It looks like the perfect system for the way I'd like to manage my colonies! Granted it won't eliminate the need for pesticides but, if it can reduce it that much, I'm happy.
I saw it. What struck me was how ineffective it was given the amount of effort involved, shuffling all those frames, and the cost to the bees in terms of time and resources spent raising 8 frames of drone larvae, even considering it was "fed back" to them. Then to top if off, it was STILL deemed necessary to treat most of the colonies come fall!
Don't get me wrong. I think trapping varroa with drone comb is an excellent method and if it's done properly, there should be no need to use any other treatment on your colonies at all. I intend to use it extensively this coming season.
The problem with the method described in the article is the same problem we have with ANY treatment: treatments are more effective when the hives are broodless, and *timing* is everything. At any given time, upwards of 60% of the mites in a hive are in cells reproducing, at which time they are not affected by treatments. This is why you have to leave acaracide strips in the hives for a period of time, or treat once a week for 3 weeks, to catch a couple of brood cycles and at that, you don't get all your mites. This is because treatments, including drone comb trapping, only affect phoretic mites.
With drone comb trapping, if the hives are not broodless, there are still lots of cells available for infestation whenever any given mite chooses to reproduce. Mites may prefer drone larvae, but they don't use it exclusively. If they're ready to reproduce, they'll happily enter a worker cell. So while you're busy trapping mites in drone comb, plenty of mites are still busily reproducing either in worker cells, or in the scattered drone cells found elsewhere in the hive. In the article, an effort was made to keep the "rogue" drone comb in the hive to less than 2 square inches per frame. Counting 18 brood frames with say 1 square inch of drone comb on each one, that's still a LOT of drone comb. Plus, your drone combs are only "available" for trapping mites for a fairly short period of time- a day or so before the cells are capped. Prior to that, the mites aren't interested in them, and after they're capped, well they're not available either. Mites remain phoretic for 6-10 days on average. When the 1-2 day "window" for your drone comb becomes available, only a small percentage of the phoretic mites in your hive are going to be ready to reproduce and only a percentage of those will choose your drone comb. This is why it was necessary in the study cited to use 2 trap combs 4 times over the course of the entire summer, and even then, they felt the need to apply an conventional treatment come fall. A rather brute-force approach if you ask me. It can be done better.
The ideal situation would be to create a broodless condition in your hive, by whatever means suit you, perhaps in late-spring after buildup and before the main flow starts up... with your hive broodless, ALL your mites will be phoretic. Now if you stick a frame of drone comb containing eggs and young larvae in your hive, the mites will think they've died and gone to heaven. After the comb is capped, remove it, freeze it, or just uncap it and shake the larvae and mites out. Do this a couple of times and your done. It doesn't take all summer, it doesn't take 8 frames of drone comb per hive, and it does remove upwards of 90% of the mites from your hive in just a few short weeks.
I think, if you can remove 85-95% of the mites in your hive ONCE per season, you're golden.