New insights into the ecology of Osmia calaminthae, an imperiled bee species in Florida

Osmia calaminthae (Hymenoptera: Megachilidae) is among the rarest, most poorly known, and geographically restricted native bee species in the Southeastern USA. It has been petitioned for listing under the Endangered Species Act and will soon undergo a species status assessment. To address critical knowledge gaps for the species and aid its conservation, we conducted extensive field studies from 2020 to 2023, focusing on its ecology, distribution, habitat requirements, and population levels. Our research has significantly expanded the known range of O. calaminthae from four to fifteen conservation properties.  We will also show results for the first capture-mark-recapture study for the species, which allowed us to estimate population-level parameters, life expectancy, and foraging range. These findings highlight the ecological intricacies of O. calaminthae and emphasize the importance of understanding its interaction with host plants for effective public land management. Our data indicate that population numbers vary significantly across the known range, underscoring the need for targeted conservation efforts. Future research should investigate how different habitat management practices affect its equally limited floral hosts and discrete populations. Understanding these mechanisms will be essential for optimizing conservation strategies to promote the survival of this rare and geographically restricted bee species.