Grace Avalos
Cameron J. Garland
Regina Trott
Olivia Hager
Mark J. Hepner
Clayton D. Raines
Karen Goodell
Rodney T. Richardson
2025
<p><span>Terrestrial environmental DNA (eDNA) techniques have been proposed as a means of sensitive, non-lethal pollinator monitoring. To date, however, no studies have provided evidence that eDNA methods can achieve detection densities on par with traditional pollinator surveys. Using a large-scale dataset of eDNA and corresponding net surveys, we show that eDNA methods enable sensitive, species-level characterization of whole bumble bee communities, including rare and critically endangered species such as the rusty pathed bumble bee (RPBB; </span><i>Bombus affinis</i><span>). All species present in netting surveys were detected within eDNA surveys, apart from two rare species in the socially parasitic subgenus </span><i>Psithyrus</i><span> (cuckoo bumble bees). Further, for rare non-parasitic species, eDNA methods exhibited similar sensitivity relative to traditional netting. Relative to flower eDNA samples, sequenced field negative controls resulted in significantly lower rates of </span><i>Bombus</i><span> detection, and these detections were likely attributable to high rates of background eDNA on environmental surfaces. Lastly, we found that eDNA-based frequency of detection across replicate surveys was strongly associated with net-based measures of abundance across site visits. We conclude that the method is cost-effective and highly scalable for semi-quantitative characterization of at-risk bumble bee communities, providing a new approach for improving our understanding of species habitat associations.</span></p>
application/pdf
10.1101/2025.05.13.649340
en
BioRxiv
Sensitive environmental DNA methods for low-risk surveillance of at-risk bumble bees
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