Pseudoneuroterus macropterus

Oak gall wasp Pseudoneuroterus macropterus

Description

The gall develops at or just behind the tip of 1-2 year old shoots. A multilocular, cigar-shaped swelling, commonly 20-50 mm in length and up to 15 mm in diameter. The gall contains many elliptical chambers oriented as a layer perpendicular to the outer wall. Each larval chamber is up to 2 mm long. The galls are formed in the 2nd part of the summer, adults emerge in August/September or year later after a prolonged diapause. The affected shoot may swell to twice its original thickness as the gall develops, and may cause have withering or stunting of the shoot. Heavy infestation may severely stunts single young trees, but the influence is regularly not significant on stand scale. Oak forests, mainly young stands.

Symptom

A multilocular, cigar-shaped swelling, commonly 20-50 mm in length and up to 15 mm in diameter. The gall contains many elliptical chambers oriented as a layer perpendicular to the outer wall.

Tree Species: Oak

Part of a plant- attacked: Branch

Pest significance: Less harmful

Pest Category: Insects

Present in EU: Yes