Phragmites, common reed

fam. Poaceae

1a larva with chitinised head; in narrow segments of the mine frass in a more or less narrow central line => 2

1b larva a maggot; in narrow sections frass in two rows => 6

1c galls, etc => 100

2a mine narrow and corridor-like till the end => 3

2b mine finally up to half as wide as the leaf => 4

3a larva whitish: Monochroa arundinetella

3b larva grey green: Donacaula forficella

4a pupation and hibernation outside the mine; most of the frass in the upper part of the mine: Elachista maculicerusella

4b pupation and/or hibernation within the mine; most of the frass low in the mine => 5

5a larva retreats at daytime in a silken tube within the mine: Cosmopterix scribaiella

5b larva free in the mine, easily visible: Cosmopterix lienigiella

6a larva: mandible with 1 tooth: Hydrellia griseola

6b mandible with at least 2 teeth => 7

7a mine entirely or partly in the leaf sheath; puparium in the sheath => 8

7b mine in the blade => 9

8a mine entirely in the outside of the leaf sheath: Cerodontha phragmitophila

8b mine begins as a, usually upper-surface, corridor in the blade, then descends into the inside of the sheath: Cerodontha denticornis

9a larva: cephalic skeleton of Phytomyzinae-type; pupation mostly within the mine; rear spiraculum either with > 10 papillae or the papillae strongly disfigured => 10

9b cephalic skeleton of Agromyzinae-type; pupation mostly outside the mine; rear spiraculum with three oval papillae => 12 *

10a puparium strongly narrowing backwards, ending in two large spiracula on long stalks : Cerodontha phragmitidis

10b puparium not narrowing backwards, rear spiracula small => 11

11a larva: the black warts at the outside of the rear spiracula small, without a ‘root’: Cerodontha incisa

11bthese warts large, with a deep ‘root’: Cerodontha pygmaea

12a larva: rear spiracula each on its own stalked basis; mine begins with a transverse row of oviposition marks; the emerging larvae work all in the same direction, at first each in its own corridor, but soon these merge into one elongated blotch => 13

12b rear spiracula on a common base; eggs placed singly, near the leaf margin => 14

13a larva: rear arms of the cephalic skeleton transparant: Agromyza phragmitidis

13b rear arms of the cephalic skeleton black-brown: Agromyza hendeli

14a larva: mandible with 4 teeth; rear spiracula touch each other (occurrence on this hostplant doubtful): Agromyza albipennis

14b mandible with 2 teeth; rear spiracula separated by 3 times their diameter: Agromyza graminicola

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 Meloidogynidae: Meloidogyne naasi

102 – Acari

102a Tarsonemidae: Steneotarsonemus phragmitidis

106 – Hymenoptera

106a Eurytomidae: Tetramesa phragmitidis

107 – rust fungi

107a Pucciniaceae: Puccinia alnetorum, coronata, graminis, magnusiana, phragmitis, tepperi, isiacae

108 – smut fungi

108a Tilletiaceae: Neovossia moliniae

108b Ustilaginaceae: Ustilago grandis

109 – powdery and downy mildews

109a Erysiphaceae: Blumeria graminis

109b Peronosporaceae: Sclerophthora macrospora

110 – other causers

110a Fungi, Apiosporaceae: Arthrinium phragmites

110b Fungi, Capnodiales: Scirrhia rimosa

110c Fungi, Ceratobasidiaceae: Ceratorhiza rhizoides

110d Fungi, Clavicipitaceae: Claviceps purpurea

110e Fungi, Mycosphaerellaceae: Deightoniella arundinacea, roumeguerei

* See also the key of grass-inhabiting Agromyza larvae.

Not included in the key: Agromyza baetica; Cosmopterix coryphaea, Cosmopterix orichalcea; Thrypticus bellus.

17/03/2017