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.

Psyllopsis fraxinicola is not a gall-causer, but may be found as an inquiline inside the P fraxini agg. galls.  The nymphs are pale green, without black markings.

Gall Adult

Anywhere that Ash is present.

Gall appears in spring and summer with the arival of the leaves, adult from June to November.

The time when the larvae leave the eggs mainly coincides with the beginning of foliation of Ash. Under the influence of toxins from larvae's glands, the edges of leaves swell, folding backwards, towards the middle, turning into loose galls which become brown and wither, but do not fall. The mature forms appear in early July.

To follow

Status in Leicestershire and Rutland to follow.