This easy trap will help control carpenter bees that threaten your home without the need for baits or poisons, and it will not attract or harm any other kind of bee or insect. The trap will not lure carpenter bees in from a great distance, but will trap those that are intent on damaging the protected structure. Wood-boring female carpenter bees enter the pre-made holes, then they become dessicated by the sun in the capture bottle. The first day this trap was installed, it caught the four bees shown in the photo.
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There is nothing special about the components and their dimensions. Feel free to substitute, though I would not use plywood for the sides of the box because its exposed glue might deter the bees.
Wood for box, solid, one inch thick, 4 inches wide, does not need to be weathered
Wood for box lid, I used a scrap of 1/4-inch thick marine plywood 4 and 3/8 inches square
4 drywall screws for attaching lid to box
wood glue for outdoor use, such as Titebond II, to assemble the wood box, or alternatively drywall screws
Rectangular plastic 500 ml Fiji bottled water bottle and its cap (WalMart). This is the only rectangular bottle I could find, and it is sturdier than most other water bottles.
Deer Park Aqua Pod 325 ml plastic bottled water bottle and its cap (grocery store).
Metal grommet for connecting the bottle caps together, sold as part of a kit for placing grommets in tarpaulins; alternatively, outdoor tape