Aggression is not always the fault of the   queen.
Many years ago I had  to move an apiary for a season due to construction
work,. These bees were bred for docility and could be handled in shirt
sleeves, often with a class of thirty children standing around with just
veils, no other protective clothing. The bees were moved to the edge of a
deep railway cutting, the only place available at the time. Opposite the
entrances were telephone wires, a dozen or more only a few feet away. A light
diesel train ran through every hour duinng the day. Those bees became so mean
that all work with the children had to be suspended.
They just went wild as soon as opened. Only during a nectar flow could they
be handled and even then gloves were necessary.
Clearly the  trouble was due to the location, whether the train or the wires
or both. When they were moved back the following year they became their usual
docile selves within a few days.
                                                     Sid P.