Dean Stiglitz made a similar observation, but I just did this from the BIP 2017 loss survey.
The concept and terminology ?mite bomb? is a recent invention to deal with the cognitive dissonance that ?treaters? have when they treat and their colonies still die. Since they treated, they think someone who didn?t treat must be the cause. The idea is that treatment free beekeepers are not treating so when their hives die as they are failing the robbing bees from the ?treater?s? hive are robbing it out and bring home all the mites. I will go into the reasons this doesn?t make sense in a moment but let?s digress on what cognitive dissonance is.
Let me illustrate the problem of cognitive dissonance with a real life experience. When my children were young, we were all returning from a church pot luck and I put the pumpkin pie on the floor of our van under my theory that you should always figure out where something will fall and put it there instead. So I pointed out to all the children where the pie was and warned them to be careful not to step in it. There were no interior lights in the van until I exited, went to the other side, opened the door and flipped the switch, and I knew the kids would not wait that long. So we arrived home and my son got out and then proceeded to start yelling at his sister that she was stepping in the pie. He had in his head where it was, though he could not see it in the dark, and she was stepping there. She insisted she was not stepping in the pie. He looked down at his feet and then exclaimed ?Sarah stepped in the pie and got it all over my shoes!? This is cognitive dissonance. Something disrupts your view of the world and rather than adjust your view of the world to reality, you try to explain it away. And it?s not like you don?t believe your explanation.
Colonies dying from Varroa in my climate die in the cold when no one is robbing their hives, so the mite bomb "model" simply does not work in any cold climate. Maybe in California.
For argument's sake let's assume there is such a thing as a "mite bomb", let?s put it in perspective by looking at actual numbers. These are from the BIP survey of hive loss done in 2017. The treatment group includes the commercial people who happened to respond to the BIP survey in 2017. They represent, in this survey, 446,115 hives that are treated. They usually move from place to place and seldom do any swarm control. Those would have probably cast about half a million swarms of bees that probably cannot survive without treatments (being weak treated bees) which will crash. Of the ones they kept and treated a quarter of those died for a total of 600,000 treated colonies and their cast swarms dying from Varroa and becoming potential ?mite bombs.? That of course is based on only the responders to the survey. The number is likely much higher. I would guess that the commercial beekeepers are less likely to respond to surveys so these numbers are likely much higher... but that is not provable so we will stick with the survey data. We do know that the losses are at a minimum 114,000 by the survey results even ignoring the cast swarms.
The BIP numbers for treatment free hives were a reported 35,018 hives at a loss of 45.2% which would be 15,828 treatment free hives that died from Varroa. I would guess that hobbyists and sideliners are more likely to respond to surveys, but that's not provable either. If the numbers are skewed, though, these are likely over, not under represented meaning the spread is likely greater than this. You are not identifying the real problem when you point at treatment free beekeepers. The real problem of crashing hives becoming mite bombs is the commercial beekeepers.
Assuming crashing hives are mite bombs:
Treatment: 600,000 mite bombs
No Treatment: 15,000 mite bombs
Ignoring cast swarms, just for the sake of a conservative argument:
Treatment: 114,000 mite bombs
No Treatment: 15,000 mite bombs
Treaters are definitely causing at least ten times the crashing hives that could become ?mite bombs? than non treaters and more likely they are creating 40 times as many.
http://bushfarms.com/beesmitebombs.htm