Pine Needle Scale Fact Sheet

Fact Sheets > Insect Fact Sheets > Pine Needle Scale

The Pine needle scale, Chionaspis pinifoliae (Fitch) is a native insect and a serious pest of ornamental pines in Pennsylvania. It affects pines in landscapes, nurseries and Christmas tree plantations, and is spread by the wind, birds, mammals and the touching branches of trees. Heavy infestations, left untreated, can cause twig and branch dieback.

Plants Attacked

The most frequently damaged host plants are the mugo pine (Pinus mugo) and Scotch pine (Pinus sylvestris). Other pines affected to a lesser extent are Austrian pine (Pinus nigra), red pine (Pinus resinosa) and eastern white pine (Pinus strobus). It can also infest spruces (Picea), firs (Abies), Douglas-fir (Pseudotsuga menziesii) and cedars (Cedrus).

Insect Identification

The adult scales are easily recognized by their white, oyster shell-shaped wax covers, measuring 1/16" to 1/8" long when fully grown. The male have similarly colored markings as the females but are usually smaller. Both male and female have a yellowish spot, the exuvim, on one end. Pine needle scale eggs and newly hatched crawlers are bright red changing to pale yellow then tan, once they start feeding.

Newly hatched pine needle scale crawlers	Settled crawler showing color change before producing white waxy covering

Life History

Winter	The reddish eggs over-winter beneath the female scale cover.
Spring	The female lays approximately 40 eggs, beneath her scale covering, which hatch in mid to late May. (A second hatching occurs in July). The reddish nymphs crawl to a new site on the host plant or are blown or carried to a new host. The nymphs insert their mouthparts into the needles of the host plant and begin to feed.
Summer	The nymph continues to feed and increase in size. The male molts and emerges as a winged adult. The female molts into a wingless nymph-like adult. The male mates with the female and then dies. The female continues to grow for a few weeks before laying her eggs.

There are two generations of pine needle scale per year in Pennsylvania.

Damage Symptoms

The scale uses its piercing-sucking mouthparts to feed on juices from the needles of the host, causing the needles to turn yellowish-brown. Heavy infestations can give the plant a frosted appearance. Untreated infestations may result in sparse foliage and eventual death of the tree.

Needle discoloration and terminal branch dieback from a pine needle scale infestation	A mugo pine covered with pine needle scale adults

Management Options

Biological	Several species of lady beetles (including the twice-stabbed lady beetle) and wasp parasitoids feed on the pine needle scale. If beneficial predators are present, the use of "predator friendly" insecticides, such as insecticidal soap or horticultural oils, should be used. Pest populations should be closely monitored
Mechanical	In nursery and Christmas tree farms, the removal of mature trees that act as infestation sources may prevent the spread of the scale and reduce the need for spraying entire plantations.
Chemical	Horticultural oil, soap sprays and insecticide sprays have been effective if used after the eggs have hatched but before new white waxy coverings have begun to form. Control Measures for Pine Needle Scale

Download Printable Fact Sheet

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

Sources:
Hoover, G.A. (2000). Woody Ornamental Insect, Mite, and Disease Management. Penn State College of Agricultural Sciences. pp.45. http://woodypestguide.cas.psu.edu

Hoover, G.A. (2002). Pine Needle Scale. Department of Entomology. Penn State College of Agricultural Sciences - Cooperative Extension. http://www.ento.psu.edu/extension/factsheets/pineneedscale.htm

Johnson, W.T. & Lyon, H.H. (1976). Insects That Feed On Trees And Shrubs,
pp.108. Comstock Publishing Associates. Cornell University Press.

Saxe, N. E. (1998). Pine Needle Scale. The Plant & Pest Diagnostic Laboratory at
Purdue University. http://www.ppdl.purdue.edu/ppdl/expert/Pine_Needle_Scale.html.

Shetlar, D. J. (2000). Pine Needle Scale. Ohio State University
Extension Fact Sheet. http://www.ohioline.osu.edu/hyg-fact/2000/2553.html