Pine Needle Scale
Contact: Eric Day, Manager, Insect Identification Laboratory
Publication 444-269, August 1996
Pine Needle Scale
Homoptera: Diaspididae, Phenaeaspis pinifoliae
Plants Attacked
Scotch, mugho, Austrian Pine; also present but
seldom damaging on Eastern White Pine, Norway Spruce, and some
other conifers.
Description of Damage
Damage is not apparent until large
populations have been present for more than 1 or 2 seasons.
trees are stunted, grow slowly, have short needles and shoots.
Occasionally the feeding of scales produces chlorotic, yellowish
flecks no the needles, but normally this is not apparent.
Heavily infested plants are seriously weakened and may be in a
state of decline.
Identification
Scale covers are about 1/8" long, white,
elongate, narrow in front and broad in back. Eggs under the
scale covers are purplish in color. Crawlers and settled nymphs
are reddish brown. Females are reddish in color beneath the
white scale covers.
Life History
The hatching period is relatively short (7-10
days) in mid May and again in mid to late July. The first
generation crawlers settle on old needles, since new growth is
not fully developed until later. Second generation crawlers
settle primarily on the current year's growth. Females produce
5-30 reddish purple eggs. Although the number of eggs laid is
relatively small, two generations a year permits rapid buildup of
infestations. In areas where infestations are large, lady beetle
(especially the twice-stabbed lady beetle) is an effective
predator.
Control
Sprays are effective if applied after most eggs have
hatched. Experience has shown that treatments for the summer
generation may be more effective than the first. Control may be
applied at either time.
Remarks
Pine needle scale can be a serious pest of Christmas
trees as well as ornamental trees and shrubs. Crawlers are blown
by the wind and can be carried on birds.