1a blotch, from which eventually a round or oval excision is cut => 2

1b fleck mine => 4

1c lower surface tentiform mine: Phyllonorycter junoniella

1d corridor or blotch (no excision) => 9

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

2a excision round; egg deposited in the leaf tissue => 3

2b excision oval; egg on the leaf => 4

3a mine in the centre of the leaf; May-June: Incurvaria masculella

3b mine near the leaf margin; July-August: Incurvaria oehlmanniella

3c mountain species: Incurvaria vetulella

4a case wrapped in a mined, withered and crumpled leaf: Coleophora uliginosella

4b composite leaf case => 5

4c spathulate leaf case => 8

4d sheath case (exceptional): Coleophora pyrrhulipennella

5a case composed of a large number of narrow rings; rear end strongly curved down: Coleophora vitisella

5b case composed of 3-6 leaf fragments; rear end straight => 6

6a the larva feeds at the upper side of the leaf: Coleophora vacciniella

6b the larva feeds at the underside => 7

7a on Vaccinium vitis-daea (rarely myrtillus): Coleophora idaeella

7b on Vaccinium uliginosum: Coleophora plumbella

8a larvae still feed actively in spring: Coleophora glitzella

8b larvae are fully fed in autumn, do not feed any more after the hibernation: Coleophora murinella

9a mine begins at an egg shell; larva lives in the mine till, or just before, pupation => 10

9b no egg shell visible; older larva lives free between spun leaves => 11

10a corridor, usually forming a secondary blotch; pupation outside the mine: Stigmella myrtillella

10b a corridor, widening into a primary blotch; pupation within the mine: Fomoria weaveri

11a mine tiny; mining larvae around June and October: Rhopobota myrtillana

11b mine not unusually small; mining larvae in April, May => 12

12a larva whitish: Rhopobota ustomaculana

12b larva yellowish brown: Argyroploce arbutella