I don't  know about any standard practice to kill swarms in this area. I do know that I get a lot of calls to collect swarms. I think the big practice is 'if you pay me I'll spray them'. Although I've talked to a lot of people who called an exterminator before calling me about swarms and bees in houses. It seems that most exterminators don't want to kill honeybees. But that's just my take from what I've heard. 
  Ed


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