6 BULLETIN 170, U. S. DEPARTMENT OF AGRICULTURE. 
larva then makes a silk-lined chamber within one of the hollow 
shoots and here it pupates. After about three weeks the spiny pupa 
pushes itself half way out through the dry wall of its chamber and 
the moth, or adult, issues. 
The full life history of the species in America has not been ascer- 
tained, because a full year has not elapsed since it was first dis- 
covered here. While in the main it is the same as in Europe, a very 
distinct difference has already been noticed, due to the longer and 
warmer summer and fall in this country. In Europe the young larva 
attacks only one bud and attains very little growth before it enters 
the dormant winter season, but in the warmer climate of America 
the larva eats out two, three, or more buds and attains nearly half 
of its growth before winter. This, of course, tends to make the 
species even more injurious here than it is in Europe. 
While it is altogether probable that the species has here only one 
generation annually, as in Europe, the possibility is not absolutely 
excluded that on account of the longer season it may eventually de- 
velop two generations annually like the allied native species. This, 
of course, would greatly increase its power for injury. 
CHARACTER OF INJURY. 
During the entire spring the infested twigs are very noticeable by 
reason of the dead and injured buds and young shoots, and the empty 
pupa skin sticking out of the destroyed shoot is also a familiar and 
easily noticed sight during the summer months ; but the extent of the 
injury caused by this insect is only realized later in the season, 
when the new growth is found to be either quite destroyed or perma- 
nently injured. 
As may be gathered from the foregoing account of the life history, 
each one of these insects does very considerable damage, not only by 
destroying a large number of buds and young shoots but by injuring 
the adjoining shoots which remain and which normally should sup- 
plant the destroyed leaders ; thus the trees are permanently disfigured. 
These injured shoots bend downward and outward and afterwards 
grow upward again in a curve, in the attempt to continue the normal 
upward growth of the tree. This results in a characteristic malfor- 
mation (Pis. IY, Y, YI), so familiar in European pine forests that it 
has a popular name in each country— as " posthorn " and " waldhorn " 
in Germany and Holland and " baionnette " in France, while the few 
examples wTiich have so far occurred in America have suggested the 
name " Dutch pipe " to those who have noticed it. This injury does 
straighten out somewhat during the successive years' growth, but 
never can be fully remedied and will always be noticeable and a seri- 
ous detriment to the timber (PL I). Injury of this character is the 
result even when the species is present in only small numbers, the 
