Small, newly transplanted trees or weakened or stressed trees due to drought, compacted soils, poor fertilization, etc., are the ones most likely to exhibit major branch or crown dieback, or even death. CFAES COVID-19 Resources:   Safe and Healthy Buckeyes   |   COVID-19 Hub   |   CFAES Calendar. Do not contaminate forage, streams, or ponds. Copyright © 2015, The Ohio State University, David J. Shetlar and Jennifer E. Andon, Department of Entomology, ©  2020 The Ohio State University, College of Food, Agricultural, and Environmental Sciences, College of Food, Agricultural, and Environmental Sciences, Ohio Agricultural Research and Development Center, 2120 Fyffe Road | Room 3 Ag Admin Bldg. Cottony maple scales will produce white cottony egg sacs by mid-June. Severely prune back heavily infested branches and protect new growth with insecticide applications. ; birch, Betula spp. For an accessible format of this publication, visit cfaes.osu.edu/accessibility. The crawlers, or immature scale insects, produce large amounts of honeydew while feeding on leaves. 2120 Fyffe Road | Room 3 Ag Admin Bldg. This fact sheet is a revision of HYG-2019. This soft scale overwinters as a second instar nymph on the bark of host twigs and branches. Their eggs are white to pale yellow and are meshed in a white, cottony ovisac which may be up to 5mm wide and 12mm long. JavaScript seems to be disabled in your browser. The cottony maple leaf scale is so named because the females exude their eggs in an elongated, white, cottony structure called an ovisac which are stuck onto the underside of leaves. There are several predators and parasitoids that will naturally keep cottony maple scale populations in check. Immature females are flat and inconspicuous. Description of cottony maple scale. The cottony maple scale (Pulvinaria innumerabilis) is one of the largest and most conspicuous scale insects in this country. Second instar cottony maple scale nymphs. Dormant oil sprays have been traditionally used to manage many scales on ornamental trees. Mature cottony maple scales are small, flat, oval, brown insects without obvious legs, antennae or wings. Unfortunately, these natural enemies are also extremely susceptible to pesticide applications, so timing chemical treatments properly is very important. Fig. Immature females are flat and inconspicuous. Several insecticides are registered for control of scale crawlers and newly settled crawlers. When we do see it, however, the show is spectacular. These lady beetles continue to feed on the nymphs that settle on the leaves. It looks like white puffs of rice with a black spot on one side of the puff. Also, when this soft scale feeds on leaves and twigs, a large quantity of honeydew is excreted. Soaps and oils only kill the pests on contact. Soft scales feed in vascular components of plants. During the summer, the scale enlarges by secreting wax resulting in a body several times greater than the overwintering form. The developing females and nymphs produce copious amounts of honeydew which can collect on foliage and branches and cause growth of sooty mold. Dispose of empty containers right away, in a safe manner and place. Its favored host is silver maple, Acer saccharinum. Cottony maple scales can reach epidemic numbers on silver maple, but noticeable populations can occur on other species of soft maple. A close examination of the ovisacs reveals the eggs are held inside a sack-like matrix of sticky, silk-like material. Cottony Maple Scale. ; hackberry, Celtis spp. This is a result of a poorly timed pesticide application that kills most of the parasites and predators but allows survival of the resistant scale stages, protected by their waxy covering. Rarely, heavy infestations have been found to kill stressed or weakened trees. The fungus is on almost every leaf. ; sycamore, Platanus spp . This site designed and maintained by CFAES Marketing and Communications. 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. By late May to early June, the females have matured, and they begin to produce their ovisacs. Some of the leaves look like they are being eaten by the fungus. When the sap begins to flow in the spring, the females continue to feed and grow, producing considerable amounts of honeydew. The cottony maple scale is a large, flat, brown scale insect found on the twigs and branches of various trees. The white cottony egg masses, which resemble popcorn, are the most distinguishing feature of this scale. A close examination of the ovisacs reveals the eggs are held inside a sack-like matrix of sticky, silk-like material. The cottony maple scale is one of the largest and most conspicuous soft scale insects that attack ornamental plants. Timing pesticide application to the crawler stage is very important. Damage to the host tree is caused when heavy populations of cottony maple scale withdraw sap from the plant, resulting in branch and twig dieback. CFAES Diversity  |  Nondiscrimination notice  |  Site Map. 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? The cottony maple scale, Pulvinaria innumerabilis (Rathvon), is a highly modified insect pest that commonly attacks silver and red maples in Ohio. Honeydew often drops onto leaves or plants below. Q: I have what I think is a fungus on the underside of my red maple. However, in some years, the scale population increases above “normal” and becomes large enough to get noticed. We work with families and children, farmers and businessowners, community leaders and elected officials to build better lives, better businesses and better communities to make Ohio great. Each mass usually contains 1,000-1,500 eggs. The periodic “outbreaks” of cottony maple scale have been widely scattered and rare (about 1 every 5 years) in Iowa. 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. Cottony maple scale crawlers along leaf veins in the summer. A large number of other deciduous trees are also attacked including other species of maple, such as boxelder, A. negundo ; basswood, Tilia americana ; white ash, Fraxinus americana ; dogwood, Cornus spp ; locust, Robinia spp. However, every few years, these natural controls seem to fail and the cottony maple scale can reach epidemic proportions. By this time, the scales look like two different kinds: a translucent white to pink form and a larger, flat, tan form. They are black, flat, and oval. The insect overwinters as a female scale. Pesticides are poisonous. Soaps and horticultural oils can be very effective in managing the freshly settled crawlers. Maple cotton scale is found on several other common hardwood trees such as ash, elm and boxelder. Heavy infestations can result in branch dieback and in rare instances, tree death. Honeydew promotes the growth of a black sooty mold, that imparts a blackened appearance to leaves, twigs, branches, and other substrates beneath an infested host plant. Heavily infested branches can be killed by the cottony maple scale. 1). It has been reported on over a dozen species of trees, but is most common on silver and red maple. Q: I have what I think is a fungus on the underside of my red maple. View our privacy policy. Other species of wax scales include tree dwellers like the cottony maple scale (Pulvinaria innumerabilis) or the calico scale (Eulecanium cerasorum). Accessibility Accommodation. The "cotton" is actually a waxy secretion enveloping the ovisac, which may contain over 1,500 eggs. One of the insects we see on rare occasion in Iowa is the cottony maple scale. These materials also have minimal adverse effects on the adult lady beetles and parasites already in settled crawlers. Here, they reinsert their mouthparts and settle down for the remainder of their life. The body is covered with flakes of clear wax. .• Insecticidal Sprays Horticultural oils kill by suffocation or after penetrating over-wintering stages of the insect. As honeydew collects on leaves and branches, bees, wasps and ants are attracted to the area to feed. Description and Biology Cottony camellia scales, Pulvinaria floccifera, are cream to tan, elongate oval, and relatively flat. Other host preferences include: This damage causing insect is a sucking insect that has a straw like mouth it uses to feed itself on the leaves of the host tree. 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. 1. The biggest problem is the honeydew dripping down on decks, picnic tables, lawn chairs and parked cars. At maturity, the females produce the white, cottony egg masses, called ovisacs, over a period of several weeks. Frequently, feeding results in the secretion of a clear sticky substance called honeydew. Types of Cottony Maple Scale There are many types of scale insects and several of those produce a white cotton-like mass. COTTONY MAPLE SCALE . 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. Pulvinaria innumerabilis. Both the adults and larvae enter ovisacs to feed on the egg masses. The rest of the time the scale is present but in numbers too low to attract attention. They become active and feed on the leaves between June and July. These are male and female scales, respectively. Severely infested trees appear as though they were covered with a string of popcorn. | Columbus, Ohio 43210. The most important predators are several black lady beetles. Mature cottony maple scales are small, flat, oval, brown insects without obvious legs, antennae or wings. Following a recommended fertility program and watering regime will promote plant health. Apply registered products in mid-July and again in the second week of August for best control. If practical, improve plant sites to reduce stress and promote growth. Cottony taxus scale is a soft scale (produces a thin, waxy outer covering attached to insect) as opposed to a hard scale (produces a harder, outer shell not attached to the insect). Cottony Maple Scale . The cottony maple leaf scale is so named because the females exude their eggs in an elongated, white, cottony structure called an ovisac which are stuck onto the underside of leaves. Cottony Maple Scale is starting to hatch in the Treasure Valley. You must have JavaScript enabled in your browser to utilize the functionality of this website. The crawlers walk onto the leaves and tend to attach alongside the major leaf veins, usually on the underside. By entering your email, you consent to receive communications from Penn State Extension. Just before leaf drop in the fall, nymphs move back to host plant twigs and branches to overwinter. The cause of this annoyance is a tiny insect known as Cottony Maple Scale. For technical support please contact the CFAES Helpdesk. These pesticides, again, often need to be applied in sufficient spray quantity to wet both the leaf upper and lower surfaces to be effective. | Columbus, Ohio 43210 | 614-292-6181 Did you know this is actually an insect? Cottony maple leaf scale females form their ovisacs on leaves, not on branches. Coffee scale is a major agricultural pest in coffee crops. The cottony maple scale is most easily recognized by the characteristic egg masses on twigs and branches. They are firmly attached to the twigs and branches of various trees and may be ¼ to ⅜ inch in diameter. Mature females are pale to dark brown, convex, and about 3-6 mm long (Fig. The cottony maple scale is most easily recognized by the characteristic egg masses on twigs and branches. Every 5 to 10 years we experience an "outbreak" of cottony maple scale somewhere in the state. These scales flatten themselves against tree branches to feed. This pest has numerous parasites and predators that normally keep its populations in check. Some of the leaves look like they are being eaten by the fungus. These eggs hatch from mid-June to August, and the young nymphs called scale crawlers emerge… College of Food, Agricultural, and Environmental Sciences At maturity, the females produce the white, cottony egg masses, called ovisacs, over a period of several weeks. The cottony maple scale is one of the largest and most conspicuous soft scale insects that attack ornamental deciduous plants. The pest is very common in … Normally, this peculiar scale is a mere curiosity and a nuisance. COTTONY MAPLE SCALE is an insect pest of maples, especially silver maples and locust trees primarily, but also will infest several other species. Cottony maple leaf scale females and egg sacs. This pest spends the remainder of the summer feeding on leaves. Inappropriate timing is not only ineffective, but (76) Photo: John Davidson be controlled as crawlers and immatures. They send us twigs which are covered over with some kind of louse , and ask us what they can do to preserve the foliage of their trees . Here, the nymphs produce copious amounts of honeydew and grow by molting once. Eggs masses are conspicuously white and cottony in appearance. CFAES provides research and related educational programs to clientele on a nondiscriminatory basis. The most common one, Hyperaspis signata, has a larva that looks like a mealybug. The cottony maple scale, Pulvinaria innumerabilis, is a common insect pest in midMichigan. The body of the scale is white and resembles a kernel of popcorn. ; elm, Ulmus spp. Their eggs are white to pale yellow and are meshed in a white, cottony ovisac which may be … Symptoms & Life Cycle The scale, adults and nymphs, sucks sap and weaken plants. Consequently, they may not be effective where several l… The egg sac contains 600 to 800 red eggs and may become two to three times as long as the body of the female; the resulting length of the female plus the egg sac can be almost 1/2 inch ( Figure 2 ). For more information, visit cfaesdiversity.osu.edu. Cottony maple scale is always present in Iowa but in most years is too low in abundance to attract attention. The body of the female cottony cushion scale is orangish brown, but its most distinguishing feature is the elongated, fluted white cottony egg sac that is attached to its body. In September, the male scales emerge as tiny winged gnatlike insects that move around on the leaves in search of females. In some cases, premature loss of foliage may result from an infestation of this soft scale insect. What makes management of this scale more difficult is the fact that insecticide applications may actually cause the scale problem to continue longer than normal. 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. In early summer mature females begin to secrete white, waxy, cottony-appearing egg sacs in which they lay as many as 1,500 eggs. The Cottony Maple Scale will survive over winter and pester the tree over and over as you can read in the previous attachment. A favored host is silver maple, but it will attack other species of maple as well. These tiny crawlers are small, flat, oval insects with two distinct eyes, short antennae and tiny legs. 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. Certain insecticides may cause damage to soft maples; do not apply insecticidal soap to Japanese maple. These eggs hatch from mid-June to August, and the young nymphs called scale crawlers emerge. Male scales are tiny, winged insects. Mature female scales are brown, roundish, and about one-quarter inch in … List of files and visuals associated with this text. This scale looks like cotton balls attached to the stem. Application of soaps or oils should be made in mid-July and again in early August, if additional crawlers are found. Authored by: Gregory A. Hoover, Sr. Extension Associate. These wasps lay eggs inside the nymphs, in which their developing larvae feed on the pest from the inside out. If you have a disability and experience difficulty accessing this content request accommodation here. The 1/4-inch white cottony ovisac, or egg sac, is deposited on bark. Cottony Maple Scale Adult females are about 3/16 inch long. Cottony Maple Scale starts off as an unnoticeable, brown scale. If abundant, a sooty mold fungus may colonize the honeydew, resulting in a black sooty appearance on the leaves, twigs, and branches. Entering your postal code will help us provide news or event updates for your area. In extreme conditions, a tree may be killed. After mating, the males die and the females soon withdraw their mouthparts and crawl back onto small twigs and branches. Cottony maple leaf scale females are 3 to 4mm long and 2 to 4mm wide. Affected scales often turn brown or black and have tiny round emergence holes on their back surface. Overwintering nymphs may be managed with an application of horticultural oil made in early spring before new growth starts as adormant treatment. Cottony maple scales are occasionally confused with a close relative, the cottony maple leaf scale, Pulvinaria acericola. See All Pest, Disease and Weed Identification, See All Beer, Hard Cider, and Distilled Spirits, See All Community Planning and Engagement. 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