Eryngium sea holly, field eryngo

Dichotomous table for leafminers

1a larva with thoracic feet and chitinised head; mine for a large part in the rind of the stem => 2

1b larva a maggot; mine intirely in the leaf => 3

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

2a larva with prolegs: Stomopteryx detersella

2b no prolegs; only on E. amethystinum, campestre: Dibolia timida

3a blotch mine, may be preceded by a short broad corridor; feeding lines conspicuous: Euleia heraclei**

3b corridor mine => 4

4a puparium in the mine, usually in an lower-surface pupal chamber; frass in isolated grains: Chromatomyia horticola

4b puparium formed after the mine has been vacated; frass in strings or absent => 5

5a corridor short, not strongly branched, almost without frass: Euleia heraclei**

5b corridor pinnately branched or branches fanning out from the leaf basis: Liriomyza strigata

** Eryngium is an unsuitable hostplant for Euleia heraclei and most larvae die early, before they have formed a blotch.

Not included in the key: Dibolia cryptocephala; Tebenna micalis.

mod 6.iv.2018