MEXICO: Spiders can be identified from the DNA they leave on webs, say US scientists.
Analysis of genetic material stuck to spiders webs also reveals what they have eaten weeks after catching their prey.
The research may have future uses in monitoring endangered species or tracking down spider pests, experts report in the journal, Plos One.
The study looked at black widow spiders kept in a zoo.
If the technique works on other types of spider, it could have widespread practical uses, say experts from the University of Notre Dame in Indiana.
Lead researcher, Charles Xu, extracted mitochondrial DNA from the webs of black widow spiders kept at Potawatomi Zoo in Indiana.
He found that both the spider species and its prey – in this case crickets – can be identified from DNA spider web samples.
Spider webs can potentially be used to collect DNA without having to capture the spiders themselves, he says.
“In the past, identification of spiders has relied on morphology, especially looking at the genitalia of spiders because they’re very different between different species of spider,” he told BBC News.
“But there are a lot of errors associated with these kinds of methods and now with the advent of new genetic technologies we can more accurately identify these species.
“The really cool part about our study is that we used non-invasive samples – so these web samples – where we don’t even have to directly observe or capture these spiders to get their DNA.”
