The Bug in a teacup – Monitoring arthropod-plant associations with environmental DNA from dried plant material

Environmental DNA analysis has revolutionized the field of biomonitoring
in the past years. Various sources have been shown to contain eDNA of
diverse organisms, for example water, soil, gut content and plant
surfaces. Here we show that dried plant material is a highly promising
source for arthropod community eDNA. We designed a metabarcoding assay to
enrich diverse arthropod communities, while preventing amplification of
plant DNA. Using this assay, we analyzed various commercially produced
teas and herbs. These samples recovered ecologically and taxonomically
diverse arthropod communities, a total of over a thousand species in more
than 20 orders, many of them specific to their host plant and its
geographic origin. Atypically for eDNA, arthropod DNA in dried plants
shows a very high temporal stability, opening up plant archives as a
source for historical arthropod eDNA. Considering these results, dried
plant material appears excellently suited as a novel tool to monitor
arthropods and arthropod-plant interactions, detect agricultural pests,
and identify the geographic origin of imported plant material. The ability
to detect highly diverse arthropod communities from all over the world in
tea bags also highlights the utility of our approach for outreach purposes
and to raise awareness about biodiversity.