8 N. H. AGRI. EXPERIMENT STATION [Bulletin 247 



of the same diameter was spliced on and wound with thread to hold it in 

 position. With few exceptions this technique was entirely satisfactory. 

 Three or fom- successive splices on one leader often were made. Usually 

 it was not necessary to furnish water more than once a month. 



The insectary cage and greenhouse are located in Durham, N. H. Most 

 of the field observations were made in Madbury, seven miles north of 

 Durham. Certain field work was carried on in Durham plantations and 

 a plot outside of Dover, seven miles northeast of Durham. 



SEASONAL LIFE HISTORY AND HABITS 



In brief, the life history of the weevil is as follows: 



The adults leave hibernation about the last of April or the first of May 

 and make their way to the leaders of white pine. Here they feed in the 

 vicinity of the new growth and tender buds before moving down the lead- 

 er to feed and oviposit. They are found on the leader until the middle of 

 July, at which time they either die or go to other parts of the tree. The 

 eggs, inserted in the cambium, hatch in from 6 to 20 days. The larvae 

 work their way down the leader, feeding on the inner bark and cambium. 

 After they have fed for three or four weeks each one enters the wood and 

 constructs a pupal cell where it remains for a varying length of time be- 

 fore pupating. The larval stage occupies about 36 days. The pupal 

 stage lasts about two weeks and is followed by the eclosion of the adult. 

 The adults remain within the leader for two or more weeks. After emerg- 

 ing the adults are found feeding on the branches of the white pine in in- 

 creasing numbers from the middle of September until the middle of Oc- 

 tober. On the advent of cold weather they hibernate in the duff. 



Some adults, as discovered in this work, do not die after completing 

 egg-laying but remain alive until a second season when they again lay 

 eggs. 



APPEARANCE IN THE SPRING 



In the latter part of April or the first of May, depending on weather 

 conditions, the weevils leave hibernation and make their way to leaders. 



The following dates were noted in this study: 



May 5, 1926, at Durham, an adult was noted cling to the top of a hiber- 

 nating cage in which several weevils had been confined since November, 

 1925. Weevils were first noted at Barrington Depot, May 6. 



In 1927 weevils were found on leaders April 20. 



In 1928 the first observation for the year was made May 6. On that 

 date numerous weevils, feeding and copulating, were found on leaders 

 and buds exposed to the sun. 



In 1929 weevils were first observed April 24. 



The work of Graham (1926) with tanglefoot bands on the lower inter- 

 nodes of white pine showed that the weevil after leaving hibernation may 

 either fly or crawl up the trunk in order to reach the leader. We have 

 obtained similar results. 



