Pulvinaria floccifera (formerly Pulvinaria camelicola; soft scale)

Cottony camellia scale with egg sac. Photo: Tawny Simisky
Scientific Name: 
Pulvinaria floccifera (formerly Pulvinaria camelicola; soft scale)
Common Name: 
Cottony Camellia Scale (or Cottony Taxus Scale)
Growing Degree Days (GDD's): 
802-1388 GDD's for crawlers reported, Base 50F, March 1st Start Date (Source: Cornell Cooperative Extension)
Host Plant(s) Common Name (Scientific Name): 
American Beautyberry (Callicarpa americana)
Boxwood (Buxus microphylla)
Camellia (Camellia spp.) *Preferred host.
Common Camellia (Camellia japonica) *Preferred host.
English Ivy (Hedera helix)
Euonymus (Euonymus spp.) *Preferred host.
Evergreen Euonymus (Euonymus japonicus)
Hinoki Cypress (Chamaecyparis obtusa)
Holly (Ilex spp.) *Preferred host.
Hydrangea (Hydrangea spp.)
Japanese Maple (Acer palmatum) *Preferred host.
Japanese Nutmeg-Yew (Torreya nucifera)
Japanese Plum-Yew (Cephalotaxus harringtonii)
Japanese Yew (Taxus cuspidata)
Magnolia (Magnolia spp.)
Mulberry (Morus spp.)
Pittosporum (Pittosporum spp.) *Preferred host.
Rhododendron (Rhododendron spp.)
Tea Camellia (Camellia sinensis)
Yew (Taxus spp.) *Preferred host.
Insect Description: 

One generation per year. Overwinters as an immature on the twigs of the host. Adult females are mottled tan/yellowish in color and oval in shape with a convex appearance. They are approximately 3 mm. in length. Adult females will move to the underside of the leaf to lay eggs in a white, fluffy and elongated egg sac. Once the eggs are laid, the female dies and drops from the plant. Egg sacs will remain, containing up to 1000 eggs. Upon egg hatch, crawlers will move to the leaves and feed with piercing-sucking mouthparts. The white egg sacs are probably the most noticeable stage of this insect.

Damage to Host: 

Seen primarily in early spring and late summer, damage from this insect typically includes off-color, light green foliage. Honeydew buildup can occur and this may promote the presence of sooty mold.

Monitoring: 

Look for honeydew or sooty mold followed by scale insects on the undersides of leaves or the oblong, white egg sacs on the undersides of leaves. The egg sacs left behind by the adult females are perhaps the most noticeable clue that cottony camellia (taxus) scale is present. Dieback caused by this insect is not considered to be common. If the infestation is light, it might only result in an aesthetic problem (honeydew and sooty mold), and management might not be necessary.

Cultural Management: 

Spray off scales with a strong jet of water if practical.

Natural Enemies & Biological Control: 

A tiny wasp parasite, Coccophagus lycimnia, has been reported to be associated with this insect (Johnson and Lyon, 1991). Additional foes reported include two others in the same genus: Coccophagus japonicus and Coccophagus yoshidae (Tachikawa, 1956). However, parasites are not noted to provide adequate population regulation for the scale.

Chemical Management: 

Abamectin (NL)

Acephate (NL)

Acetamiprid (L)

Azadirachtin (NL)

Buprofezin (NL)

Carbaryl (L)

Chlorpyrifos (N)

Clothianidin (NL)

Cyantraniliprole (NL)

Cyfluthrin (NL)

Dinotefuran (NL)

Flonicamid+cyclaniliprole (N)

Gamma-cyhalothrin (L)

Horticultural oil (L)

Imidacloprid (L)

Insecticidal soap (NL)

Lambda-cyhalothrin (L)

Neem oil (NL)

Pyrethrin+sulfur (NL)

Pyriproxyfen (for eggs) (L)

Spinetoram+sulfoxaflor (N)

Notes: 

GDDs are listed for what is known about the best timing to treat the crawler (mobile immature) stage. Chemical management is also effective for overwintering immatures. Concentrate treatments to the twigs and undersides of foliage. 

Active ingredients that may be applied systemically include: abamectin (injection), acephate (injection), acetamiprid (injection), azadirachtin (injection, soil drench), clothianidin (soil drench), cyantraniliprole (soil drench, soil injection), dinotefuran (soil drench), imidacloprid (soil drench), and neem oil (soil drench).

Make insecticide applications after bloom to protect pollinators. Applications at times of the day and temperatures when pollinators are less likely to be active can also reduce the risk of impacting their populations.

Note: Beginning July 1, 2022 neonicotinoid insecticides are classified as state restricted use for use on tree and shrub insect pests in Massachusetts. For more information, visit the MA Department of Agricultural Resources Pesticide Program.

Read and follow all label instructions for safety and proper use. If this guide contradicts language on the label, follow the most up-to-date instructions on the product label. Always confirm that the site you wish to treat and the pest you wish to manage are on the label before using any pesticide. Read the full disclaimer. Active ingredients labeled "L" indicate some products containing the active ingredient are labeled for landscape uses on trees or shrubs. Active ingredients labeled "N" indicate some products containing the active ingredient are labeled for use in nurseries. Always confirm allowable uses on product labels. This active ingredient list is based on what was registered for use in Massachusetts at the time of publication. This information changes rapidly and may not be up to date. If you are viewing this information from another state, check with your local Extension Service and State Pesticide Program for local uses and regulations. Active ingredient lists were last updated: September 27, 2024. To check current product registrations in Massachusetts, please visit the MA Department of Agricultural Resources Pesticide Product Registration page and click on "Search Pesticide Products Registered in Massachusetts - Kelly Solutions".