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Aspidiotus cryptomeriae

Cryptomeria scale. Photo: John A. Davidson, University of Maryland, Bugwood.
Scientific Name: 
Aspidiotus cryptomeriae
Common Name: 
Cryptomeria Scale
Growing Degree Days (GDD's): 
600-800 GDD's (1st generation crawlers); 1750-2130 GDD's (2nd generation crawlers), Base 50F, March 1st Start Date. (Source: Cornell Cooperative Extension)
Host Plant(s) Common Name (Scientific Name): 
Black Pine (Pinus thunbergii)
Cedar (Cedrus spp.)
Chinese Juniper (Juniperus chinensis)
Cryptomeria (Cryptomeria spp.)
Deodar Cedar (Cedrus deodara)
Douglas Fir (Pseudotsuga spp.)
Eastern Hemlock (Tsuga canadensis)
European Silver Fir (Abies alba)
False Cypress (Chamaecyparis spp.)
Fir (Abies spp.)
Hinoki Cypress (Chamaecyparis obtusa)
Japanese Cedar (Cryptomeria japonica)
Japanese Douglas-fir (Pseudotsuga japonica)
Japanese Yew (Taxus cuspidata)
Juniper (Juniperus spp.)
Manchurian Fir (Abies holophylla)
Momi Fir (Abies firma)
Northern Japanese Hemlock (Tsuga diversifolia)
Pine (Pinus spp.)
Plum Yew (Cephalotaxus spp.)
Sawara Falsecypress (Chamaecyparis pisifera)
Southern Japanese Hemlock (Tsuga sieboldii)
Spruce (Picea spp.)
Yew (Taxus spp.)
Insect Description: 

This scale is found on the underside of host plant needles. It looks like a "fried egg" and mature females are approximately 1/20 of an inch in length. Mature males have wings and are rarely observed. Two generations per year have been reported in Maryland. Second instar nymphs (immatures) have been reported as overwintering. Adults may be observed in March and April. Eggs are reportedly laid by females in June which develop into second generation adults by mid-July. (Eggs are yellow in color and oval in shape.) A second generation of eggs is laid in late August and September. Crawlers appear in June and August, and their emergence may last several weeks. Crawler emergence is thought to peak approximately 2-3 weeks after eggs are laid. Each generation is not synchronous, meaning not all individuals mature at the same time and so multiple life stages may be present. 

Damage to Host: 

Yellowing or yellow spotting may be seen on host plant needle surfaces, particularly on hemlock. Pines and firs may develop blotchy, yellow-brown coloration. In addition to discoloration, branch dieback may occur with heavy infestations. This insect can be a major pest in Christmas tree plantations.


Look for discolored needles on susceptible host plants. Check the undersides of needles for the hardened scale covers and/or yellow crawlers. Crawlers present in June and August. Scout for scale insects on the underside of needles on the inside of bottom branches first. Scouting on overcast days may make it easier to see the symptoms caused by cryptomeria scale infestation. Yellow sticky cards can be placed in infested trees to aid in scouting for adult (winged) male emergence. Egg laying will begin soon after males are seen. Check scale covers for round exit holes left behind by natural enemies.

Cultural Management: 

If infestations are restricted to a single branch or small area that may be pruned out without otherwise impacting the overall health of the host or its aesthetic value, the removed material may be discarded/destroyed. In Christmas tree production, if the scales are found on only a few trees, consider cutting and destroying those trees to prevent the scales from spreading further.

Natural Enemies & Biological Control: 

Hymenopteran parasites have been observed. Look at the armored scale tests (coverings) for round exit holes indicating parasite activity. If the activity seems common, use only insecticidal soap or horticultural oil applications to manage this scale in ornamental landscapes. Encarsia citrina, Chilocorus renipustulatus, Comperiella bifasciata, and Comperiella indica have all been reported to attack cryptomeria scales (Murakami, 1970 and Japoshvili et al, 2013).

Chemical Management: 

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) (L)

Spinetoram+sulfoxaflor (N)


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: January 2024. To check current product registrations in Massachusetts, please visit: .