I have had a major infestation of small hive beetles in my beehives. A base mounted trap was purchased and tested. The instructions said that oil was to be put in the kill tray. I did that and found it did kill the beetles, but it was very messy and the oil turned rancid. I found out others had replaced the oil with pickling lime, garden lime, or diatomaceous earth. I chose the lime and it is less messy and does not turn rancid. You do have to remove the dead beetles when there are so many that the surface is blinded off.
This summer a thunderstorm blew over a neighbors cedar board fence. He replaced it and was going to burn the old fence, I rescued the fence. The bottom 10 inches were cutoff and discarded because of decay. I then cut up the cedar to make the frame pieces. For the metal tray I had rescued some sheet metal when my furnace was replaced and the cold air return was modified to accept the new furnace. I also rescued . some other from the sides of refrigerator that had stopped working. The screen was purchased new since I had not rescued any 1/8x1/8 hardware clothe (I had 1/4x1/4 but it is too large) The hive bases were purchased at an estate auction several years ago
Step 1: Building the Tray
The tray is made of 26 ga sheet metal (you can use whatever you have available). Cut the tray to size and form. A box and pan brake is the easiest , but a block and hammer can also be used to form the tray. The corners are soldered if you want to use oil, with a dry powder the corners can be pop riveted. The pop riveted should be flattened with a hammer and dolly. A wooden stiffener is made for the tray and a drawer handle is attached.
Step 2: Cleanup an Existing Base and Cut the New Parts
The 1-1/2" pieces are screwed to the base. The screen is stapled to the frame. The 1/2" are nailed in place with 3/4" brads. And finally the metal strips are also attached with the 3/4" brads.
All pieces are dimensioned to the nominal have size, in most cases the pieces had to be modified to fit these older bases.
The trays were my first try at using a box and pan brake and they had some taper in them so the trays were fitted to each base with small end facing toward the hive opening end, and the sides were positioned so the tray would slide easily.
Step 3: Installing the Screen
The screen is bent at 90 degrees and fitted into the slot. This is the entrance for the bees and the slot covers the sharp ends of the screen. The screen is stapled to the end and then down each side, stopping 6" from the end. Then the top strip is clamped to screen and stapled from the bottom. The strip is then positioned on the end of the base and the last 6" on each side is stapled. Finally the screen is trimmed to fit the base.
Step 4: Installation of the Top Strips
The top strips are installed with 3/4" brads on two sides. The end is left open for the bees to enter the hive.
Step 5: Never Wet Excluder Strips
Jeff Willard came up with using a Rust-oleum Never Wet as a slippery surface that hive beetles will not walk on.
28 ga flashing is cut into strips and coated with Never Wet. The strips are then positioned around the three sides of the base trap so that the beetles have to crawl upside down to get into the hive. A fourth strip is place on the entrance side brood box.
The base/trap is attached to the bottom brood box super with tie straps made from repurposed gutter hangers. Strip chalk (3M 08578) is placed between the extruder strips and the brood box. (known is the Navy as Monkey Poop and in the Automotive Industry as DumDum) This is a clay like chalk that does not dry out or get had with age.
Step 6: Results
The lime filled tray was placed under the hive. In four days the trap had captured several hundred beetles. The lime was replaced with fresh and the used was sifted with a colander sifter to remove the beetles and the lime was saved for reuse. When collecting the beetles be aware that the beetles might not be dead yet, so put the lime into a covered container and when sifting again be sure they are all dead. I take the sifted beetles in a plastic bag, seal, and put in the garbage.