1a at the oviposition site a shiny oval, blackish-brown drop of dried secretion => 2

1b no such drop => 3

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

2a the most common species, occuring furthest words the NW; on various Juncus-soorten species: Aphanisticus emarginatus

2b Mediterranean region, on Juncus subulatus: Aphanisticus angustatus

2c Mediterranean region, on Juncus acutus: Aphanisticus distinctus

2d Mediterranean region, perhaps on Juncus acutus: Aphanisticus pygmaeus

3a larva with feet and chitinised hea => 4

3b larva a maggot => 7

4a larva: eye is only 1 facet (sawfly larva): Eutomostethus luteiventris

4b eye composed of several facet (Lepidoptera larva) => 5

5a larva exceptionally slender: Ochsenheimeria bubalella

5b larva with normal proportions => 6

6a larva with brown head; frass in a dark mass in the middle of tje mine: Elachista scirpi

6b larva with black head; frass concentrated in the lowest part of the mine, light green at first, later grey: Elachista utonella

7a very fine gallery, spiralling around rhe base of the leaf: Hydrellia nigricans

7b rather broad, irregular gallery running lengthwise through the leaf => 8

8a larva with 8 pairs of spiracula and with transverse ridges over the , armed with small hooks: Thrypticus bellus

8b larva with 2 pairs of spiracula, without transverse ridges => 9

9a puparium in the mine; Juncus effusus: Cerodontha luctuosa

9b pupation outside the mine; Juncus gerardi: Metopomyza junci