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



When new leaders were inserted from time to time it was found that 

 these females continued to lay fertile eggs until July 17, the end of the 

 oviposition period in the insectarj^ cage. 



Graham (1926) cites an example where a female apparently was fertil- 

 ized before entering hibernation. This is probably a rare occurrence. 

 In the light of recent observations the instance was more likely that of a 

 weevil hibernating a second winter. If insemination should happen to 

 take place in the fall it is a question whether fertile eggs could be laid in 

 the spring. 



RESPONSES 



The death-feigning habit of the white pine weevil is strongly developed. 

 A shadow or movement close to the weevil will cause it to drop from the 

 leader. This habit appears stronger on bright warm days when the wee- 

 vils are active. During cool, windy, or rainy weather they remain in a 

 sluggish condition at the top of the leader among the buds. 



The weevil is negatively geotropic and positively phototropic. The 

 former response is easily demonstrated by completely covering an 8 inch 

 vial with black paper. When a leader and eight adults were inserted in 

 such a vial and placed in a block, the feeding punctures were concen- 

 trated in the top inch of the leader, the remainder containing but few 

 punctures. 



When a similar vial was completely covered except for a quarter of an 

 inch around the top, 20 punctures were found in the first inch, 26 in the 

 next 4% inches, and 8 in the last 2 inches of the leader. When such a 

 vial was completely covered, except for a band 2 mm. wide at the base, 

 a more general distribution of the feeding punctures occurred. 



The fact that the weevil is positivel.v phototropic is used to advan- 

 tage in control by silvicultural methods. 



PREOVIPOSITION 



The preoviiiosition period extends from the time the adults emerge 

 in the fall until shortly after their appearance on the leaders in the 

 spring, at which time oviposition begins. Histological studies of the 

 ovaries of the weevil (Plummer, 1929) before and during hibernation 

 have proved that the oocytes are only partially developed. The weevil 

 is unable to oviposit in the fall, previous to hibernation. 



OVIPOSITION 



The oviposition period extends from the time the females begin laying 

 eggs in the spring until some time in July, when they disappear from the 

 leader. Thus, the oviposition period may last two months or more. 

 July 8, 1926, no adults could be found in the field. In 1927 the ovi- 

 position period in the field terminated on July 9; in 1928, July 12. Wee- 

 vils confined in a glass moist chamber continued to lay eggs until Sep- 

 tember 9, 1927. 



