44 INSECTS INJURIOUS TO THE APPLE. 



ill a pailful. Painting the twigs and branches with linseed 

 oil has also been tried with success. 



As a precautionary measure, every young tree should be 

 carefully examined before being planted, and if found infested 

 should be thoroughly cleansed. 



No. 17. — The Scurfy Bark-louse. 



Chionaspis furfur us (Fitch). 



This insect, which has long been known under the name of 

 Harris's Bark-louse, Aspidiotus Harrisii Walsh, is now found 

 to have been first described by Dr. Fitch, and hence must in 

 future bear the name given to it by him. It resembles in some 

 respects the oyster-shell bark-louse, yet is sufficiently dissimilar 

 to be readily distinguished from it. In this species the scale 

 of the female, which is by far the most abundant, is oblong 

 in form, pointed below, very flat, of a grayish-white color, 

 and about one-tenth of an inch long. (See Fig. 35, 1 and 

 1 c; the latter represents a scale highly magnified.) The eggs 

 under the scale of the oyster-shell bark-louse during the 

 winter are white, while these are purplish red. The eggs of 

 this species hatch about the same date as the other, but the 

 larvse are red or reddish brown in color. This insect does 

 not mature so rapidly as the oyster-shell species ; the eggs 

 are said not to be fully developed under the scale until the 

 middle of September. The scale of the male, which is very 

 much smaller and narrower, and not more than one-thir- 

 tieth of an inch long, is shown in the figure, magnified, at 1 a; 

 the male insect in the winged state, highly magnified, at 1 b. 



This is a native insect, which has existed from time imme- 

 morial in the East, West, and South, its original home being 

 on the bark of our native crab-trees. In the warmer parts 

 of the South it is more common than the oyster-shell bark- 

 louse. It is found chiefly on the apple, but sometimes affqcts 

 the pear and also the mountain-ash. It is far less common 

 than tiie imported oyster-shell bark-louse, and is nowhere 

 anything like so injurious as that insect. 



