I've previously treated one of my hives for varroa with Apistan because I found a couple of varroa in the hive after doing a 24 hour survey. It probably wasn't strictly needed but I did it anyway.
I now have a full infestation that will need treating as soon as I have taken my honey supers off. This photo is the result of opening 3 drone cells. There are at least 6 mites in this photo. I had shivers down my spine as I watched one mite climb onto the back of a bee. The bee could obviously feel it as it desperately scratched at its back, trying to knock the mite off. The mite disappear into the gap between the abdomen and thorax. To make matters worse I had heard that a bee having a mite on its back is comparable to a human having a large rat attached to them and sucking their blood. Makes me feel for the bees as they seem to be completely unable to do anything about it and the mites can move very fast.
To get an idea of the scale have a look at the photo on the right. The worker bee to the right of the queen has a mite just under her right wing.
Spotting the mites is quite easy. I found, once I knew what I was looking for, that I could pick a mite on the back of a bee, on a frame will of bees, with no problem at all. I suppose that once you 'have your eye in' for what is normal, the abnormallity of the mite sticks out like a sore thumb.
One of the most common techniques is to open a drone cell and have a look for the mites there. The mites prefer drones as they take a few days longer than the workers to mature. These few extra days give the mites a little longer to breed, resulting in one or two extra mites per brood cell.
Many people use a capping scratcher but I've found just busting up the drone cells with my hive tool to be sufficient. A healthy pupae is quite white so the mites are obvious. This drone pupae has two mites clearly visible on it. You can see that I have just removed a patch of drone cells.
Next month, as funds allow, I plan to buy some drone frames and use the technique described in this study (and this one) to see if I can knock the mite population back to a managable level. I suspect I'll still have to resort to Apistan, or something similar, to ensure the colonies health throughout winter.
The most encouraging part of this study is stated in the abstract.
"These data demonstrate that drone brood removal can
serve as a valuable component in an integrated pest management program for V. destructor and may
reduce the need for other treatments on a colony-by-colony basis."
To get an idea of the scale have a look at the photo on the right. The worker bee to the right of the queen has a mite just under her right wing.Spotting the mites is quite easy. I found, once I knew what I was looking for, that I could pick a mite on the back of a bee, on a frame will of bees, with no problem at all. I suppose that once you 'have your eye in' for what is normal, the abnormallity of the mite sticks out like a sore thumb.
One of the most common techniques is to open a drone cell and have a look for the mites there. The mites prefer drones as they take a few days longer than the workers to mature. These few extra days give the mites a little longer to breed, resulting in one or two extra mites per brood cell.
Next month, as funds allow, I plan to buy some drone frames and use the technique described in this study (and this one) to see if I can knock the mite population back to a managable level. I suspect I'll still have to resort to Apistan, or something similar, to ensure the colonies health throughout winter.
The most encouraging part of this study is stated in the abstract.
"These data demonstrate that drone brood removal can
serve as a valuable component in an integrated pest management program for V. destructor and may
reduce the need for other treatments on a colony-by-colony basis."
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