Heptamelus ochroleucus (Stephens, 1835)
Long corridor in the petiole, descending down to within the leaf sheath, then running upwards from some distance. The petiole turns black, and the leaf is malformed and crumpled. Frass in coarse grains. Locally, mainly at the concave side of the petiole, the mine is situated just below the epidermis (contrary to the mine of Chirosia griseifrons). The larva vacates the mine just before pupation through an exit opening at the outside of the leaf sheath (de Meijere, 1911a, Lorenz & Kraus, 1957a).
Forsius (1932a), who says to know the mine well, writes that it can easily be distinguished from Diptera mines in the petiole because the mine is not black, but rather transparent, “like an air bubble”.
Blechnaceae, Dryopteridaceae, Polypodiaceae Woodsiaceae; narrowly polyphagous
Larvae found in July (de Meijere, 1911a). Two generations in Latvia, the first, most common, with larvae in June (Forsius, 1932a).
BE recorded (Fauna Europaea, 2008).
NE recorded (de Meijere, 1911a; van Ooststroom, 1976a).
LUX recorded (Chevin, Ellis & Schneider, 2011a).
distribution within Europe
From Sweden and Finland to Italy, and from Ireland to the Ukraine (Fauna Europaea, 2008).
The larva is violet in colour with a grey brown head and clear thoracic feet (de Meijere, 1911a, Hering, 1957a). Forsius (1932a) however describes the larva as whitish, turning violet only just before pupation At that point also the grey frontal plate looses its marks, which looked like a white horse shoe with its arms diverging downwards. Anal valves sepia.
Beneš & Holuša (2015a), Blank ao (1998a), Chevin, Ellis & Schneider (2011a), Forsius (1932a), Haris (2012a), Hering (1957a), Liston (1995b), Lorenz & Kraus (1957a), de Meijere (1911a), van Ooststroom (1976a), Pschorn-Walcher & Altenhofer (2006a), Savina & Chevin (2012a), Shaw & Bailey (1991a), Sønderup (1949a), Taeger, Altenhofer, Blank, ao (1998a), Taeger, Blank & Liston (2006a).