In the world of beekeeping there are many controversial subjects. One of those is re-queening.
Sometimes your hive goes queenless. In about 30% of those cases the hive does not successfully re-queen itself. It then becomes necessary to re-queen that hive rapidly to avoid laying workers from taking possession of the hive. Laying workers take control soon after the last developing brood is capped. The combination of queen and brood pheromones tends to keep the laying workers in check. Addition of a frame of eggs and uncapped brood from another hive can delay the laying workers. Re-queening in this situation is not controversial. It is then just a matter of whether to use local/regional raised or factory raised queens.
NOTE: “Factory Raised” queens is a term referring to large scale queen breeders that raise thousands, no tens of thousands, of queens. This can cause a genetic bottleneck since both the queens and drones come from a small (not genetically diverse) population.
Local/regional raised queens in theory have become acclimatized to the local/regional weather and forage. This should help with winter survival. Whereas, factory raised queens probably come from California or one of the southern states. These queens may not be acclimatized to our severe winter weather.
A second reason to re-queen is to keep the average age of your queens lower. Young queens are less likely to be superceded in the following year. The probably of a supercedure of a 3 year old queen is rather high. If a supercedure is just prior to the honey flow, the multi-week process could cut into the nectar gathering potential of the hive, since the hive bee population normally dips at this time. There is some data that indicates 2nd year queens are the most productive. After that the queen productivity declines. Re-queening allows the beekeeping to somewhat prevent unplanned supercedure and to also keep the queen productivity in the optimum range and hopefully increase honey yield.
A third reason to re-queen is to alter the genetic makeup of the bees in your apiary. Most beekeepers start with packages that come with factory raised California or southern queens. Historically these queens did not have anti-varroa characteristics and are thus more susceptible to winter failure from varroa related viruses. Recently selectively breed bees with anti-varroa characteristics have been developed. These are VSH (varroa sensitive hybrids), Primorsky Russians, Purdue Ankle Biters, regional survivor stock (such as Michigan Mutts) and others. Ah ha, the topic for another blog article; designer bees! Although technically not re-queening many beekeepers incorporate improved genetics when doing splits in the spring.
Re-queening for the second and third reason is usually done in late summer after the honey harvest. Queens are usually in short supply at that time; so plan ahead.
The alternate approach is to do no re-queening and let nature take its course.