Hello Everyone,
As a commercial beekeeper, yards were often worked at the worst times.
Often too much time was spent in a yard at the wrong time of the year,
etc. Removing all the lids worked well. After 15 minutes or the so the
robbing frenzy would decrease to a level that would allow the yard to be
finished.
I have known some beekeepers to remove the lids and spray the hive
entrances with a flavoring or essential oil- water mixture. A drop of
diesel fuel on the bottom board has been use by some in an emergency
(yuck!).
I don't know what happens after the yard is worked this way as i've only
used it in the fall when most of the hives were strong enough to defend
themselves and with enough stores for winter. Maybe progressive robbing
continues and if used at other times of the year would result it colony
death.
Best Wishes
Dennis