Searching for a bee-gone era: A re-survey approach to assessing biodiversity in north-central Florida bee communities

While there is global concern over insect population declines, described by some as “Insect Armageddon”, the factors contributing to recorded population declines are varied and complex. Site-specific re-survey studies allow for direct assessment of temporal change and collectively can provide insight into specific drivers of change across environmental and spatial gradients. This approach has gained in popularity among ecologists, particularly with respect to plant taxa, but has not seen the same level of use in insects. This study seeks to capitalize on the advantages of a site-specific re-survey approach to assess changes in bee biodiversity and community composition across several sites in north-central Florida. Surveys conducted across 16 collection sites in 2006-2009 documented 2,590 specimens of bees across 34 genera and representing 111 species. This study re-surveys 11 of the original 16 sites using similar collection methodologies, including active netting and passive collection through bee bowls. General biodiversity parameters including species richness and evenness, adjusted for sampling effort, were quantified and compared between the two data sets to assess temporal changes in bee communities. Furthermore, multi-species occupancy models, i.e. tools for estimating species occupancy rates given imperfect detection, will be used to fully characterize the current community dynamics at these sites. Our study illustrates how site-specific re-surveys benefit our understanding of population declines and community dynamics in bees, and explores the limitations inherent in comparing historical and modern datasets.