Insecticide For Euonymus Scale

Euonymus scale is one of the most common household pests found in Florida. They can be found feeding on many different species of trees and shrubs. Insecticide is commonly used to treat this insect pest. Wasps, hornets are also a problem during the summer months. They love to feed on Euonymus scale, so when treating for this pest, you will need to time your applications around the wasp season, which is from June 25th through September 30th in Florida.

Insecticide For Euonymus Scale

Euonymus scale is a non-native scale that attacks evergreen shrub and vine forms of Euonymus (e.g., wintercreeper).  In addition, this insect attacks privet, bittersweet and pachysandra.

Appearance: Euonymus scale females grow up to 1/16 inch in length, are brown and are shaped like tiny oyster shells.  Euonymus scale males are smaller than females, white and elongated.

Symptoms and Effects: Euonymus scales feed on plant sap.  Feeding damage first appears as yellow spots on leaves.  When infestations are heavy, scales encrust leaves and branches, with feeding damage causing defoliation and branch dieback.

Life Cycle: Euonymus scale has two generations per year in Wisconsin.  Eggs are protected under female scales and hatch in early June.  The immature stages of the insect are called nymphs and an early mobile nymph stage is called the crawler stage.  Nymphs are active over a period of a few weeks, and develop into adults after four to five weeks.  A second generation of scales is produced in late July and August.  This second generation matures, and the adults overwinter.

Control: Euonymus scale can be difficult to control.  Heavily infested branches should be removed.  Spray insecticides containing carbaryl, cyfluthrin, horticultural oil, insecticidal soap, malathion, or permethrin can be used for control of the crawler stage of Euonymus scale.  Adults are protected from these insecticides by their scale coverings, and only young crawlers can be killed with spray treatments.  Therefore, spray treatments should be started in early June, and three applications made at 10 to 12 day intervals are needed to achieve control.  Thorough coverage of both the upper and lower leaf surfaces is required for spray insecticides to be effective.

Systemic insecticides such as imidacloprid can also be used for control.  However, while these products reduce scale populations, they typically do not provide 100% control of Euonymus scale on woody plants.  Imidacloprid-containing insecticides are used as soil drenches and should be applied in the fall.

Finally, two parasitic wasps and two predatory beetles have been introduced into the US to help control Euonymus scale.  The lady beetle Cybocephalus nipponicus can be purchased by homeowners and released to aid in control.

Insecticide For Euonymus Scale

Euonymus scale is a common insect pest that can threaten the health of your Euonymus shrubs. The insect is light brown and has a hard shell, which makes it difficult to see. It also makes it more difficult to treat. The best way to control this pest is by using insecticide made specifically for Euonymus scale.

Using an insecticide that isn’t made for Euonymus scale may cause more harm than good. Insecticide made specifically for Euonymus scale will not kill beneficial insects, like ladybugs, which eat the scales and help keep them under control.

List Of Insecticide For Euonymus Scale