Cottony camellia scale (Pulvinaria floccifera) is a soft scale of mostly aesthetic damage, though it can weaken plants making them susceptible to other insects/diseases. Cottony ovisacs make this scale relatively easy to identify along with copious amounts of honeydew.
Treatment Strategy
This is not an overly difficult insect to control. It is capable of laying up to 1,000 eggs at a time though, so monitoring is important. Large populations of scales are more difficult to control Systemic options like Transtect and Xytect should work very well. Distance can only be applied twice a year. If preserving pollinators is a concern, apply Transtect after flowering in the spring.
Other Treatment Practices
- Maintain plant health and monitor closely for this insect.
- 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 moisture levels 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.
Limb/Foliar Spray or Soil Application Using Transtect
Limb/Foliar Spray or Soil Application Using Xytect 2F
Limb/Foliar Spray or Soil Application Using Xytect 75WSP
Foliar Spray Using Proxite + RTSA Horticultural Oil
Foliar Spray Using RTSA Horticultural Oil
Expected Results
Good results should be possible with the above treatments.
Signs of Damage
- Light green leaves
- The insect is 1/8 inch long, oval, yellowish tan, with a brown margin
- Often on underside of foliage
- Sooty mold is often associated with CCS
- Scales are cream to tan and elongate oval and relatively flat body
- Young females have a dark stripe down the middle and mottling at the sides
- Older scales are dark brown
- Eggs are laid in an ovisac produced beneath and behind female
- Ovisacs are two or more times longer than the scales and are relatively flat, white, and fluffy
Photo: Patrick Anderson, Rainbow Ecoscience
Trees At Risk
- Camellia
- Holly (Ilex spp.)
- Yew (Taxus spp.)
- Euonymous Maple (Acer spp.)
- Mulberry (Morus spp.)
- Hydrangea
- Rhododendron
- English Ivy (Hedera helix)
Biology
- Cottony ovisacs are laid in spring
- Crawlers hatch in late spring early summer(802-1388 GDD)
- Female insect over winter as instars
- Females mature in spring, and lay eggs
- One generation per year
References
North Carolina State University
https://content.ces.ncsu.edu/cottony-camellia-scale-1
Washington State University
http://hortsense.cahnrs.wsu.edu/Search/MainMenuWithFactSheet.aspx?CategoryId=1&SubCatId=4&PlantDefId=16&ProblemId=408
Insects that Feed on Trees and Shrubs
Johnson and Lyon
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.
