Pheromone Lures can be used to increase the likelihood of capturing swarms or retaining them in your own hives.
Some are commercially available... And otherscan be prepared at home. In the case of those commercially available,the lure is a synthetic pheromone that mimics the nasanov scent.
Swarm lure made from unwanted queens... Thismethod came from Dee Lusby and was developed from an idea of Butler.
Dee's method... Is to take unwanted queens, not old ones that are about to expire, but viable young or virgin specimens and steep them in a jar of alcohol. Dee comments "The alcohol really takes on a good color if left for years with queens submerged within. Also, we get more scouting bees with virgin queen lure and more drones in swarms that are eventually hived."
To use this "tincture of virgin queen" as a lure, it is dabbed on woodwork of bait hives... Three or four drops from an eye dropper when the bait hive is made up and a few more drops after six weeks.
The oil from lemon or lime peel of freshly picked fruits can be rubbed on the inside faces of a bait hive and in some parts of the world this is all that is done... The rest of the box being completely empty.
Beeswax itself is an attractant and can be melted on to, or rubbed over inside faces of a box. Honey, propolis and slum gum have also been used for baiting purposes.
Recipe for Artificial Pheromone
2 parts Citral
1 part Geroniol
1 Drop Lemon Oil
Store mixed ingredients in a refrigerator
To use this mixture... Take a small vial filled with cotton wool wadding or other absorbent material. Absorb approximately 1 ml of the concentrate into the filling and plug the mouth with a rubber bung. At time of use remove the bung and place the vial just inside the entrance of the swarm box.
The pheromone compound may be absorbed into a matrix or mixed with wax or plastic in the liquid state so that the resulting solid can be used as a lure. In the case of wax the block may be rubbed across the grain of a wooden surface to render a hive box more attractive.
I have never used swarm lures and don't see a need to. There is a view becoming common that if you put enough lures close to an apiary there is no need to inspect colonies and perform swarm control. I believe this to be a method of encouraging beekeepers not to look after their bees properly, as there are plenty of things to do in the summer, other than check colonies for the possibility of swarming. From my discussions with beekeepers from a wide area it seems this is a short cut to becoming lazy and may attract people into beekeeping who may think they don't have to be beekeepers but "swarm lure keepers". I would prefer people to become much better beekeepers than rely on what is effectively cheating. Having said that I have no problem with home made lures.
As far as attracting swarms from elsewhere is concerned I have no problem with putting out bait hives, but in my experience the placing of them where at least two ley lines cross is pretty effective. Why not do what the bees would do naturally?