What are the small holes in the sides of my nesting tubes?

Small holes in the sides of your paper or cardboard nesting holes were made by parasitic wasps. Parasitic wasps are sneaky and use their ovipositor to lay their eggs inside the developing mason bee larvae. When the parasitic wasp eggs hatch they chew their way out of the side of your paper or cardboard nesting tubes and they leave a small hole behind.

Follow the instructions in our Learn 8 Pests & Diseases page.