PEST PROFILES: SCALE INSECTS
Picture of Scale

Picture of a Barnacle Scale
Barnacle Scale

Picture of Euonymus Scale
Euonymus Scale

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Scale Insects

Description:
Wax scales are globular and coated with a layer of beige, pinkish, whitish or grayish wax. They may grow to over 1/8 inch (Florida wax scale) to almost 1/4 inch (barnacle scale) in diameter. Several species of wax scales occur in Texas.

Damage:
Wax scales infest ficus, gardenia, hawthorn, holly, and ornamental pear, pyracantha and other landscape trees and shrubs. They are a minor citrus pest. Wax scales injure plants by removing large quantities of plant sap and they produced sticky honeydew.

Life cycle:
Eggs are oval, orangish, and fill the inside of the female scale insect. Eggs hatch over a period of 2 to 3 weeks. First instar crawlers settle on leaves, twigs and stems of host plants. After settling, nymphs begin to secrete wax in tufts around the body that give these insects a star-like appearance. Nymphs of the barnacle scale migrate from leaves to the woody tissue soon after molting to the third instar. There may be 2 or more generations per year.