Oxalic acid ?'s

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WI-USA-BEEK

New Bee
Joined
Oct 15, 2010
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Location
USA
Hive Type
Langstroth
Number of Hives
36
Hello all

Im from the state of Wisconsin in the USA so my climate should be close or similar to the UK for the most part. For starters, here are my average high and low tmeps in my area if I can post links

http://www.weather.com/weather/wxclimatology/monthly/graph/54729

The whole reason I joined this forum is hopefully to gain some knoledge of the ins and outs of oxalic acid drip. It is not very popular here but I want to switch to organic chemicals to control varroa. I curently keep 20 colones and plan on expanding to around 50 next season. Right now I have apistan strips in my colonies for varroa but Im pretty sure the mites have gained resistance to it as they have across the county. I also plan on using formic acid next year. I want to use formic in spring and oxalic in fall. I was thinking about fromic this fall but there is a large risk of queen loss if you dont have your method down so gave in to the apistan varroa strips once again. I have been feeding corn syrup heavily and pollen patties so my bees have not shut down brood production yet. I will end feeding this week or the following week.

Anyway, I hope I did not type in circles there but my question is this, when do you apply the oxalic acid drip, and at what temps? Do the bees need to fly after application? Is there queen loss?

I am going to do a mite drop check at end of this month and apply the acid to any that still have a mite count or all if they need it if I feel confadent Im not doing more damage than good!

Thank you all for any help you can provide!
 
Do your bees have a broodless period ? This is the time to apply an acid drizzle as all the mites will be phoretic and you can kill upwards of 90% with the oxalic drizzle
 
Having once visited Wisconsin in January I would say your climate is ideal for oxalic acid trickling which is at its most effective during a long broodless period as MBC says. The system is widely used in Northern Europe where they have similar low temperatures. The UK is much warmer in winter than you experience in your State where for example ice fishing (tent, fishing rod and 6 pack of beer) is practised throughout the winter) so in the UK it is sometimes not as effective as it should be.

I would think a 3.5% solution would be correct applied at the end of December. Don't do it too early or there may still be brood and the varroa in the sealed cells will not be touched. Don't worry about the bees being chilled, just work quickly and apply 5mls* into the gap between each frame where there are bees. If you are running on double brood boxes then apply it to the top box only, don't try and split them.

There are recipes for making the syrup on the forum if you do a bit of searching.

*We normally use plastic syringes and are best fitted with a plastic tube on the end so the OA syrup can be sucked up from the bottle.
 
There are now a whole load of beeks in the UK that have never known beekeeping without varroa.

I would be inclined to think that your winters are probably colder and drier (dryer?) than ours. UK winters are typically mild with lots of rain and to have daytime temps below freezing is increasingly less common. We might get snow once or twice a winter but snowfall is usually of the order of an inch or so that melts and which disappears in a day or two.

Most UK beeks have given up using Apistan/Bayvarol. Our Government a while back promoted the use of small test kits to test the resistance of varroa, and it was pretty widespread. However, some beeks have talked of a return to using Apistan/Bayvarol and make the claim that fluvalinate is at least worth using from time to time.

Personally, I trickle oxalic acid in winter and use lactic acid/water solution during the active season.

With lactic acid the volume you apply is larger than with oxalic acid. I spray frames of bees whenever colonies are broodless. I have not heard of any cases of queen loss, but there are claims that if you spray with brood in the hive some of it can get aborted by the workers. However, on the couple of times that I have sprayed lactic acid with brood in the hive in error, no aborting of brood was witnessed. The lactic acid is used in water solution at 15% and is available from suppliers, and I have typically used it in May/June and on swarmed stocks.


Oh, the whole point with oxalic acid trickling is to do it when the bees are clustering. The idea is for the bees to work the relatively small amount of syrup over their bodies and over a longish timescale. No point in trickling during a mild spell of weather and when it will not contact as many bees and will quickly get removed from the hive. Some people fork out brood at the same time as they trickle, assuming there is brood in the hive. I would guess that a lot of colonies in the UK, and especially in the milder south, have at least some brood all year around.

Not tried formic acid yet.
 
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Yes my bees do have a bloodless period as far as I know. Queens mated before July would have slowed down dramatical if not for me providing syrup and pollen patties. I have put on the last feed for the season and within the next week or two they should shut down brood production for the most part. By mid November I should be mostly bloodless.

Im worried by mid November I may not see above freezing temps. I should have a few days here and there though. I have read it is fine to apply as long as its a couple degrees above freezing and to try to do it when they will have warm enough weather to make cleansing flights after application. This may not be feasible unless I get lucky.

I was thinking about starting with 3.2% solution. As far as not doing it too early I dont know that I would ever get a day above freezing in December. We had about ten years of very mild winters here up until 2007 or 08 where im sure above freezing would have occurred but we seem to back to old fashioned winters with temps below freezing from late November into march with a few stray warm days. That said how critical is it to be above freezing. There are many days that reach into the upper 20's Fahrenheit with good sun. I put a wall of plywood and cover it with roofing felt behind hives. I then wrap hives in insulation then black roofing felt. I have brought a digital thermometer out to yards on sunny days in January when outside temp was in teens and the felt wall and felt around hives makes colonies quite warm. In fact I got readings up to 65 degrees next to hives.

So that all said, maybe I would be safe doing the treatment in December on a mild day with no wind and full sun?

Here is an example of conditions you would find in middle of winter on a warm day. [ame]http://www.youtube.com/watch?v=RqoADSyHL3E[/ame]
 
OK then. I think Ill try it in mid November or December. Maybe Ill even shot a video and do a mite drop check.

I am like a kid and already cant wait for next spring.
 
OK then. I think Ill try it in mid November or December. Maybe Ill even shot a video and do a mite drop check.

I am like a kid and already cant wait for next spring.

I know exactly how you feel. Our mentor has told us to leave ours alone now for winter, just open to top up the feed. I want more bee action lol. I suppose topping up will just have to do for now, at least I can peep down through the holes in the cb.......oooo, must remember to ask if I should cover those lol
 

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