Tea scale (Fiorinia theae) is an invasive armored scale insect originating from South East Asia. This pest affects a wide variety of plants, but is most serious on camellias and holly species. Early symptoms of the pest are mottled leaf yellowing, which is an indication of the insect feeding on the leaf’s underside. Severe infestations can lead to leaf drop and reduction in plant vigor.
Treatment Strategy
Because all life stages are present throughout the growing season multiple foliar applications throughout the growing season may be prudent. Systemic applications of Transtect can be a great option.
Other Treatment Practices
- Promote health and vigor with proper irrigation, mulching, proper pruning and prescription based fertilization practices.
- Adequate water is a key factor in maintaining stress free plants. A slow, deep watering event once every few weeks during dry conditions will help maintain soil moisturelevels and minimize stress.
- Mulch is very beneficial for all trees because it reduces competition with turf and moderates soil temperature and moisture levels. The addition of 3 inches of wood chips or shredded bark under the drip line can have a very beneficial effect by holding in moisture and promoting healthy fibrous roots.
- Cambistat can be also be used to promote tree health and reduce the incidence and severity of stress mediated diseases and insect problems on trees growing in urban areas.r
- Prune heavily affected areas of the plant. Do not over fertilize, as it can lead to increased scale populations.
Foliar Spray, Soil Application, or Lower Basal Bark Spray Using Transtect
Trunk Injection Using Transtect Infusible
Foliar Spray Using Proxite + RTSA Horticultural Oil
Foliar Spray Using RTSA Horticultural Oil
Foliar Spray Using Up-Star Gold
Expected Results
Dinotefuran shows promising results based upon nursery trials.
Signs of Damage
- Feeding creates yellow blotching on the top sides of affected leaves
- Insects are found on the undersides of leaves
- Female test is elongated, oval, or boat shaped and are flat, hard, and brown
- Males produce a soft white narrow test with a narrow ridge down the middle
- Male nymphs produce a cottony secretion
- Crawlers are flat and yellow with six legs and two antenna
Photo: isuagcenter.com
Photo: forestryimages.org
Photo: canr.msu.edu
Trees At Risk
- Camellia (Camellia spp.)
- Holly (Ilex spp.)
Biology
- Females produce 10-15 eggs under the test, which hatch 7-21 days depending upon temperature.
- Crawlers hatch throughout the year, and may be present from February to November in USDA Hardiness zone 7-10.
References
North Carolina State University
https://projects.ncsu.edu/project/pestmngt3/AG189/html/Tea_Scale.HTML
University ofFlorida
http://entnemdept.ufl.edu/creatures/orn/scales/tea_scale.htm
Clemson University
http://www.clemson.edu/extension/hgic/pests/plant_pests/shrubs/hgic2053.html
Always refer to product label for rates and approved uses. Some images courtesy of forestryimages.org or Wikimedia Commons. Use of the images does not imply endorsement of treatments.
