Clothes moths offer forensic clues by building fuzzy, hair-flecked cases; larvae pick up tresses from corpses to make their homes.
RENO, Nev. -- Clothes moths will eat more than our wardrobe. Given a chance, they'll eat us too.
Casemaking clothes moth caterpillars can digest human hair and will feed on corpses. But it's not all bad news, scientists say. Hair bits nipped off of corpses by Tinea pellionella can yield enough DNA to identify the deceased, according to Sibyl Bucheli of Sam Houston State University in Huntsville, Texas.
"It's important to think outside the box," says Jeff Tomberlin of Texas A&M University in College Station. He ranks Bucheli's idea as unusual but credible.
Particularly helpful is the caterpillars' habit of retreating to nearby, out-of-the-way corners when it's time to stop feeding and metamorphose into small tan moths, Bucheli said November 16 at the annual meeting of the Entomological Society of America. The human body they've been feeding on may get moved away, but left-behind caterpillar cases can still tie the body to the location, she said.
Scientists have discovered clothes moths--one of two major wardrobe attackers in North America--nibbling on corpses before, according to Bucheli. And clothes moth larvae in the wild will graze on dead animals. "They had to eat something before people invented wool sweaters," she said.
This species takes its common name from the half-inch long, skinny, fiber-fuzzed cases that young larvae build. Each youngster surrounds itself with an open-ended case. As caterpillars forage, they stick out their front ends, like chilly campers refusing to climb out of warm sleeping bags.
Bucheli and her colleagues discovered human hair in the cases when a forensics team asked for help with an abandoned body discovered in a Texas house. Investigators asked Bucheli whether the insects around the body offered any clues to when in the past year the person had died. Investigators presented Bucheli with hundreds of insects, including clothes moth larvae in their cases. The parts of the cases made most recently bristled with stubs of human hair.
The hair shafts yielded enough mitochondrial DNA for Bucheli's team to sequence a repetitive bit of genetic material commonly used for forensic identification. To determine the timing, the team relied on the insect assemblage, which lacked some of the species that routinely visit fresh corpses in warm weather. Thus, the person probably had died during cool weather, not in summer as some witnesses had suggested.
|Printer friendly Cite/link Email Feedback|
|Date:||Dec 20, 2008|
|Previous Article:||Mars conceals buried icy treasure; frozen water reserves discovered in mid-latitude regions.|
|Next Article:||Fish that travel together make wiser decisions; when they choose a leader, sticklebacks think as a group.|