Folsomia fimetaria - <p>I thought the brown dorsal stripe was gut contents when I was taking the photos and it may be partly, but you can also see pigment and the setae are brown too above it so... I've been finding these over the last week, at home and in the local woods, all with the same stripe. Edit- the brown really is just gut contents- From Frans.... "The brown stripe indeed is gut contents, not skin pigmentation. Juveniles are always feeding. The brown setae are an artefact, a side-effect of the illumination/reflection/refraction." </p> © Andy Murray - CC BY-SA 2.0 - Wikimedia Commons