Synthetic spiderwebs trap DNA in outdoor tests

A bag of faux webs from a Halloween store became a biological net when Angela McGaughran wrapped the material around coat hangers and hung it outside in New Zealand. The synthetic webs collected environmental DNA from nearby cows and sheep, as well as exotic birds at a nearby aviary, while detecting fungal spores better than real webs.

The trick relies on eDNA — genetic material shed by living things. Spiderwebs are naturally sticky: they retain traces from the spiders that made them, their prey, and nearby plants and animals, including material carried through the air. Researchers can then use those traces to identify organisms without having to see or trap them.

The case for webs grew from a comparison led by Joshua Newton, a molecular ecologist at Curtin University in Perth, Australia. Near a zoo and wildlife sanctuary, his team compared spiderwebs with vegetation swabs, water, soil and a fan fitted with a filter. Vegetation swabs found more forest mammals and water samples identified more fish, but no passive tool matched spiderwebs’ ability to identify vertebrates. Similar results came from a study in France.

There was a clear cost: gathering meaningful data required destroying about 40 webs. Newton said that removing an organism’s home runs against the purpose of conservation work, creating an opening for McGaughran’s synthetic alternative.

So what changes in practice? If larger experiments confirm the early findings, researchers could deploy artificial webs as a cheap, passive way to watch biodiversity and detect fungal threats, without dismantling natural spider habitats. For now, McGaughran’s group is still developing those experiments, so the method remains a research-stage prospect rather than a monitoring system in service.