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Hemiptera: Asterolecaniidae (Pit Scales), Coccidae (Soft Scales), Diaspididae (Armored Scales), Eriococcidae (Felt Scales), Kermesidae (Gall-like Scale Insects), and Matsucoccidae (Formerly Margarodidae).

Small, rounded galls (red and light green spots) on the upper leaf surfaces of sweetgum caused by the feeding of the sweetgum scale, a native armored scale. Samples from South Hadley, MA collected on 9/19/2022. Photo: Tawny Simisky, UMass Extension.
Scientific Name: 
Hemiptera: Asterolecaniidae (Pit Scales), Coccidae (Soft Scales), Diaspididae (Armored Scales), Eriococcidae (Felt Scales), Kermesidae (Gall-like Scale Insects), and Matsucoccidae (Formerly Margarodidae).
Common Name: 
Growing Degree Days (GDD's): 
See individual species entries for further detail.
Host Plant(s) Common Name (Scientific Name): 
Alberta spruce (Picea glauca 'Conica')
Alder (Alnus spp.)
American beautyberry (Callicarpa americana)
American elm (Ulmus americana)
Andromeda (Andromeda spp.)
Apple (Malus spp.)
Arborvitae (Thuja occidentalis)
Arborvitae (Thuja spp.)
Austrian pine (Pinus nigra)
Basswood (Tilia spp.)
Beech (Fagus spp.)
Birch (Betula spp.)
Black locust (Robinia pseudoacacia)
Boxelder (Acer negundo)
Boxwood (Buxus microphylla)
Buttonbush (Cephalanthus spp.)
Camellia (Camellia spp.)
Common Camellia (Camellia japonica)
Crabapple (Malus spp.)
Cucumber magnolia (Magnolia acuminata)
Cypress (Cupressus spp.)
Dogwood (Cornus spp.)
Elm (Ulmus spp.)
English ivy (Hedera helix)
Euonymus (Euonymus spp.)
Evergreen Euonymus (Euonymus japonicus)
Firethorn (Pyracantha spp.)
Hackberry (Celtis spp.)
Hawthorn (Crataegus spp.)
Hickory (Carya spp.)
Hinoki cypress (Chamaecyparis obtusa)
Holly (Ilex cornuta, Ilex crenata, and Ilex opaca)
Honeylocust (Gleditsia spp.)
Honeysuckle (Lonicera spp.)
Hydrangea (Hydrangea spp.)
Jack pine (Pinus banksiana)
Japanese maple (Acer palmatum)
Japanese nutmeg-yew (Torreya nucifera)
Japanese plum-yew (Cephalotaxus harringtonii)
Japanese yew (Taxus cuspidata)
Juniper (Juniperus spp.)
Lilac (Syringa spp.)
Lily magnolia (Magnolia liliiflora)
Linden (Tilia spp.)
Loblolly pine (Pinus taeda)
Magnolia (Magnolia spp.)
Maple (Acer spp.)
Mulberry (Morus spp.)
Norway spruce (Picea abies)
Oak (Quercus spp.)
Osage orange (Maclura pomifera)
Pachysandra (Pachysandra spp.)
Peach and plum (Prunus spp.)
Pear (Pyrus spp.)
Pittosporum (Pittosporum spp.)
Platycladus orientalis
Poplar (Populus spp.)
Redbay (Persea spp.)
Redbud (Cercis spp.)
Red pine (Pinus resinosa)
Rhododendron (Rhododendron spp.)
Rose (Rosa spp.)
Saucer magnolia (Magnolia x soulangeana)
Scotch pine (Pinus sylvestris)
Shortleaf pine (Pinus echinata)
Silver fir (Abies alba)
Sourgum (Nyssa sylvatica)
Southern magnolia (Magnolia grandiflora)
Spruce (Picea spp.)
Star magnolia (Magnolia stellata)
Stone fruits (Prunus spp.)
Sumac (Rhus spp.)
Sweetgum (Liquidambar spp.)
Swiss mountain/Mugo pine (Pinus mugo)
Sycamore (Platanus spp.)
Tea Camellia (Camellia sinensis)
Tuliptree (Liriodendron spp.)
Virginia creeper (Parthenocissus quinquefolia)
Virginia pine (Pinus virginiana)
Western red cedar (Thuja plicata)
White pine (Pinus strobus)
Willow (Salix spp.)
Yew (Taxus spp.)
Insect Description: 

Scale insects are common and often frustrating-to-manage insect pests of ornamental trees and shrubs. There are also many different kinds (Families) of scales, in addition to a large number of species of scale insect pests of important host plants in our landscapes. The main Families of scale insects discussed in this guide, and corresponding species are combined and sorted by Family here:

Asterolecaniidae (Pit Scales)

  • Asterodiaspis variolosa - golden oak scale

Coccidae (Soft Scales)

  • Eulecanium spp., Parthenolecanium spp. and others - lecanium scales

  • Neolecanium cornuparvum - magnolia scale

  • Neopulvinaria innumerabilis (formerly Pulvinaria innumerabilis) or Pulvinaria acericola - cottony maple scales

  • Parthenolecanium fletcheri - Fletcher scale

  • Parthenolecanium quercifex - oak lecanium scale

  • Physokermes hemicryphus - spruce bud scale

  • Pulvinaria floccifera - cottony camellia scale/cottony taxus scale

  • Toumeyella liriodendri - tuliptree scale

  • Toumeyella parvicornis - pine tortoise scale

Diaspididae (Armored Scales)

  • Aspidiotus cryptomeriae - cryptomeria scale

  • Carulaspis juniperi - juniper scale

  • Carulaspis minima - minute cypress scale

  • Chionaspis pinifoliae - pine needle scale

  • Comstockaspis perniciosa - San José scale

  • Dynaspidiotus californicus - black pineleaf scale

  • Dynaspidiotus tsugae - shortneedle evergreen scale

  • Fiorinia externa - elongate hemlock scale

  • Hemiberlesia ithacae - hemlock scale

  • Lepidosaphes pallida - Maskell scale

  • Lepidosaphes ulmi - oystershell scale

  • Lepidosaphes yanagicola - scale on Euonymus alatus (fire bush scale)

  • Melanaspis obscura - obscure scale

  • Melanaspis tenebricosa - gloomy scale

  • Pseudaulacaspis pentagona - white peach scale

  • Pseudaulacaspis prunicola - white prunicola scale

  • Unaspis euonymi - euonymus scale

Eriococcidae (Felt Scales)

  • Acanthococcus azaleae - azalea bark scale
  • Cryptococcus fagisuga - beech scale
  • Gossyparia spuria - European elm scale

Kermesidae (Gall-like Scale Insects)

  • Allokermes spp. - Kermes oak scale

Matsucoccidae (Formerly Margarodidae)

  • Matsucoccus gallicolus - pine twig gall scale

See individual entries for each species within this Guide for further details and specifics.

Damage to Host: 

Damage to the host plant depends upon the species of scale insect and possibly also the host plant involved. Scales, in general, can cause discoloration of the foliage, needle or leaf loss, chlorosis, dieback, pit formation, and even host plant mortality. See each individual species entry for further details. Some scale insects also make it easier for certain species of fungi to invade their host plants, thus leading to disease. The host list above is abridged to hosts of the soft scales (Coccidae) included in this Guide, only.


See each individual species entry for further information. Monitoring times (during the season) vary depending upon scale species. Crawlers may be active at different times of year, or overlapping generations may be present. Additionally, symptoms of scale infestation may be slightly different depending upon the species of scale or host plant involved. See each individual species entry for further details.

Cultural Management: 

Trees under drought stress in managed landscapes or urban forests may have more trouble with scale infestations than those without stress. Practices such as adequate watering during these times may help support tree health and reduce additional stressors. Prune and remove and destroy heavily infested branches if possible without compromising tree shape or health. Some soft scales are large enough to remove from host plants (when practical) with a soft brush. See each individual species entry for further details.

Natural Enemies & Biological Control: 

Parasitoid wasps, lady beetle and other insect predators, pathogens, and certain abiotic conditions as well as competition can influence scale populations. See each individual species entry for further details.

Chemical Management: 

Abamectin (NL)

Acephate (NL)

Acetamprid (L)

Azadirachtin (NL)

Buprofezin (NL)

Carbaryl (L)

Chlorpyrifos (N)

Clothianidin (NL)

Cyantraniliprole (NL)

Cyfluthrin (NL)

Dinotefuran (NL)

Flonicamid+cyclaniliprole (N) (soft scales)

Gamma-cyhalothrin (L)

Horticultural oil (L)

Imidacloprid (L)

Insecticidal soap (NL)

Lambda-cyhalothrin (L)

Neem oil (NL)

Pyrethrin + sulfur (NL)

Pyriproxyfen (L)

Spinetoram + sulfoxaflor (N)


See individual scale species for information regarding specific host plants.

Active ingredients that may be applied systemically include: abamectin (injection), acephate (injection), acetamprid (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: .