would certainly be enough to protect them against Varroa infestation. More recent work in this area has shown that this is true and may explain why bees given certain essential oil treatments protect immature bees from invading Varroa mites.

Technical Abstract: Essential oils and oil components were fed to honey bees in a sugar syrup and liquid protein diet in order to determine if the oils were being incorporated into the bee larvae and could be traced by means of SPME. The compounds used were origanum, 2-heptanone, thymol and connamon oil. The main component of origanum is carvacrol and when fed in sugar syrup, this compound was found in Day 4 and Day 9 larvae. The four day old bee larvae had 0.13ppb of carvacrol and the nine day old larvae had over 3000ppb. Carvacrol ws also detected in the cocoons. There was no activity in any bee larvae for the two different 2-heptanone formulations fed in sugar syrup. When the oils were fed in liquid protein diet, the Day 4 larve had no detectable levels of either origanum (carvacrol) or thymol. The Day 6 larvae had 0.01ppg of carvacrol but no thymol. Both Day 9 larvae and cocoons had large amounts of both carbacrol and thymol. The highest was over 1 million ppb in the whole Day 9 larvae. The thymol was only detected in the Day 9 larvae at 51,097ppb. No 2-heptanone or cinnamon oil added to the liquid protein diet was detected in any of the larvae. The very high levels of both carvacrol and thymol in the whole Day 9 larvae would certainly be enough to protect them against Varroa infestation. More recent work in this area has shown that this is true and may explain why bees given certain essential oil treatments protect immature bees from invading Varroa mites.

 

[itma]

The NBU Varroa booklet is well out of date. I can't see any bee inspector these days saying anything other than beekeepers should keep varroa levels as low as possible by appropriate treatment at the recommended times of the year - irrespective of what the varroa count might be - because it can be a very unreliable guide to the number of mites present.

Ummm.

Maybe you haven't met the two Bee Inspectors I've met in the last two months? One was actually giving a talk on non-chemical varroa controls.

Both stressed the importance of being aware of current mite-drop levels.
Both said don't try and eliminate or keep as low as possible (with its risks of over treating), rather treat to keep the problem at a tolerable level.
And both referred to the NBU/FERA/DEFRA booklet as the current gospel.

 

[Suzi Q]

'Hopit, I'm a newbee, I can't do any reprimanding! But I am going to move them, as soon as there is a prolonged cold snap I'm going to move them to a different site about 150 feet away. Is that far enough?

 

[drstitson]

Just been reading a paper from 2004 where they modelled mite populations together with DFV & APV and concluded:

"Our study shows that the current policy will help control
viral diseases in bee colonies. Autumn is the time at which the colony
is at greatest risk from viruses and maintaining a mite
population below 2500 will prevent APV epidemics
and confine DWV to low levels. To prevent DWV epidemics
would require treatment at smaller mite populations i.e. reducing the mite population to below 700. If prevention of DWV is an aim then this may be more easily achieved at the start of the summer when the threshold mite load required to eliminate DWV is larger."

http://www2.math.uu.se/~david/web/SumpterMartin04.pdf

 

[For want of a better word]

'Hopit, I'm a newbee, I can't do any reprimanding! But I am going to move them, as soon as there is a prolonged cold snap I'm going to move them to a different site about 150 feet away. Is that far enough?

You may be a newbeek, but that probably makes you more aware of bee diseases... possibly more than an oldbeek who is not keeping up to date... particularly on varroa mite control and consequences!

A varroa mite can hop quite a few millimeters, and that could be onto the back of one of your bees 150 meters... 1500 meters or even 3+ Km away.

We all have to treat!!!

perhaps you could pin a leaflet to the over infected hive????????

 

[itma]

... It's reasonably obvious that I should try and keep the mite levels as low as possible.

Someone has a sig with a quote about every question having an answer that is simple, obvious and wrong.

If you try and get the varroa population as low as possible (oxalic and shook swarm, and brood trapping, and drone culling, and Apiguard, etc - all in the same year) you will be over-treating - to the detriment of your bees and your crop.
The idea is just to keep the population - at all times - low enough to be tolerable.

Maybe I should have phrased the question differently:

1) What "natrual" mite drop level should I expect over a fixed period (e.g. 3 days) for a single brood BN hive in mid season?

2) And the same question again but while treating with Apiguard?

This depends on what the level of your varroa infestation actually is.

If you can read the graph on page 31 of "Managing Varroa" you'll recognise that a natural average daily drop of more than 10 at any time of the year means "effective controls" are required. Also, you'd see that from April to July, a drop of 1/day or less suggests that no control is "yet required".

As you will have seen from this thread, successful Apiguard treatment can knock down from hundreds to thousands of mites.
However a thinking beekeeper, having seen a daily natural mite drop of more than 10, but getting a treatment drop only in the low hundreds, should be questioning whether that treatment was successful. Apiguard for example needs warm weather, some headroom above the tray and a reasonably draught-free hive - to stand a good chance of success.

 

[RoofTops]

Itma - you are quoting me correctly but not reading what your are quoting. What I said was:

"...keep varroa levels as low as possible by appropriate treatment at the recommended times of the year"

The key words "...appropriate treatment at the recommended times of the year." I said nothing about over-treating or trying to eliminate the varroa.

 

[itma]

It helps,if done correctly.

Submitted to: Journal of Apicultural Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 30, 2009
Publication Date: August 1, 2009
Citation: Sammataro, D., Finley, J.V., Leblanc, B.W., Wardell, G., Ahumada-Segura, F., Carroll, M.J. 2009. Feeding Essential Oils and 2-Heptanone in Sugar Syrup and Protein Diets to Honey Bees (Apis mellifera L.) as Potential Varroa Mite (Varroa destructor) Controls and Traced by SPME (Solid Phase Micro Extraction) Fibers. Journal of Apicultural Research 48(4):256-262.

Interpretive Summary: Essential oils and oil components were fed to honey bees in a sugar syrup and liquid protein diet in order to determine if the oils were being incorporated into the bee larvae and could be traced by means of SPME. The compounds used were origanum, 2-heptanone, thymol and cinnamon oil. The main component of origanum is carvacrol and when fed in sugar syrup, this compound was found in Day 4 and Day 9 larvae. The four day old bee larvae had 0.13ppb of carvacrol and the nine day old larvae had over 3000ppb. Carvacrol was also detected in the cocoons. There was no activity in any bee larvae for the two different 2-heptanone formulations fed in sugar syrup.

When the oils were fed in liquid protein diet, the Day 4 larvae had no detectable levels of either origanum (carvacrol) or thymol. The Day 6 larvae had 0.01 ppg of carvacrol but no thymol. Both Day 9 larvae and cocoons had large amounts of both carvacrol and thymol. The highest was over 1 million ppb in the whole Day 9 larvae. The thymol was only detected in the Day 9 larvae at 51,097 ppb. No 2-heptanone or cinnamon oil added to the liquid protein diet was detected in any of the larvae. The very high levels of both carvacrol and thymol in the whole Day 9 larvae would certainly be enough to protect them against Varroa infestation. More recent work in this area has shown that this is true and may explain why bees given certain essential oil treatments protect immature bees from invading Varroa mites.

If I'm reading that right, it says Origanum/Carvacrol was transferred to the bee larvae from both syrup and "liquid protein diet". And that Thymol also transferred from the liquid protein.
But I'm not seeing any mention of Thymol transfer from the syrup ... ?

I'm also wondering whether (or not) these oils were emulsified into the syrup, as that would surely be helpful to increase their uptake?

 

[itma]

Itma - you are quoting me correctly but not reading what your are quoting. What I said was:

"...keep varroa levels as low as possible by appropriate treatment at the recommended times of the year"

The key words "...appropriate treatment at the recommended times of the year." I said nothing about over-treating or trying to eliminate the varroa.

The point I was attempting to highlight is that the official advice, echoed by the Bee Inspectors I have chatted with informally, is that the appropriate treatment is not to constantly try to minimise varroa numbers.
The 'biggest hammer' available (at any particular time of year) is not always the most appropriate tool.

There is no dispute that treatments should only be applied at the times recommended for those treatments.
There might be some dispute as to whether any specific treatment ought to be used routinely at the same time, every year, completely regardless of the level of the varroa problem at that time.

 

[Hivemaker.]

Thymol contains carvacrol,and yes emulsified is best.

 

[drstitson]

"The oils were added in either sucrose syrup (origanum and 2-heptanone) or in a liquid protein diet (origanum oil, cinnamon oil, thymol, and 2-heptanone), because sugar and protein sources are differentially utilized in food fed to larvae of different ages. "

so they didn't try thymol in syrup for some reason known only to themselves.

 

[Suzi Q]

Umm hope this is not a silly question, so essential oils are ingested by larvae and that is a deterrent to varroa, but what effect, if any, does that have on the developing bees, other than deterring varroa?

 

[Hivemaker.]

This is an extract of how some use the essential oils in feed,i use thymol,lemon grass,and tea tree.

..........................................................................................................

1:1 cane sugar syrup with a dosing of specially formulated Red Thyme Oil, Oil of Oregano, and Lemongrass Oil with an extremely high level of Carvacrol which is derived from these oils as the main active ingredient...

We fed selected colonies with this before the buildup so the bees would feed this syrup to the brood for at least one full cycle... killing all of the wintering mites in the process... we have yet to find any mites in those colonies... and the mite counts within those yards are still only averaging 1 in ether wash tests... we will repeat the treatment in fall to any package production hives that have a count of 4 or more (assuming we can find any this year... its almost like they all went on vacation or something.. lol)... the fall treatment is to be fed to the last wave of brood that will become the winter bees... again killing off any mites that may have made it to the hives... thus going into the winter with no mites and a slow trickle of a mite killing agent being fed directly to the hosts that the mites would need to live off of... its a different approach than most other treatments take... there are no fumes (it does smell like a pizza resteraunt, but the smell is not the active agent), no oils or powders that the bees must spread throughout the hives as they try to clean it out or cross it, no temperature requirements and in fact its best if its used right in those cold days that the bees break cluster to take it up, but store it closely around the cluster due to the cold, meaning it gets used in its most effective manner earlier and later, and all of it is consumed well before the season really starts allow the buildup to be fed off of the true stores which gets there guttural enzymes back in order right away...