Pollinator eDNA: Rates of deposition and decay

Pollinator populations have declined worldwide, necessitating surveys of their biodiversity trends to protect against and adapt to the impacts on the environment and economy. Traditional survey methods (e.g., trapping, netting), however, are limited by high labor costs, large time investments, and the dwindling taxonomic expertise needed to identify specimens. Environmental DNA (eDNA) is a relatively novel method for characterizing biodiversity in which samples taken directly from the environment are processed for residual DNA left behind by visiting organisms. Recent innovations made in terrestrial eDNA have greatly improved the potential for applying eDNA to pollinator community characterization, showing potential for increasing efficiency and quality of results, but requires ground-truthing prior to extensive implementation. To address the knowledge gap regarding DNA deposition rates by target species as well as detection efficiency of widely used yet novel protocols, honey bees (Apis mellifera) were placed in petri-dishes lined with filter paper to determine the baseline detectability of honey bee DNA in a controlled lab environment. The effects of variables such as time, temperature, and UV exposure on DNA detection were analyzed. To compare lab data to field data, artificial flowers lined with filter paper were placed in a large hoop house and restored prairie sites. Detection rates were then compared to lab data. We predict that longer contact with a substrate will result in higher DNA deposition, and that exposure to elements such as UV will degrade detection rates. We also predict that our controlled lab environment will inform field-level sampling.