With All Our Mites

With All Our Mites

Monday, December 11, 2017 - 09:00

ENCORE  You are not alone.  You can’t see ‘em, but your face is a festival of face mites. They’ve   evolved with us for millennia.  And a new study finds that hundreds of different tiny spiders, beetles, and – our favorite - book lice make your home theirs.  But before you go bonkers with the disinfectant, consider: eradicating these critters may do more harm than good.  Some are such close evolutionary partners with humans that they keep us healthy and can even reveal something about our ancestry.

But then there are bed bugs.  Pests without redemption.  However, their newly-sequenced genome may help us end their nightly nuisances.  And of course some microscopic critters are deadly.  So when it comes to bugs: when do we accommodate and when do we attack?  


  • Michelle TrautweinCurator of entomology, California Academy of Sciences
  • Matt Bertone –  Entomologist, North Carolina State University
  • Joshua Benoit -- Insect molecular biologist, University of Cincinnati 
  • Thomas McDadeBiological anthropologist, Northwestern University

Descripción en español

Face mite results, per Michelle Trautwein:

"About the results- well, you both had 2 species of face mites- Demodex brevis and Demodex folliculorum (which is exciting...I don't get both species off of people very often. Of course, most people have both species, but they are tricky to sample).

For both species, your mites clustered in broadly Europeans lineages, but not together. When it comes to hosts from Europe, most mites are pretty genetically similar- so I don't find big differences between Irish and Italian hosts, for example. It might be, though, that because I am sampling people from the US who are usually of mixed ancestry- the signal is muted. The big differences I find are between mites from Africa, South Asia, South East Asia, Latin America, Europe and East Asia.
Folliculorum: Seth actually clustered with a group of Europeans next door to a group of East Asians. Molly with an Italian - along with other people of European ancestry
Brevis: Again- both in a European lineage- Molly next to someone from France.
So, European nationality distinctions aren't very meaningful when it comes to face mites, unfortunately...."


originally aired February 15, 2016