Scales also cover themselves with waxy material that protects and hides them. AgCenter, The LSU AgCenter and the LSU College of Agriculture, 101 Efferson Hall
In addition, this insect attacks privet, bittersweet and pachysandra. Light, paraffinic oil, such as Year-Round spray oil and All Seasons spray oil, however, can be used during the summer. When they first hatch out of their eggs, scale insects are mobile. Control: Euonymus scale can be difficult to control. Unfortunately, it is not completely effective on all stages. When infestations are heavy, scales encrust leaves and branches, with feeding damage causing defoliation and branch dieback. Nymphs are active over a period of a few weeks, and develop into adults after four to five weeks. There are many others. Be aware that other sucking insects, such as whitefly and aphids, also produce honeydew that can lead to sooty mold. Systemic insecticides for use on landscape plants include neonicotinoids (acetamiprid, dinotefuran, imidacloprid, and thiamethoxam) and the organophosphate acephate (Lilly Miller Ready-to-Use Systemic, Orthene). Treatment involves pouring the mixed insecticide at the base of the plant. Once the crawlers have settled down to feed, they create their protective covering and contact insecticides are largely ineffective. Baton Rouge, LA 70803
Heavily infested branches should be removed. Acephate, imidacloprid and dinotefuran are three commonly used systemic insecticides that are effective against scale. Brand names of spray oils include Volck (use only during cool weather), All Seasons and Year-Round. Horticultural oil sprays will kill the eggs, crawlers (immatures) and the adult scales. A second generation of scales is produced in late July and August. The lady beetle Cybocephalus nipponicus can be purchased by homeowners and released to aid in control. If the insects are on the underside of the leaves and the oil is only applied to the upper surface, it will have no effect on them. Finally, two parasitic wasps and two predatory beetles have been introduced into the US to help control Euonymus scale. That’s one reason that the mild weather of spring is an excellent time to use them. Thank you for your question.Yes, Systemic Insect Control is effective on all types of scale including euonymus scale. Acephate (various brands) and imidacloprid (Bayer Advanced Tree and Shrub Insect Control and other brands… Acephate, imidacloprid and dinotefuran are three commonly used systemic insecticides that are effective against scale. Imidacloprid (Bayer Advanced Garden Tree & Shrub Insect Control Concentrate) is applied as a drench around the root zone of infested plants. Oils are also effective against aphids, whiteflies, spider mites and the crawler stage of scales, yet they are less harmful than other insecticides to beneficial predatory insects. The plant absorbs the insecticide into its tissue, and it gets into the plant’s circulatory system and into the sap. Systemic insecticides such as imidacloprid can also be used for control. Thorough coverage of both the upper and lower leaf surfaces is required for spray insecticides to be effective. The sooty mold will not quickly disappear when the scale has been controlled, but as the food supply is exhausted the sooty mold will eventually weather off. Photo by Dan Gill/LSU AgCenter, False oleander scale on magnolia. Because scale insects are difficult to kill, one or two follow-up applications should be made after the first one. Adults are protected from these insecticides by their scale coverings, and only young crawlers can be killed with spray treatments. Florida wax scales look like waxy, white domes about the size of a nail head and occur on a wide variety of plants. Phil Pellitteri, UW Insect Diagnostic Lab, UW-Extension Revised: 8/6/2012 Item number: XHT1153. Photo by Dan Gill/LSU
Adults are protected from these insecticides by their scale coverings, and only young crawlers can be killed with spray treatments. Soil Applied Systemic Insecticides: Although soil treatments with common products containing imidacloprid will control some tree and shrub pests, such as soft scales, aphids and white flies, these products do little to control armored scales. The safest effective way to control scale is with a horticultural oil spray. This water soluble insecticide is taken up by the roots and transported throughout the plant where it is ingested by sap feeding insects. The insects are suffocated rather than being killed by a toxic material. High populations of Euonymus scale can cause leaf loss and twig death. You may find them feeding on trees, shrubs and even on indoor plants. We teach, learn, lead and serve, connecting people with the University of Wisconsin, and engaging with them in transforming lives and communities. 225-578-4143
Crawlers can be controlled with contact insecticides such as insecticidal soap or malathion, but most gardeners never notice them and miss the opportunity. These insecticides contain oil in a form that will mix with water. Systemic insecticides provide an option for control when temperatures limit the use of an oil spray or when drenching around the base of the plant is more practical.