Hive-Mounted Pollen Traps

A pollen trap (as a hive part) is a hive component fitted at the entrance or between the floor and the first box, which collects pollen by making the bees pass through a perforated plate. When fitted correctly, the trap sits on the hive without gaps, all other entrances are closed, the drone exit stays open, and the drawer can be emptied without opening the hive. Because the trap also affects the hive's ventilation and traffic, it is fitted according to the state of the colony.

Where is a pollen trap fitted on the hive?

A pollen trap is placed so that it becomes the only way into the hive. According to its position on the hive, there are three types:

The trap should be chosen to fit the outer dimensions of the hive type you use (Langstroth, Dadant, etc.). With a trap that does not fit, the bees pass through gaps at the edges and the trap does not work, or the gaps are gradually sealed with propolis and wax.

What are the parts of a pollen trap?

• Perforated plate (grid): The plate with holes of about 5 mm that the bees pass through. It can usually be removed or slid aside, so that the trap can be disabled without taking it off.
• Wire mesh: Fine mesh below the plate that lets falling pollen through but not the bees. It stops the bees taking the pollen back.
• Collection drawer: The drawer, with a ventilated base, in which the pollen collects. It is pulled out from the back or the front of the hive.
• Drone exit: A one-way escape route through which drones can leave but not return.
• Body frame and rain cover: The wooden or plastic housing that attaches the trap to the hive, and a roof that protects the drawer from rain.

How is a bottom-type pollen trap fitted? Step by step

1. Choose the time: Work in the middle of a warm day when the bees are flying; the hive is calmer when most of the foragers are out.
2. Lift the hive: Take the body (and upper boxes) off the floor and set them temporarily to one side on a cloth or an upturned roof.
3. Place the trap: Set the trap in place of the floor, or on top of the floor as described by the manufacturer; check the direction of the drawer.
4. Set the body in place: Put the body on top of the trap so that no gaps are left. To avoid crushing bees, slide the body into position slowly.
5. Close the other entrances: The old bottom entrance, the upper entrance, the crown board hole and any cracks in the woodwork must be closed; every hole left open makes the trap ineffective.
6. Set it to the acclimatisation position: Leave the plate removed or in the open position; let the bees get used to the new entrance for a few days.
7. Put it into operation: Fit the plate, insert the drawer and check that the drone exit is open.

How is an entrance-type pollen trap fitted?

• Remove the entrance reducer and mouse guard, if fitted.
• Seat the trap on the landing board so that the perforated plate rests fully against the front of the hive.
• Make sure there are no gaps at the sides and top; if necessary, secure the trap with a strap, hooks or screws.
• Close any other entrance on the hive.
• Check that the drawer is protected from rain and pulls out easily.

How does a pollen trap affect the working of the hive?

• Ventilation: The perforated plate reduces airflow through the entrance. On hot days the bees may cluster at the entrance; if needed, extra ventilation is provided through the crown board, but this opening must be covered with mesh the bees cannot pass.
• Traffic: During a heavy flow, congestion builds up in front of the plate. Traps with wide plates are preferred for strong colonies.
• Drones: Without an exit, drones stay inside or on the plate; dead drones block the holes.
• Floor and varroa tray: When a bottom trap is fitted, a varroa monitoring tray or mesh floor may not be usable; periods when the trap is disabled are chosen for varroa monitoring.
• Moving: In migratory beekeeping, before hives fitted with traps are moved, the plate and drawer are secured or the trap is removed.

When should a pollen trap be removed?

The trap is run only intermittently, during periods of abundant pollen and on strong colonies. If the brood area is shrinking, the pollen arch is getting thinner or a treatment is to be applied, the plate is disabled immediately. At the end of the season, entrance traps are removed and the entrance reducer and mouse guard are refitted. Some beekeepers leave bottom traps in place all year with the plate removed; in that case the drawer should be kept empty and clean and the entrance reduced for winter.

Common fitting mistakes

• Leaving the upper entrance or crown board hole open: the bees bypass the trap.
• Fitting a trap that does not fit the hive dimensions: bees get through the gaps at the edges.
• Leaving the drone exit closed, or using a trap with no drone exit.
• Putting the trap straight into operation without acclimatisation: there is prolonged congestion at the entrance.
• Fitting a trap without a rain cover to a hive that is not tilted forward: the drawer fills with water.