Oxalic Acid Vapourising - Time of Day

[Swift Nick]

This is my first bee keeping winter, so far so good, the bees are still there & some are often out flying at the warmest part of the day.
I intend to vapourise my hives with oxalic acid in the next few days. I have got myself familiar with the method & PPE, but I am unsure what time of day would be best. My only thought was if vaping makes some of the bees leave the hive, then maybe I should do it at the warmest (or least cold) part of the day.
Thanks Nick

 

[Beefriendly]

Nick, bees live in darkness. Outside air temperature may be more relevant as a guide; as in warmer= looser cluster.... vapor penetrates better? I speculate this may be the case and am myself waiting for warmer days to vape...The answer isn't black and white.

 

[fatshark]

I did mine - a few weeks ago now - at about 8pm in the pitch dark, by the light of a red head torch. It was the warmest evening of the month (~12C) so, as Beefriendly suggests, the cluster was dispersed and so was the vapour.

Even if they are flying it's not an issue. Those that return will find there's a dose waiting for them on every surface in the hive. That's why it's an effective treatment for recently hived swarms.

 

[Hachi]

Just finished vapping just under 10 hives for a good friend.

only a few bees came out on a single hive for a look.

 

[Swift Nick]

Thanks for the replies, I will vape them early afternoon on Saturday, we are forecasted for 13 degrees, that’s probably as good as it will get.
Cheers Nick

 

[Erichalfbee]

Thanks for the replies, I will vape them early afternoon on Saturday, we are forecasted for 13 degrees, that’s probably as good as it will get.
Cheers Nick

OAV is good down to 4 degrees

 

[Beefriendly]

OAV is good down to 4 degrees

Interesting, have you got a reference/source for the 4oC figure?

 

[Erichalfbee]

Interesting, have you got a reference/source for the 4oC figure?

https://www.sussex.ac.uk/webteam/ga...atmentoxalicacid-a4-1page-2016(2).pdf&site=60

 

[Beefriendly]

https://www.sussex.ac.uk/webteam/ga...atmentoxalicacid-a4-1page-2016(2).pdf&site=60

How accurate do you reckon is a quoted range of effective treatment temperatures of between 4-16oC?

 

[Erichalfbee]

How accurate do you reckon is a quoted range of effective treatment temperatures of between 4-16oC?

No idea
I have never vaped as low as 4 though often above 16
I suspect LASI are describing OAV in winter

 

[jenkinsbrynmair]

the cluster would have been loose as they'd spent the previous five minutes ripping all the brood out

 

[Eyeman]

How accurate do you reckon is a quoted range of effective treatment temperatures of between 4-16oC?

Big difference between a thin uninsulated wooden box and a poly hive.

 

[Beefriendly]

the cluster would have been loose as they'd spent the previous five minutes ripping all the brood out

So the 4oC figure may simply refer to the minimum temperature the researchers were prepared to work at.....

 

[bontbee]

That's the temperature specified on the instructions provided with a Varrox vapouriser, if that's any help...

http://www.thorne.co.uk/image/data/Documents/GA_VARROX_2012_print.pdf
(para. 3.1)