scales

Armored and soft scales: 

Dr.Vera Krischik Department of Entomology University of Minnesota www.entomology.umn.edu/cues Armored and soft scales

European elm scale scale: elm: 

Eriococcid, felt scale summer adult female with crawlers European elm scale scale: elm

Tuliptree scale: linden, walnut: 

soft scale summer male summer female and crawlers Tuliptree scale: linden, walnut

Tuliptree scale: linden, walnut: 

soft scale summer females male covers Tuliptree scale: linden, walnut

Euonymus scale: euonymus: 

armored scale spring adult females and males males Euonymus scale: euonymus

Pin oak kermes,Pubescent kermes scale: oak: 

gall-like scale summer females Pin oak kermes, Pubescent kermes scale: oak

Taxonomy of scales: 

Taxonomy of scales Order Hemiptera, formerly placed in order Homoptera related to aphids and mealybugs Diaspididae: armored scales Coccidae, Eriococcidae: soft scales

Characteristics of armored and soft scales: 

Long stylets for feeding Males have different shaped covers Males look like winged aphids Crawler stage High density can kill branches Oils, chlorpyrifos Imidacloprid (soft only) Egg, crawler, nymph, immature, adult Characteristics of armored and soft scales

Life-history traits of armored scales (Diaspididae) and soft scales (Coccidae, Eriococcidae): 

ARMORED SCALE SOFT SCALE soft cover attached to the scale no yes eggs laid in sac-like structure yes yes overwintering stages eggs/mated mated/2nd seasonal time for crawlers late Apr/June Apr/Aug ability to move after crawler stage no yes honeydew production no abundant feeding site on the plant parenchyma phloem Life-history traits of armored scales (Diaspididae) and soft scales (Coccidae, Eriococcidae)

Armored scales (Diaspididae): 

ARMORED SCALES black pineleaf scale euonymus scale gloomy scale juniper scale obscure scale oystershell scale pine needle scale scurfy scale Armored scales (Diaspididae)

Soft scales (Coccidae, Eriococcidae): 

SOFT SCALES calico scale cottony maple scale European fruit lecanium scale Fletcher scale pine tortoise scale spruce bud scale tuliptree scale FELT SCALES European elm scale (Eriococcidae) Soft scales (Coccidae, Eriococcidae)

European Elm Scale: 

European Elm Scale Gossyparia spuria Family Eriococcidae Introduced pest Hosts: Elm, Celtis species, and zelkova.

European Elm Scale: 

European Elm Scale Life History: Eggs in May, crawlers in June and July. One generation a year. Overwintering: Immatures in bark cracks. winter immatures

European Elm Scale: 

European Elm Scale Damage: Stunted, chlorotic foliage, premature leaf drop, branch dieback, sooty mold. Monitoring: Look for honeydew, mature females, crawlers, and damage. summer crawlers

European Elm Scale: 

European Elm Scale Chemical Control: Insecticides, oil. Biological Control: Beneficials usually occur. summer adult female with crawlers

Calico Scale: 

Calico Scale Eulecanium cerasorum Family Coccidae Native pest Hosts: Crabapple, dogwood, elm, firethorn, maple, sweet gum, star magnolia, zelkova, and all stone fruit trees. Life History: One generation per year. Crawlers feed on leaf veins during summer.

Calico Scale: 

Calico Scale Overwintering: Second instar. Monitoring: Look for adults and crawlers, honeydew, and sooty mold. Chemical Control: Dormant oil, horticultural oil or soap residual insecticides. Biological Control: Minute pirate bugs, lacewings, lady beetles, predaceous midges; parasitoids Aphytis, Coccophagus, Encarsia, and Metaphycus; yellow-rumped warbler.

Cottony Maple Scale: 

Pulvinaria innumerabilis Family Coccidae Native pest Hosts: Maples, honeylocust, linden, other hardwoods. Cottony Maple Scale

Cottony Maple Scale: 

Life History: Immature females emerge in spring. Eggs and crawlers appear in summer. Overwintering: Mated females on twigs. winter adult females Cottony Maple Scale

Cottony Maple Scale: 

Damage: Sooty mold, leaf yellowing, foliage drop, dieback. Monitoring: Look for old egg sacs and crawlers on the underside of leaf margins. Chemical control: Insecticides, horticultural oil or soap. Cottony Maple Scale summer crawlers

Cottony Maple Scale: 

Cottony Maple Scale Biological Control: Minute pirate bugs, lacewings, lady beetles, predaceous midges; parasitoids Aphytis, Coccophagus, Metaphycus, and Encarsia; English sparrow. summer females with eggs

European Fruit Lecanium: 

European Fruit Lecanium Parthenolecanium corni Family Coccidae Native pest Hosts: Flowering fruit trees, maples, others. Life History: Females mature in spring and lay eggs. Crawlers feed in summer. One generation per year spring adult females

European Fruit Lecanium: 

European Fruit Lecanium Overwintering: Immatures. Damage: Honeydew, sooty mold, dieback. Monitoring: Look for adult females, crawlers, honeydew, and sooty mold. Chemical Control: Soil application of insecticides, oil sprays. winter immatures

European Fruit Lecanium: 

European Fruit Lecanium Biological Control: Minute pirate bugs, lacewings, lady beetles, predaceous midges; parasitoids Aphytis, Coccophagus, Encarsia, and Metaphycus. summer eggs under cover

Fletcher Scale: 

Fletcher Scale Parthenolecanium fletcheri Family Coccidae Native pest Hosts: Yew, arborvitae, juniper. Life History: Immatures in spring, eggs in May and June. Crawlers feed on needles. One generation per year. spring adult females

Fletcher Scale: 

Fletcher Scale Overwintering: Immatures on shoots and undersides of leaves. Damage: Honeydew, sooty mold, yellow needles, needle drop. Monitoring: Look for honeydew, sooty mold, and the insects. winter nymphs

Fletcher Scale: 

Fletcher Scale Chemical Control: Soil application of insecticides, horticultural oil. Biological Control: Minute pirate bugs, lacewings, lady beetles, predaceous midges; parasitoids Aphytis, Coccophagus, Encarsia, and Metaphycus. above: male and female covers below: adult females

Pine Tortoise Scale: 

Pine Tortoise Scale Toumeyella parvicornis Family Coccidae Native pest Hosts: Pines. Life History: One generation per year on twigs. Overwintering: Immatures on twigs. Damage: Sooty mold, yellowing of branch tips, dieback.

Pine Tortoise Scale: 

Pine Tortoise Scale Monitoring: Look for scale covers and reddish crawlers. Look for ants seeking honeydew, sooty mold, and needle yellowing. spring adult females

Pine Tortoise Scale: 

Pine Tortoise Scale Physical Control: Remove and destroy infested branches. Chemical Control: Dormant oil sprays. spring adult females

Tuliptree Scale: 

Tuliptree Scale Toumeyella liriodendri Family Coccidae Native pest Hosts: Tuliptree, magnolia, basswood, hickory, buttonbush, linden, redbay, and walnut. summer female and crawlers

Tuliptree Scale: 

Tuliptree Scale Life History: Females mature in spring, males emerge in June, live crawlers are produced. One generation per year. Overwintering: Second instars on twigs. male covers summer male

Tuliptree Scale: 

Tuliptree Scale Damage: Honey dew, sooty mold, leaf yellowing, leaf drop, and dieback. above: summer dead female and settled crawlers left: summer nymphs

Tuliptree Scale: 

Tuliptree Scale Monitoring: Look for black immatures overwintering on twigs. Look females and ants tending aphids. winter immatures

Tuliptree Scale: 

Tuliptree Scale Chemical Control: Dormant oil sprays, oil or soap in late June. summer females

Spruce Bud Scale: 

Spruce Bud Scale Physokermes picea Family Coccidae Native pest Hosts: Spruce. Life History: Females complete mature in April. Crawlers appear in June and July. One generation per year. Overwintering: Immatures on the underside of needles.

Spruce Bud Scale: 

Spruce Bud Scale Damage: Honey dew, sooty mold. Monitoring: Look for adult females, honeydew, sooty mold, and dieback. Chemical Control: Dormant oil sprays, oil or soap in late June. summer females

Armored scales (Diaspididae): 

ARMORED SCALES black pineleaf scale euonymus scale gloomy scale juniper scale obscure scale oystershell scale pine needle scale scurfy scale Armored scales (Diaspididae)

Black Pineleaf Scale: 

Black Pineleaf Scale Nuculaspis californica Family Diaspididae Native pest Hosts: Douglas fir, jack and mugo pines, other pines. Life History: One generation per year on needles. Overwintering: Immature stages. summer adult females

Black Pineleaf Scale: 

Black Pineleaf Scale Damage: Yellow needles, loss of needles, short needles. Monitoring: Look for adults and crawlers, yellow and short needles. Chemical Control: Dormant oil, insecticides. Biological Control: Parasitic wasps, Prospaltella sp. and Physcus varicornis. summer adult females

Scurfy Scale & Elm Scurfy Scale: 

Scurfy Scale & Elm Scurfy Scale Chionaspis furfura & C. americana Family Diaspididae Native pests Hosts: Elm, apple, crabapple, mountain ash, aspen, willow, dogwood. top and bottom: summer females

Scurfy Scale & Elm Scurfy Scale: 

Scurfy Scale & Elm Scurfy Scale Life History: Crawlers appear in June mature in August, mate and lay eggs. One generation, possibly two, per year. Overwintering: Eggs under dead mother scale. Damage: Twig and branch dieback. crawlers

Scurfy Scale & Elm Scurfy Scale: 

Scurfy Scale & Elm Scurfy Scale Monitoring: Look for scale covers and crawlers. Cultural Control: Most populations can be controlled by reducing tree stress. Avoid killing natural enemies with insecticides. Chemical Control: Horticultural oil or soap during crawler emergence. male and female covers

Pine Needle Scale: 

Pine Needle Scale Chionaspis pinifoliae Family Diaspididae Native pest Hosts: Douglas fir, fir, hemlock, pine, spruce. summer adult females

Pine Needle Scale: 

Pine Needle Scale Life History: Crawlers hatch and mature during the summer and eggs are laid in the fall. One generation per year. Overwintering: Eggs under scale covers. nymphs

Pine Needle Scale: 

Pine Needle Scale Damage: Brown needles, loss of needles. Monitoring: Look for scale covers and crawlers. adult females

Pine Needle Scale: 

Pine Needle Scale Physical Control: Remove and destroy heavily infested branches. Chemical Control: Dormant oil sprays. parasitoid parasitoid and predator

Gloomy Scale: 

Gloomy Scale Melanaspis tenebricosa Family Diaspididae Native pest Hosts: Red and silver maples, boxelder, catalpa, elm, hackberry, mulberry, sycamore. spring adult female

Gloomy Scale: 

Gloomy Scale Life History: Eggs and crawlers in June and July, adults in August. One generation a year. Overwintering: Mated females. spring adult female

Gloomy Scale: 

Gloomy Scale Damage: Stunting and dieback. Monitoring: Look for scale covers and crawlers. Chemical Control: Dormant oil. Biological Control: Minute pirate bugs, lacewings, lady beetles, predaceous midges; parasitoids Aphytis, Coccophagus, Encarsia, and Metaphycus.

Obscure Scale: 

Obscure Scale Melanaspis obscura Family Diaspididae Native pest Hosts: Oaks. Life History: Adults in May, eggs in June, crawlers in July. One generation a year. Overwintering: Immature stages. Damage: Dieback on small branches. Monitoring: Look for scale covers and crawlers.

Obscure Scale: 

Obscure Scale Cultural Control: Avoid over-fertilizing. Chemical Control: Dormant sprays, summer oil sprays. summer adults

Juniper Scale: 

Juniper Scale Carulaspis juniperi Family Diaspididae Introduced pest Hosts: Juniper, cryptomeria, northern white cedar, cypress. Life History: Crawlers appear in late June. One generation per year. spring adult males and females

Juniper Scale: 

Juniper Scale Overwintering: Adult females on needles. Damage: Failure of new growth to develop, yellowing, dieback. Monitoring: Look for yellowing and scale covers. Chemical Control: Dormant oil. Do make further insecticide applications if natural enemies are present. Biological Control: Lady beetles Hippodamia, Cryptolaemus, and Rhizobius.

Euonymus Scale: 

Euonymus Scale Unaspis euonymi Family Diaspididae Introduced pest Hosts: Euonymus, bittersweet, and pachysandra. Life History: Two generations per year. Females on bark, males on leaves. Overwintering: Mated females.

Euonymus Scale: 

Euonymus Scale Damage: Yellow spots on leaves, loss of leaves, dieback. Monitoring: Look for white male covers on leaves, brown female covers on bark, and damage.

Euonymus Scale: 

Euonymus Scale Cultural Control: Plant resistant species of Euonymus, such as E. alatus and E. kiautschovicus. Chemical Control: Dormant oil. Biological Control: The lady beetle Chilocorus kuwaanae.

Oystershell Scale: 

Oystershell Scale Lepidosaphes ulmi Family Diaspididae Native pest Hosts: Ash, beech, birch, boxwood, cotoneaster, elm, fruit trees, lilac, maple, poplar, willow. brown adults

Oystershell Scale: 

Oystershell Scale Life History: Nymphs mature in mid-summer to mate. Eggs in late summer and early fall. One generation a year. Overwintering: Eggs under the cover of the dead mother scale. winter crawlers

Oystershell Scale: 

Oystershell Scale Damage: Cracked bark and chlorotic, stunted foliage, yellowing, wilting, dieback. Monitoring: Look for crawlers, scale covers, and damage. Cultural Control: Remove and destroy heavily infested branches. Chemical Control: Horticultural oils. summer gray adults

San Jose Scale: 

San Jose Scale Quadraspidiotus perniciosus Family Diaspididae Hosts: Rosaceous flowering fruits and plants. Life History: Generations overlap from mid-May through September. Yellow crawlers are active from late June to early July. Overwintering: First instars on bark.

San Jose Scale: 

San Jose Scale Damage: Inner bark turns red. Leaf wilting, dieback. Monitoring: Look for scale covers, yellow crawlers, and damage. Physical Control: Remove and destroy heavily infested branches and braches showing dieback. Chemical Control: Dormant and summer oil sprays, insecticides.

White Peach Scale: 

White Peach Scale Pseudaulacaspis pentagona Family Diaspididae Hosts: Mulberry, peach, persimmon, and redstemmed dogwoods. Life History: Several generations a year. Overwintering: Adult females.

White Peach Scale: 

White Peach Scale Damage: Leaf yellowing, leaf drop, dieback. Monitoring: Look for damage, white male covers, and pink crawlers. Physical Control: Prune out heavily infested limbs that are showing dieback. Remove accessible white patches on healthy trees by scrubbing. Chemical Control: Horticultural oil or soap. Use residual insecticides sparingly.

White Prunicola Scale: 

White Prunicola Scale Pseudaulacaspis prunicola Family Diaspididae Hosts: Prunus spp., lilac, privet. Life History: Several generations a year. Overwintering: Adult females on bark.

White Prunicola Scale: 

White Prunicola Scale Damage: Leaf yellowing, leaf drop, dieback. Monitoring: Look for damage, white male covers, and white and pink crawlers. Physical Control: Prune out heavily infested limbs that are showing dieback. Remove accessible white patches on healthy trees by scrubbing. Chemical Control: Horticultural oil or soap. Use residual insecticides sparingly.

Pubescent Leaf Kermes & Pin Oak Kermes : 

Pubescent Leaf Kermes & Pin Oak Kermes Nanokermes pubescens & Allokermes galliformis Family Kermesidae Native pests Hosts: Oak. Life History: Females on leaf stems, males on branches. Eggs in June and July. One generation per year. summer female

Pubescent Leaf Kermes & Pin Oak Kermes: 

Pubescent Leaf Kermes & Pin Oak Kermes summer females Overwintering: Crawlers in bark.

Pubescent Leaf Kermes & Pin Oak Kermes: 

Damage: Leaf distortion, flagging, yellowing, dieback. Monitoring: Look for the insects. Chemical Control: Dormant oils, residual insecticides. Biological control: Parasitic wasps (family Encrytidae), the lady beetle Chilocerus stigma. Pubescent Leaf Kermes & Pin Oak Kermes