Sacchiphantes viridis

Woolly adelgid

Description

This member of the woolly adelgid family is a tiny winged aphid with ca. 2 mm long body. The pest overwinters in larval stage at the spruce bud base. In spring it reaches maturity soon and lays new eggs. Tiny larvae then hatch, their sucking disfiguring the spruce shoot with a distinct plum-sized gall. The gall is green first, later it often gets reddish. Its plumshaped case is usually 2.5-4 cm large. The larvae live inside the gall. The disfiguration appears at the shoot base, making the twig appear to grow through the gall. In July the galls get dry and open up, with the mature insect crawling out and flying to invade larch trees. The galls may remain on the spruce for many years. The pest attack causes deformation of spruce branches, resulting in dieback of 10-15 year-old trees in case of massive invasion.

Symptom

Tiny larvae sucking disfiguring the spruce shoot with a distinct plum-sized gall. The gall is green first, later it often gets reddish. Its plumshaped case is usually 2.5-4 cm large. The larvae live inside the gall.

Tree Species: Spruce, Larch

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

Pest significance: Harmful

Pest Category: Insects

Invasive Species: No

Present in EU: Yes

Seasonal frequency of occurrence