The genetic rest of the bugs is much smaller, but a sexy tarantula in a teacup makes for much better visuals. Photo credit: Benzstock/Shutterstock.com
The genetic spirits of over 1,000 beetles have been discovered in tea samples, suggesting your morning cup may contain rich ‘diverse tea’. The scientists behind this particular pun coined it after discovering that eDNA suggests there’s much more to the delicious dried plant matter than just savory notes and caffeine.
While brewing bugs may not sound particularly appealing to some, that doesn’t mean you should look for spider legs in your oolong (disclaimer: we can’t guarantee you’ll never find a spider in your tea), but set one up instead alternative approach to assessing species richness in an ecosystem.
The study, published in the journal Biology Letters, looked for the presence of environmental DNA (eDNA) in dried tea leaves and herbs purchased from grocery stores in Germany. eDNA samples are a bit like genetic breadcrumbs left behind by living things, and they can be enriched and sequenced to work backwards to determine which species live in specific environments.
Scientists have searched for eDNA in wet and dry environments, but this study was unique in searching for signs of life preserved on dried samples of plant material. When brewing tea, dried plant products are steeped in hot water, so drinks like chamomile and green tea can be analyzed in this way.
“In total, we recovered 3,264 arthropods [taxonomic units] They represent 3 classes, 22 orders, 281 families, 1,068 genera, and 1,279 species, including herbivores, carnivores, parasitoids, and detritivores,” the authors wrote.
“Every single sample recovered more than 200 [taxonomic units] on average, with green tea having the highest mean [variety of bug eDNA].”
While the genetic remains of a thousand beetles may not be the earthy notes hoped for, the discovery could prove very useful for future research into arthropod biodiversity and conservation, as well as for monitoring pests and plant imports.
“Atypical for eDNA, arthropod DNA in dried plants shows a very high temporal stability, which opens up plant archives as a source for historical arthropod eDNA,” say the authors.
“In light of these results, dried plant material appears excellent as a novel tool to monitor arthropods and arthropod-plant interactions, detect agricultural pests, and identify the geographic origin of imported plant material.”
Dried plant material as a monitoring tool also has the advantage of being easy to collect, dry and store, meaning that large libraries of non-perishable arthropod biodiversity archives can be produced with relative ease. We will toast to that.