We report the first records of Pseudoanthidium nanum (Mocsáry) in Illinois and Minnesota in 2016 and 2018, respectively. This represents a relatively rapid expansion since P. nanum was first detected in New Jersey in 2008. In order to help monitor the spread of this bee, we provide information on how to identify P. nanum and provide images of the general habitus, diagnostic features, and male genitalia. Finally, we confirm the taxonomic identity of P. nanum in the United States and highlight potential impacts on native anthidiines.
Portman, Zachary M.; Burrows, Skyler J.; Griswold, Terry; Arduser, Mike; Irber, Aaron J.; Tonietto, Rebecca K.; and Cariveau, Daniel P.
"First Records of the Adventive Pseudoanthidium nanum (Mocsáry) (Hymenoptera: Megachilidae) in Illinois and Minnesota, with Notes on its Identification and Taxonomy,"
The Great Lakes Entomologist, vol 52
Available at: https://scholar.valpo.edu/tgle/vol52/iss1/6