Last modified: Jan. 18, 2020, 12:01 p.m.
A rare and local species in Belgium, first observed in 2007 in NA. More observed in the Kempen area.
Forewing ground colour unicolorous ochreous brown with some darker brown scales along the costa and in the apical area.
A rather large, yellowish brown blotch mine with fine concentric grey-green arcs on the upperside of a leaf. Already in a rather young stage, the caterpillar constructs a semi-circular pupation chamber in which it rests and presumably also moults. The last instar larva detaches this pupation chamber leaving a circular space in the upper cuticula. The frass is ejected from the mine.
See also bladmineerders.be
The egg is deposited on the upperside of a leaf.
In contrast with the other Tischeria species, the last instar larva of T. decidua detaches the semi-circular pupation chamber from the upper cuticula of the leaf and drops with it to the ground. The species hibernates in the larval stage and pupates in early spring.
One generation a year in May and June.
Xerothermic forest margins and clearings.