278 



INSECTS AFFECTING SHADE TREES 



Pine Bark Aphid. The wingless female of this species (Chermes 

 pinicorticis Fitch) is enclosed in a woolly mass which is seen stick- 

 ing to the bark (Fig. 282). Eggs are found in downy bundles near 

 the bases of needles, and vary in number from five to sixty or more 

 in each mass. 



The life history is doubtless approximately the same as other 

 aphids. The winter appears to be passed by fertilized females 



which lay eggs in early spring. 

 It is possible there is an alter- 

 nate food plant. 



Injury. Patches of this 

 flocculent, downy matter may 

 be observed upon the smooth 

 bark of white pine. The pres- 

 ence of this insect in large num- 

 bers naturally reduces the vi- 

 tality of the tree, and leaves 

 it in a sickly condition which 

 ultimately results in death (Fig. 

 283). 



Control. Where a forcible 

 spray of cold water can be used, 

 this affords perhaps the simplest 

 and most effective remedy. 

 The flocculent masses may be 

 sprayed with kerosene emulsion 

 at the rate of one part of the 

 stock emulsion (see page 45) 

 to nine parts of water; or use 

 .The pine bark aphid, white pine w hale-oil soap at the rate of one 



louse, 'pine blight. . . c 



pound to nine gallons of water. 



Pine Leaf Scale. This is an elongated, whitish scale (Chermes 

 pinifolice Fitch) seen on the needles of the various pines. The 

 winter is passed in the egg stage under the scale, the young hatch- 

 ing in the spring. Winged adults fly to spruce, the alternate host, 

 and there the female lays her eggs. The scale from these eggs forms 

 a characteristic gall on spruce (Figs. 283 and 284), from which later 

 adults fly back to the pine, there secreting the permanent scale. 



Like other sucking insects, the attacks of this pest in any 

 numbers reduce the vitality of the trees. It has many natural 

 enemies. 



FIG. 282.- 



