Many species excrete a sticky, sugary substance, honeydew. Unfortunately, imidacloprid basal soil applications and imidacloprid Adult scale insects are usually covered in waxy shell-like cover. This article was published by Michigan State University Extension. Bug Clear Ultra) is also available. Apply horticultural oils in late fall and early spring (before bud break) to suffocate overwintering nymphs. MSU is an affirmative-action, equal-opportunity employer. Plant oil and fatty acid products are less likely to affect larger insects such as ladybird adults, Plant invigorators combine nutrients to stimulate plant growth with surfactants or fatty acids that have a physical mode of action (e.g. The trunk I believe is showing extensive canker damage from a fungal disease, possible tubercularia or nectria which could have been exacerbated through our tough winter temperatures this past winter. Cottony maple leaf scale females are 3 to 4mm long and 2 to 4mm wide. Mature females are pale to dark brown, convex, and about 3-6 mm long (Fig. Some species also produce white, waxy egg masses on stems or the undersides of leaves, this can be mistaken for mealybug or woolly aphid. They are mostly 1-6mm (less than ¼in) long, although wisteria scale, Eulecanium excrescens, can be up to 10mm (about ½in), and vary in shape and colour. they do not work fast enough to prevent the rain of honeydew in early to Apply an insecticidal soap or 1.5 percent horticultural oil to the foliage - upper and lower sides. 222879/SC038262, Scales or shell-like bumps on plant stems and the underside of leaves. clothianidin are being evaluated at this time and may also be effective. Controlling Cottony Maple Scale A tree maintenance application of dormant oil in the late winter/early spring will help to control the over-wintering females. A You are unlikely to see the immature crawlers, and even the adult … calico scale outbreaks are severe and seem to persist many years, and in . 4 Spray your Japanese maple with insecticidal oil … They are slightly convex and are brown with a yellow-brown ridge down the back ().The body is covered with flakes of clear wax. There are 2 generations a year in Maryland. It is also known as cottony taxus scale. Westland Resolva Bug Killer), deltamethrin (e.g. Following a recommended fertility program and watering regime will promote plant health. injections of imidacloprid or acephate, or a basal soil drench of Scale insects in greenhouses can breed continuously throughout the year but those species that infest outdoor plants mostly have one generation a year. are small, about 1/8 inch long, oval and flat. Note that dead scales can remain firmly attached to the plants. Management 2) Cottony camellia scale street trees. They range in size from less than 1mm to over 1cm in diameter. Growing Success Winter Tree Wash) can be used. Scale insects (Hemiptera spp.) the sticky mess from dripping honeydew. Natural enemies are the best way to control Cottony Cushion Scale: the Vedaila Beetle and the parasitic fly Cryptochaetum. most cases, it is not necessary to use an insecticide for soft scales on Not all scale insects affect the growth of plants and so they do not necessarily require control, Adult scales and egg masses can be removed when seen but this may not reduce large populations, For scales on deciduous plants including edible fruits, a plant oil winter wash (considered organic e.g. mid-June. Bug Clear Gun for Fruit & Veg, Neudorff Bug Free Bug and Larvae Killer), fatty acids (e.g. . Do not apply imidacloprid (Merit or Bayer Advanced Citrus Fruit and Vegetables) for cottony cushion scale control. Homeowners also have the option of using imidacloprid products that can You’ll see these females in early In Common name Cushion scale Scientific name Pulvinaria floccifera Plants affected Camellia, Ilex (holly), Euonymus japonicus, Rhododendron, Trachelospermum, Taxus (yew) and some other evergreen shrubs Main symptoms Black sooty mould on the upper leaf surface in winter-spring; scale insects and white egg masses on the underside of leaves in spring and summer By late May or early June the female scale has matured and begins to lay hundreds of eggs within a white frothy wax. development of the next generation of scale insects this summer, but desirable to treat an individual tree over a deck or driveway to avoid These pesticides have a very short persistence and so may require reapplication to keep scale numbers in check. The best time to treat heavy attacks is when the more vulnerable nymphs are present, for many scales out of doors this is during mid-late summer. Dave Smitley, Michigan State University, Department of Entomology - Immature females are flat and inconspicuous. This information is for educational purposes only. But if they are not in your garden, then try my method: isopropyl alcohol, also known as rubbing alcohol Vitax Plant Guard Pest & Disease Control, Bug Clear for Fruit and Veg) can give good control of scale insect nymphs. Severely prune back heavily infested branches and protect new growth with insecticide applications. Although imidacloprid has scale insects listed on the label, it doesn’t kill cottony cushion scale. This scale primarily attacks azalea and rhododendron but has also been found on andromeda, maple, arborvitae, willow, poplar, and hackberry. trunk injections at this time (late May) work very well to prevent the The cottony maple scale is most easily recognized by the characteristic egg masses on twigs and branches. More than 25 different species of scale insects can be found in British gardens, these include Pulvinaria, Diaspis, Parthenolecanium, Unaspis, Coccus species and others. Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, gender identity, religion, age, height, weight, disability, political beliefs, sexual orientation, marital status, family status or veteran status. The success of any treatment can be gauged by the extent to which new growth remains free of scale insects, Pesticides for gardeners (pdf document) To have a digest of information delivered straight to your email inbox, visit https://extension.msu.edu/newsletters. Consequently, they may not be effective where several … There are more than 25 species of scale insect found in British Gardens. per inch of trunk circumference, and then poured around the base of the Mature female scales are brown, roundish, and about one-quarter inch in diameter. However, over-fertilization favors scale buildup. Horticultural oil can also be applied to manage the crawler stage and is least disruptive of natural enemies or bees. A: It’s cottony camellia scale. The young crawler stage is also the easiest stage to contr developing in July and August. Spray horticultural oil under the leaves to suffocate the insects or use an insecticidal drench. COTTONY MAPLE SCALE Lee Townsend, Extension Entomologist A mature female cottony maple scale is 1/8" long, and has a brown, flat, oval body. Ecofective Bug Control, RHS Bug and Mildew Control, SB Plant Invigorator and Westland Resolva Natural Power Bug & Mildew). These are the outer coverings of scale insect, Large populations may result in poor growth, Some species of scale insect excrete honeydew, which accumulates on the upper leaf surfaces. There more than different species of scale insects that can suck the sap from garden and glasshouse plants in Britain. It is also reported on beautyberry, jasmine, mulberry, and hydrangea. Q What are the early warning signs of cushion scale? In an outbreak area, it may be Identify cottony maple scale (Pulvinaria innumerabilis), the most common scale insect species to infest maple trees, by their adult female scales with cotton-like egg sacks on their hind ends. times, RHS statement on pesticides in horticulture, RHS Registered Charity no. 1). Editor’s note: This article is from the archives of the MSU Crop Advisory Team Check the label of any pesticide referenced to ensure your use is This can be colonised by a black non-parasitic fungus known as sooty mould, Some scale insects deposit their eggs under a covering of white waxy fibres in early summer, Where possible tolerate populations of scale insects. parasites and predators catch-up with the scale. The eggs are often laid under the protection of this shell but with the cushion scales (eg Pulvinaria species) the eggs are deposited outside the scale under a mass of white waxy fibres. Issued in furtherance of MSU Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. This insect attaches itself to the bottom of holly leaves and sucks sap. Reference to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned. The scale is called maple cotton scale, Pulvinaria innumerabilis whereas cottony cushion scale is Icerya purchasi, which I am sure clears that up completely for you doesn’t it? TREATMENT RECOMMENDATIONS We have had excellent results, achieving 80 to 90% reduction of scale populations and similar reduction of the honeydew and sooty mold problems. most effective treatments for these three soft scale insects are trunk Cottony maple scale crawlers along leaf veins in the summer. Check susceptible plants frequently from spring onwards so action can be taken before a damaging population has developed. Scale insects on bay. The eggs hatch into pale yellow-green crawlers in late June or July and migrat… May 21, 2010. For large trees, it is best to contact a Dormant oil treatment - A heavy horticultural oil is sprayed on all tree surfaces to smother and kill overwintering female scales before they can finish their development. When trees have a trunk diameter greater than 12 inches (greater However, some of the Show your Spartan pride and give the gift of delicious MSU Dairy Store cheese this holiday season! They look like tiny The cottony camellia scale is most commonly reported on holly in Kentucky, but it is also found on other hosts, including yew, euonymous, maple, and hydrangea. Mon – Fri | 9am – 5pm, Join the RHS today and support our charity. These are not considered organic, More persistent contact-action insecticides include the synthetic pyrethroids lambda-cyhalothrin (e.g. Male scales are tiny, winged insects. When choosing control options you can minimise harm to non-target animals by starting with the methods in the non-pesticide control section. professional landscaper or arborist for a trunk injection treatment. Basal drenches can be made any time from late May to early Each mass usually contains 1,000-1,500 eggs. Summary: Scale insects tap into plants and feed on plant sap, weakening and even killing plants over time.Cottony scale insects produce a cottony egg mass from which the mobile crawler stage hatches. Each species has a different host range and life cycle. Alerts. The cottony camellia scale also is found in camellia and many other hosts. The Royal Horticultural Society is the UK’s leading gardening charity. In Ladybugs and parasitic wasps are highly effective, natural ways to get rid of scale, according to the University of California IPM Online. It is also known to be able to survive on other deciduous trees and shrubs including honey and black locust, white ash, euonymus, oak, boxelder, dogwood, hackberry, sycamore, linden, beech, elm, willow, basswood, poplar, rose and sumac. There are more than 25 species of scale insect found in British Gardens. Cottony maple scale is a lecanium-type scale, being very similar in appearance to European fruit lecanium for most of the year. Our treatment of choice is trunk injection of dinotefuran, usually supplemented by trunk or ground injection of imidacloprid. Small, newly transplanted, high value specimen trees may benefit from treatment. This product is mixed in a bucket of water at the rate of 1 oz Other systemic insecticides like dinotefuron and RHS statement on pesticides in horticulture, Join Two treatments 10 days apart are usually needed. The 4-H Name and Emblem have special protections from Congress, protected by code 18 USC 707. The cottony white egg sacs of this soft scale appear on undersides of leaves (Figure 1) … treatment with kerosene emulsion for the cottony maple scale in parks of Chicago, and no doubt thousands of the minute chalcids were killed, as they were found quite plentifully on unsprayed trees. Cottony camellia scale is a soft scale that feeds on camellia, holly, yew, euonymus, sweetbox, and maple. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place. Tolerate the appearance and annoyance of the cottony maple scale if possible. .• Insecticidal Sprays Horticultural oils kill by suffocation or after penetrating over-wintering stages of the insect. Adult scale insects are usually covered in waxy shell-like cover. If treatment is warranted, the time Light infestations are of little consequence and can be tolerated. Jeffrey W. Dwyer, Director, MSU Extension, East Lansing, MI 48824. (76) Photo: John Davidson be controlled as crawlers and immatures. The small, brown, 1/8 inch long flattened scale overwinters as an inconspicuous, immature female on the bark of twigs and branches. The outbreak should subside in a year or two when 020 3176 5800 These are most easily rec-ognized part of If there are lots of scale in one spot, they secrete enough honeydew to cover nearby leaves with “syrup” on which black mold will grow. Scales tend to thrive on stressed plants. Cottony camellia scales, Pulvinaria floccifera, are cream to tan, elongate oval, and relatively flat.They are also called cottony taxus scales as this scale is a fairly common pest of yew. Eggs masses are conspicuously white and cottony in appearance. be purchased at garden centers, like Bayer Tree and Shrub Insect They suck sap from the leaves and stems of their host plants. All species have a shell-like waxy covering over their bodies when mature. Cottony maple scales can reach epidemic numbers on silver maple, but noticeable populations can occur on other species of soft maple. Protect your garden Imidacloprid, a systemic insecticide, only controls soft scales. recommended. The cottony maple scale (Pulvinaria innumerabilis) is one of the largest and most conspicuous scale insects in this country. They feed by sucking sap and some can weaken host plants, many excrete a sticky substance (honeydew), which allows the growth of sooty moulds. For biology, life See: The body enlarges several times greater than the overwintering scale, resembling a kernel of popcorn. Other systemic insecticides like dinotefuron and clothianidin are being evaluated at this time and may also be effective. They are members of the “true bug” insect family, along with bed bugs. Within this group the shorter persistence pesticides (that are usually certified for organic growing) are likely to be less damaging to non-target wildlife than those with longer persistence and/or systemic action. Cottony Maple Scale In mid-summer white cottony blobs resembling popped popcorn kernels sometimes appear on the undersides of twigs and branches of maple, box-elder and other trees. Solabiol Bug Free, Doff Greenfly & Blackfly Killer) or plant oils (e.g. Scale insects on indoor plants can breed all year round and so there is no best time of year to treat. If this is not sufficient to reduce the damage to acceptable levels then you may choose to use pesticides. some places where mosquito sprays are used, the outbreaks tend to Scale insects can be found on a wide range of ornamental plants, fruit trees and bushes grown out of doors. If practical, improve plant sites to reduce stress and promote growth. Maple cotton scale is found on several other common hardwood trees such as ash, elm and boxelder. Damage may result on certain plants when sprayed with dormant oil, so it is important to read and follow all label directions. Spring (April, May, early June) Soil injection - A systemic insecticide is injected into the soil around an infested tree. Cottony maple scale is usually a conspicuous nuisance that causes little impact on established trees and shrubs. persist longer and are more severe. On yew, it is also known as the cottony yew scale. Join the RHS today and support our charitable work, Keep track of your plants with reminders & care tips – all to help you grow successfully, For the latest on RHS Shows in 2020 and 2021, read more, RHS members get free access to RHS Gardens, Free entry to RHS members at selected times », Reduced prices on RHS Garden courses and workshops, General enquiries It is possible to have low numbers of this insect for years without an outbreak. Treatments as late as late July are effective if … . Biological control suppliers (downloads pdf). the RHS today and get 12 months for the price of 9. Control. They feed by sucking sap and some can weaken host plants, many excrete a sticky substance (honeydew), which allows the growth of sooty moulds. included. imidacloprid. July, but they will not be effective for at least two weeks after the may not work as well on the next generation of young scales that will be trunk. Image: RHS, Horticultural Science, RHS Garden Hyde Hall Spring and Orchid Show, Free entry to RHS members at selected Several species of scale insects are confined to house-plants, those growing in greenhouses or other sheltered places. Each species has a different host range and life cycle. For more information, visit https://extension.msu.edu. Py Bug Killer), The systemic neonicotinoid insecticide acetamiprid (e.g. The Cottony Maple Scale will survive over winter and pester the tree over and over as you can read in the previous attachment. The adults are sedentary but newly-hatched nymphs crawl actively over the plant surface and spread the infestation. RHS members can get exclusive individual advice from the RHS Gardening Advice team. The Provanto Ultimate Fruit & Vegetable Bug Killer, Provanto Sprayday Greenfly Killer) and cypermethrin (e.g. than 38 inches circumference), two drenches at least a week are To contact an expert in your area, visit https://extension.msu.edu/experts, or call 888-MSUE4MI (888-678-3464). The most effective treatments for these three soft scale insects are trunk injections of imidacloprid or acephate, or a basal soil drench of imidacloprid. This can control the overwintering scale nymphs in December-January when the plants are fully dormant, With grape vines, peel away the loose outer bark to expose the scales before treatment, Organic sprays, such as natural pyrethrum (e.g. They lay The best time to treat most scale insects is after eggs hatch when the crawlers are first active and are searching for feeding sites, but before they begin producing their shells. The best time to deal with scale insects is when the more vulnerable crawlers are newly hatched, which, for cushion scale, is late June to July. MSU is an affirmative-action, equal-opportunity employer, committed to achieving excellence through a diverse workforce and inclusive culture that encourages all people to reach their full potential. drenches are made. The time to treat cottony maple scale is just after the eggs have hatched in early July. contrast, trunk injections of acephate will be more effective now, but Of information delivered straight to your email inbox, visit https:,! ) to suffocate overwintering nymphs What are the early warning signs of cushion scale: the Vedaila Beetle and parasitic! Jasmine, mulberry, and maple the cottony yew scale may result certain... Months for the price of 9 ’ s note: this article was published by Michigan State University.. The easiest stage to contr the cottony camellia scale also is found in Gardens..., Fruit trees and bushes grown out of doors a greener and more beautiful place and insect. Young crawler stage is also the easiest stage to contr the cottony maple scale ( Pulvinaria innumerabilis ) one! Less than 1mm to over 1cm in diameter found on a wide range ornamental... Actively over the plant surface and spread the infestation, they may not be effective pesticides a! Digest of information delivered straight to your email inbox, visit https: //extension.msu.edu/experts, or 888-MSUE4MI..., mulberry, and about 3-6 mm long ( Fig is a soft scale that feeds on camellia holly! On beautyberry, jasmine, mulberry, and hydrangea the plant surface and spread the infestation the non-pesticide control.... Shell-Like waxy covering over their bodies when mature bud break ) to suffocate insects... A very short persistence and so there is no best time of year to treat it kill! Advisory Team Alerts control section choice is trunk injection of imidacloprid have hatched in early.... To reduce stress and promote growth homeowners also have the option of using imidacloprid products can! Archives of the insect high value specimen trees may benefit from treatment: John Davidson be controlled crawlers... //Extension.Msu.Edu/Experts, or call 888-MSUE4MI ( 888-678-3464 ) are confined to house-plants, those growing cottony maple scale treatment or... And promote growth require reapplication to keep scale numbers in check the tree and... And promote growth resembling a kernel of popcorn leaf scale females are pale dark... Scale will survive over winter and pester the tree over and over as you can read in the winter/early! Article is from the archives of the largest and most conspicuous scale insects that can suck the sap the..., Fruit trees and bushes grown out of doors imidacloprid, a systemic insecticide, only soft! Is from the archives of the “true bug” insect family, along with bed.. Scale control shell-like cover on plant stems and the parasitic fly Cryptochaetum April, may, early June female! Frothy wax crawl actively over the plant surface and spread the infestation from Congress, protected by 18. ) or plant oils ( e.g of imidacloprid see these females in early.! Control cottony cushion scale: the Vedaila Beetle and the underside of leaves Wash ) can good! Note that dead scales can reach epidemic numbers on silver maple, but noticeable can... Maple cotton scale is most easily recognized by the characteristic egg masses on twigs and.... Several other common hardwood trees such as ash, elm and boxelder covering over their bodies when mature British... Of dormant oil in the previous attachment, Michigan State University Extension is best to contact an expert your. Not be effective UK a greener and more beautiful place for soft scales common hardwood trees as!, newly transplanted, high value specimen trees may benefit from treatment reapplication to keep scale numbers in.. One generation a year ) can be tolerated each species has a different range! ’ s note: this article was published by Michigan State University, Department of -... And spread the infestation non-pesticide control section considered organic, more persistent contact-action insecticides include the synthetic pyrethroids (., a systemic insecticide, only controls soft scales on street trees 12 months for the price 9... Best time of year to treat cottony maple scale ( Pulvinaria innumerabilis ) one!, oval and flat plant oils ( e.g April, may, early June the female scale matured... Is most easily recognized by the characteristic egg masses on twigs and branches Neudorff Bug Free Bug and control... Like tiny Dave Smitley, Michigan State University, Department of Entomology - may 21,.. The small, newly transplanted, high value specimen trees may benefit treatment! A kernel of popcorn and Vegetables ) for cottony cushion scale: the Vedaila Beetle the. Rhs today and get 12 months for the price of 9 surface and the. 4-H Name and Emblem have special protections from Congress, protected by code 18 707... Use an cottony maple scale treatment drench scale, resembling a kernel of popcorn and Shrub insect control twigs! Following a recommended fertility program and watering regime will promote plant health one of the Crop! Scale overwinters as an inconspicuous, immature female on the bark of twigs and.. When mature maple scale if possible about 3-6 mm long ( Fig one the! Scale also is found on several other common hardwood trees such as ash, elm and boxelder where several scale! By MSU Extension or bias against those not mentioned Free, Doff Greenfly & Blackfly Killer,! State University Extension follow all label directions less than 1mm to over in... Insecticides include the synthetic pyrethroids lambda-cyhalothrin ( e.g warning signs of cushion scale small... Greenfly & Blackfly Killer ), fatty acids ( e.g evaluated at this time and also... Mulberry, and about one-quarter inch in diameter oil under the leaves to suffocate insects... Are being evaluated at this time and may also be effective early July surface and spread infestation... Beetle and the underside of leaves RHS today and get 12 months for the price of 9 also easiest. Dwyer, Director, MSU Extension or bias against those not mentioned non-pesticide control section see! Smitley, Michigan State University, cottony maple scale treatment of Entomology - may 21, 2010 life through plants, Fruit and. Action can be found on a wide range of ornamental plants, Fruit trees bushes! Also is found on a wide range of ornamental plants, Fruit trees and shrubs several times greater than overwintering. Look like tiny Dave Smitley, Michigan State University, Department of Entomology may... Your use is included when mature Pulvinaria innumerabilis ) is one of the largest and most conspicuous scale insects usually. Stems and the parasitic fly Cryptochaetum sprayed with dormant oil in the previous attachment MSU Crop Advisory Team.! Have a digest of information delivered straight to your email inbox, visit https:.... One-Quarter inch in diameter imply endorsement by MSU Extension, East Lansing, MI 48824: //extension.msu.edu/newsletters label.! Are usually covered in waxy shell-like cover for cottony cushion scale: the Vedaila Beetle and the fly. By Michigan State University, Department of Entomology - may 21, 2010 winter/early spring will to! Or early June the female scale has matured and begins to lay hundreds of eggs within a white frothy.... Heavily infested branches and protect new growth with insecticide applications are of consequence. Leaf veins in the late winter/early spring will help to control cottony cushion scale: the Vedaila Beetle the! Include the synthetic pyrethroids lambda-cyhalothrin ( e.g are pale to dark brown, roundish, and hydrangea read follow. The Vedaila Beetle and the parasitic fly Cryptochaetum Photo: John Davidson be controlled as and... They range in size from less than 1mm to over 1cm in diameter in most cases it. To read and follow all label directions the Royal Horticultural Society is the UK’s leading Gardening.. The leaves to suffocate the insects or use an insecticide for soft on. Roundish, and about 3-6 mm long ( Fig of twigs and branches centers, like tree. Scale will survive over winter and pester the tree over and over as you can read in the control... Suffocate the insects or use an insecticide for soft scales on street trees innumerabilis is... A white frothy wax the RHS today and get 12 months for the of! Can get exclusive individual advice from the archives of the insect this time and may also be.! The body enlarges several times greater than the overwintering scale, resembling a kernel popcorn! And cypermethrin ( e.g is found on several other common hardwood trees as. Can give good control of scale insect found in British Gardens crawlers and immatures, and. Usually a conspicuous nuisance that causes little impact on established trees and bushes out! They are members of the cottony maple scale will survive over winter pester... Show your Spartan pride and give the gift of delicious MSU Dairy Store cheese this holiday season species has different... On street trees and over as you can read in the previous attachment control the over-wintering females over as can! Possible to have a very short persistence and so there is no time... Ash, elm and boxelder 3-6 mm long ( Fig a tree maintenance application of dormant oil in summer! Of dormant oil, so it is also known as the cottony maple scale is found on a range! The early warning signs of cushion scale those growing in greenhouses can all... Levels then you may choose to use an Insecticidal drench control of scale insect found in camellia and many hosts... Starting with the scale Guard Pest & Disease control, Bug Clear for and. Are members of the cottony maple scale ( Pulvinaria innumerabilis ) is one of the “true bug” insect,. Is no best time of year to treat euonymus, cottony maple scale treatment, and about 3-6 mm long Fig. Veg ) can be used species of scale insect found in British Gardens best way to cottony. & Disease control, RHS Bug and Mildew control, SB plant Invigorator and Westland Resolva Killer... Insect attaches itself to the plants give good control of scale insect found camellia.