Cerastium, mouse-ear chickweed

fam. Caryophyllaceae

1a fleck mine => 2

1b corridor or blotch => 7

1c gall, etc => 100

2a larva mines from a silken tube that is fixed to the plant: Scythris siccella

2b larva mines from a portable case => 3

3a hole in the mine not neatly round; case helicoidal: Apterona helicoidella

3b hole precisely round; larva in a tubular case => 4

4a case with a dorsal keel that soon (less than halfway the end) splits into two parallel keels: Coleophora lithargyrinella

4b dorsal keel, if at all present, not cleft => 5

5a case with c. 5 dark length lines: Coleophora nubivagella

5b no ligth lines => 6

6a case c. 6 mm; sharp bend just behind the mouth, mouth angle therefore 30°: Coleophora chalcogrammella

6b case c. 8 mm; case straight, mouth angle 45°: Coleophora solitariella

7a larva with chitinised head => 8

7b larva a maggot; mine may occupy the entire leaf; larva remains in the mine => 13

8a larva without feet, remains in the mine until close to pupation; frass, as far as present, in a central line: Orthochaetes insignis

8b larva, with abdominal and thoracic feet, soon leaves the mine and continues feeding between spun leaves; fras not in a central line => 9

9a silk is deposited within the mine, causing it to pucker => 10

9b no silk, mine remains completely flat => 12

10a larva: pinacula colourless (the bases of the setae themselves are black) : Cnephasia incertana

10b pinacula black => 11

11a larva: behind/below the anus a chitinous comb: Cnephasia asseclana

11b anal comb absent: Cnephasia stephensiana

12a mountain species: Caryocolum petrophila

12b lowland species: Caryocolum alsinella, C. junctella, C. proxima

13a short corridor, seems to end upon the midrib: Ophiomyia melandricaulis

13b mine different => 14

14a larva also mines the top of the stem, causing this part of the plant to wilt : Delia echinata

14b larva exclusively in the leaf => 15

15a a corridor from start to end; puparium in the mine, in a, usually lower-surface, pupal chamber: Chromatomyia horticola

15b mine finally a blotch; larva leaves the mine before pupation => 16

16a frass in coarse blackish green lumps; at the start of the mine one (or more?) elliptic egg shell => 17

16b frass not in big lumps; no egg scale at the start of the mine => 19

17a mine generally a corridor: Pegomya holosteae

17b mine generally a blotch => 18

18a imago: abdomen yellow: Pegomya flavifrons

18b abdomen black: Delia florilega

19a mine whitish; frass in black scattered grain => 20

19b mine greenish; frass powdery, in green clouds, mostly along the sides and in the end of short side branches of the mine: Scaptomyza graminum

20a imago: tibiae reddish: Amauromyza flavifrons

20b tibiae black: Delia coronariae

100a Nematoda => 101

100b Acari => 102

100c Coleoptera => 103

100e Diptera => 104

100f Hemiptera => 105

100d Hymenoptera => 106

100g rust fungi => 107

100h smut fungi => 108

100i powdery and downy mildews => 109

100j other causers => 110

102 – Acari

102a Eriophyidae: Aceria cerastii

103 – Coleoptera

103a Curculionidae: Sibinia subtriangulifera

104 – Diptera

104a Cecidomyiidae: Dasineura cerastii, fructum, lotharingiae

105 – Hemiptera

105a Aphididae: Brachycolus cerastii

105b Triozidae: Trioza cerastii

107 – rust fungi

107a Pucciniaceae: Puccinia arenariae, behenis, hysteriiformis, isiacae; Uromyces dianthi ?

107b Pucciniastraceae: Melampsorella caryophyllacearum

108 – smut fungi

108a Glomosporiaceae: Thecaphora cerastii

108b Microbotryaceae: Microbotryum duriaeanum, stellariae

109 – powdery and downy mildews

109a Erysiphaceae: Erysiphe buhrii

109b Peronosporaceae: Peronospora cerastii-anomali, cerastii-brachypetali conferta, fontana, helvetica, paula, septentrionalis, tomentosa

110 – other causers

110a Fungi, Synchytriaceae: Synchytrium aureum, stellariae

Not included in the key: Caryocolum jaspidella, marmorea, Caryocolum tricolorella (improbable), vicinella; Coleophora galbulipennella, rectilineella; Trachystyphlus alpinus.