
PEST TYPE
- Piercing-sucking insect (many species)
- Related to aphids
COMMONLY AFFECTED TREE SPECIES
Conifers
- Douglas fir
- Hemlock
- Larch
- Pine
- Spruce
DAMAGE/ SYMPTOMS
- Galls, swollen twigs.
- White, cottony tufts on bark, branches, needles, cones.
- Needle yellowing and dieback.
- Stunted growth.
MANAGEMENT
CHEMICAL:
- Ace-Jet (acephate), Criterion/Merit (imidacloprid).
- Green option: insecticidal soap.
CULTURAL:
- Prune out affected tree branches.
- Avoid heavy nitrogen fertilizers.
BIOLOGICAL:
- Lady beetles, lacewings, aphid flies, predaceous midges.
RHYME ZONE
"Adelgids settle on conifers far and wide,
Be it Douglas firs, hemlocks, spruce, or pine,
They feed on the tree's sugary sap,
Until it starts to yellow and decline."
Resources:
Missouri Botanical Garden
UC IPM
UMass Extension