There are at least 450 species of bees, classified in 6 different families, in Pennsylvania. The number of bee species is shown by family, to highlight the comparative diversity of each group.

 Many studies have recently shown that bee populations are declining around the world. However, baseline data on bee species composition is lacking for most regions, which hinders the detection of changes in bee communities over time. Documenting the diversity of non-managed, native bee communities is critical for identifying how ecological interactions between bees, plants, and diseases and parasites can evolve, as well as for assessing conservation status.

Checklists provide information about the species found in a defined region and serve as baselines for detecting species range expansions, contractions, or introductions. We are developing an updated checklist of the bees of Pennsylvania, USA, using the first checklist (Donovall & vanEngelsdorp 2010; 371 species) as baseline data. Since 2010, thousands of additional bee specimens have been collected and databased in the state, new species have been described in the region, new introduced and invasive species have arrived, and the taxonomic status of some bee species has changed. Therefore, frequent revisions are imperative to detect changes in pollinator communities.

Our approach has been to review (1) new specimen data from insect collections, (2) published scientific literature, (3) specimen databases from monitoring and other studies, and (4) public records such as those available at the Discover Life website. We are also collecting information about the social behavior, nesting habitat, body size, phenology, and diet breadth of each bee species.

 Number of bee species by family, and numbers of species recorded per study, in Pennsylvania. Compared to the previous checklist (Donovall & vanEngelsdorp 2010),

As of January 2019, 83 new species records have been recorded for Pennsylvania. These results bring up the total number of species for the state to at least 450. New county records and information on species persistence is also being collected. We will make all of the results of this study publicly available through this website.

Want to learn more about the diversity of bee species and where they are found in Pennsylvania?

Click on each family of bees to find out more!

Members of the bee family Melittidae generally do not have common names. Four species of melittid bees, all native to North America, have been recorded in Pennsylvania (Donovall and vanEngelsdorp 2010). Worldwide, there are 203 species in this family (Ascher and Pickering 2018).


Penn State Center for Pollinator Research: Group of faculty, postdocs, and students who are working on developing and implementing integrative, multidisciplinary approaches to improving pollinator health, conservation, and management.

Pennsylvania Pollinator Protection Plan (P4): Outlines best management practices for supporting and expanding pollinator populations in Pennsylvania including pesticide use, forage, and habitat.

Penn State Insect Identification: Free service from Penn State for insect identification.

Connect with and follow our project in social media

1. Create your post on social media (FacebookTwitter and Instagram)

2. Add the hashtag #BeesofPA

3. Tag our lab using @LopezUribeLab

Questions about this research? 

Please contact Shelby KilpatrickThank you for your interest! 


Donovall, L. R., and D. vanEngelsdorp. 2010. A Checklist of the Bees (Hymenoptera: Apoidea) of Pennsylvania. J. Kans. Entomol. Soc. 83: 7-24.

How to site this page

Kilpatrick, S.K., J. Gibbs, M.M. Mikulas, S. Spichiger, N. Ostiguy, D. Biddinger, and M.M. López-Uribe. 2019. Checklist of the Bees of Pennsylvania.

Updated 1 March 2019