Elymus couch-grass
incl. Agropyron, Elytrigia, Hordelymus, Leymus, Roegneria, Sitanion; Thinopyrum intermedium = Elymus hispidus = Elytrigia intermedia
(For a dichotomous table for galls on Elymus s.l. by Hans Roskam click here)(For a dichotomous table for galls on Leymus by Hans Roskam click here)Dichotomous table for leafminers
1a fleck mine: Coleophora lixella
1b corridor or blotch => 2
1c galls, etc => Tables for all parasites per species
(For a dichotomous table for galls on Leymus by Hans Roskam click here)Dichotomous table for leafminers
1a fleck mine: Coleophora lixella
1b corridor or blotch => 2
1c galls, etc => Tables for all parasites per species
Dichotomous table for leafminers
1a fleck mine: Coleophora lixella
1b corridor or blotch => 2
1c galls, etc => Tables for all parasites per species
2a larva with chitinised head; in narrow parts of the mine the frass lies in a central line => 3
2b larva a maggot; in narrow parts the frass in two rows along the sides => 5
3a larva: rear margin of head excised in a deep V; terminal segment with a pair of spine-like spiracula: Hispa atra
3b rear margin of head not excised; no such spiracula => 4
4a recorded from Leymus arenarius (Lyme-grass): Elachista argentella, littoricola
4b recorded from Elymus caninus (Bearded Couch): Elachista adscitella, apicipunctella
4c recorded from Elymus repens (Scutch): Elachista albifrontella, argentella, cingillella, griseella, littoricola, maculicerusella, pollinariella, pullicomella
4d recorded from Elymus hispidus: Elachista pollutella
4e recorded from Hordelymus europaeus: Elachista obliquella
5a larva: mandible with 1 tooth; mine usually begins in a leaf sheath; there, at the outside, an egg shell: Hydrellia griseola
5b mandible with at least 2 teeth; mine begins in the blade; no egg shell => 6
6a pupation outside the mine => 7
6b puparium within the mine => 11
7a larva: cephalic skeleton of Agromyzinae-type => 8 *
7b cephalic skeleton of Phytomyzinae-type => 9
8a larva: bands of spinulation on the segments unusually wide; on abd 8 the spinulation occupies dorsally the entire width of the segment: Agromyza nigrociliata
8b bands of spinaluation smaller: Agromyza rondensis
9a larva and puparium set with long spine-like papillae: Pseudonapomyza atra
9b larva nor puparium with such spines => 10
10a mine a narrow corridor; larva: rear spiraculum with 3 papillae: Liriomyza flaveola
10b mine broad; rear spiraculum with over 10 papillae: Cerodontha flavocingulata
11a puparium: spiracula penetrate the epidermis => 12
11b puparium not in contact with the outside world => 13
12a puparium orange brown: Chromatomyia nigra
12b puparium black: Cerodontha muscina
13a mine begins in the leaf blade, descending from there into the leaf sheath: Cerodontha denticornis
13b mine remains in the blade => 14
14a rear spiracula on two high diverging cones: Cerodontha calosoma
14b rear spiracula on a broad common base => 15
15a rearwards pointing arms of the cephalic skeleton largely dark; larva solitary => 16
15b these arms transparent (unknown in C. hammi); larvae communal => 17
16a puparium: rear spiracula seen from above form a V: Cerodontha lateralis
16b they form a U: Cerodontha superciliosa
17a puparia anchored in the mine with a silken strand => 18
17b puparia free in the mine Cerodontha hammi
18a larva: the black warts at the outside of the rear spiracula small, without a “root”: Cerodontha incisa
18b these warts large, with a deep “root”: Cerodontha pygmaea
* See also the key to grass-inhabiting Agromyza larvae.
Not included in the key: Aphanisticus pygmaeus; Cerodontha spencerae, zuskai; Elachista fasciola; Ochsenheimeria urella, vaccuella.