eDNA Analysis for Native Cavity‐Nesting Bee Ecology: A Comparison of Data From Brood Cells Contents and Larval DNA

While the colonial honeybee is widely recognized by the public as a pollinator, thousands of native bees play an important but often under‐recognized role. Their solitary or semi‐solitary life histories and small population sizes make them difficult to study at scale. Traditional approaches such as pan‐trapping, netting, or larval collection are invasive and may be unsuitable when species at risk are present. Although environmental DNA (eDNA) methods have expanded rapidly in honeybee research, analogous non‐invasive approaches for native bees remain limited and often provide only indirect data. Here, we test whether biological material contained within brood cells of cavity‐nesting bees can serve as an eDNA reservoir capable of reproducing the ecological information obtained from larval metabarcoding. We analyzed 2966 paired samples of larvae and their associated brood cell contents collected from artificial bee homes in four locations. Our data strongly suggest that taxonomic detections across insects, fungi, plants, and bacterial communities are highly similar, with sample type explaining less than 1% of the variation in community composition, with most discrepancies restricted to rare taxa. Co‐occurring taxa, including the larva itself, pollen‐derived plant DNA, potential pathogens, and environmental microbes, were detected from both larva and brood cell debris, suggesting that both larval feeding and female provisioning leave detectable, interpretable DNA signatures. Our findings demonstrate that brood cells function as robust DNA repositories. This approach offers a scalable ecological alternative to lethal sampling and provides a powerful tool for monitoring native bee ecology and informing conservation strategies.