To make queen liqueur or tincture of queen, beekeepers soak recently dead or pinched queens in a small vial of rubbing alcohol. The alcohol preserves the queen and, supposedly, her pheromones as well. Come swarm season, a beekeeper can wet a cotton ball with the juice, place the cotton in a baggie with a few small holes punched through, and put the homemade swarm lure in a swarm trap or bait hive.
This is reputed to draw swarms in much the same way as any other swarm lure. Some references recommend that you re-wet the cotton every few days, and some say to put an entire preserved queen in the plastic bag.
I have never tried this. Alcohol evaporates in a flash, so I can’t imagine it would stay effective for long. And, if you’re like me, you seldom have a lot of extra queens laying about. Still, it is an interesting idea, and I would rather use dead queens than toss them to the birds.
If you have ever used this method of making a swarm lure, I’d love to hear about it. Thanks!