PINE NEEDLE SCALE ( Chionaspis pinifoliae )
The pine needle scale, can disfigure trees and stunt growth. High populations of this insect can cause death of needles or twigs, and the death of whole (young) trees. The pine needle scale feeds on needles of conifers including Scots, mugo, Austrian, and red pines and less often on spruce and Douglas-fir.
Adult females appear as white flecks on the needles. Females bear eggs in late summer that hatch the following spring, some time between mid-May and early June in New York State, (298-448 GDD). Two generations usually occur each year in New York. The bright red pine needle scale crawlers are very tiny (less than 1/32 inch long), and look like red dust against the dark green needles. Female crawlers settle in one place where they feed, while forming and enlarging a protective covering, until they reach maturity and lay eggs.
Monitor insect activity to pinpoint the best time for control of the pine needle scale. Begin scouting in late-April, and scout for 4-5 weeks. Choose a slightly overcast day to do your scouting, and take time to examine lower and upper branches on all sides of the crown. Begin by plucking a few needles which show the white shells ("tests") of the adult females, and pry back the test of a dozen or more mature females. Examine the feeding sites with a hand lens, and when the tiny red crawlers become active, you should be able to see them. Crawlers may feed for only a few days before they settle and begin to make their own protective covering The best control can be gained by treating the unprotected crawlers.
Control scales by rogueing heavily infested trees, especially if the trees are at or near harvest, and thus represent a liability to you. Heavily infested trees should be removed and destroyed during the winter season to prevent spread of the insect to other trees. Also, remove affected windbreak or forest trees because they will otherwise serve as reservoirs for future infestations. Apply chemical controls during the time when the crawlers are active as determined by your monitoring activities.
Fig. 1. A twice stabbed lady bird beetle is a natural predator of the pine needle scale.
Fig. 2. Note how tiny the red pine needle scale crawlers are in comparison to adult scale insects.
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