The saying is a throw back to skep days and has no relevance to todays methods .There's an old saying. A swarm in may is worth a load of hay. A swarm in june is worth a silver spoon. A swarm in july, let the b*****s fly. Even so, I'd give it a crack; what have you got to lose?
I know that I am not often sober!!! but this time i was! Had cleared up a mess of an old hive for someone - no bees, wasp robbed out and moth mangled, set it up ready to get going this year (swarms had moved in previously aparently so I was hopeing the same would happen again) that was the last week in september, 2 weeks later owner called to say she had seen a swarm move in!!!Swarm in October?
Not when you're Sober!