These diagnostic tools will guide you step-by-step through diagnosing a plant problem or identifying a weed or insect. Cottony maple scale is most easily noticed in late spring. Usually one generation per year in Minnesota, but a second generation may occur. This is a brown, oval, soft scale on the bark of the branches of silver and red maple in winter, but in June the large egg masses are formed, and their wax covering resembles a tuft of cotton. Scales overwinter as second instar nymphs in bark cracks and crevices. Eggs hatch in mid-late July and mobile crawlers feed on new needles into August. The European fruit lecanium scale is the most common soft scale in Utah. Consequently, they may not be effective where several l… Psuedococcidae or ‘Mealybug’. Since yours are larger, I would guess probably oyster scale, which has a white waxy feel to it, and can grow quite large. Nymphs mature in late July through early August. Insecticidal soaps and horticultural oils. Infestations are most easily noticed during the summer when females produce white, cottony egg sacs that resemble pieces of popcorn on a twigs. The most noticeable stage is the brown adult female with a large cottony mass (egg sack) protruding from the rear. Lecanium scale, calico scale and cottony maple scale are covering branches of silver maple, honeylocust and many other species of hardwood trees in southeast Michigan, the Saginaw Valley region, and a few other parts of the state. Mature females lay eggs in May that hatch in mid-late June. You can take stem samples to your Agriculture Extension Office or to a local plant nursery with personnel who can identify local pests. The scale does not usually affect the vigour or flowering of it's host plants, it does however produce a sticky honeydew excrement. The most common scale insect we have on camellias is the tea scale—but they are small and look almost like grains of salt coating the stems and leaves. They closely resemble the buds of their host tree. Host plants include ash, dogwood, lilac, maple, and willow. The conspicuous, cottony egg sac of the mature form is two to three times the length of the scale body. Combining systemic treatment with a crawler spray … The young crawl in July and some of them live for a time on the leaves, but return to the twigs to pass the winter. The body is covered with flakes of clear … Source: davidshort. Grow quickly in spring and produces noticeable damage and honeydew. If you see honeydew, look closely for signs of soft scales. Contact information for each states diagnostic laboratory for U.S. residents, Cottony Maple Scale a Problem in Parts of NW Iowa. Pesticide treatments should be made the same season they are observed on the plant. If control of either these soft scales is required, both can be managed with fall soil drench or soil injection applications using imidacloprid (e.g. In cases where a tree is very heavily infested, you may notice yellowing and prematurely falling leaves, or even some branch dieback. Mobile crawlers feed on new needles where they form their scale shell. Flip over suspiciouslooking bumps on twigs and branches with a thumbnail. Cottony Cushion Scale, (Icerya purchase Maskell), Family Margarodidae Plants Damaged: This large scale attacks a wide range of woody and herbaceous plants including fir, maple, boxwood, cedar of Lebanon, citrus, cypress, elm, laurel, locust, magnolia, nandina, Boston ivy, pear, oak, rose, and willow. Please see our website for current forms, fees, and instructions on preserving and mailing insects. This is a brown, oval, soft scale on the bark of the branches of silver and red maple in winter, but in June the large egg masses are formed, … Open the drawers to find pictures and more information about the types of scales found on conifers in Minnesota. The cottony maple scale, Pulvinaria innumerabilis (Rathvon), is a highly modified insect pest that commonly attacks silver and red maples in Ohio. Large amounts of honeydew support sooty mold growth. Most common lecanium scale on Minnesota deciduous plants is the European fruit lecanium scale (. 175 Fig. In spring, when depositing eggs, scales on twigs resemble strings of popcorn. Scales are not a part of the insect, but are a protective barrier. Crawlers appear in June and begin feeding on leaves, branches and trunks. Hosts: Lilac, apple, poplar, birch, ash, cotoneaster, willow and many other deciduous trees and shrubs. Galls are present every year, though the abundance varies greatly from year to year and from tree to tree.Maple bladder galls are a "pouch" gall. … Lecanium scales are difficult to distinguish one from another. Dieback of twigs and branches and entire plants can occur in heavy infestations. Crawlers hatch in June and July and migrate to leaves to feed. (76) Photo: John Davidson be controlled as crawlers and immatures. Look for a product that lists as the active ingredient “potassium or sodium salts of fatty acids.” Mix and apply commercial products according to label directions. But, if many scale insects are present, you might need to use pesticides. The scale overwinters in the egg stage under the females' protective cover. imidacloprid, a popular systemic insecticide (discussed below), controls soft scales and certain other scales but does not control armored scales or cottony cushion scale. There are many species of scale insects that feed on a wide range of host plants. The scales grow to adulthood on the leaves and mate in August or September before the females return to the twigs to spend the winter. Scorch symptoms tell us that one or more of the following factors are affecting the tree: 1. Inappropriate timing is not only ineffective, but may be counterproductive. Annual, heavy infestations can kill branches or entire trees. Magnolia scale populations can build rapidly within one generation. Eriococcidae is a family of scale insects commonly called ‘felt scales’. The plant may be covered in sooty mold as a result of the large quantities of honeydew produced by the calico scale… Appearance: Adult females are reddish-brown, wrinkled, helmet-shaped and occur in clusters on twigs. Live through the winter as immature, flat females on twigs. Heavy, persistent infestations can reduce the vigor in trees, but this is uncommon. Females greatly enlarge by late spring and lay eggs. Large numbers of egg sacs look like popcorn strung along the stems and branches. Imidacloprid is highly effective against this species. Light to moderate feeding cause needles to turn yellow and drop. Newly emerged scales crawl to the leaves and settle on the undersurface and begin a sedentary existence of feeding on the tree’s sap. Scales are unusual insects in appearance. Severe infestations that go on for several years may cause twig dieback and only under extreme conditions will entire trees be killed. Consider the product labels when selecting these (or any) insecticide. Pour the soap into a spray bottle and spray the plant, including the undersides of the leaves and stems, until the soap solution begins to drip. Insecticidal soap is available from garden center, hardware and department stores under various trade names. Combining systemic treatment with a crawler spray is the most effective method. These soft scales are usually first noticed during the summer months when the female produces a conspicuous white egg sac, called an ovisac, that appears as a ¼- to ½-inch long ball of cotton. Cottony maple scale crawlers along leaf veins in the summer. (on oak, hickory, ash, birch, beech, honeylocust, yews, arborvitae, Prunus spp. Nymphs mature in August, mate and lay overwintering eggs. Contact information for each states diagnostic laboratory for U.S. residents. Pulvinaria innumerabilis or known as Cottony Maple Scale on succulent. What people most often notice is the reddish brown protective cover of the adult female scale; on the cottony maple scale, the covering puffs out as the “cotton” becomes visible. Hosts: Crabapple, poplar, birch, mountain ash, cherry, plum and many other deciduous plants. Honeydew will stick leaves together and attract many insects (. Overwinter as nymphs on undersides of needles. Ames, IA 50011-2031 Start to look for the presence of crawlers just before they are expected to appear. They are small and immobile with no visible legs. Felt scales look a lot like mealybugs. Newly hatched crawlers look for feeding and overwintering sites. Shake infested branches over a white sheet of paper or white paper plate to look for reddish or yellowish colored crawlers. Porec Harbor, Istria, Croatia - Piles of colorful fishing net and rope. Copyright © 2020ISU Extension and Outreach “Normal” populations usually have one, or at most, a few egg sacs at each twig crotch, while severe infestations may have enough eggs sacs to completely cover most twigs. Cottony Bromeliad seeds dispersing from their pods . Leaf Scorch: On maple (Acerspecies) trees a number of problems cause symptoms that are generally classified as leaf scorch. Cracked bark and yellowish (chlorotic), stunted leaves. Apply horticultural oils in late fall and early spring to smother overwintering nymphs. Treatments as late as late July are effective if thorough application to lower leaf surfaces is achieved. Eriococcidae is a family of scale insects commonly called ‘felt scales’. Apply imidacloprid in the fall. Insecticides differ in their effectiveness for certain scale types. Scale insects are a unique group, that look quite different from other insects. Some premature leaf drop may result but small to moderate populations cause no harm to trees. A few of the species that fall into the armored scales are oystershell scale, San Jose scale, euonymus scale, and pine needle scale. Immature females are flat and inconspicuous. Honeydew created by the scales attracts ants, wasps and other insects. Pesticides might not reach the insect because the scale acts as a barrier. It has one pair of black antennae and three pairs of black legs. Armored Scales (see photo gallery) Armored scales, family Diaspididae, have a flattened, platelike cover that is less than 1/8 inch in diameter. This is best applied when the scale are in their younger nymph stages, so make sure to regularly check your landscape for pests. In extreme cases, it is possible to lose the tree. Adult scale insects are usually covered in waxy shell-like cover. The Iowa State University Plant & Insect Diagnostic Clinic will identify your insect, provide information on what it eats, life cycle, and if it is a pest the best ways to manage them. Most tree and shrub insecticides can also be used, but the destruction of natural enemies caused by these insecticides should be carefully weighed against the benefit of reduced annoyance. Maple cotton scale is found on several other common hardwood trees such as ash, elm and boxelder. Eggs masses are conspicuously white and cottony in appearance. Cottony Explosion. The scale cover is a waxy secretion that protects the insects. On the underside of the head is a short rostrum that hold the stylets used for feeding. If scale populations are heavy enough the tree may show twig and limb dieback as the … Only a tiny proportion of the eggs ever hatch and few of the new scales survive. As crawlers, they are highly mobile, six-legged, have no protective cover, and are usually smaller than a pinhead. Two treatments 10 days apart are usually needed. Physiological leaf scorch is the most common. However, at maturity, scale insects are immobile, have no visible legs or antennae, and in the case o… Severe infestations can cause needle stunting and death in young trees and weakening of mature trees. Natural controls generally maintain cottony maple scale at nondamaging levels and … No significant damage to plant health as natural enemies control this insect well. Males are similar in appearance but smaller. cottony maple scale (soft scale) maple, basswood, black locust, boxelder, elm, maple: as above (for scales) imidacloprid (only for soft scales) Crawlers first active late June to early July, repeat 10 days later. Black sooty mold growing on honeydew secretions can blacken infested limbs. The biggest problem comes from the droplets of honeydew raining down from infested trees in May and early June. Use dinotefuran as a soil application or as a bark treatment in the spring. Crawlers appear in mid-June and feed on new growth. Newly hatched scales are called crawlers. Timing of these applications when the crawlers are active is crucial for effective control. Severely prune back heavily infested branches and protect new growth with insecticide applications. Crawlers feed on leaves throughout the summer, and then migrate to branches before leaves drop in the fall. Black sooty mold fungus thrives on the honeydew accumulations and further adds to the aesthetic disruption. Mealy bugs are soft bodied scales that have a white cottony growth covering them. By late spring the insect has developed into a mature female and begins laying as many as 1,000 eggs. Eggs laid in the fall overwinter beneath the dead mother scale and hatch in mid-late May. These scales flatten themselves against tree branches to feed. Infested branches and twigs can be weakened and growth slowed. European elm scale (felt scale… A cottony maple scale infestation doesn’t usually cause significant damage to the host plant, although the combination of “cotton balls” and sooty mold attracted by the honeydew can be an unsightly nuisance. Lower branches are most commonly attacked. They are slightly convex and are brown with a yellow-brown ridge down the back (Figure 1). (on oak, hickory, ash, birch, beech, honeylocust, yews, arborvitae, Prunus spp. Scorch symptoms are light brown or tan dead areas between leaf veins or around the leaf margins. Soap sprays have no residual activity and only control insects that are contacted directly. Barkis usually intact beneath a scale. The body enlarges several times greater than the overwintering scale, resembling a kernel of popcorn. Scale insects are sap feeding insects. This is a different family than the common soft scales (Coccidae) that includes species like wax scale, lecanium scale, terrapin scale, and cottony maple leaf scale. These oils can also be applied during the winter when the scales go dormant in the cold. The University of Minnesota is an equal opportunity educator and employer. This is best applied when the scale are in their younger … Large, healthy, established trees should be watched but do not need to be treated except in cases where honeydew dripping from heavily infested trees may be unacceptable. If you live outside of Iowa please do not submit a sample without contacting the Plant & Insect Diagnostic Clinic. This causes branch death, reduced tree strength and slow tree growth. Neonicotinoids and most other insecticides cannot be … Use dinotefuran as a soil application or as a bark treatment in the spring. Females then seek overwintering sites on twigs and branches. Apply systemic pesticides after flowering to reduce pesticide exposure to bees. You have two methods to learn how to get rid of cottony cushion scale. Systemic pesticides are effective for scale control on soil or bark. 2150 Beardshear Hall Globular, reddish-brown, adult females are found in clusters of 3 to 8 individuals at the base of new growth. Damage from cottony maple scale insects is usually very limited. Other species of wax scales include tree dwellers like the cottony maple scale (Pulvinaria innumerabilis) or the calico scale (Eulecanium cerasorum). Cottony camellia scale produce a lot of honeydew that causes holly leaves, particularly inner leaves, to get covered in black sooty mold. Life History. Many armored scales match the color of the bark of their host tree and are not spotted until the damage is noticeable. Coffee scale is a major agricultural pest in coffee crops. Scales vary in appearance depending … Scale insects on Minnesota trees and shrubs, Outdoor biting insects and insect relatives. A mature female cottony maple scale is 1/8" long, and has a brown, flat, oval body. The one that is most abundant now is the oak eriococcid scale. They typically appear as a rounded or elongate pouch on a slender, short stem or neck (though highly variable). In the Northeast states of the US, this mayor pest is called Cottony Maple Leaf Scale. The cottony maple scale and the European fruit lecanium scale are two of the more common scales in our area (Figure 1). Overwinter as eggs beneath the dead mother's scale. Merit, Xytect, etc. Females mature in late May, mate and begin laying eggs. Check plants for live scale infestations. It can be discouraging to notice these pests in your plants, but take comfort in Tiny crawlers appear in late June to early July and begin feeding on needles. Some soft scales are cottony maple scale, magnolia scale, and tuliptree scale. . Honeydew and sooty mold affects the primary host as well as neighboring plants. If this timing does not match with the time when crawlers are active, use another control method. Control of these scales could include systemic neonicotinoids such as imidacloprid, dinotefuran, thiamethoxam, or acetamiprid. The cottony maple scale (Pulvinaria innumerabilis) is becoming very noticeable on maples, though the insect can also be found on buckeyes (as seen in the picture on the next page) and lindens. However, over-fertilization favors scale buildup. It also is known to survive on other species of maple, honey and black locust, white ash, euonymus, oak, boxelder, dogwood, hackberry, sycamore, beech, elm, willow, basswood, and poplar. Both types live inside the scales they produce. Pest description and crop damage This scale overwinters on grape canes as an immature brownish to black scale of about 0.06 to 0.14 inch long and has a flat and oval outline. Live through the winter as nymphs on one- or two-year-old twigs. Mix about 5 tablespoons of insecticidal soap or a very mild dish soap into 1 gallon (3.8 L) of water. Females are about 1/2 inch (12 mm) in diameter, smooth, elliptical, spherical, pinkish-orange to brown insects that are covered with a waxy coating. Maple cotton scale is found on several other common hardwood trees such as ash, elm and boxelder. and many others) have a similar life cycle to the calico scale. Scale feeding can cause stunted, chlorotic (yellowed) leaves, premature leaf drop and branch dieback. The time to treat cottony maple scale is just after the eggs have hatched in early July. All rights reserved. Appearance: Round, brown scales on twigs, at the base of the needles. Heavy infestations covering branches can cause branches and entire plants to die. Egg sacs may grow to as large as 1/2 inch … Remember, the label is the law. Females without egg sacs are 1/8 inch (2-3 mm) long, flat, pale to dark brown and soft. Cottony maple scale is always present in Iowa but in most years is too low in abundance to attract attention. This scale prefers maples, particularly silver maple, but may occur on many other hardwood trees and shrubs. This soft scale overwinters as a second instar nymph on the bark of host twigs and branches. The cottony maple scale is most easily recognized by the characteristic egg masses on twigs and branches. The cottony maple scale is most easily recognized by the characteristic egg masses on twigs and branches. Life cycle cottony maple scale. Cottony maple scale (on silver maples and honeylocust) and severval Lecanium scale spp. Combine systemic treatment with a crawler spray for the most effective management. A mature female cottony maple scale is 1/8" long, and has a brown, flat, oval body. Skip to navigation Skip to content. Insecticides differ in their effectiveness for certain scale types. It is important to properly identify the scale species present. Residual insecticides (acephate, pyrethroids, carbaryl). Cottony maple leaf scale adults (Pulvinaria acericola) (Walsh and Riley, 1868). When honeydew falls from a tree, leaves shouldbe inspected for live soft scales or mealybugs. University of Minnesota Extension discovers science-based solutions, delivers practical education, and engages Minnesotans to build a better future. Crawlers hatch in late June to early July and move to the undersides of leaves to feed. In the Northeast states of the US, this mayor pest is called Cottony Maple Leaf Scale. Open the drawers to find pictures and more information about the types of scales found on deciduous trees in Minnesota. Mated females move back to twigs for the winter. Each species has a different host range and life cycle. Overwinter as eggs under the dead mother scale on branches and trunks. ROTATE between Insecticide Resistance Action Committee (IRAC #) Format: [IRAC Group #]: Chemical name (Trade names) ... Imidacloprid … Most are eaten or attacked by a complex of natural enemies, especially lady beetles. Cottony maple scale is most easily noticed in late spring. The body of the adult ‘female’ is up to 10 mm long, pale to dark brown and covered in white or pale yellowish wax, with long black hairs and setae. Weather and natural enemies team up to keep the cottony maple scale populations low in most years. Felt scales look a lot like mealybugs. To protect bees, take precautions when using pesticides: CAUTION: Mention of a pesticide or use of a pesticide label is for educational purposes only. While most people don’t realize that mealybugs are a form of scale, they are. To make your own insecticidal soap spray solution, mix 5 tablespoons of liquid dishwashing detergent in 1 gallon of water. The adult scale is flat, 1/8-inch in diameter and yellowish-tan. You may substitute ordinary dishwashing detergent for the commercial products with little risk of injury to maple trees. Hosts: Spruce, particularly Norway spruce. If practical, improve plant sites to reduce stress and promote growth. The Cottony cushion scale has four ('female') or five (male) developmental stages. Nancy Gregory, University of Delaware. Check the tape for crawlers. Insect Problems:Cottony maple scale, Pulvinaria innumerabilis. Eggs have formed under female … Crawlers hatch in late May to early June and seek suitable feeding sites on branches and trunks. Cottony camellia scale (Pulvinaria floccifera) is a soft scale that infests not only camellia, but also holly, hydrangea, English ivy, euonymus, maple, rhododendron, yew, and pittosporum. Hosts: Pine, spruce, fir, hemlock and Douglas fir. Cottony maple scale infestations are usually controlled by natural enemies and do not usually need to be managed. There are two general types of scale– armored scale and soft scales. © You have two methods to learn how to get rid of cottony cushion scale. The eggs hatch into pale yellow-green crawlers in late June or July and migrat… Annoying, large quantities of honeydew, a sugary solution excreted by the scale insects, may drip from infested trees onto porches, sidewalks, cars, windows and people. Appearance: Mature females are up to 2/5 inch (10 mm), oval and brown with a white, waxy fringe. Regents of the University of Minnesota. Imidacloprid (Merit) applied as a soil systemic treatment should also be effective, provided sites are irrigated. Overwintering nymphs are dark gray with a red-brown ridge down the middle. Appearance: Purplish-gray, about 1/8 inch (3 mm) long and shaped like tiny oyster shells. During June, the inconspicuous female scales that spent the winter on the stems expand and begin producing a large, white, cottony egg sac. The scale overwinters as an immature female on the twigs of the host. Feed on individual plant cells (instead of the phloem) and do not produce honeydew. 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