Eastern Spruce Gall Adelgid – Adelges abietis

Eastern Spruce Gall Adelgid (Adelges abietis)

Latin Name: Adelges abietis

Common Name: Eastern Spruce Gall


The galls created by this pest are brief, pineapple-shaped growths. They are generally less than 25 mm long and start green before becoming brown when the adults emerge. White waxy filaments encircle the eggs.

Hosts plants: Primarily Norway spruce (Picea abies) and White spruce (P. glauca),

Territory: In the northeastern United States, the eastern spruce gall adelgid is a significant pest of Norway spruce.

Damage caused by Eastern Spruce Gall: 

Galls induce curling, stunting, and eventual mortality of new growth by interfering with the normal production of twigs. The creation of a gall at the base of the current year’s growth is stimulated by feeding this species. Infested trees are rarely eliminated. However, their aesthetic value might be significantly reduced.

Description of Leaf chewers:

Insects chew the leaves, stems, roots, and flowers of plants. Biting and chewing mouthparts or piercing and sucking mouthparts are found on most insects that cause plant damage. The chewing insects swallow the infected parts. Leaf beetles, flea beetles, and juvenile caterpillars are chewing insects that devour leaves in pits. The most typical perpetrators for uneven scratches around the borders of leaves are weevils, larger caterpillars, grasshoppers, and katydids. Perfect semicircular cut pieces of leaves show the presence of leafcutter bees. The process of mining entails merely eating the contents of leaves. Leaf miners live in beetles, flies, sawflies, and moths.

Life History and Habits: 

Immature females overwinter near the base of the host plant’s buds. They restart growth in the early spring and lay eggs around the time of bud break. In around ten days, the eggs hatch, and the immature begin to feed on the fresh needles. This eating stimulates gall development around the nymphs. New galls may appear to be typical green growth at first, but only a detailed examination will disclose the abnormalities. These galls will dry out, split open, and the young adelgids will emerge as winged, egg-laying females by late August. In late summer, the eggs normally found on the needles hatch, and the nymphs settle down at the base of fresh buds on healthy shoots.