Hylaeus basalis, H. ellipticus and H. verticalis nested in wooden traps during a two-year study in Upper Michigan. Bees were given a choice of traps with varying bore diameters, heights, and entrance orientations. Nests were completed between 1 July and 15 September. These three Hylaeus species partitioned available nest site resources (traps) based on diameter and height. H. ellipticus selected traps with smaller bore diameters than did the other two species which selected traps of the same bore diameters. H. verticalis nested in traps at higher locations than H. basalis which limited its nesting to only the two lowest heights available. Entrance orientation had no effect on trap selection by any of the species. Seasonal differences in choice of traps are discussed.
Scott, Virginia L.
"Phenology and Trap Selection of Three Species of Hylaeus (Hymenoptera: Colletidae) in Upper Michigan,"
The Great Lakes Entomologist, vol 27
Available at: https://scholar.valpo.edu/tgle/vol27/iss1/5