Pest identification
What's eating my western arborvitae zebrina?
Bagworm (Thyridopteryx ephemeraeformis) — mainly US
Signs: Foliage bags on branch tips; progressive defoliation of heavily infested specimens
Control: Hand-pick bags from late autumn; Bt spray in late June at larval hatch
Deer
Signs: Lower foliage browsed in winter and early spring when other food is scarce; young specimens most at risk
Control: Deer repellent sprays; wire cages on young plants; this species is less palatable than T. occidentalis
Vine weevil (Otiorhynchus sulcatus) — UK/container
Signs: Notched leaf margins; root damage from grubs causes wilting and sudden decline in pots
Control: Nematode drench (Steinernema kraussei) in September; check root ball of declining container plants
Juniper scale (Carulaspis juniperi)
Signs: White scale encrustations on stems and foliage; yellowing and die-back of heavily infested branches
Control: Horticultural oil spray at crawler stage in late spring; prune and dispose of worst-affected stems
Keep western arborvitae zebrina pest-free
Healthy plants resist pests best. Get the basics right:
- What eats western red cedar — the species this cultivar belongs to
- What's wrong with my plant? — the diagnosis apps compared
- Common western arborvitae zebrina problems & fixes
- Western Arborvitae Zebrina watering schedule
- Western Arborvitae Zebrina light requirements
- Full western arborvitae zebrina care guide
Western Arborvitae Zebrina pests — FAQ
What is eating my western arborvitae zebrina?
Western Arborvitae Zebrina (Thuja plicata) is more vigorous and deer-resistant than T. occidentalis, but deer will still browse it when food is scarce. Bagworms and phytophthora root rot are the main concerns. In the UK, vine weevil targets container specimens. Scale insects occasionally colonise stressed plants.
How do I get rid of bagworm (thyridopteryx ephemeraeformis) — mainly us on western arborvitae zebrina?
Foliage bags on branch tips; progressive defoliation of heavily infested specimens Hand-pick bags from late autumn; Bt spray in late June at larval hatch
How do I get rid of deer on western arborvitae zebrina?
Lower foliage browsed in winter and early spring when other food is scarce; young specimens most at risk Deer repellent sprays; wire cages on young plants; this species is less palatable than T. occidentalis
How do I get rid of vine weevil (otiorhynchus sulcatus) — uk/container on western arborvitae zebrina?
Notched leaf margins; root damage from grubs causes wilting and sudden decline in pots Nematode drench (Steinernema kraussei) in September; check root ball of declining container plants
How do I get rid of juniper scale (carulaspis juniperi) on western arborvitae zebrina?
White scale encrustations on stems and foliage; yellowing and die-back of heavily infested branches Horticultural oil spray at crawler stage in late spring; prune and dispose of worst-affected stems