Figure 46. Ranges of nesting tunnel diameters used by species native to North Carolina. Specific ideal diameters for the blue orchard bee (7.5 mm, 19/64″) and alfalfa leafcutting bee (6 mm, 15/64″) are indicated with larger black dots on the range lines. Bees are shown in black, wasps in red.
Holes from 5/64” to 1/2” and the bees that use each size.