Humulus, hop

fam. Cannabaceae

1a fleck mine; larva mines from a case: Coleophora violacea

1b corridor or blotch; larva mines from the inside => 2

1c galls, etc => 100

2a full depth corridor, overlying the main veins, covered at the inside with silk and therefore opaque; from the corridor broad transparant lobes enter the leaf disc: Cosmopterix zieglerella

2b not this combination of corridor and lobes => 3

3a larva with thoracic feet and a chitinised head; older larvae live free = > 4

3b larv a maggot, mines all its life => 6

4a larva with 4 pairs of abdominal prolegs: Cnephasia incertana

4b 3 pairs of abdominal prolegs => 5

5a small triangular blotch in a vein axil; older larva in a a rolled leaf margin: Caloptilia fidella

5b irregular blotch, not at a definite location; older larva between spun leaves: Hypena proboscidalis

6a corridor long and narrow, following a major vein over a long distance; when the mine gets old this often causes the leaves to tear: Agromyza igniceps

6b corridor shorter and wider, running freely through the leaf => 7

7a corridor widening only little; pupation in the mine in a, usually lower-surface, pupation chamber; rare on this host plant: Chromatomyia horticola

7b corridor strongly widening; larva leaves the mine prior to pupation; very common on this host: Agromyza flaviceps

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 Heteroderidae: Heterodera humuli

105 – Hemiptera

105a Aphididae: Phorodon humuli

109 – powdery and downy mildews

109a Erysiphaceae: Golovinomyces orontii; Podosphaera macularis

109b Peronosporaceae: Pseudoperonospora cubensis

110 – other causers

110a Fungi, Synchytriaceae: Synchytrium aureum

110b Lepidoptera, Choreutidae: Anthophila fabriciana

110c Lepidoptera, Pyralidae: Ostrinia nubilalis

Not included in the key (xenophagy): Agromyza anthracina, A. reptans; Lyonetia clerkella.

01/04/2017