Treating swarms with OA

[jezd]

Sounds like sense to me given that we strive to treat Winter colonies when they have no brood - does it make sense to treat newly caught swarms with OA as soon as possible, followed by giving them a frame of brood from another hive.

Makes sense? (this maybe already in the big book of beekeeping )

Jez

PS Happy New Year to all

 

[victor meldrew]

I think you will find this topic has been visited on more than one occasion on this and other sites bbka for one . and yes oa trickling is recommended as a treatment for swarms !.

John Wilkinson

 

[jezd]

Its so cold here I could not reach the search button

 

[Finman]

Its so cold here I could not reach the search button

This perhaps helps

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

 

[jezd]

booo, speaking of dummies, I downloaded "Beekeeping Dummies 2nd ed", if anyone want a copy PM me

 

[victor meldrew]

Its so cold here I could not reach the search button

I surprised no one has jumped in to state 'swarms are relatively free of mites as they are in the brood of the parent colony during swarming time' .

John Wilkinson.
Ps it's damned cold here but the snow has disappeared for now at least .

 

[Poly Hive]

Happy New Year John and I for one have given up on other sites.

Personally I would have thought that the vast majority of mite load would be left behind and so treating the swarm might be to little benefit.

Treating them as part of the apiary management in due course, ie now when broodless would be my way of proceeding.

PH

 

[RoofTops]

I am not sure it is correct to say swarms have few mites. We often hear that 85% of the mites will be in sealed brood, which means the remaining 15% must be on the bees.

A swarm is therefore like carrying out a varroa treatment which is only 85% effective - which means in about 3 months or so (from the graphs in the CSL leaflet on varroa) the mite population will have risen to potentially dangerous levels.

I have used formic acid on swarms and used bait frames - and will continue to do so. I haven't tried OA on a swarm but will give that a go as well, as an alternative to the formic acid. Formic acid is convenient as it can be kept in the bottle whilst OA has to be made up as I chuck any surplus away after the winter treatment.

The advantage of a chemical treatment on a swarm is you can see any mites which fall - which you can't with a bait frame, but the latter is chemical free and effective.

 

[tonybloke]

I have been advised to use a tray of 'apiguard' on newly-hived swarms. ?

 

[gavin]

Some swarms can be covered in mites. One advantage they have is that by the time the new queen's brood gets sealed the mites will be rather old and tired, so anything to knock them back further will give the colony a better start and a longer time before numbers build up again. Last summer I had a big untreated colony (I was trying to raise mites to challenge tolerant colonies) and it remained queenless for a long time as the new queen didn't mate properly. Eventually managed to get a new one established but before that there was a drone layer, and the drone comb I sent a researcher who wanted living mites only contained dead ones, even though I hadn't treated. Earlier in the season drone comb sent through the post had lively mites.

Some use lactic acid for swarms, but I'm not sure what the advantage is over other organic acids. The sacrificial frame of unsealed brood has to be a good idea, and you can pick some open if you are curious about the degree of infestation in the swarm.

 

[oliver90owner]

followed by giving them a frame of brood from another hive.

That is the bit that I noticed. Not sealed brood, I hope. Or you may be introducing as many mites when this hatches as was on the swarm!

The 20% (or 15%, if you subscribe to a more precise figure) on the bees is a bit of an assumption also. Assuming half the bees went with the swarm is halving the number of mites with the swarm and that is assuming the varroah are evenly distributed throughout the worker bees, which they are not (varroah will not necessarily especially choose not to cling to a non-flying house bee, just because the colony is about to swarm).

So Victor is right, there will be relatively few mites with a swarm (always relative, of course).

There are better ways to treat (virtually as effectively) as oxalic acid without the possible down-sides of oxalic acid treatment (on the queen mainly, as the rest of the bees will be dead within a couple of months).

For instance, removing the first capped brood from the swarm will trap most of the mites without any risk of using potentially damaging chemicals. KISS principle in operation here?

Regards, RAB

 

[RoofTops]

I also wondered about the levels of mite loading between a shook swarm and a natural swarm and wondered if the shook swarm would have a higher loading. However, after a good strong cup of coffee (wonder why I need that today?) if the mites are evenly distributed amongst the bees then the percentage load will be the same. For example, if half the bees swarm they will take half the mites with them - so the percentage remains the same - half the mites but also half the bees. However, possibly a few extra mites will be carried over in a shook swarm if they were wandering around the frames.

I am not at all sure about uncapping the first sealed brood - this is exactly when you want the brood as these are the young bees which are going to replace the ones which swarmed and which by definition, if it is a natural swarm, are old bees and on their last legs.

This is why a bait frame of unsealed brood, taken when doing a shook swarm from the orginal colony, works so well. There is no need to re-invent the wheel. This is what Finman refers to as the Dutch method and it is proven to work.

 

[gavin]

For instance, removing the first capped brood from the swarm will trap most of the mites without any risk of using potentially damaging chemicals. KISS principle in operation here?

Regards, RAB

Yes, but adding a frame with unsealed brood from another colony prior to the new queen coming into lay will get this over with faster and be less of a check on the new colony.

all the best

G.

Journal of Apicultural Research
Vol. 44 (4) pp. 190 - 194
DOI 10.3896/IBRA.1.44.4.11
Date December 2005

Article Title Distribution of Varroa destructor between swarms and colonies

Author(s) Jerzy Wilde, Stefan Fuchs, Janusz Bratkowski and Maciej Siuda

Abstract Bee colonies reproduce by colony division during swarming. In colonies infested by the parasitic mite, Varroa destructor, colony division will at the same time split the mite population between the swarms and the remaining parent colonies. The present investigation compares infestation of swarms with that of parent colonies. We found that an average of 25 ± 9% of mites left the colonies with natural swarms, while 75 ± 9% remained in parent colonies of which 39 ± 11% were on bees and 36 ± 10% were within sealed brood cells. The relative swarm infestation did not differ from that of the remaining parent colony in this study, but very low proportions of mites within sealed worker brood and a clear negative correlation to the proportion of mites in sealed brood strongly suggest that swarm infestation is asymmetric and lower than that of the remaining colonies.

 

[oliver90owner]

Gavin,

I quite agree.

Shame he didn't mention it! But putting loads back in and taking a few out might be counter productive!

The point I was making was that there are better and simpler ways than oxalic acid treatment. An empty drawn comb would give her somewhere to lay before the swarm produced enough wax. Lots of options if one considers the problem rather than be blinded by 'oxalic is best'.

Regards, RAB

 

[gavin]

All good points Rab. Rather like encouraging drone brood for removal - forget to take them out and you are making things worse. Not appropriate for swarms, of course, they're not in a mood to raise drones.

Yes, lots of options and it is well worth doing something to reduce the mite load in a swarm.

G.

 

[RoofTops]

Thanks Gavin, the findings suggest a higher mite load in swarms than I thought, in other words, the 85%/15% ratio I quoted shoud have been 75%/25%. Also interesting that in rough numbers the mites left behind were 50/50 in brood and on the bees which means, again rounding off the numbers, before the swarm left the ratio was about 60% on the bees, 40% in the brood.

I wonder if this is the steady state position or does it change prior to a swarm emerging? The queen is supposed to stop laying a few days before the swarm but I am not sure this would alter things. There will be brood and mites emerging during this period but also mites jumping into cells layed up before the queen stopped laying. If the ratio did change prior to a swarm emerging it would have to be the mites themselves sensing the opportunity to travel. I wouldn't put it past them, given there must be a changes in pheromones prior to a swarm leaving, but I haven't seen any research on this.

 

[Poly Hive]

Lactic (from distant memory) will not penetrate the cappings and so is useless for sealed brood, is considered a bit milder than formic and so useful for bees with no brood.

Pre oxalic it was sprayed onto the frames of bees in broodless conditions but of course caused more disturbance.

PH

 

[gavin]

Hi RTs

I suspect that you are right about a skewed distribution with fewer mites in sealed brood than would normally be the case at the point of swarming. This could have adaptive significance for the mites. You might expect that diving into sealing cells would be a good strategy as you will then deliver young, healthy mites for the brood of the new resident queen, but the down-side is that you may become the victim of absconding-type cleansing. Absconding behaviour is less common in domesticated strains of Am mellifera but does happen, and is a regular means of shedding brood pests in some asian bees.

The abstract above also hinted that the distribution of mites into the swarm was lower than you might have expected, and perhaps that is the mites somehow anticipating the casts to follow?

G.

 

[victor meldrew]

I am not sure it is correct to say swarms have few mites. We often hear that 85% of the mites will be in sealed brood, which means the remaining 15% must be on the bees.

A swarm is therefore like carrying out a varroa treatment which is only 85% effective - which means in about 3 months or so (from the graphs in the CSL leaflet on varroa) the mite population will have risen to potentially dangerous levels.

I have used formic acid on swarms and used bait frames - and will continue to do so. I haven't tried OA on a swarm but will give that a go as well, as an alternative to the formic acid. Formic acid is convenient as it can be kept in the bottle whilst OA has to be made up as I chuck any surplus away after the winter treatment.

The advantage of a chemical treatment on a swarm is you can see any mites which fall - which you can't with a bait frame, but the latter is chemical free and effective.

Don't forget , 'the house bees remain in the parent hives and thus carry their own mite load for the sake of accuracy you can increase 85% to nearer 95% .

John Wilkinson

 

[gavin]

Isn't it the case John that swarms contain bees of most ages? In any case, the reference above (and personal observation) suggests that swarms can carry a lot of mites. It may be the brood break stressing and ageing the mites that has the best effect, plus the spare time the bees have to pick mites off and throw them away!

G.