Checkmite and Hive Beatles
First - I'm not advocating for or against this product, just relating a recent experience with it.
I've done a lot of increase this year so I have quite a few smallish colonies going. I lost one to hive beetles - the unfortunate series of events probably went something like this - robbing, starvation, stress, mites, hive beetles. Anyway, after I shook it out I decided that if I had anymore circle the drain I was going to sacrifice them as a bait hive for hive beetles just to see what happened.
So, a few days ago I came across another one that was about to start the final stages of meltdown - No brood, no stores, few eggs, weak population (4 med frames maybe) - but a perfectly good looking queen - lots (LOTS) of adult beetles and 2-3 tablespoons full of larva and frass on the bottom board which I mashed thoroughly. This hive is doomed. So I moved it to a brand new location a few feet apart from my other hives - so It lost all of it's foragers - then I put it in my junkiest equipment - plenty of ways for SHB to march right in - but with a robber screen - along with several frames of nasty comb that is slated for disposal anyway - 24 frames in all - and I gave them a frame of honey, because I hate for them to just starve. Right? And to finish the setup 3 checkmite + strips - one hanging in the middle of each of the 3 boxes. What I was hoping was that all that unguarded nasty comb, and those weak failing bees would attract hive beetles from all over and the coumaphos would kill them. Which it has. There's a bunch of dead beetles in the bottom board. I don't know that It has made any difference to my other hives, but it has killed a lot of beetles in the last 10 days.
Here's the kicker - that hive isn't failing anymore - there's a couple of frames of open brood now, no beetles and no larva. I wasn't really planning for that.
BTW, checkmite is approved for both mites and SHB - the way I used it in this case is like you would use it for mites, and not how you should use it in a production hive for hive beetles. Furthermore - coumaphos the active ingredient is one of the worst of the hard chemical treatments - it is no longer effective against mites, and it persists in wax apparently forever. So, don't use it like this in a hive that you intend to keep in use. It is however very effective against hive beetles - for now.