Oxalic Acid...too late?

[clare]

Snow, flu and heavy rain have all thwarted my planned forays into my two hives to treat with Oxalic acid. When should I consider it too late? If I am too late is there anything else that I should/could do later in the spring. Thanks, Clare.

 

[Poly Hive]

I don't think so and am planning on doing mine this weekend.

If there is brood now there will not be much so most of the mites will still be exposed.

PH

 

[sputnam]

Ideally I would have done mine at the end of the very cold spell at Christmas, but time defeated me. I shall be doing mine tomorrow.

 

[drstitson]

if you are wanting to treat then i would say you have nothing to lose - yes there may be a little brood present but the chance to knock down any mites on bees will at least help reduce further the burden come spring.

 

[crazy_bull]

I'm planning to do mine this weekend as well so don't worry,

C B

 

[Rosti]

Snow, flu and heavy rain have all thwarted my planned forays into my two hives to treat with Oxalic acid. When should I consider it too late? If I am too late is there anything else that I should/could do later in the spring. Thanks, Clare.

OA is a direct mite contact treatment episode. Too late is quite simply when brood starts getting laid again and the mites have the opportunity to start their prefered 'standard' breeding cycle. You can treat when ever they are broodless - and that includes a freshly caught swarm and after an artificial swarm.

The only other consideration is chilling the colony when you open to apply so that will also affect when you now choose to administer. R

 

[keithgrimes]

should be fine as there will be little or no brood. Needs to be above 2 degrees C and not windy/raining. Plenty of people slightly delayed this year due to bad weather.

 

[sleepingbear]

Arguments aside as to whether OA should be used at all for your colonies (that will, amongst other things, depend on levels of varroa infestation and that's another story!!!) as long as you feel confident that there is no or at worst very little brood (this of course depends on your bees and local climate) you should be fine. Try and choose a dry, still day with temp just above double figures - easier said than done I know!!!

Good luck........

 

[Midland Beek]

Yeah, still time to do it now. I would aim to do it on a cold day though and when the bees are clustering. No point doing it on a warmish days with bees over every comb in the hive.

 

[Teemore]

....... Try and choose a dry, still day with temp just above double figures - easier said than done I know!!!

Sleepingbear, I agree with the still, dry day bit but why do you consider that OA should be applied when temperatures are slightly above double figures?

 

[RoofTops]

You want it reasonably cold for OA syrup treatment. I certainly wouldn't do it when the temps were in double figures. Half the bees are likely to out flying and would miss the treatment. They are also likely to be a bit more lively - e.g. nippy in the warmish weather. In the current weather do it in the early morning when the air temps are still low and the bees are clustered.

There really isn't a "too late" time for OA syrup but as the amount of brood increases so the effectiveness of the treatment diminishes significantly. There can also be some loss of open brood but the amount is not normally considered too serious. However, the OA syrup will still kill mites.

If the treatment is not effective, and it will be hard to tell if it was as the amount of mites falling will not give an indication of how many are in sealed brood, so a second treatment with thymol in early spring would be recommended - although I would probably do a shook swarm myself and probably give them a second dose of OA syrup straight afterwards.

 

[Hivemaker.]

They may have brood already,so to make sure yo get just about all the mites,as the brood emerges, you could give them four treatments of oxalic acid,about sixteen days apart.

 

[sleepingbear]

Hi Teemore,

Only because my own bees tend to still be in a good tightish cluster at that temp, say 11 or 12c, and also means if the temp drops quickly as it can do on winter days it also means it reduces the temp decreasing effect of the OA on the outer part of the cluster as the outside bees, as I'm sure you know, can be pretty cold already.

Having said, that I have had to do it at 6/7c (and I'm sure loads of people have, with no ill effect) when the weather wasn't doing what I wanted. It's just my personal preference (because of the nature of my bees) or at least it was as I don't do OA anymore!

 

[Arfermo]

Contrary to advice elsewhere in this thread, brood is very unlikely so early especially when one severly cold spell is barely gone and another seems to be on the way. As for oxalic, not too late. Any time up to mid January is definitely OK, give or take a day or two. I've just given mine a second dose. If you haven't already done one dose, then it is essential you do so now.

 

[For want of a better word]

Don't forget to WARM OA syrup !!!!

 

[RoseCottage]

Just thinking to myself....

I am picking up my pre-made OA treatment from Thornes tomorrow.
If its a contact application wouldn't it be better in an aerosol than the little squeezy bottle it comes in? This way it would hit far more girls.
Never really knew if last years dribbles were effective.

Sam

 

[oliver90owner]

The first oxalic acid delivery system used was a spray, not quite as fine as an aerosol, but effective and suitable for purpose.

Found to be more intrusive for the bees and trickling eventually was found to be as, or more, effective and faster, less intrusive etc.

In between were the sublimators.

Trickling has since been adopted by the majority for speed and reduced risk of operators dosing themseves instead/as well as the bees.

Regards, RAB

 

[RoseCottage]

Thanks Rab as always right on the money.
All the best
Sam

 

[Hebeegeebee]

Contrary to advice elsewhere in this thread, brood is very unlikely so early especially when one severly cold spell is barely gone and another seems to be on the way. As for oxalic, not too late. Any time up to mid January is definitely OK, give or take a day or two. I've just given mine a second dose. If you haven't already done one dose, then it is essential you do so now.

1) How do the bees know that another cold spell is on the way - maybe weather forcasting traits of bees could be used by the BBC?

2) Second dose? Is this necessary?