Plant Parasites of Europe

leafminers, galls and fungi


Trigonella fenugreek

Dichotomous table for leafminers

1a larvae with obvious head and thoracic feet; after a while they leave the and continue living free among spun leaves => 3

1b larvae are maggots; they mine until just before pupation => 4

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

2 no longer applies

3a larva: pinacula colourless (the bases of the setae themselves are black) : Cnephasia incertana

3b pinacula black: Cnephasia asseclana

4a gallery from start to end; possibly some sections close together may form a secondary blotch => 5

4b gallery that eventually widens into a (primary) blotch => 8

5a pupation within the mine in a, generally lower-surface, pupal chamber; frass in widely dispersed grains: Chromatomyia horticola

5b puption external; frass not in widely dispersed grains => 6

6a gallery pinnately branched; main and side branches on top of midrib and side veins: Liriomyza strigata

6b gallery little, irregularly branched, unrelated to the venation of the leaf => 7

7a frass in a green central band, with tiny black granules at either side: Liriomyza congesta

7b frass in black strings: Liriomyza bryoniae

8a frass powdery, in dark green “clouds”, mostly in corners of the mine; often visible only after the mine has been opened => 9

8b frass coarser, black, in more or less sizable grains or lumps => 10

9a larva: end of the rear spiraculum dark, bud-like: Scaptomyza graminum

9b end of rear spiraculum light coloured, inverse bottle-shape: Scaptomyza flava

10a mine shallow, whitish; larva: cephalic skeleton with three rearwards pointing arms: Agromyza nana

10b mine deeper, greenish; cephalic skeleton with two rearwards pointing arms: Liriomyza xanthocera

Not included in the key: Liriomyza trifolii.

Tables for all parasites per species

Last modified 9.x.2017