Ash - Fraxinus excelsior

Dasineura fraxinea

The larva of the gall midge Dasineura fraxinea causes galls to form on Ash.  The galls are in the leaf blade, 3 to 8 mm diameter with an irregular opening at the underside; often several in a leaflet. Larva solitary, white.

Phyllactinia fraxini

Phyllactinia fraxini is a powdery mildew occurring primarily on Ash (Fraxinus) species, but can also affect other members of the family Oleaceae (Olive and Lilac family).

Aulagromyza heringii

The larva of the Agromyzid fly Aulagromyza heringii mines the leaves of Ash producing an upper surface, long corridor or irregular blotch mine, beginning with a small yellowish-brown pustule.

Gracillaria syringella

The larvae of the moth Gracillaria syringella mine the leaves of Lilac, Ash, Privet and Jasmine, often gregariously, in a large blotch mine.

Caloptilia cuculipennella

The larva of the moth Caloptilia cuculipennella mines the leaves of Ash and Privet.  On Ash, the larva makes a thin silvery gallery mine on the upper leaf surface which causes a slight upward fold of the leaf-edge.  It then leaves the mine and feeds inside a cone caused by a double leaf-fold at the tip, eventually pupating inside.

Shaggy Bracket

The Shaggy Bracket fungus (Inonotus hispidus) is usually found on Ash but sometimes found on Poplar, Beech and Oak.

Nut Scale

Nut Scale (Eulecanium tiliae) affects various woody plants including trees and shrubs such as Hawthorn, Oak, Ash, Hornbeam, Field Maple and fruit trees such as Apple and Pear.

Cottony Ash Psyllid

The Cottony Ash Psyllid (Psyllopsis discrepans) is very similar to P. fraxini but with less intense wing markings. It causes marginal leaf-fold galls on ash leaves, which are pale with reddish/violet marking; the galls cannot be distinguished from others in the Psyllopsis fraxini species aggregate.  The nymphs inside the galls are pale green with black markings and white wax. 

Psyllopsis fraxini

The adult males are found on Ash, and can be identifed to species by examination of external genitalia (terminalia) - see RES guide to Psylloidea.

Psyllopsis fraxinicola

Psyllopsis fraxinicola is an inquiline in galls of Psyllopsis fraxini agg. on Ash. The nymphs are green without black markings.

Dasineura acrophila

This species galls the leaves of Ash with many white larvae in a pod formed by partial or complete thickening and upfolding of leaflet over the midrib

Dasineura fraxini

The larva of the gall midge Dasineura fraxini causes a gall to form on the underside of the main vein of Ash leaves. The area becomes swollen to form one or more pouches with a slit-like opening on the upperside, 5 to 30 mm long.

Cauliflower Gall Mite

The Cauliflower Gall Mite (Aceria fraxinivora) causes galls to form on the inflorescences of Ash trees.These galls are irregular, woody encrustations, green at first and gradually turning to brown and black, which remain on the tree for up to two years; sometimes called Cauliflower Galls. 

Psyllopsis fraxini agg.

The jumping plant louse Psyllopsis fraxini causes a gall to form on the leaves of Ash. The gall is usually on the leaf edge causing it to swell and roll. It starts green but gradually becomes redder with age, often with a chequer-board pattern.

Psyllopsis fraxini galls on Ash are indistinguishable from those produced by P. discrepans and P. distinguenda and have been treated as an aggregate for our recording purposes.