Dynaspidiotus californicus (Formerly Nuculaspis californica)

Black pineleaf scale. Photo: Whitney Cranshaw, Colorado State University, Bugwood.
Scientific Name: 
Dynaspidiotus californicus (Formerly Nuculaspis californica)
Common Name: 
Black Pineleaf Scale
Growing Degree Days (GDD's): 
None available at this time.
Host Plant(s) Common Name (Scientific Name): 
Digger pine (Pinus sabiniana; California foothill pine)
Douglas fir (Pseudotsuga menziesii)
Jack pine (Pinus banksiana)
Jeffrey pine (Pinus jeffreyi)
Knobcone Pine (Pinus attenuata)
Longleaf pine (Pinus palustris)
Pinyon Pine (Pinus cembriodes)
Monterey pine (Pinus radiata)
Mugo pine (Pinus mugo)
Pitch pine (Pinus rigida)
Pine (Pinus spp.)
Ponderosa pine (Pinus ponderosa)
Red pine (Pinus resinosa)
Shore pine (Pinus contorta; lodgepole pine)
Shortleaf pine (Pinus echinata)
Sugar pine (Pinus lambertiana)
Insect Description: 

Infestations of this scale insect are found only on needles of the host. One generation of this scale is known to occur in the Northeast, however in warmer climates 2-3 generations per year are possible. Overwintering has been observed in multiple immature stages. Eggs (approx. 40 per female; Miller and Davidson, 2005) or live crawlers are laid/born live individually over long periods of time. Crawlers are amber in color and move to feed in new areas on the same needle or adjacent needles. Crawlers can also be dispersed by the wind. Males are winged and mate with females by mid-June. The new generation is produced around July.

Damage to Host: 

Damages the host by removing plant juices through piercing-sucking mouthparts. Infested needles are spotted with yellow blotches. Heavy infestations may cause premature needle drop and in some cases, tree death. (However, severe infestations are not known to be common outside of western North America.) Damage may be first noticed as a thinning of the crown, followed by discoloration (may be red), chlorosis, and necrosis of the needles. Trees infested for multiple years may show a shortening of the needles. (Johnson and Lyon, 1991)

Monitoring: 

Scales often found on face of needles and between two needles, and are therefore difficult to see. Close attention is needed when monitoring for this pest. Trees under stress are more susceptible. (Examples of tree stress known to make black pineleaf scale infestations worse: soil moisture deficit, soil compaction, root damage, smog, and trees found along dusty dirt roads. Johnson and Lyon, 1991 speculates that the dust might have deleterious effects on natural enemies of black pineleaf scale, leading to higher populations.) Commonly found with the pine needle scale, Chionaspis pinifoliae, but easily differentiated from that white-colored scale. 

Cultural Management: 

Trees under additional stress, such as a lack of soil moisture, soil compaction, damage to the roots, and other stressors are more likely to become infested by this scale. Cultural management options include correction of these additional stresses.

Natural Enemies & Biological Control: 

Natural enemies recorded for black pineleaf scale include but are not limited to: Coccobius howardi, Coccobius varicornis, Encarsia citrina, and Raphidia spp. This native scale is found in the USA, Mexico, and Canada (Miller and Davidson, 2005).

Chemical Management: 

For crawlers:

Abamectin (NL)

Acephate (NL)

Acetamiprid (L)

Azadirachtin (NL)

Buprofezin (NL)

Carbaryl (L)

Chlorpyrifos (N)

Clothianidin (NL)

Cyantraniliprole (NL)

Cyfluthrin NL)

Dinotefuran (NL)

Gamma-Cyhalothrin (L)

Horticultural Oil (L)

Imidacloprid (L)

Insecticidal Soap (NL)

Lambda-cyhalothrin (L)

Neem oil (NL)

Pyrethrin+sulfur (NL)

Pyriproxyfen (eggs only) (L)

Spinetoram+sulfoxaflor (N)

Notes: 

Active ingredient 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".