Avenula, oat-grass

Incl. Avenastrum, Avenochloa, Helictochloa, Helictotrichon.

1a fleck mine; larva in a transportable case: Coleophora lixella

1b gallery or blotch => 2

1c galls, etc => 100

2a larva with chitinised head => 3

2b larva a maggot => 4

3a larva squat, without thoracic feet: Hispa atra

3b larva slender, with thoracic feet. Of these Elachistidae the mines are not very diagnostic and the larvae are too badly known to enable the construction of a key: Elachista albifrontella, argentella, bedellella, canapennella, herrichi, pullicomella, subnigrella, unifasciella

4a larva: mandible with 1 tooth; at the start of the mine (often within a leaf sheath) at the outside an egg shell: Hydrellia griseola

4b mandible with 2 or more teeth; no egg shell visible => 5

5a puparium in the mine => 6

5b pupation outside the mine => 6

6a puparium orange brown; the front spiracula penetrate the epidermis: Chromatomyia nigra

6b puparium metallic black, without connection to the outside world: Cerodontha pygmaea

7a larva solitary; mine narrow, with distinct frass grains: Liriomyza flaveola

7b larvae communal; mine broad; frass grains ill-defined, greenish-deliquescent: Agromyza nigrella / A. mobilis *

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: Abacarus hystrix; Aceria cornuta, tenuis

104 – Diptera

104a Cecidomyiidae: Contarinia avenae

104b Chloropidae: Chlorops pumilionis

107 – rust fungi

107a Pucciniaceae: Puccinia coronata, graminis, pratensis, sardonensis, versicoloris

108 – smut fungi

108a Georgefischeriaceae: Jamesdicksonia dactylidis

108b Ustilaginaceae: Ustilago avenastri, striiformis

109 – powdery and downy mildews

109a Erysiphaceae: Blumeria graminis

119 – other causers

110a Fungi, Clavicipitaceae: Epichhloë typhina

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

Not included in the key: Agromyza nigrociliata; Chromatomyia fuscula.

08/02/2017