Many solitary bees and wasps construct brood cells in pre-existing natural cavities such as beetle borings or in excavations of pithy stems and twigs like Sambucus and Juglans. Artificial nesting materials are also acceptable and provide a convenient approach to study nest architecture, nesting activity, provisions and parasites. Arti- ficial nesting materials have included bamboo, glass tubes, plastic straws, cuttings of twigs and stems, and trap-nests. However, use of many of these materials have significant drawbacks.
Fricke, John M.
"Trap-Nest Design for Small Trap-nesting Hymenoptera,"
The Great Lakes Entomologist: Vol. 24
, Article 9.
Available at: https://scholar.valpo.edu/tgle/vol24/iss2/9