Last modified: Jan. 5, 2020, 6:36 p.m.
In Belgium this species was mentioned for the first time in 2009 and is, up to now, only found in LG.
This species, having a wingspan of 11–15 mm, is monotonous brown-grey with somewhat darker wing tips.
The antennae are alternately ringed black white till the the tip.
The full-grown larva lives in a case, measuring 10–12 mm, that is composed of three leaf fragments.
The mouth angle is about 60°.
See also bladmineerders.be.
The eggs are deposited in June or July.
The caterpillars make rather big reddish blotch mines and are fully grown in May after two years of development. After overwintering, they keep on feeding till April or even May.
Although the cases are, prior to pupation, found at the underside of a leaf, the pupation of C. idaeella occurs mostly on the upper side of a leaf of the host plant.
The adults fly in June.
Monophagous on Vaccinium vitis-idaea.