A queen excluder is a selective barrier inside a beehive that limits the queen’s access to parts of the hive. The idea behind a queen excluder is that the smaller worker bees can easily pass through the gaps and the larger queen and drone (male) bee cannot. The below image shows the three types of honey bees within a hive: the queen, the drones, and the workers.
The main use for a queen excluder is to keep the queen from laying eggs in the honey supers. The below diagram is a “typical” Langstroth beehive setup with 1 or 2 boxes for brood, a queen excluder and then 1 or 2 boxes for honey.
Queen excluders are available in different sizes, materials and shapes but are commonly made from plastic and metal.
The basic premise of all queen excluders is to confine the area of the hive the queen can roam (and lay).
The use of a queen excluder is one of the most controversial and hotly debated topics amongst beekeepers. Some beekeepers swear by them and other declare them unnatural and not required. Beekeepers are generally mild mannered folk until the topic of queen excluders is raised amongst a group of beekeepers!
Lets take a quick look at some of the pros and cons of queen excluders:
Pros of using queen excluders:
- Many commercial beekeepers use them for ease and time savings. Knowing where your queen is means you can quickly take off boxes of honey without having to inspect frames individually. When you are inspecting hundreds of hives per day, saving time matters more than if you have 1 or 2 hives.
- If the queen is in a limited space she is easier to find if the colony needs to be re-queened or you need to check brood for disease.
- Bees will typically store pollen close to the brood so honey extracted from frames that are brood free will contain less pollen and other impurities.
Cons of using queen excluders:
- Beekeepers that follow a “natural” beekeeping philosophy would not favour using excluders. When left to do things naturally in a tree cavity, the queen is free to lay eggs anywhere she pleases.
- Some beekeepers find that their bees do not like crossing excluders so will fill the brood boxes with pollen and honey. If there is no place left for the queen to lay it increases the chances of the bees swarming.
- Queen excluders can require regular maintenance as the bees can fill some of the gaps with wax or propolis.
- Some types of excluders may have sharp edges that could damage the wings of worker bees resulting in a shorter lifespan.
- Drones bees are larger than queen bees and can get stuck in the excluders. If a drone is trapped above the excluder he will get stuck and die trying to get through.
No matter what your opinion on queen excluders, there is no doubt they are a useful tool for beekeepers. For commercial apiaries in particular, the ease they provide keeping brood out of honey boxes generally outweighs any potential downside. Ultimately, using an excluder comes down to each beekeepers personal preference.