
Family Megachilidae > Genus Pseudoanthidium
Pseudoanthidium
Small Carder Bees
In Minnesota, there is one described species within the genus Pseudoanthidium—Pseudoanthidium nanum. Recently introduced to North America, this species, an exotic, non-native bee, was first documented in North America in 2008. In Minnesota, it was found in Hennepin county in 2018, but new county records will follow if this bee has become established. This species nests in pre-existing cavities aboveground that are lined and partitioned with plant hairs.
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Pseudoanthidium nanum is a small black bee with white or light yellow markings on the head, thorax, and abdomen. This species closely resembles bees in the genus Anthidium but is smaller than the four Anthidium species in Minnesota. Like Anthidium, Pseudoanthidium nanum lacks an arolium (pad between the tarsal claws). The edge of the pronotal lobe is thin and translucent, a characteristic shared by the two non-native Anthidium in Minnesota. The forewing marginal cell is shaded. Females collect pollen on hairs on the underside of their abdomen; they have five teeth on each mandible. Pseudoanthidium nanum ranges in length from 5 to 7 mm (0.2 to 0.27 inches).

Pseudoanthidium nanum
Distribution

Minnesota

Regional Map
Pseudoanthidium nanum (Mocsáry, 1880) in GBIF Secretariat (2023). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2024-12-20.
wing
position
on flowers

N0. species in MN
1
size range

Phenology


NatureServe State Conservation Status
Explore More Megachilidae Genera
Note: Two genera/species on the state list are not included in this guide: Ashmeadiella bucconis (last seen in Minnesota in 1949) and Trachusa zebrata (last seen in Minnesota in 1939). If either of these species is rediscovered in the state, they will be added to the guide at that time.
Explore Other Bee Families
Megachilidae
Resin, carder, mason, and leafcutter bees

Citations and Further Reading
Droege, S., et al. (2024). The Very Handy Bee Manual: 2.0. How to Catch and Identify Bees and Manage a Collection.
Gibbs, J., Hanuschuk, E., Miller, R., Dubois, M., Martini, M., Robinson, S., ... & Onuferko, T. M. (2023). A checklist of the bees (Hymenoptera: Apoidea) of Manitoba, Canada. The Canadian Entomologist, 155, e3.
Mitchell, T. B. (1960). Bees of the eastern United States. Technical Bulletin No. 141. North Carolina Agricultural Experiment Station.
Portman, Z. M., Gardner, J., Lane, I. G., Gerjets, N., Petersen, J. D., Ascher, J. S., ... & Cariveau, D. P. (2023). A checklist of the bees (Hymenoptera: Apoidea) of Minnesota. Zootaxa, 5304(1), 1-95.
Portman, Z. M., Burrows, S. J., Griswold, T., Arduser, M., Irber, A. J., Tonietto, R. K., & Cariveau, D. P. (2019). 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, 52(1), 6.
Wilson, J. S., & Messinger Carril, O. J. (2016). The bees in your backyard: a guide to North America's bees. Princeton University Press.
Page Photography Credits
Heather Holm
Joel Gardner CC BY-ND-NC 1.0 (Melittidae)
Martin Lucas CC BY-ND-NC 4.0 (Anthidiellum)
Public Domain (Pseudoanthidium)