1a mine in fallen leaf: Neocoenorrhinus pauxillus

1b tentiform mine => 2

1c fleck mine; larva mines from a portable case => 6

1d corridor or blotch => 9

1e galls, etc => Tables for all parasites per species

2a mine upper-surface, silvery (finally brownish): Phyllonorycter corylifoliella

2b mine lower-surface, not silvery => 3

3a older larva lives free under a folded leaf margin: Parornix anguliferella

3b the larva mines all its life, pupation within the mine (reliable identification impossible without breeding) => 4

4a species common in NW Europe => 5

4b rare in NW Europe or more southern species: Phyllonorycter hostis, Ph. mespilella

5a pupa greyish brown: Phyllonorycter oxyacanthae

5b pupa reddish brown: Phyllonorycter sorbi

6a lobe case: Coleophora violacea

6b tubular leaf case (youth case, ca. 5 mm) => 7

6c composite leaf case (> 5 mm) => 8

7a rear end of case crooked like the handle of a walking stick: Coleophora hemerobiella

7b rear end at most at right angle with remainder of the case: Coleophora spinella (+ C. prunifoliae, C. serratella)

8a case 8-11 mm; mouth angle 90°: Coleophora hemerobiella

8b case 6-7 mm, mouth angle 60°: Coleophora spinella; but see also C. prunifoliae, C. serratella

9a blotch mine => 10

9b corridor mine => 11

9c both corridor and blotch present; sometimes connected more often not, but on adjacent leaves: Lyonetia prunifoliella

10a small drop- or pear-shaped mine with very much frass; larva pear-shaped: Rhamphus oxyacanthae

10b circular blotch, with frass in concentric circles; larva slender: Leucoptera malifoliella

11a gallery < 1 cm => 12

11b gallery >> 1 cm => 13

12a gallery usually hook-like, in a vein axil; much frass: Bucculatrix bechsteinella

12b gallery irregularly branched; almost no frass: Recurvaria nanella

13a frass partly coiled; at the start of the mine a shining egg shell; larva green: Stigmella oxyacanthella

13b frass throughout in a narrow central line; no egg shell; larva whitish: Lyonetia clerkella