Eastern Spruce Gall Adelgid

How to identify it

• Galls are short pineapple-shaped growths under 25 mm, green at first and brown once they open.^[1]
• Eggs are covered with white waxy filaments.^[1]

Where it lives

It's a key pest of Norway spruce in the northeastern US, occasionally on white, red and Colorado blue spruce.^[1]

US map: public records from 22 states since 1990 (GBIF). View the map

Biology and life cycle

Female nymphs overwinter at bud bases; each adult lays 100 to 200 eggs as buds open.^[1]

Nymphs feed in the buds, and their feeding makes a gall form where needles should develop.^[1]

Damage and signs

• Infested trees are seldom killed, but their looks can suffer greatly.^[1]

Health risk

It feeds on plants; Penn State Extension mentions no risk to people.^[1]

Control

Traps and physical control

On a few small trees, prune and destroy green galls in June or July, before they open.^[1]

Pesticides

Dormant horticultural oil, or treatment mid-September to early October or in April before budbreak, targets overwintering stages.^[1]

Common questions

What are the pineapple-shaped lumps on my spruce?

They're likely galls made by the eastern spruce gall adelgid.^[1]

Will horticultural oil hurt my blue spruce?

It removes the blue bloom from Colorado blue and Koster spruce.^[1]

Sources

1. Penn State Extension, “Eastern Spruce Gall Adelgid.” extension.psu.edu/eastern-spruce-gall-adelgid (accessed 2026-10-06)
2. iNaturalist, “Adelges abietis taxon page (order and family).” www.inaturalist.org/taxa/204565 (accessed 2026-10-06)