The sad truth seems to be that late season influx is the new normal and mite management must adapt. We used to believe that a late summer treatment would allow for time to raise a crop of winter bees in a low mite environment and all would be well. That treatment is still necessary but can now only be considered a stop gap and a post influx treatment is also required. The influx timing seems to be that late summer / early fall time when the bees are aggressively trying to stock up for winter. Collapsing feral and unmanaged colonies are no doubt the source. The influx is far from uniform but enough colonies test above threshold after treatment that unless one is able to test every colony and treat accordingly another "post frenzy" treatment is needed. One might say that once brood rearing is vastly reduced that the colony could tolerate a high mite load as they did in the pre virus days. ( I know there have always been viruses but not like now) With the horizontal transmission of viruses by phoretic mites I believe that those newly emerged winter bees are at risk and should not wait for the winter OX treatment. This fall I found a small percentage of colonies with counts in the teens and a few in the 20s after the late summer round of OAV. In some of the tested colonies post treatment counts were higher than pre treatment. Since I believe that OAV is relatively benign and formic pads (mite wipes for me) are safe in the cooler temps I did an early Oct, round. Far faster to treat than test and I am reluctant to pull frames this late in the season. Frosty nights and only a few hours mid-day in the 50s low 60s. So we'll see how it works out next spring. They will still get their broodless late Nov. OAV.

Paul Hosticka
Dayton WA

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