Using samples gathered from the webs of black widow spiders that were fed with crickets, researchers from the University of Notre Dame were able to identify the species of the spider and its prey using DNA analysis. Referred to as noninvasive sampling, this method of obtaining genetic information could have many practical implications for various fields of research, including conservation and pest management.

Charles Cong Yang Xu - who had the idea of unmasking spider DNA during his time examining the environmental DNA of fish in his previous lab - discovered the novel noninvasive source of spider and insect DNA with a team of researchers by extracting DNA from spider webs. After obtaining the samples, the team amplified and sequenced the mitochondrial DNA gained from the webs, which allowed them to pinpoint the species of the spider and its prey.

According to Xu and his team, the spider and prey DNA remained in a detectable form for at least 88 days following the absence of living organisms on the web.

"Sticky spider webs may serve as a natural DNA sampling device for DNA from the spider and from what it's been eating," he said in a press release.

The discovery of this noninvasive genetic sampling procedure can help scientists biomonitor without the need for directly disturbing target organisms, as well as lead to applications in various fields of biology.

"Sticky spider webs are natural DNA samplers, trapping nearby insects and other things blowing in the wind," continued Xu. "We see potential for broad environmental monitoring because spiders build webs in so many places."

The findings were published in the Nov. 25 issue of PLOS One.