Calico Scale Fact Sheet

Fact Sheets > Insect Fact Sheets > Calico Scale

Calico scale, Eulecanium cerasorum (Cockerell) is a pest of a variety of woody landscape plants. The scale is believed to have been introduced into the San Francisco area in the early 1900’s and subsequently spread throughout the United States. It does not usually kill its host plant, however, it can severely weaken the plant, making it more susceptible to woodborers, drought and other stresses. Calico scale can be spread by windblown crawlers orcarried on the feet of birds between plants. They can also be spread by infested nursery stock.

Plants Attacked

Calico scale’s host range includes dogwood (Cornus), honeylocust (Gleditsia), magnolia (Magnolia), maple (Acer), sweetgum (Liquidambar styraciflua), tuliptree (Liriodendron tulipifera) and ornamental fruit trees.

Insect Identification

This colorful white and dark brown calico scale is about 1/4 inch in diameter. It is brightest at maturity and darkens with age. The first-instar nymphs are pinkish in color becoming yellowish as they enlarge. Throughout the winter the immature females are oval, flattened, and light to dark brown with a hard waxy coating.

First Instar Calico Scale	Mature Calico Scale with twice stabbed ladybird beetle predator

Calico Scale adults	Calico Scale eggs

 

Life History

Winter	In late winter/early spring they molt to the third instar stage The nymphs feeds heavily on tree sap and molt into the adult stage.
Spring/Summer	In April, the females continue to feed, and produce eggs, prior to turning brown and crusty. After egg hatch occurs in late May, crawlers move to the leaves and settle to feed for the summer months.
Summer/Fall	The nymphs move back to the woody tissue where they molt to the second instar, which is black and has a harder waxy coating.

There is one generation each year in Pennsylvania.

Damage Symptoms

Calico scale covers the branches and leaves of the host plant feeding on the phloem tissue. The plant may be covered in sooty mold as a result of the large quantities of honeydew produced by the calico scale. In large numbers, feeding can result in branch dieback.

Management Options

Biological	Some birds are predators of Calico Scale.
Chemical	Management of this pest is achieved by thoroughly covering the settled crawlers with a material labeled for calico scale. Control measures for Calico scale in Pennsylvania

Download Printable Fact Sheet

---

Authored by:
Katherine Mazzey, Penn State Extension Program Assistant
Michael Masiuk, Extension Agent, Penn State University – Allegheny County

Sources:
Insect and Mite Activity Noted in Ohio Nurseries and Landscapes: 2001. Ornamental Plants Annual Reports and Research Reviews 2001. Special Circular 186-02. Ohio State University. http://ohioline.sou.edu/sc186_sc186_7g.html.

Hubbard, J. L. & Potter, D. A. (2002). Biology and Management of Calico Scale, a Severe Pest of Trees in Kentucky Landscapes. UK Nursery and Landscape Research Rep. PR-468.

Hubbard, J. L. & Potter, D. A. (2002). Calico Scale Research Update. UK Kentucky Turfgrass Research Report.

Hubbard, J. L. & Potter, D. A. (2001). Biology and Management of Calico Scale, a Severe Pest of Trees in Kentucky Landscapes. UK Nursery and Landscape Research Rep. PR-437.

Hoover, G.A. (2000).Woody Ornamental Insect, Mite, and Disease Management.
Penn State College of Agricultural Sciences. pp.27 http://woodypestguide.cas.psu.edu

Johnson, W.T. & Lyon, H.H. (1976). Insects That Feed On Trees and Shrubs, pp.354.
Comstock Publishing Associates. Cornell University Press.