I just did some drone brood removal in my two ktbh's and thought I might share some observations. This is only my second season, and I never removed drones last year, but had huge mite numbers by last fall, and decided to try drone removal this season.
First, off I'll say that I don't like removing drone brood. It's messy, slow, and gets the bees more angry than anything else I've done to them. If I continue to do this next year, I think I might eventually buy some of that plastic, green drone comb, cut it to fit my tbh's and adhere it to a bar, with hopes of simplifying the process. At this point, there is drone brood here and there throughout the broodnests of both hives, and this makes for tedious work.
One thing I tried today and would advise, is to have a squirt bottle of water/apple cider vinegar mix on hand - as well as my usual smoke. The smoke is good for they usual puff in the entrance and under the bars to keep general calm, but when you stab into some drone larvae, the chemical release really angers the bees. The squirt bottle allows you to easily target an area of comb before you scratch it, and I found this to greatly reduce the reaction. Squirt an area, then scratch it.
I also found that having some sort of bar/comb holder (similar to Phil Chandler's on biobees) is really helpful, as it allows you to more easily hold the comb steady and secure as you work the comb.
Regardless of my smoke and cider vinegar, eventually the bees were as hostile as they've ever been to me, shooting up from between the bars and into my face near the end. So if you get into doing this. Expect magnified hostility...
I used a dinner fork, and wish I had a 'real' capping scratcher. I found the fork to work, but it was not super easy. Its narrow shape allows for going at a few cells at a time, but I do wonder if the wider cap scratcher would work better. Perhaps others can say.
Questions remaining for me are:
• How many drone larvae do you need to remove in order to get a good idea of mite counts?
• Second, should you check drones from different parts of the hive, or is one area good enough?
• Lastly, does anyone have any tried-and-true methods of keeping drone cells in one area of a tbh that they might recommend?
I removed about 100 from one hive and found two mites. I scratched a bunch more, but left most of it, as I know the bees want the drones around. This hive has over-wintered and already has some flying drones.
The second hive is a package installed June 5, and they don't have many drones yet. I removed only 10-20 drones there and found no mites.