CONE BEETLES. 6 



progress made by the adults without cutting the cone open, and 

 when thus disturbed the adult at once ceases its work. However, it 

 has been observed that the egg gallery has been extended entirely 

 through the small cones within five to eight days after attack. For 

 the same reason the period of incubation of the eggs within the cone 

 has not been definitely determined. In cones cut open, eggs that 

 had apparently just been deposited incubated in from two to four 

 days. 



One pair of parent beetles are found in each of these egg galleries. 

 A series of specimens collected from individual cones was submitted 

 to Dr. A. D. Hopkins, and from his determination of sex it was found 

 that one male and one female beetle occupy each egg gallery. As a 

 rule but one pair of beetles attack a single cone, but in some instances 

 three pairs of beetles have been found advancing as many egg 

 galleries in the same cone. The sex of the parent which makes the 

 initial attack on the cone and begins the excavation of the egg gallery 

 has not been determined. 



The immediate effect of this attack on the cone is to check all 

 further growth. Eventually the infested cone withers, then becomes 

 dry and hard, but for a period of time it hangs on the tree in a semi- 

 moist and souring condition. It is during this period that the eggs 

 of the beetle incubate and the young larvae develop. The condition 

 of the cone may be compared to that of the cambium of a pine 

 which has been infested by Denclroctonus, and is in a fading or dying 

 condition while the larvae of the new broods of beetles are developing. 



Table I. — Emergence record of the sugar-pine cone beetle (ConopMhorus lam- 

 bertianae) in California and Oregon, 1913-1//. 



Hopk. 

 U.S. No. 



Locality. 



Date of 

 collection. 



Material. 



Period of spring 

 emergence of over- 

 wintered adults. 



Pvemarks. 



11471a 

 11498 



Kyburz, Cal . . 



Pino Grande, 



Cal. 

 do 



Apr. 



May 

 May 



July 



Sept. 



Aug. 



Nov. 

 May 



Feb. 



Mar. 



11, 1913 



11,1913 

 26, 1913 



11, 1913 



5. 1913 



23. 1913 



13,1913 



2. 1914 



14. 1914 

 13, 1914 



Overwintered 

 adults in 1911-12 

 cones. 



do 



May 19-May 31, 

 1913; 43 adults. 



May 14, 1913; 12 



adults. 

 Emerging May 26, 



1913. 



June 4, 1914; 6 

 adults. 



Apr.l9-June4,1914; 



16 adults. 

 Apr. 25-May21,1914. 



June 2- June 13, 1914. 

 May 8-May 31, 1914. 



Mayl9,1914;ladult. 



Apr. 20-Mav 20, 

 1914; 10 adults. 



Breeding cage kept 

 outdoors. 



Do. 



10802 



do 



A considerable per- 

 centage of un- 

 emerged adults 

 still in cones. 



Breeding cage kept 

 in 1 aborat ory. 

 Heavy emergence 

 during Aug., 1913. 



Breeding cage kept 



10833a-2 

 10833a-3 



Hiit, Cal 



Ashland, Oreg. 



Little Butte 

 Creek, Oreg. 

 Hilt, Cal 

 do 



New adults in 1912- 

 13 cones. 



do 



10838a-2 

 10871a 



do 



do 



in laboratory. 

 Do. 



Do. 



1087 la-2 



Overwintered 

 adults in 1912-13 

 cones. 



do 





10884a 



Ashland, Oreg. 

 Hilt, Cal 



outdoors. 



10890a 



do 



in laboratory. 

 Do. 









