I've heard Wally Shaw lecture on drones passing on std's to queens and this theory has some substance, though a drone laden with virus is unlikely to outcompete healthy fellows to mate a queen. It could explain queens mated later in the season turning dlq unexpectedly.
But largely this queen problems thing has been someone else's problem, I remember Roger asking me about my experience of it and myself being at a bit of a loss because I had no tales to tell.
I did have an interesting chat with a breeder just south of me who's convinced bees have got meaner, not in defensiveness towards the beekeeper, but in aggression towards virgins, to the extent that many are a bit tired and mangled (nipped off feet when looked at closely and lost much of their body hair) by the time they go for a mating flight and so fail to mate effectively or never make it back. It fitted with what I'd seen that year of many swarmed hives failing to get their virgins mated whereas the mini nucs performed as normal, possibly due to the large numbers of mean old bees in the full hives harassing the virgin and nipping at her heals.
