2 BULLETIN 243, L r . S. DEPARTMENT OF AGRICULTURE. 



in which the larvae develop. The brood of new adults is also formed 

 in the same cone, and here the adults overwinter. 



THE SUGAR-PINE CONE BEETLE. 

 (Gonophthorus lambertianae Hopk.) 



SEASONAL HISTORY. 



Frequent observations in the field were made during the season 

 of 1914 in the vicinity of Ashland and Colestin, Oreg., and near Hilt. 

 CaL, at elevations ranging from 3.800 to 4,200 feet. The area near 

 Hilt was located where the timber-felling operations of the Cali- 

 fornia Fruit Growers' Supply Association were conducted, where 

 seed-bearing sugar-pine trees were felled daily. 



The brood of adults which overwinters in the cones infested dur- 

 ing the previous spring and summer emerges the following spring. 

 Records kept during the seasons of 1913 and 1914 from various lots 

 of rearing material show that the maximum spring emergence oc- 

 curs during May (see Table I, p. 3). Emergence from material 

 collected in the fall and kept over winter in the laboratory has varied 

 anywhere from April 19 to June 13. Emergence from material col- 

 lected in the spring which had overwintered in the field and then 

 was kept outside in muslin rearing sacks occurred from May 8 to 31. 

 Frequent examination of cones in the field also showed that the 

 emergence is occurring during this period and that it reaches its 

 maximum between May 15 and June 1. The first attacks noted upon 

 the 1913-14 cones occurred between May 25 and June 1. Continued 

 fresh attacks were observed until about June 20. The following 

 description covers all observations regarding the method of attack 

 and subsequent habits of the beetle : 



Sugar-pine cones at the beginning of the second-year growth are 

 about 2 to 2 J inches long and are attached to the limb by a 

 stalk from 2 to 3 inches long. The parent adult beetle attacks the 

 cone by boring into the stalk of the cone. The position of this ini- 

 tial entrance varies greatly; usually it is just above the base of the 

 cone, but it may occur anywhere from the base of the cone to an 

 inch or more above. The wound made by the beetle soon produces 

 a flow of resin which gradually accumulates on the surface in the 

 form of a small pitch tube (PL II, fig. 1). After boring into the 

 center of the stalk the beetle turns toward the cone and continues to 

 extend its tunnel straight outward through the axis of the cone (PL 

 II, fig. 2). After it advances well into the heart of the cone the tun- 

 nel becomes the egg gallery, and single eggs are deposited at inter- 

 vals in notches excavated along the sides of the burrow. The entire 

 length of the egg gallery is packed with sawdust. Sawdust is also 

 packed around the eggs in the egg notches (PL II, fig. 2). 



The rate at which the egg gallery is advanced by the adult has not 

 been definitely determined, as it is impossible to determine the 



