Populus Poplar
(For a dichotomous table for galls on Populus by Hans Roskam click here)Dichotomous table for leafminers
1a mine ends in a circular excision: Tachyerges decoratus
1b lower-surface tentiform mine => 2
1c corridor, not appreciably widened towards the end => 8
1d blotch, may be preceded by a corridor => 18
Dichotomous table for leafminers
1a mine ends in a circular excision: Tachyerges decoratus
1b lower-surface tentiform mine => 2
1c corridor, not appreciably widened towards the end => 8
1d blotch, may be preceded by a corridor => 18
2a mine begins with a usually lower-surface, long, epidermal corridor that terminates in a silvery tentiform mine of ca. 1 cm; larva later lives free in a folded leaf margin: Caloptilia stigmatella
2b initial corridor very short, more often invisible; the mine not silvery, > 13 mm => 3
3a lower epidermis of the mine with 1 or 2 sharp folds => 4
3b mine without sharp folds => 6
4a pupa in a flimsy cocoon; pupa: cremaster longer than wide; hooks tiny or missing: Phyllonorycter pastorella
4b pupa in a well developed cocoon => 5
5a frass in a clump in a corner of the mine; cocoon white, free from frass: Phyllonorycter apparella
5b frass incrustrated in the cocon, when lighted from behind visible as two dark lines: Phyllonorycter connexella
6a pupa in a well-developed cocoon: Phyllonorycter populifoliella
6b cocon flimsy, cobweb-like => 7
7a on Populus tremula: Phyllonorycter sagittella
7b on other poplars: Phyllonorycter comparella
8a long, upper-surface epidermal corridor, resembling a snail’s trail; mine ends upon a a small piece of upturned leaf margin; there pupation takes place => 9
8b corridor not epidermal over its entire length => 11
9a frass line narrow and well defined, brownish black: Phyllocnistis labyrinthella
9b frass line broader, vague, greenish => 10
10a on P. alba, canescens, tremula: Phyllocnistis xenia
10b on other Poplar species, in particular P. nigra and x canadensis: Phyllocnistis unipunctella
11a at the start of the mine a globular, shining-black egg shell => 12
11b no egg shell at the beginning => 13
12a on Populus tremula, rarely alba or canescens; initial corridor contorted: Stigmella assimilella
12b on Populus nigra, canadensis-hybriden, alba or canescens; initial corridor not contorted: Stigmella trimaculella
13a corridor upper- or lower-surface; larva a maggot => 14
13b corridor full depth; larva with chitinised head => 16
14a puparium in the mine: Aulagromyza populi
14b pupation outside the mine => 15
15a corridor (in fact an elongated blotch) upper-surface: Aulagromyza populicola
15b corridor lower-surface: Aulagromyza tremulae
16a corridor very short, along the midrib, continued into a frass-covered silken tube: Gypsonoma oppressana
16b corridor much longer, different => 17
17a corridor descends from the leaf tip along the leaf margin: Tachyerges decoratus
17b corridor begins on the midrib and winds through the blade at some distance from the leaf margin: Anoplus plantaris
18a triangular, full depth blotch extending from a vein axil in the leaf base => 19
18b mine not developing from the leaf base => 20
19a on Populus nigra or P. x canadensis: Ectoedemia hannoverella
19b on Populus tremula: Ectoedemia argyropeza
19c on Populus alba or P. canescens: Ectoedemia turbidella
20a large primary blotch, upper-surface, opaque, black or dark brown, without an indication of a preceding corridor => 21
20b mine without this combination of characters => 25
21a upper surface of the mine with a group of flat, glistening egg shells; larvae white: Leucoptera sinuella
21b no egg shells visible; larvae amber => 22
22a frass in discrete grains; mine greenish at first, quickly turning dark brown; larvae are maggots; oviposition spot not discernable: Agromyza albitarsis
22b frass as a black layer flooring the mine; larvae with chitinised heads; ovipisition spots recognisable as somewhat transparent points (genus Zeugophora) => 22
23a epipharynx with 6 specialised setae; mala with 5 setae: Zeugophora scutellaris
23b epipharynx with 7 specialised setae; mala with 6 setae => 24
24a pronotum with 9 pairs of setae: Zeugophora subspinosa
24b pronotum with 6 pairs of setae: Zeugophora flavicollis
25a mine begins with a mostly lower-surface, long, epidermal corridor, ending in a silvery blotch of about 1 cm; larva later lives free in an folded leaf margin: Caloptilia stigmatella
25b mine not epidermal => 26
26a larva with thoracic feet => 27
26b larva without feet => 30
27a larva: feet short, ending bluntly; pupa in a discoid cocoon in the mine => 28
27b feet more slender, ending in an acute tip; pupation outside the mine => 29
28a larva: abdomen 1 ventrally with a vague blackish spot; on Populus balsamifera: Heterarthrus vikbergi
28b no such spot; on other poplars: Heterarthrus ochropoda
29a on Populus x canadensis, nigra; larva: last pair of prolegs (“anal feet”) surrounded by a broad, dark zone: Fenusella hortulana
29b on Populus tremula; anal prolegs surrounded by a narrower, less darkened zone: Fenusella glaucopis
30a mine mostly small, elongate-pear shaped, with much frass; elliptic larva always present in the mine (no pupa): Rhamphus pulicarius
29b mine larger => 31
31a larva a maggot; puation outside the mine => 32
31b larva with chitinised head; pupation in the mine => 33
32a mine associated with the leaf margin, rather transparent; Mediterranean species; larva: cephalic skeleton of Agromyzinae type: Japanagromyza salicifolii
32b mine not associated with the leaf margin, rather opaque; western and central European species; cephalic skeleton of Phytomyzinae type: Aulagromyza populicola
33a pupation not in a cocoon; mine round or oval, brown-black: Isochnus sequensi
33b pupation in a globular cocoon => 34
34a large blotch in the apical half of the leaf; the leaf here strongly disfigured: Tachyerges salicis
33b leaf tip not disfigured => 35
35a corridor, beginning at an oviposition scar in the midrib, widening into a blotch: Tachyerges stigma
35b oviposition not in the midrib; blotch, often oriented on the leaf venation: Tachyerges rufitarsis
Not included in the key: Coleophora lusciniaepennella, serratella; Ectoedemia intimella, klimeschi; Gypsonoma minutana; Orchestes cf. jota; Phyllocnistis canariensis, extrematrix, valentinensis; Phyllonorycter chiclanella, hilarella; Tachyerges pseudostigma; Zeugophora turneri.