They also do not kill predators. “Outbreak” may be too strong a word. They excrete honeydew, an almost pure sugar solution, on which black sooty mould will grow, causing the leaves of the plant to turn black. This insect note describes an integrated pest management approach to identifying, monitoring, and managing these pests. The female passes the winter as a small, brown scale less than 1/8” long. Publication: Maple Syrup Digest Date: October 1, 2007. If practical, improve plant sites to reduce stress and promote growth. found on silver maple trees. beneath the major veins. In the United States, it was first found on the east coast, but is rapidly expanding its range. Damage to an infected tree can include: Branches covered with small bumps. This tiny insect can also attack Japanese maple, red maple, dogwood, lilac, zelkova, yellowwood, pyracantha, privet, euonymus, redbud, stewartia, cherry, magnolia and Itea. Under severe conditions an infestation may kill the entire tree. As crawlers, they are highly mobile, six-legged, have no protective cover, and are usually smaller than a pinhead. healthy tree. Japanese maple scale is an exotic, armored scale insect pest of several ornamental trees and shrubs, most commonly in urban landscapes. Contact information for each states diagnostic laboratory for U.S. residents. 1. The time to treat cottony maple scale is just after the eggs have hatched in early July. Scorch symptoms tell us that one or more of the following factors are affecting the tree: 1. Scale insects look more like tiny, immobile bumps growing on parts of the tree, rather than actual insects. Flip over suspiciouslooking bumps on twigs and branches with a thumbnail. Scale insects are a unique group, that look quite different from other insects. This species overwinters as a small immature form and moves to find feeding spots in the spring. 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. Heavily infested plants produce little new growth. Newly emerged scales crawl to the leaves and settle on the undersurface and begin a sedentary existence of feeding on the tree’s sap. Acer is also one of the most common tree genera planted in U.S. residential and commercial landscapes, parks, and public spaces (S. F., unpublished data). By June individuals become mature and egg sacs become noticeable. Most maple species, such as red maple (Acer rubrum L.), silver maple (Acer sacc… Cottony Maple Scale (Pulvinaria innumerabilis) is a soft scale insect pest that commonly attacks maple trees, but can be found on a variety on hosts. Scorch symptoms are light brown or tan dead areas between leaf veins or around the leaf margins. To get rid of scale insects from your plants, rub their stems with an old toothbrush or a cotton swab dipped in Isopropyl alcohol, which will kill any insects on them. There are more than 25 species of scale insect found in British Gardens. gardener. Females without egg sacs are 1/8 inch (2-3 mm) long, flat, pale to dark brown and soft. insecticides. In severe infestations, leaves may turn yellow and drop prematurely. Unfortunately, only 7 of the 22 kinds of scale insects listed on the soon to be released updates of the Purdue Shrub Doctor and Tree Doctor apps can be killed by dormant season applications of oil. Pest description and damage Mature cottony maple scale are small, flat, oval, brown insects 0.25 to 0.375 inch in diameter. The females mature when the plant resumes growth However, at maturity, scale insects are immobile, have no visible legs or antennae, and in the case … have provided some general information and Since 2010, we have been monitoring Japanese maple scale populations to determine the life cycle of this scale insect in Maryland. enemies eventually bring the problem under control for Other species of wax scales include tree dwellers like the cottony maple scale (Pulvinaria innumerabilis) or … Separating oystershell scale and Japanese maple scale is easiest at this time of the year. Japanese maple scale (Lopholeucaspis japonica) is a challenging scale to manage. lay 500 or more eggs in late May to early June. That most likely was European fruit lecanium scale, Parthenolecanium corni. Contact information for each states diagnostic laboratory for U.S. residents, Cottony Maple Scale a Problem in Parts of NW Iowa. Pest description and crop damage Mature cottony maple scale are small, flat, oval, brown insects 0.25 to 0.375 inch in diameter. When honeydew falls from a tree, leaves shouldbe inspected for live soft scales or mealybugs. Only armored scale insects that winter … Lecanium Scale: What A Sticky Mess! Types of Cottony Maple Scale. So far this summer, we’ve heard about cottony maple scale “outbreaks” in Dubuque, Linn, Buchanan, and Johnson counties. Scale insects form a protective covering over themselves for most They secrete the white, cottony masses beneath which, they Cottony Maple Scale (Pulvinaria innumerabilis) is a soft scale insect pest that commonly attacks maple trees, but can be found on a variety on hosts.Usually it is just a nuisance, but in very severe infestations, it can kill weakened trees or branches on otherwise healthy trees. Scale insects are sap feeding insects. The insect is Japanese maple scale (Lopholeucaspis japonica Cockerell), and, unfortunately, it infests many more plant species than just Japanese maple. spongy masses begin to appear on the underside of Scale insects are a unique group, that look quite different from other insects. Scale insects are identified by a hard shell that protects them from predators and the weather. Cottony Maple Scale. the immature females and die. Scale insects are sap feeding insects. Severely prune back heavily infested branches and protect new growth with insecticide applications. Gloomy scale occurs on the soft maples like silver and red maple. Thorough spraying of leaf undersides is important for control. If you have a sugarbush in the Northeast, you may have noticed brown scale insects, sticky dripping honeydew, and black sooty mold on your sugar maple leaves in 2005 and 2006. Although generally hardy, Japanese maples can suffer from a number of insect pest infestations, including infestations by both soft and armored scales. Maples have esthetic and horticultural qualities that make them popular among homeowners, landscape professionals, and landscape designers. Male scales are tiny, winged insects. Large numbers of egg sacs look like popcorn strung along the stems and branches. Egg sacs may grow to as large as 1/2 inch in diameter and may contain up to 1000 eggs. They may also have sticky sap or a black fungus on the leaves and stems. Most scale insects are very small, usually ranging in size from 1/16 to 1/8 inch long. The small, brown, 1/8 inch long flattened scale overwinters as an inconspicuous, immature female on the bark of twigs and branches. In late September, just before leaf drop, It is caused by dry … The eggs hatch around the first of July and the young, called The eggs hatch in June or July and immature crawlers move to leaves to feed. (800) 262-3804, Iowa State University | PoliciesState & National Extension Partners, Like us at Plant and Insect Diagnostic Clinic, Like us at Department of Plant Pathology and Microbiology. These include some important scales, like Japanese maple scale, and euonymus scales, but not other important scales like oystershell scale and calico scale. The young scale or They feed on the plant tissue by sucking the sap from leaves, stalks and stems, which can result in stunted plant growth, defoliation, and even death of the plant. Leaf Scorch: On maple (Acerspecies) trees a number of problems cause symptoms that are generally classified as leaf scorch. Cottony maple Because natural controls are usually effective, applied chemical controls are not recommended. They damage plants by sucking out plant juices. When this material drops on leaves below the insect, a fungus called sooty mold begins to grow . It is merely a sign that insects are active on the plant. the amount of honeydew will begin to decrease for this year. The eggs hatch around the first of July and the young, called crawlers, move away from the females toward the leaves. Inspect your red maple trees to determine what kind of scale insects you have by shaking the red maple tree’s branches over a sheet of paper and looking for scale insects. several years. They suck sap from the leaves and stems of their host plants. Management-cultural control. They can be cottony, smooth or They are slightly convex and are brown with a yellow-brown ridge down the back . 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. Also, when this soft scale feeds on leaves and twigs, a large quantity of honeydew is excreted. Twigs and There are systemic insecticides available that can be used to control scale. Two treatments 10 days apart are usually needed. Pulvinaria innumerabilis. Extension Ames, IA 50011-2031 Each species has a different host range and life cycle. .• Insecticidal Sprays Horticultural oils kill by suffocation or after penetrating over-wintering stages of the insect. 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. Following a recommended fertility program and watering regime will promote plant health. Japanese maple scales small size, ability to blend in, and long crawler emergence period make it difficult to control. Cottony maple leaf scale females are 3 to 4mm long and 2 to 4mm wide. Cottony maple scale is a soft scale that infest maples, boxelder, basswood, birch, elm, and linden trees. Severely infested trees look like they are covered with a string of popcorn. insecticide in early July to early August may help Damage caused by cottony maple scale In the United States, it was first found on the east coast, but is rapidly expanding its range. This post is on the Japanese Maple Scale. categories of scaled, soft and Landscape - Scale Insects: Japanese Maple Scale This is the fifth in a series on scale insects in the landscape. treated with chemicals since these will also kill Heavy scale insect populations withdraw plant fluid and cause dieback of twigs and branches. instructions on preserving and mailing insects. These pests are much more abundant and damaging in urban landscapes than natural forests. hurt the plant. This species overwinters as a small immature form … Gloomy scale is an insect that protects its self with a small covering. Unlike aphids, though, scale insects hide under elaborate coverings meant to protect them from predators and the elements, as well as acting as cover for their eggs. 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. Usually it is just a nuisance, but in very severe infestations, it can kill weakened trees or branches on otherwise healthy trees. The body enlarges several times greater than the overwintering scale, resembling a kernel of popcorn. Cottony maple scale (Pulvinaria innumerabilis) is a flattened brown scale about 1/8” long that becomes one of the most conspicuous soft scale insects attacking ornamental plants when mature females begin to secrete white, waxy, cottony-appearing egg sacs in early summer. The females mature when the plant resumes growth in the spring. If you have a sugarbush in the Northeast, you may have noticed brown scale insects, sticky dripping honeydew, and black sooty mold on your sugar maple leaves in 2005 and 2006. Since much of the vine is removed at pruning, it may be unnecessary to apply control measures unless the scale is infesting the main trunk or cordons. hard. The "cotton" is actually waxy threads covering as many as 1,500 eggs. Types of Cottony Maple Scale. When this material drops on leaves below the insect, a fungus called sooty Appearance: The most noticeable stage is the brown adult female with a large cottony mass (egg sack) protruding from the rear. crawlers, move away from the females toward the leaves. Boxwood blight and Oriental bittersweet could be found in holiday greenery and centerpieces. observations on this topic aimed at the home Please see our website for current forms, fees, and instructions on preserving and mailing insects. Since the insects are unable to fully digest the sap, they excrete the excess in the form of a thick, sweet substance called "honeydew." Even the occasional heavy populations will do little more than stunt tree growth with no lasting effect. However, in some years, the scale population increases above “normal” and becomes large enough to get noticed. Scale insects feed on many plants and appear as small bumps on the foliage, twigs and branches of trees and shrubs. This scale prefers maples, particularly silver maple, but may occur on many other hardwood trees and shrubs. Physiological leaf scorch is the most common. Insecticide applications have the chance of upsetting the natural balance of biological controls present in the trees (by killing predators and parasites) and prolonging the occasional outbreak into a more serious problem. If the infestation is severe for several years Cottony Maple Leaf Scale Entomology Insect Notes. The males mature in late August and early September, mate with Homeowners are encouraged to spray with insecticidal soap if they decide to spray in spite of the absence of any direct threat to tree health and vigor. Some common species of scale insects in Australia are pink wax scale, black scale, soft brown scale and citrus red scale. Adult scale insects are usually covered in waxy shell-like cover. Scales tend to thrive on stressed plants. Eggs masses are conspicuously white and cottony in appearance. Service for the most current, Unlike other insects, they are immobile once they lock themselves into place to … weeks after hatching, the young are vulnerable to sprays of Do not use oils sprays on sugar and Japanese begins on the tree provide excellent control of over-wintering nymphs. There are many types of scale insects and several of those produce a white cotton-like mass. Early treatments, that is, sprays applied in June before the eggs hatch are not effective. of the year while they feed on the sap of plants. infestation is unlikely to seriously stress an otherwise one generation occurs per year. If you live outside of Iowa please do not submit a sample without contacting the Plant & Insect Diagnostic Clinic. The body is covered with flakes of clear wax. Cottony maple scale is always present in Iowa but in most years is too low in abundance to attract attention. on twigs and branches. It’s often one or a few trees that are heavily loaded with fluffy, white female egg sacs that look like popcorn on the twigs. (The bumps are actually the insects.) At that point, the adult females stop feeding and The scale cover is a waxy secretion that protects the insects. 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. Scale insect control. any serious action in your landscape, check They blend in with the bark and leaves of plants and usually do not move around. 2150 Beardshear Hall The scale overwinters as an immature female on the twigs of the host. Insects and diseases can hitchhike on trees and holiday greenery. Holiday Greenery Invasive Insects. There are two broad It is a pest primarily of nurseries and is often on hollies. 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. Severe infestations that go on for several years may cause twig dieback and only under extreme conditions will entire trees be killed. The "cotton" is actually waxy threads covering as many as 1,500 eggs. The settle on the An application of a labeled We have been seeing it on hollies. In their juvenile growth stage, they are referred to as «crawlers». These pests are much more abundant and damaging in urban landscapes than natural forests. fertilized nymphs migrate from the leaves to the twigs and branches. worse in future years. Weather and natural enemies team up to keep the cottony maple scale populations low in most years. scales that can be easily reached Generally, healthy trees should not be Adult scales become stationary, feeding on one spot of the host. Scale almost always appears in clusters. maple cushion scale belong to the soft bodied type. Copyright © 2020ISU Extension and Outreach Sooty mold feeds on the sticky honeydew left by aphids and scale insects, which can sometimes be found on maple trees. This insect is active throughout the United States and attacks many shade trees and shrubs, but it is primarily found on soft Maples and Lindens. By late May or early June the female scale has matured and begins to lay hundreds of eggs within a white frothy wax. Inspect the branches for scale insects. Dormant oils sprays applied in early spring before the new growth The distinguishing characteristic of these soft scales is the white egg sac (ovisac) produced by female scales in summer. Later in the summer, they will form a protective shell and will not be On small trees, pick off female Pest description and damage Mature cottony maple scale are small, flat, oval, brown insects 0.25 to 0.375 inch in diameter. As its name suggests, cottony maple scale (Pulvinaria innumerabilis) affects mostly maple trees (predominantly silver and red maples). unable to fully digest the sap, they excrete the excess in the form of Most are eaten or attacked by a complex of natural enemies, especially lady beetles. The good news is that sooty mold won't kill your tree and can be easily treated. Maple (Acer) is the most common genus of deciduous street tree planted in eastern North America (Raupp et al. from the ground. Note: We In early June, white, The overwintering form of the cottony maple scale is a small, brown, flattened 1/8 inch long scale attached to the bark of twigs and small branches. may infest many types of trees, it is most commonly 2006). Cottony maple scale over-winters as immature females (nymphs) on twigs and branches. The cause of this annoyance is a tiny insect known as Cottony Maple Scale. Gypsy moth and elongate hemlock scale are typically moved in and around on Christmas trees and wreaths. Cottony maple scale on a silver maple. In their juvenile growth stage, they are referred to as \"crawlers\". More than 60 different kinds occur in Indiana, yet they are often overlooked or ignored until tree or shrub branches “mysteriously” start to die. Insecticidal soap is available from garden center, hardware and department stores under various trade names. Scale insects are sap suckers and a large infestation can weaken plants - especially small or stressed ones. Cottony maple scale (Pulvinaria innumerabilis) is a flattened brown scale about 1/8” long that becomes one of the most conspicuous soft scale insects attacking ornamental plants when mature females begin to secrete white, waxy, cottony-appearing egg sacs in early summer. treatment may be warranted. This insect note describes an integrated pest management approach to identifying, monitoring, and managing these pests. During June, the inconspicuous female scales that spent the winter on the stems expand and begin producing a large, white, cottony egg sac. Cooperative Eliminating them may make the infestation Scale infestations weaken the host tree, and if the infestation is severe enough the tree can die. Adult female white peach scale and white prunicola scale have a distinctive sunny side-up fried egg appearance to their rounded, white, waxy covers. As crawlers, they are highly mobile, six-legged, have no protective cover, and are usually smaller than a pinhead. You may substitute ordinary dishwashing detergent for the commercial products with little risk of injury to maple trees. underside of a leaf and insert their threadlike mouth parts into the tissue Also, keep infested trees adequately watered and fertilized leaves, stems and branches of maple trees. Scale insects are common pests of shade trees and shrubs. General Information Skip to General Information. In armored scale, these covers are waxy, hard, circular or rounded in shape and detached from their bodies. The insect’s small size and ability to blend in with natural variation in bark coloration make it a challenging scale to detect until populations are high and the scale has spread to large areas of the nursery. Since the insects are Cottony maple scale is most easily noticed in late spring. They feed by sucking sap and some can weaken host plants, many excrete a sticky substance (honeydew), which allows the growth of sooty moulds. There are many species of scale insects that feed on a wide range of host plants. hatch in early July. During the summer, the scale enlarges by secreting wax resulting in a body several times greater than the overwintering form. 2 Soft Scales Soft scale insects typically have one generation per year and generally are larger in size though there are many variations in size, shape and color (figure 4). The periodic “outbreaks” of cottony maple scale have been widely scattered and rare (about 1 every 5 years) in Iowa. Occasionally the leaf margins are yellow or chlorotic. The developing females and nymphs produce copious amounts of honeydew which can collect on foliage and branches and cause growth of sooty mold. Severely infested trees look like they are covered with a string of popcorn. The cottony maple scale is most easily recognized by the characteristic egg masses on twigs and branches. Examples include Japenese maple scale, obscure scale, gloomy scale, oystershell scale, pine needle scale, white peach scale and euonymus scale. Immature females are flat and inconspicuous. This will turn leaves and stems black but does not maples. Monitoring Scale Insects: Focusing on the crawler stage Since 2010, we have been monitoring Japanese maple scale populations to determine the life cycle of this scale insect in Maryland. That most likely was European fruit lecanium scale, Parthenolecanium corni. Tag: insects. If you have a heavy infestation outdoors, prune away the stems with the most scales. Small, newly transplanted, high value specimen trees may benefit from treatment. Showing 1 – 1 of 1 resources. In 2013, we added Indian wax scale, white prunicola scale and juniper scale to the monitoring list to better determine crawler periods. Gloomy scale is an armored scale insect pest of ornamental trees, most commonly red maple trees. Try using a gardening mix that works to protect plants. predators and parasites of the scale. Upon closer examination, these branches are likely to be covered with small bumps that are actually scale insects. Scale insects form a protective covering over themselves for most of the year while they feed on the sap of plants. Pesticides might not reach the insect because the scale acts as a barrier. They secrete the white, cottony masses beneath which, they lay 500 or more eggs in late May to early June. The insect’s small size and ability to blend in with natural variation in bark coloration make it a challenging scale to detect until Sometimes a shiny, sticky coating will be on the leaves also. Information is from the University of Maryland. Consequently, they may not be effective where several … mold begins to grow . Gloomy scale attaches to the bark of the tree’s trunk and branches. Barkis usually intact beneath a scale. Black sooty mold fungus thrives on the honeydew accumulations and further adds to the aesthetic disruption. The cottony maple scale, Pulvinaria innumerabilis (Rathvon), is a highly modified insect pest that commonly attacks silver and red maples in Ohio. Oystershell scales spend the winter as eggs under the tests of the females. Damage: Mature females are pale to dark brown, convex, and about 3-6 mm long (Fig. The distinguishing characteristic of these soft scales is the white egg sac (ovisac) produced by female scales in summer. However, you will never see just one of them, which makes them hard to miss. small branches may die back. The pest is very common in the tri-city area of Michigan at this time. a thick, sweet substance called "honeydew." These scales are usually first noticed when females produce egg sacs which appear as small cottony balls. Soap sprays have no residual activity and only control insects that are contacted directly. or the honeydew is causing serious problems beneath the tree, a chemical If scale populations are heavy enough the tree may show twig and limb dieback as the insect spends the winter on the twigs once the leaves drop off. Damage from cottony maple scale insects is usually very limited. Scale-damaged plants look withered and sickly. Although less commonly seen, gloomy scale can also infect grapes, native hollies, sweetgum, and mulberry. Although the insect does not usually cause much damage to the tree, it is truly a pest to the humans who live below because of the copious honey-dew excretions of the insect. Although biological controls of cottony maple scale have not been studied, scale insects generally are preyed upon heavily by parasitic wasps. To make your own insecticidal soap spray solution, mix 5 tablespoons of liquid dishwashing detergent in 1 gallon of water. 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