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be known by its large size and by the markings which consist of 
a number of black dots on each of the main segments, usually a 
pair on each side and two pairs near the dorsal side. 
Several writers have called attention to the migratory habits 
of the larva when partly grown; leaving the smaller branch in 
which it begins its work it proceeds to a larger branch, or in the 
case of comparatively young trees to the main trunk Here it 
bores out a large cavity often an inch wide and several inches 
long just under the bark. It then works toward the heart-wood, 
leaving a channel often one-half inch in diameter and six or more 
inches in length. The writer has observed one larva about an 
inch in length busily engaged in boring its way into the main 
trunk of a silver-maple about four inches in diameter a few inches 
above ground. The work was apparently just begun, for the 
cavity was shallow, and the body of the larva protruded from 
the new cavity half its length. 
It requires two years for the insect to complete its life cycle. 
At the end of the first season the larva is half-grown and has made 
its way to one of the larger branches. The caterpillar remains 
in a dormant state during the first winter and resumes feeding 
the next spring, and toward the end of the second summer 
attains its fullsize. The second winter is passed in this condition 
and the next spring they form their pupae near the surface. The 
adult, which is a large white moth with black spots, emerges in 
the early summer, being most abundant in late June or early July. 
The eggs are deposited either singly or in masses in the crevices 
of the bark, each adult depositing five hundred to one thousand. 
PLants ATTACKED BY THE INSECT. 
It is claimed by some that this insect attacks practically all 
deciduous shade-trees and many shrubs. A careful study of this 
insect in the New York Botanical Garden during the past season 
has shown it to be present on various trees and some shrubs, 
but some trees have thus far seemed to be free from the pest. 
The following account may be given of the plants attacked and 
the amount of damage resulting from this insect in our grounds: 
