For reasons that are not entirely clear the mite levels in my colonies are unusually low this autumn.
By 'unusually low' I mean single figure cumulative drops 7-10 days after starting the autumn treatment.
Is this good beekeeping (Ha! ... didn't think so) or a consequence of the excellent season we've had?

These colonies were last treated in early December 2017 after an extended cold-snap and during a known broodless period with a trickled Api-Bioxal. Almost all have been split during the season, had a nuc with the new queen removed and the remainder re-united back to one box. All are strong colonies, though most have limited amounts of brood at the moment after the Q stopped laying when the flow stopped.

There's been some drone brood removal (to make space, not for mite control), but not excessive and most colonies have foundationless frames which have a much higher proportion of drone brood anyway. Nothing else ... no sugar dusting, no rhubarb leaves over the crownboard, no careful location of apiaries on ley lines

For work we've individually uncapped many hundreds of pupae and not seen a single mite all season.

Many of you will be starting autumn treatment about now ... are your mite levels also unusually low?