SCALE-INSECTS, BARK-LICE, MEALY-BUGS. oh leg 
Only a few species can be described and illustrated. The 
common Lecanium hesperidum, a rather flat scale, elongated 
ova] in outline, smooth and shining, is frequently found on fruit 
and other trees. It is illustrated in Fig. 177. 
Lecanium cerasifex Fitch. (The Cherry-tree Scale). 
This is usually an uncommon species, but is now found in 
destructive numbers, not alone on the cherry, but also more fre- 
quently upon the plum; though apples, pears, and other trees 
Ml \ 
Fic. 177—Lecanium hesperidum. After Comstock, Div. of Entomology, Dep. of 
Agriculture. 
do not escape. In extreme cases the entire twigs are coated with 
scales. The shell is hemispherical in form, black, more or less 
mottled, with pale, dull-yellow dots. On lifting this shell we 
find a large amount of.whitish powder, which, closely inspected, 
proves to be minute eggs, which hatch in spring, spreading from 
the scale to succulent twigs, into which they push their delicate 
