October, 1929] WHITE PINE WEEVIL 13 



weevils from the leaders and are found only on trees infested during the 

 current season. For over a month before any of the weevils of the new 

 generation emerge from the leader these feeding areas are present. 



What percentage of the weevils enter this semi-dormant condition was 

 not determined because of the difficulty in collecting them. Usually a 

 single wee\il was found on a tree, although sometimes two or three 

 were taken. None was found in copula. In 1928, weevils, few in num- 

 ber, were continually ob.served on the lower lateral branches until Aug- 

 ust 12. Searches in the duff under infested and uninfested trees failed 

 to reveal anj' weevils. 



In 1928 adult weevils, surviving the experiment to determine the num- 

 ber of eggs laid, were foimd ali\e on November 12. In this case, where 

 the weevils were in cages, several were in copula. They died sometime 

 in the winter. In general, weevils in cages often exhibited longer pe- 

 riods of feeding, egg-laying and some other activities than those in the 

 field. 



Other species of American and European weevils in the genus Pissodes, 

 according to Hopkins (1907), may live and deposit eggs for two or 

 three years. It had been suggested that the white pine weevil might 

 live for more than one year, although no worker had secured definite 

 information to that effect. 



Barnes (1928) in a longevity experiment succeeded in carrying adults 

 through a second winter of liibernation. He states nothing concerning 

 their performance but ends his observations May 28, 1926, saying that 

 two leaden colored weevils were found at the base of the tree. 



In 1928, at Durham, screened cages, five feet high and three feet 

 square, were placed over four uninfested white pine trees slightly less 

 than five feet high. The duff under the trees was not disturbed in any 

 waj'. Ten adults known to have emerged in 1927 and marked with pur- 

 ple show-card ink on the elytra were liberated in each cage August 9. 

 1928. October 12, several adults were observed feeding at the tips of 

 the lateral branches. Fresh feeding evidences were abundant. 



Examination of the trees in the cages April 27, 1929, definitely proved 

 that the weevil maj^ live more than one year. Seven, four, two, and 

 five weevils, respectively, were noted on various parts of the trees in 

 the four cages. The paint markings on the elytra were plainly visible. 

 Numerous feeding punctures were observed on all of the leaders. Some 

 females were dissected, and fully developed eggs were found. 



A part of the marked w-eevils removed from these cages were kept 

 alive and were given access to a white pine leader. These weevils laid 

 eggs in the leader and the eggs hatched. 



The cages were removed temporarily for close examination May 18. 

 Six, three, two and six weevils were found on the trees. Thus nearlj- 

 50 per cent of these wee\ils lived for more than one year. 



The leaders were finally remo\ed from the cages August 27, 1929, and 

 were examined. At that time the leaders were dead or dying. On ex- 

 amination two dead larvae were found in one leader, three in another. 



