**Pine Bark Adelgid (Pineus strobi)**

1/16″ long, soft-bodied, aphid-like insects. Adult females are bluish-green, covered with cottony, waxy strands.
Overwinter as partially grown females, maturing into stem mothers in early spring.
Stem mothers lay 100-200 oval, brown eggs with a coating of woolly wax around budbreak.
Eggs hatch and brownish black nymphs feed on new needles, creating green, cone-shaped galls which develop around the insects who continue to feed inside of them.
In late summer, galls dry out and turn brown, open, and mature nymphs emerge, developing into winged females who will lay more eggs, which hatch into overwintering nymphs.
Causes branch thinning and dieback, weakening stems
Host plants: Norway and white spruce, occasionally red and Colorado blue spruce

Kill young stages before galls can form. Once galls form, insecticides won’t work and pruning is the only option.
Remove infested twigs and branches
Remove galls before they dry and turn brown
Consider removing severely infested trees to protect other trees
Ensure optimal tree health to reduce stress
Plant trees with generous spacing

Contact insecticides:
- Avermectins [6]: Abamectin
- Pyrethroids [3]: –thrins
Systemic insecticides:
- Tetronics [23]: Spirotetramat
- Neonicotinoids [4A]: Imidacloprid, Thiamethoxam, Dinotefuran,
- Organophosphates [1B]: Acephate
- Diamides [28]: Cyantraniliprole
Considerations:
- Use with caution. Can harm beneficial insects and lead to resistance if overused. Apply before gall formation.

Insecticidal soaps
- Will not kill eggs
Horticultural oils
- Mineral oil, neem oil
- Will kill eggs
Apply before bud break, or after galls have opened but before adelgids move to alternate hosts.

Pine Bark Adelgid