Re LASI advice on pre-Oxalic brood culling

[itma]

...
If OA is to be totally effective it should be done while there is no sealed brood. The advice we were given by Sussex Uni in November was to open the hive check for any sealed brood and remove before applying the OA, this was for both drizzle and sublimation methods.
...

This deserves a thread to itself.

Yes, LASI/Sussex (while doing a comparison of Oxalic vapourising, trickling and spraying) did 'level the playing field' by opening up and culling brood.
This was part of the protocol for that experiment. (As was opening the hives up after treatment and taking a sample of bees...)

However, while we all know that maximising Oxalic's anti-varroa efficiency means treating while the hive is broodless --- where is the research comparing the overall effect on the colony of inspection and brood-culling against conventional 'blind' treatment? ie comparing colony outcome over the next year, not merely short-term varroa kill

Yes inspection and brood culling will ensure maximal oxalic efficiency - but as many here believe, it is going to severely disrupt the colony.
Has any research been done to compare the downside (if any) of the disruption against the benefit of ensured varroa kill?

I know full well that LASI opinion is that the disruptive downside is minimal compared with the benefit of ensuring maximum varroa reduction -- but what do they base that opinion on?

And if it is actually just personal opinion - then WTF are they doing going round handing it out as "advice from Sussex Uni" ... ?




My own personal opinion (for whatever that is worth) is that, if, despite your best efforts at treatment timing, it should happen that there was sealed brood at the time of Oxalic treatment, then it simply means that, during your IPM programme, you'll be treating again, sooner rather than later.
My suspicion is that brood-culling to maximise Oxalic efficiency is only going to be worthwhile for those that do not practice IPM, and instead rely entirely upon routine autumn and winter treatment.

 

[TryingToLetThemBee]

I didnt cull brood but am mighty pleased to have KNOWN i was broodless. Opening in late autumn with the colony super-active worked for me touch wood.

 

[Honeysuckle]

Do we have any forum members from Italy? Here I once helped a beekeeper inspect his colonies. He had put each of his queens into a small matchbox sized cage. This had been done once the honey crop had just been harvested - July. The bees in attendance could get in and out of these small boxes to feed and groom the queen, but the queen could not escape. The cage was placed within the hive between frames. Three weeks later there is no brood, the queen and colony are still settled and oxalic treatment is given. The queen is then released.

It would be interesting to hear your comments on this approach...

 

[beeno]

Hi Honeysuckle,
I would not like confining the queen like that (my turn to go poor bees) assuming I could find her! The main problem would be that if you did that in Aug. then you cannot OA at Christmas (most people say only once a year based on what I don't know) and the bees will have been re-infected by then as this year's treatments have shown.

 

[drstitson]

honeysuckle -

such "blocco di covata" is an established technique in Italy.

fine approach after productive foragers produced and before winter bees needed.

queen restricted for 3 weeks - with disposal of frames of laid brood if on frames; otherwise she can be caged as described. followed by OA treatment of the colony.
various exact timings though.

can also set up to hold the "trap" frame above the crown board - "blocco di covata orizzontale"

http://www.apimobru.com/pp/pp.htm

the timings are self evident here: www.apimobru.com/pp/pdf/is3.pdf

I hosted the author of this page at local UK association apiary last year http://www.apicolturangrisani.it/tecnica-apistica/652-blocco-di-covata-con-favo-orizzontale.html

 

[MuswellMetro]

We need someone like ITLD or Danbee to put the commercial/NDB line on this, I can find no research on effects of opening brood nests in winter, though I know Fera open in temps i would not, anyone got access to a SBI or RBI to ask their veiws

Karin , is an entomolgist but does that make her a a good beekeeper/

Biography
Following a career in commercial and retail finance, I obtained a Zoology degree at Nottingham University, then a PhD in Entomology. I have worked with hoverflies, aphids (galling aphids on poplar trees), tephritid flies and it's parasitiods on knapweed, bugs and beetles of various grasslands, and now with honey bees.

She seemed more interested in other Social insects than bees when i have been to LASI, I also found her statements of london urban beehives rather inaccurate and it was later amended and appears to have a speak first ,retract later approach

me well /I am in the London micro climate plus 3c to soft Southern temperature, so i expect my bees do have brood most days of the year

 

[alanf]

...My own personal opinion (for whatever that is worth) is that, if, despite your best efforts at treatment timing, it should happen that there was sealed brood at the time of Oxalic treatment, then it simply means that, during your IPM programme, you'll be treating again, sooner rather than later...

FWIW I think that's as far as I'd go. There was some discussion on Facebook a month or more ago. Following that up there was some correspondence with the PhD student doing the research at LASI that I was shown.

Brood culling was established as part of the protocol for the LASI research, which is entirely reasonable to produce uniform starting conditions. In practice, they found that in early December only a small proportion of the colonies actually had brood, so most were not actually subject to culling. It appears that some at LASI decided to spread brood culling as advice (not the researcher). If there is any evidence to support that as general advice in the UK, I'm not aware of publication. I haven't seen anything that establishes the principle that potential harm from brood culling is always counteracted by the benefit of broodless oxalic varroa treatment. I've certainly not heard it being repeated from NBU as official advice. But they have, at most, an ambivalent attitude to oxalic; I think that's mostly connected with high level support in DEFRA for the VMD and nobody is ever going to sponsor a generic organic acid through the licence procedure.

My personal take is that the idea of treating early and opportunistically is attractive. It's well established that any varroa treatment is more effective in a broodless colony, and that is likely to apply particularly to oxalic. If it is intended to treat with oxalic at some point over winter, then there is no point in delaying until January if the colony happens to be broodless a month or two before.

As it happens, colonies I wanted to treat had no sealed brood in late December so I treated. If they had sealed brood I was expecting to close up and check again on a mild day a couple of weeks later. I don't expect that the circumstances this year will be repeated on the same dates every year, so if I decide to treat next winter I will probably start checking for sealed brood in those colonies earlier whenever a mild weather window occurs, maybe from October.

 

[oliver90owner]

Trouble is most people hear what they want to hear or interpret what they hear as what they want o hear.

Not always (and often isn't) the real truth of what was said.

Let's face it, there are many actually writing something different on the forum than what they meant to and a lot of forumers reading posts incorrectly, even when written in clear unambiguous terms.

A simple case of failing of literacy, if not hearing ability.

RAB

 

[Ely]

Good literacy is a skill I wish I had. Being heavily dyslexic and not being able to read or write until I was about 10 I have struggled to get my english skills to the standard they are now. Maybe others are the same. I still want to hear their thoughts though.

 

[mbc]

Trouble is most people hear what they want to hear or interpret what they hear as what they want o hear.

Not always (and often isn't) the real truth of what was said.

Let's face it, there are many actually writing something different on the forum than what they meant to and a lot of forumers reading posts incorrectly, even when written in clear unambiguous terms.

A simple case of failing of literacy, if not hearing ability.

RAB

my literacy obviously falls short as it took me three read throughs to get the gist of this post RAB ( and only one typo to blame, "o hear" = "to hear", I suspect).
Must try harder.

 

[BeeJayBee]

Do we have any forum members from Italy? Here I once helped a beekeeper inspect his colonies. He had put each of his queens into a small matchbox sized cage. This had been done once the honey crop had just been harvested - July. The bees in attendance could get in and out of these small boxes to feed and groom the queen, but the queen could not escape. The cage was placed within the hive between frames. Three weeks later there is no brood, the queen and colony are still settled and oxalic treatment is given. The queen is then released.

It would be interesting to hear your comments on this approach...

I know of a commercial beekeeper who has done this, but using queen excluder mesh to trap the queen on one frame. They're happy with the way it works.

It seems to be the same as DrS says, and I think it's described on Dave Cushman's site http://website.lineone.net/~dave.cushman/varroatreatment.html It isn't as harsh as it sounds, but it is a lot of work to set it all up.

 

[beeno]

As it happens, colonies I wanted to treat had no sealed brood in late December so I treated. If they had sealed brood I was expecting to close up and check again on a mild day a couple of weeks later. I don't expect that the circumstances this year will be repeated on the same dates every year, so if I decide to treat next winter I will probably start checking for sealed brood in those colonies earlier whenever a mild weather window occurs, maybe from October.

Hi alanf,
Thank you for that. It makes perfect sense to me too!

 

[beeno]

Good literacy is a skill I wish I had. Being heavily dyslexic and not being able to read or write until I was about 10 I have struggled to get my english skills to the standard they are now. Maybe others are the same. I still want to hear their thoughts though.

Hi Ely,
Well done you. Very well written, would not have known that you have had a problem!

 

[Ely]

Ah thanks. I read my posts sometimes and even I can't make sense of them.

 

[Ely]

Ah thanks. I read my posts sometimes and even I can't make sense of them.

 

[drstitson]

"but it is a lot of work to set it all up."

not if you just use the queen cage method rather than the "restrict and discard" method.

1. find HM (ok a major stumbling block for many i admit)
2. cage queen
3. wait 21-24 days
4. release queen
5. treat