Quadraspidiotus perniciosus
Quadraspidiotus perniciosus
| San Jose Scale | |
|---|---|
| Binomial: | Quadraspidiotus perniciosus |
| Order: | Hemiptera |
| Metamorphosis: | Simple |
| Damaging stages: | Nymphs |
| Vulnerable stages: | Crawler |
San Jose scale is a pest of both orchards and ornamental plants. The insect is originally from China, but introduced in North America in the late 1900s as an invasive species.
Description
[edit | edit source]Circular hard scales, generally in great numbers. Adult males are winged, females remain under the scale.
Symptoms and Signs
[edit | edit source]Severe infestations can kill the host plant if not treated.
Host plants
[edit | edit source]- Asclepias
- Buxus
- Celtis
- Cornus
- Crataegus
- Cydonia
- Fagus
- Gleditsia
- Juglans
- Ligustrum
- Lonicera
- Maclura
- Malus
- Morus (Mulberry)
- Pachysandra
- Photinia
- Prunus
- Ribes
- Robinia
- Rosa
- Rhamnus
- Sassafras
- Sorbus
- Syringa (Lilac)
- Thuja (Arborvitae)
- Tilia
- Viburnum
Control
[edit | edit source]- Trapping: Electrical tape (sticky side out) around a branch can detect the presence of crawlers.
- Physical removal: Prune out infested branches
- Organic pesticides: Horticultural Oil (dormant spray), Neem Oil
- Predators and parasites: Wasps including Encarsia perniciosi and Aphytis spp.