OA pre check

[nemphlar]

Put the sticky boards on last week to check for V natural drop. 4 hives gave 9/8/0/0 counts over the 7 days. Tempted to leave the OA this year and maybe go for an early FA treatment next year. Any strong opinions out there

[Rosie]

I would not allow natural mite drop to drive my choices as it's not reliable enough. I see oxalic acid treatment as my big opportunity to get on top the the little devils. However, I use less than most people and have been getting away with it for years. I usually open some of my hives on mild winter days to monitor egg laying so that I can best judge the application time but during the last 2 winters I never managed to find any mild days so I had to take a guess at when to apply it. Fortunately I seem to have been lucky. I am now waiting for a mild day (over say 8 degrees and bright) to check on eggs.

Rosie

[Neils]

Agree that reading too much into the natural drop probably isn't a great idea especially if deciding not to do something. Off the back of my autumn treatment counts I'll definitely be using OA this winter. I've never been a fan of treating "just in case", but the drops from the treatment more than suggest that a follow up with OA is warranted.

Last year in the run up to autumn my mite drop was negligible, once I started treating however I had hundreds of mites drop; that really hammered home to me that the natural drop should be taken with a pinch of salt especially if it seems to indicate minimal mite population.

[Jon]

I agree with Nellie. Basing varroa treatment on mite drop is a risky business.
I have seen very few mites this year, even during Apiguard treatment in August/September.
I remember last year when I treated with Oxalic most colonies only dropped a few mites but there was one strong colony which dropped over 100.

My bka has its quiz night tonight and I am bringing along 3.3 litres of 3.2% Oxalic to disburse into plastic bottles.
It cost under a fiver to make that and it will treat about 75 good sized winter clusters.

[Jon]

I underestimated the demand as we had an array of empty bottles brought in looking to get Oxalic to treat over 120 colonies.
Will need to make up some more tomorrow.

I did a talk on Oxalic treatment last month and only two of the members had ever used it before so it is good to see them taking the opportunity to zap some mites.

[Calum]

Hi
my 2p, hit them with OA as soon as they are brood free. FA has for me two problems, by the time it is warm enough to use it effectivley the colonies are already well into brood = the varroa you have now have multiplied AND early treatments of FA risk FA getting in your spring honey crop.

[Calum]

I did a talk on Oxalic treatment last month and only two of the members had ever used it before so it is good to see them taking the opportunity to zap some mites.

In our group of beekeepers in Lindau the use is 100%.
In germany I#d say the use is well over 60% the rest favouring perizin or lactic acid which is not much fun for anyone.
Catching them brood free and getting low enough temperatures will be tricky this year I think...

[Jon]

I treated 18 colonies last week.
I have monitored about half of them.
One which I treated 4 days ago had about 150 mites on the board today and will probably drop quite a few more.
Some had no mites at all and others had only one or two.
I have found this in previous years. Even though all were treated with Apiguard at the same time in late summer/autumn, the drop after oxalic trickle varies a lot.

[gavin]

Do you have colonies that seem equivalent in autumn and summer strength, summer/autumn treatment effectiveness, location, current strength, and yet drop very different numbers of mites? Can you see where I'm going with this?

G.

[Jon]

Hi Gav
The vast majority of mine seem to drop very few mites with Oxalic but last year I had a similar one with a big drop as well.
That colony is still alive with the same queen and is going well.
A colony starting the year with a couple of hundred would be in difficulties by June or July if left untreated.
The trouble with making judgements based on mite drop in winter and colony size in autumn is the other variables in play as well such as nosema.
Colonies treat the apiguard gel in different ways as well. Some have it removed within 48 hours, paper and all, whereas others seem to hardly touch it.
I don't monitor mite drop in every colony but try and get a snapshot of what is happening.
Oxalic is cheap as chips and I have not detected any detrimental effect on the bees so I just tend to treat.
PLB on beeline asked me why did I think Oxalic was harmless.
Without doing a massive amount of research I can say from observation that you don't get a heap of dead bees outside the hive the day or two after treatment, you don't find queenless colonies in Spring, and it has got to be better for a colony to start the spring build up virtually mite free.
You can always argue sub lethal effects if you can be bothered - the way they do with neonics. I don't think it is that relevant in either case.