(A) Sample Collection
Between 2019 and 2020, 33 X. sonorina and 22 X.
tabaniformis adults were collected. Bees were captured in one of three
ways: netted while foraging, caught using traps over the nest entrance
(Supplementary Figure S1) or through excavation of logs to sample entire
nests. The type of capture was recorded, with bees caught on the wing
denoted as ‘foraging’ and those captured within or exiting a log denoted
as ‘nest-caught’. Samples were obtained from Davis, CA (21 X.
sonorina ; 14 X. tabaniformis ), Anza-Borrego Desert State Park in
Southern California (1 X. sonorina , 8 X. tabaniformis ),
and Tempe, Arizona (11 X. sonorina ). Samples from Davis and
Anza-Borrego were captured during late summer and early fall while
samples from Tempe were collected in early summer (see data file for
collection date). Bee species can be distinguished morphologically, and
identifications were verified using voucher specimens at the Bohart
Museum of Entomology. Captured carpenter bees were photographed, then
killed by placing them in a -20 oC freezer where they
were stored until dissection.