Abstract
Environmental DNA (eDNA) analyses have become invaluable for detecting
and monitoring aquatic and terrestrial species and assessing site
biodiversity within aquatic environments or soil. Recent studies have
extended these techniques by using eDNA to identify the presence of
aboveground terrestrial arthropods directly from aboveground substrates.
However, while the dynamics of eDNA state, transport, and fate (its
‘ecology’) have been explored within aquatic environments and soil, they
have yet to be explored within aboveground terrestrial systems. Here we
explore the ecology of terrestrial eDNA deposited by fluid-feeding
arthropods on leaf surfaces. We carried out a series of experiments to
evaluate the optimal filter pore size for intracellular eDNA collection,
how eDNA is affected by rain events, and its degradation rate under
different solar radiation conditions. We found that the captured
concentration of intracellular eDNA was not significantly affected by an
increase in filter pore size, suggesting a wide range of viable pore
size options exist for targeting intracellular eDNA. We also found
extracellular eDNA from fluid excrement degrades more rapidly than
intracellular when exposed to solar radiation, indicating the latter is
a more viable target for collection. Finally, we identified that
rainfall or mist will remove most terrestrial eDNA present on vegetation
surfaces. We provide researchers and environmental managers key insights
into successfully designing and carrying out terrestrial arthropod eDNA
surveys that maximize detection probability.