Flecther Scale – Parthenolecanium fletcheri

Fletcher Scale: Appearance, Territory, Damage and Life

Latin name: Parthenolecanium fletcheri

Appearances: They are globular in shape, light brown in color, and 1/4 inch (6 mm) long. The first instar nymphs, known as crawlers, are oval, flat, amber to yellow eggs. Adult females are 2-4 mm in diameter, yellowish brown to tan, and nearly hemispherical. For this species, there are no known males. crawlers (mobile stage) are tiny (3/64 inch), orange-yellow, and without wings.

Nymphs are smaller, flattened, oval to globose, and brownish yellow to dark brown when they are immatures.

Host plants: red cedar is infected, but arborvitae and yews tend to host it more frequently. Other species include Western red cedar, Arborvitae, Cypress, Juniper, Pachysandra, and Yew.

Territory: Kansas has a sizable distribution of the Fletcher scale.

Damage insect caused: The majority are attached to needles and are caramel-brown in color. They may produce enormous volumes of honeydew in the late spring when they are actively growing. Taxus often suffers greater damage from this insect than arborvitae. After abundant honeydew production in the spring, it may weaken yew, cause leaves to fall, and result in a heavy covering of sooty mold on the foliage and twigs. The main places to look for this insect on yew are the twigs and stems. Small shrubs may be killed in some situations where there is a severe infestation.

Life cycle and habits: On the needles, Fletcher scale overwinters as a tiny, flattened second instar nymph. They pick up their development in the spring and grow quickly when the eggs hatch and develop. In mid- to late-June, eggs start to hatch. The yellowish crawlers normally last for two to three weeks before settling on the needles and giving rise to the yellow-brown summer form. Through the summer, there is hardly much growth and only one generation is born each year.

Fletchers’ scales have one generation every year. Nymphs in their second instar—immatures—overwinter. They start to mature in May, and by late May or early June, the females will have laid (500–600, but as many as 1000) eggs beneath their bulbous bodies.