Dactylis, cock’s-foot

fam. Poaceae

1a the larva mines from a transportable case, makes fleck mines => 2

1b the larve lives within the mine, doesn’t make fleck mines => 3

1c galls, etc => 100

2a case bent behind the mouth: Coleophora lixella

2b case straight: Coleophora ornatipennella

3a mine full depth; larvae with feet and well recognisable head => 4

3b mine upper- or lower-surface; larva a maggot => 8

4a mine small, of indefinite shape; only the young larvae do mine: later they live free among spun leaves => 5

4b mine not unusually small, corridor-like; larvae mine till just before pupation (Elachistidae) => 7

5a larva: pinacula colourless (the bases of the setae themselves are black) : Cnephasia incertana

5b pinacula black => 6

6a larva: behind/below the anus a chitinous comb: Cnephasia asseclana

6b anal comb absent: Cnephasia stephensiana

7a the species below have been reported from Cock’s-foot; the larvae are not sufficiently known to enable the construction of a key: Elachista albifrontella, apicipunctella, argentella, atricomella, bifasciella, catalana, chrysodesmella, dimicatella, elegans, freyerella,gangabella, griseella, luticomella, maculicerusella, nobilella, obliquella, pullicomella, subnigrella, unifasciella

8a larva: mandible with one tooth: Hydrellia griseola

8b mandible with two or more teeth => 9

9a larva: cephalic skeleton with three rearwards pointing arms; pupation external => 10

9b cephalic skeleton with two rearwards pointing arms; pupation internal or external => 15

10a larva: mandible with 4 teeth (nb: by alternation of the mandibles a [pair of two-teethed mandibles may seem four-teethed): Agromyza albipennis (occurrence on this hostplant needs confirmation)

10b mandibles with 2 or 3 teeth => 11

11a larva: ventrally, behind the mandibles, a field with tiny spinulose warts => 12

11b no such field: Agromyza cinerascens

12a larva: mandible with 3 teeth (the basal one smaller than the distal two) => 13

12b mandible with 2 teeth => 14

13a larva: abd-8 dorsally covered witg spinulation over its entire width: Agromyza nigrociliata

13b abd-8 dorsally spinulose only near the segment margins: Agromyza ambigua

14a larva solitary; rear end of cut off at a right angle: Agromyza rondensis

14b larva communal; cut off obliquely: Agromyza nigrella

15a puparium in the mine => 16

15b pupation outside the mine => 24

16a puparium: front or rear spiracula penetrate the epidermis => 17

16b puparium not in connection with the outside world => 20

17a puparium shining black; rear spiracula penetrating: Cerodontha muscina

17b puparium white or orange brown; front spiracula penetrating => 18

18a puparium white; rear spiracula strongly elongated, dagger-like: Chromatomyia milii

18b puparium brown; rear spiracula normal => 19

19a puparium monochromous; front spiracula indistinctly bifid: Chromatomyia nigra

19b puparium with a dark ventral length band; front spiracula fist-shaped: Chromatomyia fuscula

20a larva: rear spiraculum with 11-16 papillae; puparium in the leaf sheath: Cerodontha denticornis

20b rear spiraculum with 6 papillae at most; puparium in the blade => 21

21a 2-4 larvae in the mine; puparia anchored in the mine with a strand of silk => 22

21b larva solitary; puparium loose in the mine => 23

22a larva: the black warts at the outside of the rear spiracula small, without a ‘root’: Cerodontha incisa

22b these warts large with a deep ‘root’: Cerodontha pygmaea

23a larva: laterally to the rear spiraculum a black “wart”; puparium metallic black: Cerodontha superciliosa

23b no such wart; puparium brown: Cerodontha crassiseta

24a larva and puparium with on each segment a transverse row of long, spinelike papillae: Pseudonapomyza atra

24b no such spines => 25

25a larva: above/before the mouth a field with short hairs; rear spiraculum with > 10 papillae: Cerodontha flavocingulata

25b no such hairs field; rear spiraculum with < 10 papillae => 26

26a larva: rear spiraculum with 3 papillae: Liriomyza flaveola

26b rear spiraculum with 6-8 papillae:Liriomyza phryne

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

101 – Nematoda

101a Anguinidae: Anguina tritici; Ditylenchus dipsaci

102 – Acari

102a Eriophyidae: Abacarus hystrix; Aceria tenuis; Aculodes dubius

106 – Hymenoptera

106a Eurytomidae: Tetramesa longula

107 – rust fungi

107a Pucciniaceae: Puccinia coronata, graminis, striiformoides; Uromyces dactylidis

108 – smut fungi

108a Georgefischeriaceae: Jamesdicksonia dactylidis

108b Tilletiaceae: Tilletia controversa

108c Urocystidaceae: Urocystis dactylidina

108c Ustilaginaceae: Tranzscheliella hypodytes; Ustilago perrara, striiformis

109 – powdery and downy mildews

109a Erysiphaceae: Blumeria graminis

109b Peronosporaceae: Sclerophthora macrospora

110 – other causers

110a Fungi, Ceratobasidiaceae: Ceratorhiza rhizodes

110b Fungi, Clavicipitaceae: Claviceps purpurea; Epichloe typhina

110c Fungi, Dothideomycetes: Dilophospora alopecuri

110d Fungi, Physodermataceae: Physoderma gerhardtii, graminis

** See also the key to the gras-inhabiting Agromyza larvae.

Not included in the key: Agromyza lucida; Cerodontha lateralis; Ochsenheimeria taurella.

09/01/2017