have you kept russian bees
No. I intended to start and try them, but the sheer number of hives is now prohibitive in tat requeening them all with pure strains of resistant bees would be very expensive. I still by the less pure strains with resistance in the hopes that I am adding some resistance to my apiaries, as well as some feral colonies... Maybe one day I can drop back to 40 or less hives and get pure queens.
I assumed you were talking about your bees, but wanted to make sure you weren't using a politically correct method of slapping me!
Bakers;
You lost me. What was wasting your time? Treating for mites?
No, checking mite levels in nearly 100 hives. Sugar roll or alcohol wash or either roll etc... on that many hives would take me two or three days JUST to check them all individually.
varroa mites have developed resistance to most treatments to the point some are useless, and/or we have to change up the treatments.
i would suspect in time oxalic acid may not work as well? i don't know.
This has been a concern of mine as well. Perhaps OA alternated with another mite control of choice.
As I understand it, mites that come into contact with OA Crystals DIE, so they do not get the opportunity to build any type of resistance. it is also my understanding that the method of kill is through soft tissue, around legs, mouth etc, so unless the mites can develop a means of locomotion without having soft tissue around their legs etc, they cannot become immune.
Immunity is built in a few different ways, usually by sub lethal doses that do not kill the mites, kind of like one of us getting shots of bee venom to help build up our immunity to it.
When the mites are killed when they come into contact, it does not allow an immunity to develop.
OAV has been in use for a long time, as long or longer than most other insecticide types of treatments here in the states, and is still being used across the big pond with no apparent decrease in effectiveness. I feel it is safe to say that if the mites were going to develop immunity to OAV they would have done so long before now. JUST.. my own conclusions and deductions.
Scott