Phyllonorycter roboris (Zeller, 1839)
gold-bent midget

Quercus robur, Belgium, Viroinval

underside

the pupa seems to lie free in the mine; in reality it “floats” in an extremely loose three-dimensional network of silk
mine
A large, lower-surface tentiform mine, c. 20 mm long, often not far from the leaf base. The lower epidermis seems smooth to the naked eye, but with a lens many fine length folds are visible. Frass as a black mass in a corner of the mine. Before ecdysis the pupa works itself halfway out of the mine; unlike the other western European oak Phyllonorycter, that have the exuvium pale olive or reddish brown, in roboris it is dark, blackish (Emmet, 1975b).
host plants
Fagaceae, monophagogous
Quercus cerris, dalechampii, faginea, frainetto, x hispanica, macrocarpa, petraea & subsp. iberica, pubescens, robur & subsp. pedunculiflora.
phenology
Larvae in July and September (Hering, 1957a).
BENELUX
BE recorded (Phegea, 2009).
NE recorded (Kuchlein & de Vos, 1999a; Microlepidoptera.nl, 2009).
LUX recorded (Fauna Europaea, 2009).
distribution within Europe
All Europe (Fauna Europaea, 2009).
pop
notes
Emmet (1975b) and Emmet ao (1986a) write that the cocoon lies in a white cocoon. This difference with my observation may be caused by the fact the in Britain the species has but one generation, while it has two in the European mainland. The pictures date from end September.
references
Baldizzone (2004a), Bengtsson & Johansson (2011a), Buhr (1936a), Buszko & Beshkov (2004a), Csóka (2003a), Deutsch (2012a), Deutschmann (2008a), Drăghia (1972a), Emmet (1975b), Emmet, Watkinson & Wilson (1985a), ffennell (1975a), Gregor (1952a), Gregor & Patočka (2001a), Harper & Langmaid (1978a), Hartig (1939a), Hering (1934a, 1957a), Huemer (1986b, 2012a), Jaworski (2009a), Kasy (1983a, 1987a), Klimesch (1950c), Kollár (2007a), Kollár & Hrubík (2009a), Kuchlein & Donner (1993a), Kuchlein & de Vos (1999a), Maček (1999a), Matošević, Pernek, Dubravac & Barić (2009a), Nel &a Varenne (2014a), Patočka & Turčáni (2005a), De Prins & Steeman (2011a), Robbins (1991a), Schmid (2019a), Schütze (1931a), Sefrová (2005a), Skala (1951a), Starý (1930a), Stolnicu (2007a, 2008a), Szőcs (1977a, 1978a, 1981a), Tomov & Dimitrov (2007a), Tourlan (1980a), Yefremova & Kravchenko (2015a).