What is it?
Oystershell scale is a pest named because of its appearance. When you look closer, it is like a small clusters of oyster-shaped “shells” that cover bark on shrubs and trees. Heavy infestation of oystershell scale can cause plants being killed.
Oystershell scale will attacks many species such as fruit trees, lilac, ash, maple, dogwood, poplar, and willow. It is especially very common to be found on Cotoneaster shrub.
Oystershell scale observed on Cotoneaster hedge.
Symptoms
- As the pest is very tiny, it is hard to discover the pest until the plant is heavily infested.
- Infested branches will covered by oyster-shell like insects, which will secrete hard and waxy material to protect themselves.
Damages
- Leaves will turn yellow and branches will die back after heavy infestation.
- A gap of dead zone is spotted in the hedges.
What to do?
- Keep your plants and trees healthy and hydrated is the most crucial part to prevent pests and diseases.
- Regularly monitor you plants to identify early infestation can help control outbreaks.
- Introduce natural predators such as ladybuys, lacewings to naturally control the pest population.
- Apply Horticultural oil or Neem oil in spring time, it can help suffocate the insects when its shell is still soft.
- Use a brush to gently brush off the shell on branches that is reachable.
- Prune out heavily infested branches on trees if possible.
- If hedge is heavily infested, cutting the entire hedge to the ground and let it rejuvenate.
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