In heavy infestations, leaves may be stuck together, and the ground beneath the trees may be extremely sticky. It has also been reported from some western states. This is an armored scale and, unlike the cottony maple and calico scales, it does not produce honeydew. Cottony maple scale is a lecanium-type scale, being very similar in appearance to European fruit lecanium for most of the year. Adults were present in mid-May; I photographed one in my backyard in central Illinois at that time. Thus by mid-June, the scale eggs have hatched, the crawlers are exposed on the undersides of leaves and the lady beetles are gone. This scale feeds primarily on maple and dogwood in North Carolina, but it also infests hollies, Andromeda, and gum. At this time of year, beetles are usually in the larval stage. A&T State University. The full-grown larva is about 1/4 inch long, whitish to grayish, and covered with waxy filaments. These little buggers are so tiny and sneaky. Each mass usually contains 1,000-1,500 eggs. Cottony maple scales will produce white cottony egg sacs by mid-June. Dormant-oil treatments control overwintering female nymphs on most hosts (except sugar and Japanese maple) after leaf drop in the fall and before budbreak in the spring. In late summer, the scales crawl to the twigs where they feed for the rest of the fall, winter and early spring. Read our Egg sacks look like popcorn on the underside of small branches on the scale�s primary host (silver maple), other maples, alder, apple, beech, black locust, box elder, dogwood, elm, euonymus, honeylocust, linden, mulberry, oak, osage orange, peach, pear, plum, poplar, rose, sumac, and sycamore. When we do see it, however, the show is spectacular. The body is covered with flakes of clear wax. Scale insects tap into plants and feed on plant sap, weakening and even killing plants over time. Immature females are flat and inconspicuous. After mating, the females crawl to the leaves to lay eggs. Following a recommended fertility program and watering regime will promote plant health. Egg sacs may grow to as large as 1/2 inch in diameter and may contain up to 1000 eggs. The distinguishing characteristic of these soft scales is the white egg sac (ovisac) produced by female scales in summer. In late spring and early summer, females produce conspicuous cottony egg masses that may contain more than 500 eggs. The twice-stabbed ladybeetle, which feeds on soft-bodied insects, is commonly found dining on cottony maple scale crawlers. Cooperative Extension is based at North Carolina's two land-grant institutions, The use of brand names and any mention or listing of commercial products or services in this publication does not imply endorsement by NC State University or N.C. A&T State University nor discrimination against similar products or services not mentioned. IDENTIFICATION AND LIFE CYCLE 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. Eggs masses are conspicuously white and cottony in appearance. One spray during that period should be sufficient. Cottony Scales include Cottony Camellia Scale (Hollies and verious other plants), Cottony Taxus Scale (Yews), Cottony Maple Scales (Silver Maple, Dogwood and others) and Azalea Bark Scale (Azalea, Andromeda and Rhododendron). Pulvinaria innumerabilis (cottony maple scale) is a small, flattened, brown scale insect about 1/8" long. Infestations are most easily noticed during the summer when females produce white, cottony egg sacs that resemble pieces of popcorn on a twigs. Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. The following pesticides are effective for control of cottony maple leaf scales. See the North Carolina Agricultural Chemicals Manual for additional insecticide choices. Immature forms (crawlers) are flattened and brown to yellowish green in color; however, the conspicuous, cottony egg sac of the mature female is two to three times the length of the scale … As its name suggests, cottony maple scale (Pulvinaria innumerabilis) affects mostly maple trees (predominantly silver and red maples). The Cottony Maple Scale. They closely adhere to the undersides of leaves and are easily overlooked. Cooperative Extension county center. Types of Cottony Maple Scale There are many types of scale insects and several of those produce a white cotton-like mass. The Soft Scales (Homoptera : Coccoidea : Coccidae), The soft scale insects of Florida (Homoptera: Coccoidea: Coccidae), Soft Scale Identification and Management on Ornamental Plants, NC State Extension Plant Pathology Publications and Factsheets, NC State Horticultural Science Publications, Entomology – Insect Biology and Management, NC Receive Email Notifications for New Publications. In late September, just before leaf drop, fertilized female nymphs migrate from the leaves to twigs and branches, where they overwinter. The cottony maple scale is a pest on certain shade trees, particularly black locust and soft maple. The white cottony egg masses, which resemble popcorn, are the most distinguishing feature of this scale. There is one generation each year. They are slightly convex and are brown with a yellow-brown ridge down the back (Figure 1). Eggs hatch into the crawler stage of the scale in late June and early July in central and northern Illinois. The cottony maple scale is most easily recognized by the characteristic egg masses on twigs and branches. Consequently, they may not be effective where several l… A close examination of the ovisacs reveals the eggs are held inside a sack-like matrix of sticky, silk-like material. Several parasites and predators have been reported for the cottony maple leaf scale. Severely infested trees look like they are covered with strings of popcorn. Revised: Sept. 18, 2019. Cottony maple scale is most easily noticed in late spring. — Read our Cottony maple leaf scale females are 3 to 4mm long and 2 to 4mm wide. N.C. A lady beetle larva will move, albeit slowly, when poked or prodded; a scale egg mass will not. Cottony maple leaf scale females are 3 to 4mm long and 2 to 4mm wide. It looks very similar to the egg mass of the cottony maple scale. The crawler's waste is called honeydew. There is one generation a year. Heavily infested trees have small flowers and leaves. These eggs hatch from mid-June to August, and the young nymphs called scale crawlers emerge… Leaves may turn yellow and drop prematurely. Scales tend to thrive on stressed plants. They are slightly convex and are brown with a yellow-brown ridge down the back (Figure 1). Its cottony egg sac and profuse honeydew production make cottony cushion scale easy to spot in the landscape. Heavy infestations of this scale may cause yellowing, wilting and eventually branch dieback. Mature cottony maple scales are small, flat, oval, brown insects without obvious legs, antennae or wings. Timing pesticide application to the crawler stage is very important. Foliar applications should target crawlers. Cottony Maple Scale. Dave Smitley, Michigan State University, Department of Entomology - May 21, 2010. In some cases, the scales are quite numerous. Cottony maple scale is being found in DuPage, Livingston, and Grundy counties, on silver maple, sugar maple, honeylocust, green ash, and hawthorn. Crawlers, as their name implies, crawl to the underside of leaves, where they settle and feed on the sap. Treatments for Calico scale, cottony maple scale, and Lecanium spp. Because environmental conditions and methods of application by growers may vary widely, performance of the chemical will not always conform to the safety and pest control standards indicated by experimental data. 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. N.C. Adults are usually present in July when the crawlers are present. Mature females are pale to dark brown, convex, and about 3-6 mm long (Fig. The twice-stabbed ladybeetle, which feeds on soft-bodied insects, is commonly found dining on cottony maple scale crawlers. Honeydew often drops onto leaves or plants below. And they will ruin your citrus, unless you get it under control. Recommendations for the use of agricultural chemicals are included in this publication as a convenience to the reader. Be sure to obtain current information about usage regulations and examine a current product label before applying any chemical. Newly hatched nymphs are pale yellow or green and translucent. The rest of the time the scale is present but in numbers too low to attract attention. Crawlers hatch in late May to early June and feed on the underside of the host leaves, usually along the ribs of the leaf. commitment to diversity. In the spring, a white egg sac is developed and holds many crawlers (insect). Both scales produce white, cottony ovisacs, and both have wide host ranges; however, as its common name implies, cottony maple leaf scale produces its ovisacs on the underside of its host's leaves. 1). If larvae and/or adults of this lady beetle are present in reasonable numbers, it�s best to avoid spraying for cottony maple scale crawlers. Cottony maple scale outbreaks often subside in two to three years, due to control by natural enemies. The cottony maple scale is common on maple, boxelder, hackberry, dogwood, beech, apple, oak, linden, honeylocust, and elm. Cottony Maple Leaf Scale is one of several cottony scales in the genus Pulvinaria. In extreme conditions, a tree may be killed. A close examination of the ovisacs reveals the eggs are held inside a sack-like matrix of sticky, silk-like material. The insect overwinters as a female scale. Infestations of this magnitude can occur on silver maple but are less likely to occur on other hosts. Cooperative Extension prohibits discrimination and harassment regardless of age, color, disability, family and marital status, gender identity, national origin, political beliefs, race, religion, sex (including pregnancy), sexual orientation and veteran status. Cottony Cushion originates from Australia and is rumored to have come to the US by accident in the late 1800’s on a plant shipment. Cottony maple scale is sometimes mistaken for Cottony Maple Leaf Scale (P. acericola). Cottony Maple Scale starts off as an unnoticeable, brown scale. The eggs hatch in late June and July and the crawlers move to the leaves. List of files and visuals associated with this text. Immatures overwinter on twigs. Cottony Maple Scale . These egg-laying scales do not feed and they soon die. Other treatments should aim to control crawlers on foliage in July, when they first become active. During the dormant season, twice-stabbed lady beetles overwinter as adults under loose bark where they are not affected by the spray. If abundant, a sooty mold fungus may colonize the honeydew, resulting in a black sooty appearance on the leaves, twigs, and branches. (Other contributors to this article: Mary Pfeiffer, Grundy County Extension Unit; Mary Shier, Livingston County Extension Unit). 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. Immature lady beetles are gray but soon become covered with a thick, cottony covering of wax that makes them look like mealybugs. Cottony scales suck sap from leaves (summer) and twigs (fall, winter, early spring) depriving the tree of valuable resources. In April, male scales develop into tiny, winged, gnatlike insects which mate with females and then die. Pulvinaria innumerabilis. Cottony ovisac on maple leaf with desiccated adult female present. At maturity, the females produce the white, cottony egg masses, called ovisacs, over a period of several weeks. Unfortunately, the predators and parasites are susceptible to many insecticides used in the landscape and are often eliminated before they can adequately control the scale. They are firmly attached to the twigs and branches of various trees and may be ¼ to ⅜ inch in diameter. By late spring the insect has developed into a mature female and begins laying as many as 1,000 eggs. These cottony masses can contains hundreds of eggs each. Imidacloprid, a systemic insecticide, only controls soft scales. Nymphs are brown-translucent, 1/5 inch; females lay eggs in the white marshmallow egg-sac along the twigs and small branches; Young insects remove sap from leaves creating a speckled appearance and possibly yellowing leaves in mid to late summer Foliar applications of acephate (Orthene), malathion, or summer horticultural oils to the underside of the leaves should provide effective control of cottony maple scale. In severe infestations of cottony maple scale, chemical control may be desirable. Contact insecticides such as pyrethroids may provide less consistent control because they rely on contacting the insect whereas systemics make the plant toxic for the insect to feed on. The scale overwinters as an immature female on the twigs of the host. For assistance with a specific problem, contact your local Cooperative Extension center. In April and May, cottony maple leaf scales move to the leaves and lay up to 2,500 eggs in cottony ovisacs on the undersides (Figure 3 and Figure 4). They spend the winter in an immature stage on twigs or branches and complete development in June when the egg sacs appear. If practical, improve plant sites to reduce stress and promote growth. G = greenhouse, N = nursery, L = landscape, I = interiorscape. Cottony maple leaf scale is found throughout the eastern United States and southern Canada. Frequently, feeding results in the secretion of a clear sticky substance called honeydew. To monitor for this pest, look for tiny (1/8 inch long), oystershell shaped, and brown to gray scale covers on the bark of wilting or dead branches. scales. Cottony maple scale is a food source for many predaceous insects and parasites. Cottony Scale insects produce cottony egg masses from which young crawlers emerge. Severely prune back heavily infested branches and protect new growth with insecticide applications. Figure 4. Individuals who use agricultural chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Every 5 to 10 years we experience an "outbreak" of cottony maple scale somewhere in the state. They are black, flat, and oval. Cottony cushion scale, Icerya purchasi, can infest a number of woody ornamentals and certain crops (Figure 1). The scale itself is about 1/4 inch, and the egg sack is about 1/2 inch in size. One symptom of heavy infestations of cottony maple scale is honeydew. Adult females are about 1/8 inch long, oval and yellowish tan with a brown margin. Male scales are tiny, winged insects. In early summer mature females begin to secrete white, waxy, cottony-appearing egg sacs in which they lay as many as 1,500 eggs. Cottony Cushion Scale had taken over, right under my nose! Cottony camellia scales, Pulvinaria floccifera, are cream to tan, elongate oval, and relatively flat. It�s common for both larvae and adults to be present at the same time. Pest description and crop damage The cottony maple scale is one of the largest soft scales. Adult twice-stabbed lady beetles are about 1/8 inch long, roundish, and black, with two red spots on the back. It is also known as cottony taxus scale. During June, the inconspicuous female scales that spent the winter on the stems expand and begin producing a large, white, cottony egg sac. This is the substance that makes our cars, sidewalks, decks, you name it, sticky in the summer. These scales also produce large amounts of liquid waste Cottony maple scale reaches epidemic numbers on silver maple, but noticeable populations can occur on red maple. As the scale eggs hatch, the lady beetles leave, apparently to look for other prey. commitment to diversity. Cottony maple scale is a food source for many predaceous insects and parasites. However, over-fertilization favors scale buildup. The presence of this Insect le easily discovered during the summer months because of the white cottony masses about the size of peaa that are found on the lower sides of the limbs, especially those near the ground. Check the label of any pesticide referenced to ensure your use is included. .• Insecticidal Sprays Horticultural oils kill by suffocation or after penetrating over-wintering stages of the insect. (76) Photo: John Davidson be controlled as crawlers and immatures. Cottony camellia scale and cottony maple scale are the other common species. Its favored host is maple trees, although it has been found on a number of other species as well. In spring the female matures and lays eggs. A favored host is silver maple, but it will attack other species of maple as well. Do not use acephate on red or sugar maple. The cottony maple scale is a large, flat, brown scale insect found on the twigs and branches of various trees. Cottony Maple Scale. Figure 2. Older scales are dark brown. The most abundant are in a group of small lady beetles in the genus Hyperaspis. Only one generation of cottony maple scale occurs each year. Cottony maple scales commonly infest silver maple but can feed on several species including other maples, boxelder, basswood, birch, elm, and linden. 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. Although a heavy infestation may cause some thinning of the canopy, it rarely results in tree death. Horticultural oil can be used in winter when trees are without leaves to smother females living on branches. One of the insects we see on rare occasion in Iowa is the cottony maple scale. 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. They are also called cottony taxus scales as this scale is a fairly common pest of yew. Young females have a dark stripe down the middle and mottling at the sides. 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. Before treating for crawlers, look for twice-stabbed lady beetles. Spray when the temperature will stay above freezing for 24 hours after the spray. The biggest problem is the honeydew dripping down on decks, picnic tables, lawn chairs and parked cars. Common hosts in California are citrus, cocculus, nandina, and pittosporum. Adult lady beetles are black with small orange spots. Find more information at the following NC State Extension websites: Publication date: Aug. 1, 2010 The body is covered with flakes of clear wax. This publication printed on: Dec. 26, 2020, The Scale Insects of California: Part 1. Sooty mold is commonly found growing on the honeydew in mid- to late summer. This is the optimum time for control. Inappropriate timing is not only ineffective, but Honeydew is the sugary, liquid waste excreted by scale insects. The 1/4-inch white cottony ovisac, or egg sac, is deposited on bark. Cottony maple scale crawlers along leaf veins in the summer. Consequently infested trees are stunted and appear scorched and black. For assistance, contact your local N.C. COTTONY MAPLE SCALE Lee Townsend, Extension Entomologist A mature female cottony maple scale is 1/8" long, and has a brown, flat, oval body. 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