Cornus dogwood

Dichotomous table for leafminers

1a corridor mine: Phytomyza agromyzina

1b blotch mine, from which in the end an excision is made => 2

1c fleck mine => 6

1d galls, etc => Tables for all parasites per species

2a excision almost as large as the blotch itself, round; oviposition scar at some mm from the leaf margin => 3

2b excision much smaller than the blotch, oval; oviposition on the leaf margin => 4

3a mining larva in May-June: Incurvaria pectinea

3b mining larva in July-August: Incurvaria oehlmanniella

4a at the start of the mine some 2-7 “test punctures”; length of the excision 5.5-7 mm; larva: abdomen dorsally entirely white, except fot the anal plate: Antispila metallella (note: larvae usually feed with ventral side upwards)

4b no such puncture; excision somewhat smaller, 4-5.5 mm; larva: abdomen dorsally white or grey with a median row of black spots => 5

5a On Cornus mas: Antispila treitschkiella.

5b On Cornus sanguinea (rarely C. alba): Antispila petryi.

6a pistol case: Coleophora anatipenella

6b lobe case =>

7a the pieces of epidermis, that are used to enlarge the case, are cut out of the upper epidermis: Coleophora violacea

7b … out of the lower epidermis: Coleophora ahenella

It is surprising that among the miners of dogwood four species belong to two, closely related families characterised by making a blotch, ending with an excision. This is discussed in detail by Dziurzynski (1958a).

Steven IJland found in 2009 three lower-surface tentiform mines on one leaf of C. sanguinea, one with well-developed folds. The species could not be established.

mod 30.i.2018