Culley,
The beetles come and go and are generally worse in about February with the heat and humidity. I find if my hives are really strong they tend to be able to handle the beetles as well. This time of year I generally only find one or two in the odd hive but the queenless one had quite a few already, they really move in on a weakened hive.
Tried the water spray once, note once, and found it less than successful. Didn't expect to do anything more than just pop the tops the other day hence just the old veil.
Cheers
Rob.