# Novel Application of Existing Beekeeping Equipment to Combat Inter-colony Transmission of the Varroa Honey Bee Parasite



## James Lee (Apr 29, 2020)

Interesting compare and contrast in data. ABJ printed an article in August 2021 from Mea Mcneil, of "Bomb vs. Bond" fame from 2016 ABJ articles. It doesn't seem purposeful, but TF proponents presented her recent article as some sort of "gotcha" refuting the horizontal transmission (mite-bomb) theory.



https://meamcneil.com/a914/images/Mea_PDF/McNeil-article_August2021_June25-915M-1.pdf



Further evaluation of the actual study referenced in the title (Graduate Research, not peer-reviewed) - is actually more interesting and seems though Mea is misrepresenting the conclusions of the author?!






Final report for GNE19-206 - SARE Grant Management System







projects.sare.org





The TLDR, and maybe most helpful takeaway I glean is that in the fall, varroa goes up regardless, bees go down and they outbreed the queen at this juncture in the season. More interesting though, is the use of robber screens on colonies may provide a hedge against "mite-bombing" from high-mite colonies if they cannot be robbed out etc. If anything this would accentuate someone's treatment program and provide additional protection against late-season transmission following acceptable treatment windows.

What does this mean for the TF beekeeper? For me, I can stand to benefit the same, particularly on strong colonies that have promise - equally robbing out another untreated or treated colony, because let's face it, treated colonies can also bomb untreated colonies. The issue of the proliferation becomes another post entirely. So - this is my studying for the day. Hope you find it useful.

PS the study originator has citation but no references, I've emailed her to see if those can be provided for additional elucidation of the data.

PS I did not give as much attention to the first half of Mea's article regarding the increased mite counts following treatment and it's potential impact or lack thereof, but would like to at another date.


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## Litsinger (Jun 14, 2018)

Good stuff, James.

If you haven't already, take a look at this thread that MSL started on a similar line:









Robbing screens as an IPM tool lower mite loads


This study suggests putting a robbing screen on a hive significantly cut the fall mite growth by blocking incoming mites https://www.nature.com/articles/s41598-021-86558-8 Direct measures of Varroa infestation on adult bees from alcohol wash samples showed receiver colonies with and without...




www.beesource.com


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## James Lee (Apr 29, 2020)

Litsinger said:


> Good stuff, James.
> 
> If you haven't already, take a look at this thread that MSL started on a similar line:
> 
> ...


If we can't agree on treatments can we all agree on robber screens? 

I'll run on that platform in 2024. Robber Screens for Every Colony!


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## Litsinger (Jun 14, 2018)

Might want to promise 'A Chicken for Every Pot'...


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## James Lee (Apr 29, 2020)

Looks like the author is the same as the article you referenced Russ she responded to me and sent the article and it appears to be the same I'm going to look further to verify but I think it is the same. She did reference that the article in question for the sentinel project through be informed is an entirely different article awaiting peer review and publication. This would explain the discrepancies that are getting lost in translation.


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## Litsinger (Jun 14, 2018)

James Lee said:


> She did reference that the article in question for the sentinel project through be informed is an entirely different article awaiting peer review and publication.


Cool. Maybe you can talk her out of a pre-print.


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## James Lee (Apr 29, 2020)

Litsinger said:


> Cool. Maybe you can talk her out of a pre-print.


On it


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## psm1212 (Feb 9, 2016)

One danger of robber screens used year round is a queen returning from mating. Several years ago I had a robbing problem in one of my mating yards and put robber screens on all of the nucs. I went 0 for 12. Admittedly, I should have thought about that and anticipated the issue. However, it got me thinking that I do not always know when a colony is attempting to requeen itself after swarm, supercedure, etc. When I first read the mite bomb study msl posted, I remembered back to that experience. Net take away: I would not recommend running robber screens year-round. They may be useful in cutting down on mite migration, but they may also serve to inhibit the successful return of a queen from her mating flight. Maybe limit use to when being robbed and possibly during mite-bomb season? (i.e. Late Summer-Fall?)


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## Litsinger (Jun 14, 2018)

psm1212 said:


> Net take away: I would not recommend running robber screens year-round. They may be useful in cutting down on mite migration, but they may also serve to inhibit the successful return of a queen from her mating flight. Maybe limit use to when being robbed and possibly during mite-bomb season? (i.e. Late Summer-Fall?)


Makes good sense to me @psm1212. Thank you for pointing this out.


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## grozzie2 (Jun 3, 2011)

I can see the robber screens helping stop the healthy bees from getting into the sick hive. I don't see how a screen on the healthy hive will stop them from bringing mites back as they rob out the sick and dieing colonies.


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## Litsinger (Jun 14, 2018)

grozzie2 said:


> I don't see how a screen on the healthy hive will stop them from bringing mites back as they rob out the sick and dieing colonies.


I concur with you. If the results are conclusive and can be assumed to be fairly consistant across our bee stocks, the study suggests that the main source of late season mite incursion is not from returning robbers but rather mite-laden non-natal bees being permitted entry. Thus by limiting latent drift, one can potentially mitigate mite build-up in strong colonies.


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## ursa_minor (Feb 13, 2020)

I put robbing screens on at the beginning of the season and take them off at the end. I make my own and all three of my hives needed to get a queen mated this summer. One was a virgin swarm, one a supersedure and one replaced the queen that swarmed. All three were able to mate just fine. Maybe it was because they were put on right at the beginning so the entrance was 'normal' to them. Mine are just 8X10 wooden frames covered with 1/8" mesh and a 2" piece cut out of the top wooden bar ( which I can place a piece of wood over to reduce the hole).

While they might be useful to keep my bees from transmitting mites between hives or other robbers bringing in mites, I don't think they help if my bee rob someone else. Still, IMO, if more beekeepers used them it certainly could make a difference.

ETA I will also add that my 3 measly hives are not indicative of anything other than possibly 'dumb luck', others with more experience than I would be the better advice to follow.


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## A Novice (Sep 15, 2019)

Blame the drones.

Robbing screens stop strange drones from invading your hive.

Whether you have robbing going on or not you will get drones looking for a home.

Not all hives kick the drone out at the same time, and some hives don't appear to do it at all. I think it has something to do with the availability of pollen or bee bread, but I'm not sure.

I have seen drones being given the bum's rush, but most of my hives have quite a few drones through most of October.

If a mite infested hive kicks out its drones, they need to find another hive or die, because they need workers to feed them.

They will show up at your hive, and your bees will let them in, because that's what bees do. And your sweet worker bees will feed them like they are your own.

This is armchair science, but the question is valid, and it will be easy to test. 

Suggest to the author of the paper to build robbing screens using queen excluder material, which will also stop drones, but won't stop actual robber bees.
repeat the test.

If the result is the same, Blame the drones.
If the result is somewhat attenuated, it is both the drones and the robbers which are at fault.
If the test colonies are the same as the controls, the drones are not to blame, it is due to robbing.
(It would be best to test all three alternatives, so year to year variation won't confound the results, but any researcher will recognize that immediately.)

If it is the drones, then additional observation and experiment would be in order, to better understand if mite laden colonies are more likely to expel their drones, if mites preferentially hitch rides on drones in the fall, etc.

Potentially, drone traps to eliminate drones leaving the hives in the fall might be a good option to prevent mite drift between adjacent hives. or not.

If I had a hundred hives, just think of the things I could do!

Enjoy your bees,

Jon


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## James Lee (Apr 29, 2020)

I have her dissertation - @A Novice that is a valid suggestion. 

I will read the dissertation before commenting further.


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## psm1212 (Feb 9, 2016)

ursa_minor: My experience is also a one-time thing and should not be taken as definitive. It could have been weather, birds, dragonflies, etc. In my mind, I blamed it on the robbing screens. I clearly do not know that that was the cause of the problem. Good to hear of your experience. Makes me rethink my own.


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