1a upper-surface tentiform mine: Aspilapteryx tringipennella

1b mine upper- or lower-surface, opaque, more or less a corridor => 2

1c mine full depth, transparant => 7

1d fleck mine => 9

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

2a corridor lower-surface, epidermal (silvery): Apsilapteryx tringipennella (youth mine)

2b mine deeper, whitish-light green => 3

3a larva a maggot; in broader corridors the frass in two rows along the sides => 4

3b larva with chitinised head; in broader corridors frass in a central line => 7

4a pupation outside the mine; frass in strings: Liriomyza strigata

4b pupation in the mine (sometimes in the petiole!); frass in discrete grains => 5

5a corridor strongly branched, fanning out from the petiole; on Plantago major and media: Phytomyza griffithsi

5b corridor little branched, sometimes from the petiole; also on other Plantago-species => 6

6a corridor unusually narrow; frass grains very widely apart (at least 4 times their diameter): Phytomyza plantaginis

6b corridor with normal width, frass grains less widely spaced (about twice their diameter); uncommon on Plantago: Chromatomyia horticola

7a very narrow and short corridor in young leaves (March-April); Plantago coronopus, maritima: Scrobipalpa samadensis

7b corridor or blotch in a different season and on all Plantago-species => 8

8a mine beginning in the leaf base or a thick vein: Orthochaetes setiger

8b mine not associated with leaf base or veins: Apteropeda orbiculata, splendida

9a larva mines from a silken tube, attached to the plant, into which it retreats upon danger or during feeding pauses => 10

9b larva free: Jordanita globulariae

10a larva grey-green with whitish length lines: Scythris picaepennis

10b larva dark purple with narrow transverse white bands: Scythris siccella