Crataegus, Hawthorn

Incl. x Crataemespilus.

1a mine in fallen leaves: Neocoenorrhinus pauxillus

1b round excisions, 3-4 mm diam.: Incurvaria masculella

1c tentiform mine, > 1 cm => 2

1d small, < 1 cm, blotch or corridor => 6

1e blotch, > 1 cm, without recognisable preceding corridor => 14

1f corridor, > 1 cm, not strongly widened as the end => 20

1g corridor, > 1 cm, strongly widened at the end, or forming a secondary blotch => 22

1h fleck mine => 29

1i galls, etc => 100

2a mine upper-surface, silvery => 3

2b mine lower-surface => 4

3a fully developed mine silvery white, without black speckles: Phyllonorycter leucographella

3b fully developed mine dirty white because of numerous black speckles: Phyllonorycter corylifoliella

4a lower epidermis brownish, wrinkeld but not strongly folded; mine roundish, in a leaf lobe: Parornix anglicella

4b lower epidermis yellow-green, strongly folded; mine elongated along the leaf margin or between two veins => 5

5a pupa grey-brown, without, or in a very thin, yellow cocoon (very common on Hawthorn): Phyllonorycter oxyacanthae

5b pupa reddish-brown or yellowish, in a white cocoon:Phyllonorycter mespilella

6a drop- or pear-shaped blotch, for its greatest part filled with frass => 7

6b not this shape, or not that much frass => 8

7a larvae in May-June: Rhamphus subaeneus

7b larvae in September-October: Rhamphus oxyacanthae

8a very clear corridor or blotch of max. 3 mm, often several in a leaf => 9

8b mine less transparant and/or larger; no more than 1 in a leaf => 11

9a larva cuts upper and lower epidermis out of the mine, and drops to the ground: Incurvaria masculella

9b larva doesn’t make an excision => 10

10a larva: head golden brown: Paraswammerdamia nebulella

10b head black with brown and white lines: Scythropia crataegella

11a sides of the mine eaten out irregularly; mine often branched: Recurvaria nanella

11b sides smooth; mine usually unbranched => 12

12a mine with much frass; a hooklike corridor, mostly in a vein axil: Bucculatrix bechsteinella

12b mine with little or no frass; irregularly shaped: Ccephasia incertana

13a larva: pinacula colourless (the bases of the setae themselves are black) : Cnephasia incertana

13b pinacula black: Cnephasia asseclana

14a mine lower-surface, grey, later brown: youth mine of Parornix anglicella

14b mine upper-surface, silvery, elongated, positioned over a thick vein: youth mine of Phyllonorycter corylifoliella or Ph. leucographella

14c mine full depth => 15

15a oviposition site (usually at the tip of a leaf lobe) covered by a shining black drop of dried secretion: Trachys minutus

15b no such drop => 16

16a mine triangular, between midrib and a lateral vein; frass warm-brown: Stigmella perpygmaeella

16b mine round or irregular, frass grey or black => 17

17a larva (always present) pear-shaped: Rhamphus oxyacanthae

17b larva (if present) slender => 18

18a mine an irregular blotch; elsewhere on the leaf, or on neighbouring leaves, long slender galleries with a central frass line: Lyonetia prunifoliella

18b circular blotch; not associated with gallery mines => 19

19a mine in the centre of the leaf; frass in concentric circles: Leucoptera malifoliella

19b mine in a leaf lobe; frass concentrated in the centre, not in circles: Stigmella paradoxa

20a corridor begins at a shining globular egg shell; frass coiled: Stigmella oxyacanthella

20b no egg shell; frass in a narrow central line => 21

21a elsehwere on the leaf, or on leaves nearby, large, full depth blotch mines (sometimes connected to the corridor): Lyonetia prunifoliella

21b no associated blotch mines: Lyonetia clerkella

22a frass in the widened part of the mine, at least partly, coiled; frass warm-brown => 23

22b frass in the widened part of the mine not coiled, black or brown-black (frass may be reddish-brown in the initial corridor, and be coiled there) => 24

23a mine triangular, between two lateral veins, or between a lateral vein and the leaf margin; initial corridor largely overrun by the secondary blotch; larva yellow: Stigmella perpygmaeella

23b mine tresspassing over the lateral veins, initial corridor not overrun; larva green: Stigmella crataegella

24a mine begins upon the petiole => 25

24b mine begins in the leaf blade => 26

25a frass in the entire mine brown-black or black; larva whitish: Ectoedemia atricollis

25b frass red-brown in the initial corridor, black in the secondary blotch; larva yellow: Stigmella regiella

26a initial corrior wholly or largely free from the leaf margin, with black frass; larva with pale brown head => 27

26b initial corridor follows the leaf margin for most of its length; frass there brown or black => 28

27a Eastern Mediterranean species on Crataegus azarolus: Stigmella azaroli

27b pan-European species on different Hawthorn species: Stigmella hybnerella

28a in the initial corridor the frass is black; if the first part of the corridor is free from the leaf margin it twists around the oviposition spot; larva whitish with black-brown head: Ectoedemia atricollis

28b in the initial corridor the frass is brown; initial corridor not twisted; larva yellow with pale brown head: Stigmella regiella

29a pistol case: Coleophora anatipenella

29b lobe case: Coleophora violacea

29c tubular silken case: Coleophora trigeminella

29d composite leaf case => 30

29e tubular leaf case => 31

30a rear end of the case crooked, like the handle of a walking stick: Coleophora hemerobiella

30b rear end at most at right angle with the rest of the case: Coleophora spinella

31a case with large irregular extensions: Coleophora siccifolia

31b case without such extensions => 32

32a case 8-11 mm; mouth angle 90°: Coleophora hemerobiella

32b case 6-7 mm; mouth angle 60° => 33

33a SW Mediterranean species: Coleophora chiclanensis

33b pan-European species: Coleophora spinella (most common on Hawthorn), but see also C. prunifoliae and C serratella.

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

103 – Coleoptera

103a Curculionidae: Anthonomus spilotus, bituberculatus, pedicularius

107 – rust fungi

107a Pucciniaceae: Gymnosporangium clavariiforme, confusum, gracile

109 – powdery and downy mildews

109a Erysiphaceae: Phyllactinia mali; Podosphaera clandestina

110 – other causers

110a Angiosperma, Santalaceae: Viscum album

110b Bacteria, Rhizobiaceae: Agrobacterium tumefaciens

110c Fungi, Sclerotiniaceae: Monilinia johnsonii

110d Fungi, Taphrinaceae: Taphrina crataegi

110e Lepidoptera, Yponomeutidae: Argyresthia semifusca

Not included in the key: Coleophora adjectella (contradictions in the description), Coleophora coracipennella, Coleophora potentillael Liriomyza trifolii; Phyllonorycter blancardella (xenophagy?), Phyllonorycter macedonica (unsufficiently described); Phyllonorycter sorbi; Stigmella mespilicola (occurence on this host unconfirmed).

04/08/2016