formic acid treatment

[nemphlar]

I've now applied 140ml/65% formic acid to 4 hives, used an insulated eke and appear to have had reasonably consistent evapouration over 8 days. I had expected to see lots of dead juvenile varroa on the sticky boards, but only the odd bee larvae and varroa adult. The queens are laying well.
This is a first attempt, how do you measure success or is this a sign of no affect?

[The Drone Ranger]

Hi nemphlar
put on a thymol treatment and see what drops over the next fortnight
Thats what I would do anyway

[Jon]

Me too. A colony which appears to be varroa free can drop a couple of hundred on the first day.

[nemphlar]

thanks for the response, formic treatments have a bewildering number of recommended procedures in both time and concentration, but outwith experiments carried out within enclosd spaces I haven't yet been able to find a simple way to check effectivesness.
I have been feeding thymol treated syrup since coming off fumidil B in early May in an attempt to recover from a very poor winter. or do you mean a more concentrated type of thymol application.
Not very objective but all 4 recovering hives and queens seem to be pushing on after the treatment.

[Jon]

I was referring to a thymol varroa treatment such as Apiguard which is a thymol paste usually delivered in two doses over a 4 week period after the supers are off.
I have used Apiguard the past two years and found it to be very effective - especially when followed up by Oxalic acid in the dead of winter when the colony is broodless.

Thymol treated syrup can be effective against nosema but not sure about varroa.

[The Drone Ranger]

nemphlar
There was an earlier thread where this was covered in some depth
and a recipe or two for home made effective thymol treatments
http://www.sbai.org.uk/sbai_forum/showthread.php?551-Api-Life-Var-vs-Apiguard-vs-%28insert-favourite-non-Pyrethoid-Varroa-Treatment%29&highlight=sponges
Nip over there and check it out

:)

[nemphlar]

Thanks to both, as a DIY beke I'll try the thymol recipe and sponge application. The 4 queens are laying well and I'm hoping, building to give them a chance of winter survival, have you noticed, will this thymol treatment affect/ slow the build up?
Interesting chart you published aong other things highlighted that even in hives with apparently no natural mite drop there was a count after treatment. I found similar results and wondered about the value of natural drop as an indicator. thanks again

[The Drone Ranger]

No it won't affect laying what it might do is affect any wax building as sometimes you will find wax scales on your insert.
Some but not all bees won't come to a contact feeder at the same time as treatment so its best done around now before winter feeding
Unless the floor insert is sealed then , especially in Summer, all sorts of wasps beetles etc get in and make off with anything tasty.
The cardboard flappy type don't tell you much I feel :)