Pine Needle Scale

Pine needle scale is considered a key pest of pines in landscapes, nurseries, and Christmas tree plantations in Pennsylvania. This native insect attacks mugo pine, P. mugo; Austrian pine, Pinus nigra; red pine.

Crimson red eggs are apparent in early spring beneath the female’s white waxy cover. The waxy cover of the female is about 3 mm long, white with a yellow tip at the narrowed front end . The waxy cover of the male is white and only 2 mm long. Adult males are small winged insects that resemble tiny parasitic wasps, but they only have one pair of wings with very few veins. The crawler stage of this armored scale insect is reddish.

Life cycle:This pest overwinters as females and eggs beneath the waxy cover of the female. As many as 40 eggs may be found under each scale. In mid-to late May these hatch into crawlers which move over the needles for a few days and then settle down to feed. After settling down, they secrete the characteristic waxy covering over their bodies. These scales usually reach maturity by early July. Males emerge, mate with the females, and then die. A second generation of eggs is laid in mid-July; these scales mature in September.

Damage:This species removes plant fluids from needles with their piercing-sucking mouthparts, causing them to turn yellowish brown. A severe infestation may cause a reduction in plant health, sparse foliage, and death of infested twigs. The foliage of severely infested trees may take on a white-washed appearance.

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).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.

Control:The twice-stabbed lady beetle, a jet black beetle with two red spots, and several parasitic wasps seem to control the pine needle scale in forest stands. However, these biological controls are often killed by the pesticides used for the control of other insect pests. Careful monitoring of predators and parasites as well as using pesticides with little effect on beneficials can allow biological control to be successful.

Since these scales overwinter as eggs, dormant oil seems to have little effect. The 1% to 1.5% summer horticultural oil sprays are often effective against freshly settled crawlers and young nymphs. Horticultural oil sprays in combination with insecticidal soaps or insecticides are even more effective.

If you have any questions about how to get rid of scale check out the rest of our website or go to our blog at http://nypestpro.blogspot.com.

Beyond Pest Control.

Our pest control specialists service all NYC boroughs, including Queens, Brooklyn, Bronx, Manhattan, Long Island (both Nassau & Suffolk counties), Staten Island and even both Westchester & Rockland counties.