Dreyfusia nordmannianae

Silver fir woolly aphid

Description

It is an aphid whose larvae are only a few tenths of a millimeter long. For the most part of their development, they are coated with a white wax-like cotton wool. They overwinter on trunks at the stage called sistens. In early spring, the sistens mature and lay eggs from which larvae hatch. A part of them creeps down to the lower side of flushing needles (progrediens) and the other part remains on the trunk. Damage is caused by sucking of young larvae on the needles and young shoots. As a result of sucking, the needles curl down, turn yellow and shorten. Common occurrence of this pest causes the needles to grow only to a length of 0.5–1 cm. The shoots have a bottle-like swelling at the base. It often causes very serious damage to young fir forests stands (up to the age of 20–30 years) in mountainous areas.

Symptom

Damage is caused by sucking of young larvae on the needles and young shoots. As a result of sucking, the needles curl down, turn yellow and shorten. Common occurrence of this pest causes the needles to grow only to a length of 0.5-1 cm.

Tree Species: Fir

Part of a plant- attacked: Leaf / Needle, Branch

Pest significance: Very harmful

Pest Category: Insects

Invasive Species: Yes

Present in EU: Yes

Seasonal frequency of occurrence