I watched the video here https://www.facebook.com/watch/?v=624489460708356 and replicated the test at home, disappointed I bought an off the shelf kit now after the surface area thing was explained! I did notice the bees look damp after the shake, so much so they stick together in a clump, even from around the 10 second mark of the shake they start to clump a bit. Not surprising if you look at all the ‘yuk’ that gets blasted around in there, pause on 1:18 for instance. Does anyone else get this ‘wet look’ on the bees after the shake, does it impact counts? Am I shaking to hard?
We don’t have the mite yet, testing monthly, we want to be sure we will get results testing when they come.
Good for you for checking for mites. With any luck Tassie won’t get infested for a few more seasons, though with those ferries sailing between the north island, it’s likely to happen sooner than later.
I couldn’t find any scientific papers on CO2 varroa testing, so only anecdotal information out there. Studies on the other so called gentle test, sugar shake, proved that it is far from humane and less accurate. With sugar shake the bees rolling alone is lousy at making mites drop. To get a good result, vigorous shaking is required. In the experiments, the marked young bees were returned to the hives after shaking. During the following days the hives were inspected in search of the marked bees. It was found that the mortality was very high. There are two hypotheses suggesting either the bees suffocate from sugar blocking their spiracles(10 pairs of breathing holes along the sides of the bees), or the vigorous shaking causing fatal damage to the bees. Either way, instant death with alcohol and very fast death with soapy water is the humane option.
As for CO2, I suggest vigorous shaking is still required to drop the mites. Their serrated mouthparts can hook them in the bee on which they are feeding, preventing them dropping. Watching Cedar’s video of the homemade CO2 shaker doesn’t suggest to me that this is gentle. The severe tumbling is likely causing ejection of liquids from both ends of the bees, resulting in the sticky mess you are witnessing.
For detection, in my opinion none of the shake methods are good. You’ll find mites sooner by brood uncapping. Not just drone, skewer worker brood too, there’s more of it. As soon as you find your first mite, switch to washes to monitor mite loads to indicate when treatment is required.