Insect Damage 47 
destroy the entire leaf. But the larve of beetles also, and 
some of the beetles themselves are destructive in this 
manner. 
The leaf-miners, which skeletonize leaves, eating only 
the softer portions in patches, also come from different fam- 
ilies. Some of these, like the elm-leaf beetle and the larch- 
miner, make such extensive inroads, that the result is very 
much like the eating of the whole leaf. Others make only 
small, blotch-like mines or short tracks on. upper or lower, 
or both sides of the leaves, destroying small areas of the 
soft tissues. ‘These, as a rule, do little damage. Neverthe- 
less it is wise to reduce them by burning up the fallen leaves, 
in which they usually hibernate. 
Another set, the leaf-rollers, also coming from different 
families, roll the leaves together in various ways to make 
shelter for the caterpillars, folding the edges and sewing 
them together with silken threads, or spinning them, as in 
the case of needles of conifers, into a web. These distor- 
tions and occultations of the foliage would generally be of 
little consequence, but the insect, here sheltered, usually 
is destructive to the buds and young shoots, and, if the 
leaves in the web are eaten, as is done by some, the damage 
may become considerable. 
While the leaf insects so far mentioned feed on the foliage 
by eating it, there are a few, like the plant-lice and leaf- 
hoppers, which suck the sap by piercing the succulent leaves 
and leaf stems or even twigs, causing the leaves to crumple 
or roll, or producing gall-like swellings. Usually these 
leaf-suckers do not do much damage unless unusually abun- 
dant. There are, however, some bark-lice which do much 
more damage by puncturing the bark of twigs. 
To this group belong also various scale-insects, which, 
adhering to the small limbs, sap their life and cause them 
