Aceria carinifex (Kieffer, 1902)
Acer campestre, Hungary, Budapest © László Érsek
leaf with up to 1.5 cm long, slender depressions, open to the upperside with a narrow slit; at the underside of the leaf the gall forms a keel. At the inside white, later brown, cylindrical, spiralled hairs.
Sapindaceae, narrowly monophagous
Eriophyes macrochelus var. carinifex; Aceria macrochela crassipunctata (Nalepa, 1909).
the identification of the pictures above is somewhat hesitant, because the gall is less deep and slender, nor narrowed above to a slit, as is described in the literature.
Béguinot (2002f, 2003a, 2006b, 2012a), Buhr (1964b), Dauphin & Aniotsbehere (1997a), Farkas (1965a), Houard (1909a), Ripka (2007a), Roskam (2019a), Stănescu (2009a).