194 JOURNAL OF FORESTRY 



This forked trunk may endure throughout the life of the tree and very 

 seriously affects its commercial value. 



(2) A crooked or "bayonet" trunk, formed by a single lateral taking 

 the place of the leader. This condition may disappear entirely, the 

 trunk becoming straight, and at maturity may be as valuable as though 

 never injured. In case of repeated attacks on the same tree, which 

 often occur, particularly in open stands, the loss in quality may be great. 



In addition to this, the injuries result in a considerable loss of height 

 growths. Since the white pine produces an excurrent stem and up 

 to the age of about 60 years the leading or terminal shoot is a direct 

 vertical extension of the trunk of the tree, the removal or death of 

 this leader, then, directly reduces the height growth. This leader 

 is almost invariably longer than the lateral branches of the same age. 

 The curve (fig. i) shows the average excess of the terminal shoot 

 over the longest lateral for terminals up to 28 inches in length. This 

 curve was constructed from measurements of 300 trees. It is evident 

 that the greater the length of the terminal killed the greater will be the 

 loss in height growth. Measurements of about 500 weeviled shoots 

 show the average length of such terminals to be 16 inches in Minne- 

 sota, and in New York State 170 weeviled shoots averaged 19 inches. 

 Referring to the curve, it will be seen that for each weeviling there 

 is a loss of from 6 to 8 inches in height growth. This is assuming 

 that only the terminal is killed and that the longest lateral from the 

 topmost whorl takes the lead. If the injury extends below the top- 

 most whorl the loss is increased accordingly. The crooks and forks 

 resulting from weevil attacks increase to a considerable extent the 

 possibility of winter injury by snow and ice. 



Life History 



There is but one generation a year in New York State. The adults 

 appear on the pines about the time the earliest trees are beginning to 

 leaf out and when the pine buds are just beginning to swell. They begin 

 at once to feed upon the buds, usually those of the terminal, and in a 

 few days oviposition begins. 



The eggs are laid in chambers hollowed out of the inner bark by the 

 female, one or two eggs being placed in a chamber. As a rule, the 

 female remains on .one leader until she has deposited her full quota of 

 from 75 to 150 eggs ; but if she is disturbed she may drop to the ground 

 and is then likely to find her way to another tree, thus destroying two 

 leaders. The egg-laying continues into July. 



