Trisetum, yellow oat-grass

1a larva with feet and chitinised head => 2

1b larva a maggot => 4

1c galls, etc => 100

2a larva grey green with pale brown head: Elachista pullicomella

2b larva dirty white with black head => 3

3a larva: prothoracal shield entirely black: Elachista freyerella

3bprothoracal shield with two black length lines: Elachista pollinariella

4a puparium in the mine; narrow corridor with rather large, widely separated frass grains: Chromatomyia nigra

4b pupation outside the mine => 5

5a larva solitary; cephalic skeleton of Phytomyzinae-type; mine narrow, frass grains distinct: Pseudonapomyza atra

5b larva communal; cephalic skeleton of Agromyzinae-type; frass greenish, deliquescent: Agromyza nigrella *

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 agrostis

101b Heteroderidae: Heterodera avenae

104 – Diptera

104a Cecidomyiidae: Dasineura triseti; Lasioptera calamagrostidis

104b Chloropidae: Oscinella frit

108 – smut fungi

108a Georgefischeriaceae: Jamesdicksonia dactylidis

108b Urocystidaceae: Urocystis triseti

108c Ustilaginaceae: Tranzscheliella hypodytes; Ustilago striiformis

109 – powdery and downy mildews

109a Erysiphaceae: Blumeria graminis

110 – other causers

110a Fungi, Ceratobasidiacee: Ceratorhiza rhizodes

110b Fungi, Clavicipitaceae: Claviceps purpurea

110c Fungi, Dothideomycetes: Dilophospora alopecuri

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

Not included in the key: Cerodontha alpina, incisa; Chromatomyia opacella; Elachista albifrontella, maculicerusella.

20/02/2017