1a fleck mine; larva mines from a case => 2

1b fleck mine; larva free in the leaf => 10

1c corridor or blotch; larva not in a case => 6

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

2a case black, made of silk “sheath case” =>3

2b case different, composed of leaf material => 5

3a case narrowed behind the mouth, especially ventrally: Coleophora ditella

3b case hardly constricted behind the mouth => 4

4a case dorsally with some length ridges; ventrally a deep keel: Coleophora caelebipennella

4b case smooth dorsally; ventrally almost without a keel: Coleophora helichrysiella

5a case straight, tubular, felty hairy, large (12 mm): Coleophora directella

5b case curved, hairs longer; case much smaller: Coleophora gnaphalii

6a mine upper- or lower-surface, greenish in transparency; larva a maggot => 7

6b mine full depth; larva with thoracic feet and chitinised head => 9

7a corridor, widening into a large blotch: Phytomyza kyffhusana

7b corridor from start to end => 8

8a pupation in the mine in a, usually lower-surface, pupal chamber; corridor little if at all branched: Chromatomyia cf syngenesiae

8b pupation outside the mine; mine pinnately branched, main branch overlying the midrib: Liriomyza strigata

9a the young larva makes a long, thread thin corridor with a central frass line; older larvae live free in the leaf, making fleck mines => 10

9b youth mines similar (starting in the leaf base), but the older larva remains in the leaf, making a broad corridor or a bloch => 11

9c youth mines different; neither are fleck mines made => 12

10a larva: pronotum with black dots; on H. arenarium: Bucculatrix gnaphaliella

10b pronotum whitish; on H. italicum: Bucculatrix helichrysella

11a larva yellow, head brown; on H. arenarium: Digitivalva reticulella

11b larva pale green, head pale yellow; on H. italicum: Digitivalva eglanteriella

12a mine contains much frass: Tebenna micalis

12b almost all frass in ejected from the mine => 13

13a pupation outside the leaf; larva in a silken tube, covered with sand, from where low leaves are mined out => 14

13b pupation within the leaf, or in a cocoon that is connected to the leaf => 15

14a larva uniformly light grey: Scrobipalpula psilella

14b larva green with dark green length lines: Sophronia humerella

15a the larva makes cocoon that is fixed to a stalk; from here silken tubes are made towards neighbouring leaves, that are mined; pupation in this cocoon: Isidiella divitella

15b no such cocoon is made => 16

16a on H. arenarium: Vulcaniella pomposella

16b on H. italicum, italicum subsp. serotinum & stoechas: Vulcaniella fiordalisa