Hi Hope,
They can definitely swarm without the queen, but it is not common. While talking to Tom Parisian this past weekend up at honeybee genetics we discussed that sometimes in queen banks that the bees will decide to swarm, but the queen(s) are basically caged so can't go with the swarm, the swarm eventually returns back to the hive after some time. Also, if anything happens to the queen during the swarming process she might not end up with them. I think if the swarm loses the queen, they will likely stay grouped together and slowly die off. :(
Why are you asking? Are you not seeing eggs from a hived swarm? If swarms have a virgin queen they have to mate and I was told to be very careful around that hive. After a couple sunny days the queen will go on mating flights for a few days, her sense of direction is not nearly as good as the workers and so if you are standing near the hive when she is either leaving, or returning you can confuse her and she might not be able to return.... Mark
On Saturday, April 6, 2013 3:57:44 PM UTC-7, Hope wrote: