Steneotarsonemus spirifex (Marchal, 1902)
Avena sativa (from Houard, 1908a)
Hordeum vulgare, Hardenberg, Baalderes © Arnold Grossurt
Hordeum vulgare, Loenen (Ge) © Arnold Grosscurt
Within the leaf sheath the stem is spiralled like a corkscrew over some centimeters, and covered seemingly by flour, in fact mites that, contrary to gall midges, have 4 pairs of feet.
it seems that in the literature S. spirifex is not associated with barley; perhaps the pictures above concern a related tarsonemid, like Steneotarsonemus hordei Emmanouel & Smiley, 1985 (cf Smiley, Flechtmann & Ochoa).
Buhr (1964b), Dauphin & Aniotsbehere (1997a), Jepson, Keifer & Baker (1975a), Redfern & Shirley (2011a), Roskam (2009a), Smiley, Flechtmann & Ochoa (1993a), Tomasi (2014a).