''Psyllopsis fraxini'' is a

psyllid Psyllidae, the jumping plant lice or psyllids, are a family of small plant-feeding insects that tend to be very host-specific, i.e. each plant-louse species only feeds on one plant species (monophagous) or feeds on a few closely related plants ( ...

which lives within a

gall Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external tissues of plants, fungi, or animals. Plant galls are abnormal outgrowths of plant tissues, similar to be ...

on ash (''

Fraxinus excelsior ''Fraxinus excelsior'', known as the ash, or European ash or common ash to distinguish it from other types of ash, is a flowering plant species in the olive family Oleaceae. It is native throughout mainland Europe east to the Caucasus and Albor ...

''). Eggs are laid in the autumn on dormant buds and the

nymphs A nymph ( grc, νύμφη, nýmphē, el, script=Latn, nímfi, label=Modern Greek; , ) in ancient Greek folklore is a minor female nature deity. Different from Greek goddesses, nymphs are generally regarded as personifications of nature, are typ ...

hatch in the spring and feed on the leaves. The host plant reacts by producing extra cells and the affected areas becomes swollen and rolls downwards and encloses the wax covered nymphs. Each gall may contain two or three generations and by the end of summer contain all stages of the insect. The galls are pale-coloured with violet or red markings.

References

External links

Plant Parasites of Europe
* Psyllidae Gall-inducing insects Insects described in 1758 Taxa named by Carl Linnaeus {{Sternorrhyncha-stub