1a mine centered upoon the midrib => 2

1b mine independent of the midrib => 4

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

2a larva lives in the midrib, making from there full depth corridors and blotches into the leaf: Orthochaetes setiger

2b mine not in, but upon the midrib, upper- or lower-surface => 3

3a mine a pinnately branched corridor, rather slender; larva: cephalic skeleton of the Agromyzidae-type: Liriomyza strigata

3b main branch of the mine in the end almost a blotch, with lobed branches; cephalic skeleton of the Tephritidae-type: Cornutrypeta spinifrons

4a primary blotch => 5

4b corridor (possibly a secondary blotch) => 6

5a primary and secondary feeding lines very conspicuous: Nemorimyza posticata

5b no primary and secondary feeding lines apparent: Calycomyza solidaginis

6a corridor very long and narrow; puparium formed in the mine: Ophiomyia maura

6b corridor not extremely long and narrow; prior to pupation the larve leaves the mine through a semicircular exit slit => 7

7a larva: rear spiraculum with 3 papillae: Liriomyza pusilla

7b rear spiraculum with 9 or more papillae => 8

8a mine 6-9 cm long, exit slit usually in upper epidermis: Phytomyza solidaginis

8b mine 10-12 cm long, exit slit always in lower epidermis: Phytomyza virgaureae