Chelostoma (Prochelostoma) philadelphi (Robertson 1891)

County records: Allegan, Livingston, St. Joseph, Washtenaw, Wayne.

Notes. A native species oligolectic on Philadelphus (Saxifragaceae) . Two non-native Chelostoma are likely to occur in the state (see Appendix 1). Nests in Virginia described by Krombein (Krombein 1959, 1967). Mud is used in cell partitions.