This is how you create important living space

Which wild bees nest in the tree trunk?

A tree trunk is suitable as a nesting aid for solitary wild bee species. The size of the boreholes decides which bee species will move into the wild bee hotel:

• Drill hole with a diameter of 3-5 mm: common mask bee (Hylaeus communis), buttercup scissor bee (Chelostoma florisomne), common hole bee (Heriades truncorum)
• Borehole 6-8mm diameter: Horned Mason Bee (Osmia cornuta), Rusty Leafcutter Bee (Megachile centuncularis), Garden Leafcutter Bee (Megachile willughbiella), Steel Blue Mason Bee (Osmia caerulescens)

Which wood is suitable as a nesting aid for wild bees?

Best suited as a nesting aid for wild bees

well-seasoned hardwood, such as maple, beech, ash, oak and fruit tree wood. The less residual moisture there is in the wood, the easier it is to drill nest passages.

In contrast to this is soft coniferous wood unsuitable as building material for a wild bee hotel. The coarse wood fibers block wild bees from accessing the nesting passages. Resin formation and swelling wood fibers pose a deadly threat to the brood.

How is a tree trunk converted into a nesting aid for wild bees?

The drilling of nest passages transforms the tree trunk into a fully booked wild bee hotel. Important criteria for a premium quality nesting aid are drilling direction, drilling depth and drill hole diameter:

• Material requirements: tree trunk or tree disc, drilling machine,(€52.00 at Amazon*) sharp drills with 3mm to 8mm, sandpaper.
• Drill nest passages with different diameters.
• Distance between each hole is 1cm to 2cm (the bigger the hole, the bigger the distance).
• Drilling depth corresponds to the length of the drill bit (do not completely drill through the tree trunk).
• Always drill in the longitudinal direction of the wood (across the wood fibers).
• Smooth the entrance to the borehole with sandpaper.