[marant]

I am working on a trap for small hive beetles and need to know the proper size hole to drill that will allow them in but keep the bees out.

Also, the trap will be enclosed and horizontal. Should I drill the holes in the sides or in the top?

 

[FlowerPlanter]

When using hardware cloth for SBB beetle traps you use #8 which is 1/8 "
Some have beetles that are too big for #8 so they make their traps out of #6 hardware cloth (hard to find).
So I would try a 3/16 bit.
Bee can get through 1/4 so that would be too big.

 

[dynemd]

Per Michael Bush: For wire cloth, extrapolate to holes?
#8 - no bee can pass. pollen gets stuck.
#7 - as long as there are no bent wires, no bee can pass. Pollen falls through. Good for the bottom of a pollen trap to let the pollen fall into the tray.
#6 - worker bees can squeeze through (and will) but they have to wiggle and squirm a lot. Drones and queens cannot.

I have heard that bees can enter an opening as small as 3/16"

 

[marant]

Thanks, everyone. Based upon this information and some from other forums I have decided to go with 5/32 holes. Will let you know how it works out.