14 N. H. AGRI. P:XPERIMEXT STATION [Bulletin 247 



and a dead weevil was found in a third leader. The fourth leader con- 

 tained no stage of the weevil, although many feeding punctures were 

 present. 



The writers have been unable to find any gross or histological details 

 to distinguish the weevils living for more than one year. 



DISPERSION 



Knowledge concerning the dispersion of Pissodes strobi is incomplete. 

 At present it is believed that dispersion does not take place in the fall 

 )n-cvious to hibernation. Repeated observations before and after hi- 

 bernation show that the weevils are found on trees or in the duff below 

 trees that were infested during the current season. Graham (1926) 



made similar observations. 



Seldom has the weevil been seen in flight in the course of this study. 

 It was first observed June 12, 1928, on a bright, warm afternoon. A 

 slight breeze was blowing. The observation from field notes is as fol- 

 lows: "First it walked to the tip of a needle, parallel with the ground, 

 near the top of a leader. This tree was about five feet high. The wee- 

 vil stamped its legs rapidly and then flew to another tree about the 

 same height 15 feet distant. It alighted on the tip of one of the lateral 

 branches about two feet from the ground. As soon as it alighted the 

 weevil walked quickly to the trunk of the tree, paused a short time, 

 walked about six inches down the trunk and then turned and went to the 

 top part of the leader." 



Graham (1926) had much the same experience for he says, "Only once 

 in the course of these investigations has it been observed on the wing. 

 This one occasion was in mid-afternoon of a warm day in the early spring 

 of 1916. On that day many weevils were flying. They were strong fliers 

 and when in the air their movements were similar to such bark beetles as 

 Hylurgops. This unusual occurrence suggests the possibility of a short 

 period of flight during the early spring whereby the weevils become wide- 

 ly disseminated, followed by a period when it seldom, if ever, takes 

 wing." 



On bringing P. strobi, collected from the leaders of young white pine, 

 into the laboratoiy on May 14th, 1926, the weevils, after turning them- 

 selves about several times, unfolded their wings and flew toward the win- 

 dow, one by one. 



Barnes (1928), in studies of dispersion, used a five foot staff stuck 

 through a circular disc of cardboard and projecting four inches above the 

 disc. The edges of the cardboard were smeared with tanglefoot to pre- 

 vent the weevils from walking in the wrong direction. A string was at- 

 tached to the disc to tell the direction of the wind. He recorded flight 

 paths of the weevil by placing several adults on the cardboard disc. The 

 weevils would crawl to the top of the staff where several splinters of 

 wood vrere tacked so that they could take wing more easily. 



He states, "125 flight paths over young trees showed that the weevil 



