Packard.] 
mSECTS OE THE EOREST. 
239 
eluding many spiders, mites and thousand-legs which con¬ 
gregate in these retreats. 
Now turning our steps towards the hard wood growths we 
shall find that the oak harbors a great number of insect 
inhabitants. We could enumerate from thirty to forty dif¬ 
ferent kinds injurious to the oak in the northern states. 
The walnut is infested by a still larger number, fully seventy 
species. The elm struggles against the attacks of about 
twenty-five different kinds, while the locust and maple have 
a less number of species specially injurious. 
The oak suffers from the attacks of numerous gall-flies, 
which, not content with deforming the branches and leaves 
with unsightly tumors, sting even the roots, producing excres¬ 
cences like ground nuts on the smaller rootlets. These little 
root gall-flies are wingless and look like little black ants. 
They are, strange to say, found only early in winter on the 
snow. They are rare and more curious than destructive. 
If one will examine a pile of freshly cut red oak wood he 
will find the sticks of cord wood pretty thoroughly riddled 
with large holes and tunnels, nearly half an inch in diame¬ 
ter. This is the work of a large fleshy caterpillar, the j'oung 
of the Cossus. It is the most destructive of all the insects 
feeding upon the oak, as after the worm is hatched, — and 
there are a good many of them, since the female lays about 
three hundred eggs,—they bore directly into the heart of 
the tree, leaving a passage for the rain and moisture, which 
aid ill the work of destruction. The caterpillar is thought 
to be three years in attaining its full size, its life being an 
unusually long one, as few caterpillars are known to live 
longer than one season. It also infests the locust tree. 
If a favorite shade tree has been attacked, the best way to 
prevent farther mischief is to soap the trunk in June and 
July, and thus prevent the moth from depositing its eggs, or 
after the holes appear to plug them up in order to keep the 
water out. 
15 
